Partial Pressure: The pressure that would be exerted by one component of a mixture of gases if it were present alone in a container. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Pressure: A type of stress exerted uniformly in all directions. Its measure is the force exerted per unit area. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Blood Pressure: PRESSURE of the BLOOD on the ARTERIES and other BLOOD VESSELS.Oxygen: An element with atomic symbol O, atomic number 8, and atomic weight [15.99903; 15.99977]. It is the most abundant element on earth and essential for respiration.Carbon Dioxide: A colorless, odorless gas that can be formed by the body and is necessary for the respiration cycle of plants and animals.Blood Gas Analysis: Measurement of oxygen and carbon dioxide in the blood.Hydrostatic Pressure: The pressure due to the weight of fluid.Pulmonary Gas Exchange: The exchange of OXYGEN and CARBON DIOXIDE between alveolar air and pulmonary capillary blood that occurs across the BLOOD-AIR BARRIER.Atmospheric Pressure: The pressure at any point in an atmosphere due solely to the weight of the atmospheric gases above the point concerned.Blood Gas Monitoring, Transcutaneous: The noninvasive measurement or determination of the partial pressure (tension) of oxygen and/or carbon dioxide locally in the capillaries of a tissue by the application to the skin of a special set of electrodes. These electrodes contain photoelectric sensors capable of picking up the specific wavelengths of radiation emitted by oxygenated versus reduced hemoglobin.Hypocapnia: Clinical manifestation consisting of a deficiency of carbon dioxide in arterial blood.Helium: Helium. A noble gas with the atomic symbol He, atomic number 2, and atomic weight 4.003. It is a colorless, odorless, tasteless gas that is not combustible and does not support combustion. It was first detected in the sun and is now obtained from natural gas. Medically it is used as a diluent for other gases, being especially useful with oxygen in the treatment of certain cases of respiratory obstruction, and as a vehicle for general anesthetics. (Dorland, 27th ed)Anoxia: Relatively complete absence of oxygen in one or more tissues.Oxygen Consumption: The rate at which oxygen is used by a tissue; microliters of oxygen STPD used per milligram of tissue per hour; the rate at which oxygen enters the blood from alveolar gas, equal in the steady state to the consumption of oxygen by tissue metabolism throughout the body. (Stedman, 25th ed, p346)Tidal Volume: The volume of air inspired or expired during each normal, quiet respiratory cycle. Common abbreviations are TV or V with subscript T.Blood Pressure Determination: Techniques for measuring blood pressure.Respiration: The act of breathing with the LUNGS, consisting of INHALATION, or the taking into the lungs of the ambient air, and of EXHALATION, or the expelling of the modified air which contains more CARBON DIOXIDE than the air taken in (Blakiston's Gould Medical Dictionary, 4th ed.). This does not include tissue respiration (= OXYGEN CONSUMPTION) or cell respiration (= CELL RESPIRATION).Capnography: Continuous recording of the carbon dioxide content of expired air.Hypercapnia: A clinical manifestation of abnormal increase in the amount of carbon dioxide in arterial blood.Air Pressure: The force per unit area that the air exerts on any surface in contact with it. Primarily used for articles pertaining to air pressure within a closed environment.Noble Gases: Elements that constitute group 18 (formerly the zero group) of the periodic table. They are gases that generally do not react chemically.Respiratory Transport: The processes of diffusion across the BLOOD-AIR BARRIER, and the chemical reactions coupled with diffusion that effect the rate of PULMONARY GAS EXCHANGE, generally at the alveolar level.Acid-Base Equilibrium: The balance between acids and bases in the BODY FLUIDS. The pH (HYDROGEN-ION CONCENTRATION) of the arterial BLOOD provides an index for the total body acid-base balance.Hemodynamics: The movement and the forces involved in the movement of the blood through the CARDIOVASCULAR SYSTEM.Transducers, Pressure: Transducers that are activated by pressure changes, e.g., blood pressure.Hypertension: Persistently high systemic arterial BLOOD PRESSURE. Based on multiple readings (BLOOD PRESSURE DETERMINATION), hypertension is currently defined as when SYSTOLIC PRESSURE is consistently greater than 140 mm Hg or when DIASTOLIC PRESSURE is consistently 90 mm Hg or more.Heart Rate: The number of times the HEART VENTRICLES contract per unit of time, usually per minute.Intracranial Pressure: Pressure within the cranial cavity. It is influenced by brain mass, the circulatory system, CSF dynamics, and skull rigidity.Hyperventilation: A pulmonary ventilation rate faster than is metabolically necessary for the exchange of gases. It is the result of an increased frequency of breathing, an increased tidal volume, or a combination of both. It causes an excess intake of oxygen and the blowing off of carbon dioxide.Krypton: A noble gas that is found in the atmosphere. It has the atomic symbol Kr, atomic number 36, atomic weight 83.80, and has been used in electric bulbs.Intraocular Pressure: The pressure of the fluids in the eye.Blood Pressure Monitoring, Ambulatory: Method in which repeated blood pressure readings are made while the patient undergoes normal daily activities. It allows quantitative analysis of the high blood pressure load over time, can help distinguish between types of HYPERTENSION, and can assess the effectiveness of antihypertensive therapy.Argon: Argon. A noble gas with the atomic symbol Ar, atomic number 18, and atomic weight 39.948. It is used in fluorescent tubes and wherever an inert atmosphere is desired and nitrogen cannot be used.Respiratory Mechanics: The physical or mechanical action of the LUNGS; DIAPHRAGM; RIBS; and CHEST WALL during respiration. It includes airflow, lung volume, neural and reflex controls, mechanoreceptors, breathing patterns, etc.Respiration, Artificial: Any method of artificial breathing that employs mechanical or non-mechanical means to force the air into and out of the lungs. Artificial respiration or ventilation is used in individuals who have stopped breathing or have RESPIRATORY INSUFFICIENCY to increase their intake of oxygen (O2) and excretion of carbon dioxide (CO2).Respiratory Distress Syndrome, Adult: A syndrome characterized by progressive life-threatening RESPIRATORY INSUFFICIENCY in the absence of known LUNG DISEASES, usually following a systemic insult such as surgery or major TRAUMA.Positive-Pressure Respiration: A method of mechanical ventilation in which pressure is maintained to increase the volume of gas remaining in the lungs at the end of expiration, thus reducing the shunting of blood through the lungs and improving gas exchange.Respiratory Dead Space: That part of the RESPIRATORY TRACT or the air within the respiratory tract that does not exchange OXYGEN and CARBON DIOXIDE with pulmonary capillary blood.Hyperbaric Oxygenation: The therapeutic intermittent administration of oxygen in a chamber at greater than sea-level atmospheric pressures (three atmospheres). It is considered effective treatment for air and gas embolisms, smoke inhalation, acute carbon monoxide poisoning, caisson disease, clostridial gangrene, etc. (From Segen, Dictionary of Modern Medicine, 1992). The list of treatment modalities includes stroke.Venous Pressure: The blood pressure in the VEINS. It is usually measured to assess the filling PRESSURE to the HEART VENTRICLE.Oximetry: The determination of oxygen-hemoglobin saturation of blood either by withdrawing a sample and passing it through a classical photoelectric oximeter or by electrodes attached to some translucent part of the body like finger, earlobe, or skin fold. It includes non-invasive oxygen monitoring by pulse oximetry.Alkalosis, Respiratory: A state due to excess loss of carbon dioxide from the body. (Dorland, 27th ed)Respiratory Insufficiency: Failure to adequately provide oxygen to cells of the body and to remove excess carbon dioxide from them. (Stedman, 25th ed)Isoflurane: A stable, non-explosive inhalation anesthetic, relatively free from significant side effects.Oxyhemoglobins: A compound formed by the combination of hemoglobin and oxygen. It is a complex in which the oxygen is bound directly to the iron without causing a change from the ferrous to the ferric state.Diving: An activity in which the organism plunges into water. It includes scuba and bell diving. Diving as natural behavior of animals goes here, as well as diving in decompression experiments with humans or animals.Neon: Neon. A noble gas with the atomic symbol Ne, atomic number 10, and atomic weight 20.18. It is found in the earth's crust and atmosphere as an inert, odorless gas and is used in vacuum tubes and incandescent lamps.Regional Blood Flow: The flow of BLOOD through or around an organ or region of the body.Cerebrovascular Circulation: The circulation of blood through the BLOOD VESSELS of the BRAIN.Hydrogen-Ion Concentration: The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH = log 1/2[1/(H+)], where (H+) is the hydrogen ion concentration in gram equivalents per liter of solution. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Altitude: A vertical distance measured from a known level on the surface of a planet or other celestial body.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Vascular Resistance: The force that opposes the flow of BLOOD through a vascular bed. It is equal to the difference in BLOOD PRESSURE across the vascular bed divided by the CARDIAC OUTPUT.Arterial Pressure: The blood pressure in the ARTERIES. It is commonly measured with a SPHYGMOMANOMETER on the upper arm which represents the arterial pressure in the BRACHIAL ARTERY.Ventricular Pressure: The pressure within a CARDIAC VENTRICLE. Ventricular pressure waveforms can be measured in the beating heart by catheterization or estimated using imaging techniques (e.g., DOPPLER ECHOCARDIOGRAPHY). The information is useful in evaluating the function of the MYOCARDIUM; CARDIAC VALVES; and PERICARDIUM, particularly with simultaneous measurement of other (e.g., aortic or atrial) pressures.Xenon: A noble gas with the atomic symbol Xe, atomic number 54, and atomic weight 131.30. It is found in the earth's atmosphere and has been used as an anesthetic.Air: The mixture of gases present in the earth's atmosphere consisting of oxygen, nitrogen, carbon dioxide, and small amounts of other gases.Anesthetics, Inhalation: Gases or volatile liquids that vary in the rate at which they induce anesthesia; potency; the degree of circulation, respiratory, or neuromuscular depression they produce; and analgesic effects. Inhalation anesthetics have advantages over intravenous agents in that the depth of anesthesia can be changed rapidly by altering the inhaled concentration. Because of their rapid elimination, any postoperative respiratory depression is of relatively short duration. (From AMA Drug Evaluations Annual, 1994, p173)Pulmonary Ventilation: The total volume of gas inspired or expired per unit of time, usually measured in liters per minute.Gases: The vapor state of matter; nonelastic fluids in which the molecules are in free movement and their mean positions far apart. Gases tend to expand indefinitely, to diffuse and mix readily with other gases, to have definite relations of volume, temperature, and pressure, and to condense or liquefy at low temperatures or under sufficient pressure. (Grant & Hackh's Chemical Dictionary, 5th ed)Blood Flow Velocity: A value equal to the total volume flow divided by the cross-sectional area of the vascular bed.Inhalation: The act of BREATHING in.Oxygen Inhalation Therapy: Inhalation of oxygen aimed at restoring toward normal any pathophysiologic alterations of gas exchange in the cardiopulmonary system, as by the use of a respirator, nasal catheter, tent, chamber, or mask. (From Dorland, 27th ed & Stedman, 25th ed)Holcus: A plant genus of the family POACEAE that contains Hol l 1 and Hol l 5 allergens.Ventilation-Perfusion Ratio: The ratio of alveolar ventilation to simultaneous alveolar capillary blood flow in any part of the lung. (Stedman, 25th ed)Hemoglobins: The oxygen-carrying proteins of ERYTHROCYTES. They are found in all vertebrates and some invertebrates. The number of globin subunits in the hemoglobin quaternary structure differs between species. Structures range from monomeric to a variety of multimeric arrangements.Nitrous Oxide: Nitrogen oxide (N2O). A colorless, odorless gas that is used as an anesthetic and analgesic. High concentrations cause a narcotic effect and may replace oxygen, causing death by asphyxia. It is also used as a food aerosol in the preparation of whipping cream.Dogs: The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065)Lung: Either of the pair of organs occupying the cavity of the thorax that effect the aeration of the blood.Halothane: A nonflammable, halogenated, hydrocarbon anesthetic that provides relatively rapid induction with little or no excitement. Analgesia may not be adequate. NITROUS OXIDE is often given concomitantly. Because halothane may not produce sufficient muscle relaxation, supplemental neuromuscular blocking agents may be required. (From AMA Drug Evaluations Annual, 1994, p178)Hyperoxia: An abnormal increase in the amount of oxygen in the tissues and organs.Cardiac Output: The volume of BLOOD passing through the HEART per unit of time. It is usually expressed as liters (volume) per minute so as not to be confused with STROKE VOLUME (volume per beat).Methyl Ethers: A group of compounds that contain the general formula R-OCH3.Central Venous Pressure: The blood pressure in the central large VEINS of the body. It is distinguished from peripheral venous pressure which occurs in an extremity.Apnea: A transient absence of spontaneous respiration.Chemoreceptor Cells: Cells specialized to detect chemical substances and relay that information centrally in the nervous system. Chemoreceptor cells may monitor external stimuli, as in TASTE and OLFACTION, or internal stimuli, such as the concentrations of OXYGEN and CARBON DIOXIDE in the blood.Pulmonary Wedge Pressure: The blood pressure as recorded after wedging a CATHETER in a small PULMONARY ARTERY; believed to reflect the PRESSURE in the pulmonary CAPILLARIES.Hydrogen: The first chemical element in the periodic table. It has the atomic symbol H, atomic number 1, and atomic weight [1.00784; 1.00811]. It exists, under normal conditions, as a colorless, odorless, tasteless, diatomic gas. Hydrogen ions are PROTONS. Besides the common H1 isotope, hydrogen exists as the stable isotope DEUTERIUM and the unstable, radioactive isotope TRITIUM.Anesthesia, Inhalation: Anesthesia caused by the breathing of anesthetic gases or vapors or by insufflating anesthetic gases or vapors into the respiratory tract.Acclimatization: Adaptation to a new environment or to a change in the old.Insufflation: The act of blowing a powder, vapor, or gas into any body cavity for experimental, diagnostic, or therapeutic purposes.Prospective Studies: Observation of a population for a sufficient number of persons over a sufficient number of years to generate incidence or mortality rates subsequent to the selection of the study group.Antihypertensive Agents: Drugs used in the treatment of acute or chronic vascular HYPERTENSION regardless of pharmacological mechanism. Among the antihypertensive agents are DIURETICS; (especially DIURETICS, THIAZIDE); ADRENERGIC BETA-ANTAGONISTS; ADRENERGIC ALPHA-ANTAGONISTS; ANGIOTENSIN-CONVERTING ENZYME INHIBITORS; CALCIUM CHANNEL BLOCKERS; GANGLIONIC BLOCKERS; and VASODILATOR AGENTS.Anesthesia: A state characterized by loss of feeling or sensation. This depression of nerve function is usually the result of pharmacologic action and is induced to allow performance of surgery or other painful procedures.Respiratory Physiological Phenomena: Physiological processes and properties of the RESPIRATORY SYSTEM as a whole or of any of its parts.Monitoring, Physiologic: The continuous measurement of physiological processes, blood pressure, heart rate, renal output, reflexes, respiration, etc., in a patient or experimental animal; includes pharmacologic monitoring, the measurement of administered drugs or their metabolites in the blood, tissues, or urine.Atmosphere: The gaseous envelope surrounding a planet or similar body. (From Random House Unabridged Dictionary, 2d ed)Arteries: The vessels carrying blood away from the heart.Pneumoperitoneum: A condition with trapped gas or air in the PERITONEAL CAVITY, usually secondary to perforation of the internal organs such as the LUNG and the GASTROINTESTINAL TRACT, or to recent surgery. Pneumoperitoneum may be purposely introduced to aid radiological examination.Carbon Monoxide: Carbon monoxide (CO). A poisonous colorless, odorless, tasteless gas. It combines with hemoglobin to form carboxyhemoglobin, which has no oxygen carrying capacity. The resultant oxygen deprivation causes headache, dizziness, decreased pulse and respiratory rates, unconsciousness, and death. (From Merck Index, 11th ed)Nitrogen: An element with the atomic symbol N, atomic number 7, and atomic weight [14.00643; 14.00728]. Nitrogen exists as a diatomic gas and makes up about 78% of the earth's atmosphere by volume. It is a constituent of proteins and nucleic acids and found in all living cells.Asphyxia: A pathological condition caused by lack of oxygen, manifested in impending or actual cessation of life.Monitoring, Intraoperative: The constant checking on the state or condition of a patient during the course of a surgical operation (e.g., checking of vital signs).Swine: Any of various animals that constitute the family Suidae and comprise stout-bodied, short-legged omnivorous mammals with thick skin, usually covered with coarse bristles, a rather long mobile snout, and small tail. Included are the genera Babyrousa, Phacochoerus (wart hogs), and Sus, the latter containing the domestic pig (see SUS SCROFA).Pulmonary Atelectasis: Absence of air in the entire or part of a lung, such as an incompletely inflated neonate lung or a collapsed adult lung. Pulmonary atelectasis can be caused by airway obstruction, lung compression, fibrotic contraction, or other factors.Osmotic Pressure: The pressure required to prevent the passage of solvent through a semipermeable membrane that separates a pure solvent from a solution of the solvent and solute or that separates different concentrations of a solution. It is proportional to the osmolality of the solution.Acidosis: A pathologic condition of acid accumulation or depletion of base in the body. The two main types are RESPIRATORY ACIDOSIS and metabolic acidosis, due to metabolic acid build up.Systole: Period of contraction of the HEART, especially of the HEART VENTRICLES.Intubation, Intratracheal: A procedure involving placement of a tube into the trachea through the mouth or nose in order to provide a patient with oxygen and anesthesia.Prone Position: The posture of an individual lying face down.Analysis of Variance: A statistical technique that isolates and assesses the contributions of categorical independent variables to variation in the mean of a continuous dependent variable.Anesthesia, General: Procedure in which patients are induced into an unconscious state through use of various medications so that they do not feel pain during surgery.Pulmonary Alveoli: Small polyhedral outpouchings along the walls of the alveolar sacs, alveolar ducts and terminal bronchioles through the walls of which gas exchange between alveolar air and pulmonary capillary blood takes place.Laser-Doppler Flowmetry: A method of non-invasive, continuous measurement of MICROCIRCULATION. The technique is based on the values of the DOPPLER EFFECT of low-power laser light scattered randomly by static structures and moving tissue particulates.Isoptera: An order of insects, restricted mostly to the tropics, containing at least eight families. A few species occur in temperate regions of North America.Atmosphere Exposure Chambers: Experimental devices used in inhalation studies in which a person or animal is either partially or completely immersed in a chemically controlled atmosphere.Bicarbonates: Inorganic salts that contain the -HCO3 radical. They are an important factor in determining the pH of the blood and the concentration of bicarbonate ions is regulated by the kidney. Levels in the blood are an index of the alkali reserve or buffering capacity.Perfusion: Treatment process involving the injection of fluid into an organ or tissue.Exhalation: The act of BREATHING out.Rats, Sprague-Dawley: A strain of albino rat used widely for experimental purposes because of its calmness and ease of handling. It was developed by the Sprague-Dawley Animal Company.Smoke Inhalation Injury: Pulmonary injury following the breathing in of toxic smoke from burning materials such as plastics, synthetics, building materials, etc. This injury is the most frequent cause of death in burn patients.Models, Biological: Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.Liquid Ventilation: Artificial respiration (RESPIRATION, ARTIFICIAL) using an oxygenated fluid.Middle Cerebral Artery: The largest of the cerebral arteries. It trifurcates into temporal, frontal, and parietal branches supplying blood to most of the parenchyma of these lobes in the CEREBRAL CORTEX. These are the areas involved in motor, sensory, and speech activities.Acidosis, Respiratory: Respiratory retention of carbon dioxide. It may be chronic or acute.Methanobacteriaceae: A family of anaerobic, coccoid to rod-shaped METHANOBACTERIALES. Cell membranes are composed mainly of polyisoprenoid hydrocarbons ether-linked to glycerol. Its organisms are found in anaerobic habitats throughout nature.Cell Hypoxia: A condition of decreased oxygen content at the cellular level.Polarography: An electrochemical technique for measuring the current that flows in solution as a function of an applied voltage. The observed polarographic wave, resulting from the electrochemical response, depends on the way voltage is applied (linear sweep or differential pulse) and the type of electrode used. Usually a mercury drop electrode is used.Cardiovascular Physiological Phenomena: Processes and properties of the CARDIOVASCULAR SYSTEM as a whole or of any of its parts.Pulmonary Artery: The short wide vessel arising from the conus arteriosus of the right ventricle and conveying unaerated blood to the lungs.Embolism, Air: Blocking of a blood vessel by air bubbles that enter the circulatory system, usually after TRAUMA; surgical procedures, or changes in atmospheric pressure.Bufonidae: The family of true toads belonging to the order Anura. The genera include Bufo, Ansonia, Nectophrynoides, and Atelopus.Hemodilution: Reduction of blood viscosity usually by the addition of cell free solutions. Used clinically (1) in states of impaired microcirculation, (2) for replacement of intraoperative blood loss without homologous blood transfusion, and (3) in cardiopulmonary bypass and hypothermia.Altitude Sickness: Multiple symptoms associated with reduced oxygen at high ALTITUDE.Microcirculation: The circulation of the BLOOD through the MICROVASCULAR NETWORK.Sheep: Any of the ruminant mammals with curved horns in the genus Ovis, family Bovidae. They possess lachrymal grooves and interdigital glands, which are absent in GOATS.Respiratory Function Tests: Measurement of the various processes involved in the act of respiration: inspiration, expiration, oxygen and carbon dioxide exchange, lung volume and compliance, etc.Pulse: The rhythmical expansion and contraction of an ARTERY produced by waves of pressure caused by the ejection of BLOOD from the left ventricle of the HEART as it contracts.Xylazine: An adrenergic alpha-2 agonist used as a sedative, analgesic and centrally acting muscle relaxant in VETERINARY MEDICINE.Enflurane: An extremely stable inhalation anesthetic that allows rapid adjustments of anesthesia depth with little change in pulse or respiratory rate.Diastole: Post-systolic relaxation of the HEART, especially the HEART VENTRICLES.Pulmonary Diffusing Capacity: The amount of a gas taken up, by the pulmonary capillary blood from the alveolar gas, per minute per unit of average pressure of the gradient of the gas across the BLOOD-AIR BARRIER.Fetal Hypoxia: Deficient oxygenation of FETAL BLOOD.Random Allocation: A process involving chance used in therapeutic trials or other research endeavor for allocating experimental subjects, human or animal, between treatment and control groups, or among treatment groups. It may also apply to experiments on inanimate objects.Diffusion: The tendency of a gas or solute to pass from a point of higher pressure or concentration to a point of lower pressure or concentration and to distribute itself throughout the available space. Diffusion, especially FACILITATED DIFFUSION, is a major mechanism of BIOLOGICAL TRANSPORT.Blood Substitutes: Substances that are used in place of blood, for example, as an alternative to BLOOD TRANSFUSIONS after blood loss to restore BLOOD VOLUME and oxygen-carrying capacity to the blood circulation, or to perfuse isolated organs.Hematocrit: The volume of packed RED BLOOD CELLS in a blood specimen. The volume is measured by centrifugation in a tube with graduated markings, or with automated blood cell counters. It is an indicator of erythrocyte status in disease. For example, ANEMIA shows a low value; POLYCYTHEMIA, a high value.Photosynthesis: The synthesis by organisms of organic chemical compounds, especially carbohydrates, from carbon dioxide using energy obtained from light rather than from the oxidation of chemical compounds. Photosynthesis comprises two separate processes: the light reactions and the dark reactions. In higher plants; GREEN ALGAE; and CYANOBACTERIA; NADPH and ATP formed by the light reactions drive the dark reactions which result in the fixation of carbon dioxide. (from Oxford Dictionary of Biochemistry and Molecular Biology, 2001)Manometry: Measurement of the pressure or tension of liquids or gases with a manometer.Lactic Acid: A normal intermediate in the fermentation (oxidation, metabolism) of sugar. The concentrated form is used internally to prevent gastrointestinal fermentation. (From Stedman, 26th ed)Body Temperature: The measure of the level of heat of a human or animal.Oceans and Seas: A great expanse of continuous bodies of salt water which together cover more than 70 percent of the earth's surface. Seas may be partially or entirely enclosed by land, and are smaller than the five oceans (Atlantic, Pacific, Indian, Arctic, and Antarctic).Rats, Wistar: A strain of albino rat developed at the Wistar Institute that has spread widely at other institutions. This has markedly diluted the original strain.Nitric Oxide: A free radical gas produced endogenously by a variety of mammalian cells, synthesized from ARGININE by NITRIC OXIDE SYNTHASE. Nitric oxide is one of the ENDOTHELIUM-DEPENDENT RELAXING FACTORS released by the vascular endothelium and mediates VASODILATION. It also inhibits platelet aggregation, induces disaggregation of aggregated platelets, and inhibits platelet adhesion to the vascular endothelium. Nitric oxide activates cytosolic GUANYLATE CYCLASE and thus elevates intracellular levels of CYCLIC GMP.Disease Models, Animal: Naturally occurring or experimentally induced animal diseases with pathological processes sufficiently similar to those of human diseases. They are used as study models for human diseases.Cerebrospinal Fluid Pressure: Manometric pressure of the CEREBROSPINAL FLUID as measured by lumbar, cerebroventricular, or cisternal puncture. Within the cranial cavity it is called INTRACRANIAL PRESSURE.Humidity: A measure of the amount of WATER VAPOR in the air.Temperature: The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.Dose-Response Relationship, Drug: The relationship between the dose of an administered drug and the response of the organism to the drug.Gills: Paired respiratory organs of fishes and some amphibians that are analogous to lungs. They are richly supplied with blood vessels by which oxygen and carbon dioxide are exchanged directly with the environment.Treatment Outcome: Evaluation undertaken to assess the results or consequences of management and procedures used in combating disease in order to determine the efficacy, effectiveness, safety, and practicability of these interventions in individual cases or series.Adaptation, Physiological: The non-genetic biological changes of an organism in response to challenges in its ENVIRONMENT.Acute Lung Injury: A condition of lung damage that is characterized by bilateral pulmonary infiltrates (PULMONARY EDEMA) rich in NEUTROPHILS, and in the absence of clinical HEART FAILURE. This can represent a spectrum of pulmonary lesions, endothelial and epithelial, due to numerous factors (physical, chemical, or biological).Extravascular Lung Water: Water content outside of the lung vasculature. About 80% of a normal lung is made up of water, including intracellular, interstitial, and blood water. Failure to maintain the normal homeostatic fluid exchange between the vascular space and the interstitium of the lungs can result in PULMONARY EDEMA and flooding of the alveolar space.Continuous Positive Airway Pressure: A technique of respiratory therapy, in either spontaneously breathing or mechanically ventilated patients, in which airway pressure is maintained above atmospheric pressure throughout the respiratory cycle by pressurization of the ventilatory circuit. (On-Line Medical Dictionary [Internet]. Newcastle upon Tyne(UK): The University Dept. of Medical Oncology: The CancerWEB Project; c1997-2003 [cited 2003 Apr 17]. Available from: http://cancerweb.ncl.ac.uk/omd/)Reproducibility of Results: The statistical reproducibility of measurements (often in a clinical context), including the testing of instrumentation or techniques to obtain reproducible results. The concept includes reproducibility of physiological measurements, which may be used to develop rules to assess probability or prognosis, or response to a stimulus; reproducibility of occurrence of a condition; and reproducibility of experimental results.Exercise: Physical activity which is usually regular and done with the intention of improving or maintaining PHYSICAL FITNESS or HEALTH. Contrast with PHYSICAL EXERTION which is concerned largely with the physiologic and metabolic response to energy expenditure.Reference Values: The range or frequency distribution of a measurement in a population (of organisms, organs or things) that has not been selected for the presence of disease or abnormality.Portal Pressure: The venous pressure measured in the PORTAL VEIN.Methane: The simplest saturated hydrocarbon. It is a colorless, flammable gas, slightly soluble in water. It is one of the chief constituents of natural gas and is formed in the decomposition of organic matter. (Grant & Hackh's Chemical Dictionary, 5th ed)Brain: The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.Pulmonary Circulation: The circulation of the BLOOD through the LUNGS.Hypotension: Abnormally low BLOOD PRESSURE that can result in inadequate blood flow to the brain and other vital organs. Common symptom is DIZZINESS but greater negative impacts on the body occur when there is prolonged depravation of oxygen and nutrients.Calcium Carbonate: Carbonic acid calcium salt (CaCO3). An odorless, tasteless powder or crystal that occurs in nature. It is used therapeutically as a phosphate buffer in hemodialysis patients and as a calcium supplement.Regression Analysis: Procedures for finding the mathematical function which best describes the relationship between a dependent variable and one or more independent variables. In linear regression (see LINEAR MODELS) the relationship is constrained to be a straight line and LEAST-SQUARES ANALYSIS is used to determine the best fit. In logistic regression (see LOGISTIC MODELS) the dependent variable is qualitative rather than continuously variable and LIKELIHOOD FUNCTIONS are used to find the best relationship. In multiple regression, the dependent variable is considered to depend on more than a single independent variable.Water: A clear, odorless, tasteless liquid that is essential for most animal and plant life and is an excellent solvent for many substances. The chemical formula is hydrogen oxide (H2O). (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Cross-Over Studies: Studies comparing two or more treatments or interventions in which the subjects or patients, upon completion of the course of one treatment, are switched to another. In the case of two treatments, A and B, half the subjects are randomly allocated to receive these in the order A, B and half to receive them in the order B, A. A criticism of this design is that effects of the first treatment may carry over into the period when the second is given. (Last, A Dictionary of Epidemiology, 2d ed)Predictive Value of Tests: In screening and diagnostic tests, the probability that a person with a positive test is a true positive (i.e., has the disease), is referred to as the predictive value of a positive test; whereas, the predictive value of a negative test is the probability that the person with a negative test does not have the disease. Predictive value is related to the sensitivity and specificity of the test.Heart Arrest: Cessation of heart beat or MYOCARDIAL CONTRACTION. If it is treated within a few minutes, heart arrest can be reversed in most cases to normal cardiac rhythm and effective circulation.Ultrasonography, Doppler, Transcranial: A non-invasive technique using ultrasound for the measurement of cerebrovascular hemodynamics, particularly cerebral blood flow velocity and cerebral collateral flow. With a high-intensity, low-frequency pulse probe, the intracranial arteries may be studied transtemporally, transorbitally, or from below the foramen magnum.Sympathetic Nervous System: The thoracolumbar division of the autonomic nervous system. Sympathetic preganglionic fibers originate in neurons of the intermediolateral column of the spinal cord and project to the paravertebral and prevertebral ganglia, which in turn project to target organs. The sympathetic nervous system mediates the body's response to stressful situations, i.e., the fight or flight reactions. It often acts reciprocally to the parasympathetic system.Lactates: Salts or esters of LACTIC ACID containing the general formula CH3CHOHCOOR.Acute Disease: Disease having a short and relatively severe course.Cardiopulmonary Resuscitation: The artificial substitution of heart and lung action as indicated for HEART ARREST resulting from electric shock, DROWNING, respiratory arrest, or other causes. The two major components of cardiopulmonary resuscitation are artificial ventilation (RESPIRATION, ARTIFICIAL) and closed-chest CARDIAC MASSAGE.Rabbits: The species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.Pressoreceptors: Receptors in the vascular system, particularly the aorta and carotid sinus, which are sensitive to stretch of the vessel walls.Lung Diseases, Obstructive: Any disorder marked by obstruction of conducting airways of the lung. AIRWAY OBSTRUCTION may be acute, chronic, intermittent, or persistent.Renin: A highly specific (Leu-Leu) endopeptidase that generates ANGIOTENSIN I from its precursor ANGIOTENSINOGEN, leading to a cascade of reactions which elevate BLOOD PRESSURE and increase sodium retention by the kidney in the RENIN-ANGIOTENSIN SYSTEM. The enzyme was formerly listed as EC 3.4.99.19.Seawater: The salinated water of OCEANS AND SEAS that provides habitat for marine organisms.Carotid Body: A small cluster of chemoreceptive and supporting cells located near the bifurcation of the internal carotid artery. The carotid body, which is richly supplied with fenestrated capillaries, senses the pH, carbon dioxide, and oxygen concentrations in the blood and plays a crucial role in their homeostatic control.Rats, Inbred SHR: A strain of Rattus norvegicus with elevated blood pressure used as a model for studying hypertension and stroke.Retrospective Studies: Studies used to test etiologic hypotheses in which inferences about an exposure to putative causal factors are derived from data relating to characteristics of persons under study or to events or experiences in their past. The essential feature is that some of the persons under study have the disease or outcome of interest and their characteristics are compared with those of unaffected persons.Capillaries: The minute vessels that connect the arterioles and venules.Oxidation-Reduction: A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).Fibrosarcoma: A sarcoma derived from deep fibrous tissue, characterized by bundles of immature proliferating fibroblasts with variable collagen formation, which tends to invade locally and metastasize by the bloodstream. (Stedman, 25th ed)Fluorocarbons: Liquid perfluorinated carbon compounds which may or may not contain a hetero atom such as nitrogen, oxygen or sulfur, but do not contain another halogen or hydrogen atom. This concept includes fluorocarbon emulsions and fluorocarbon blood substitutes.Acetazolamide: One of the CARBONIC ANHYDRASE INHIBITORS that is sometimes effective against absence seizures. It is sometimes useful also as an adjunct in the treatment of tonic-clonic, myoclonic, and atonic seizures, particularly in women whose seizures occur or are exacerbated at specific times in the menstrual cycle. However, its usefulness is transient often because of rapid development of tolerance. Its antiepileptic effect may be due to its inhibitory effect on brain carbonic anhydrase, which leads to an increased transneuronal chloride gradient, increased chloride current, and increased inhibition. (From Smith and Reynard, Textbook of Pharmacology, 1991, p337)Breath Tests: Any tests done on exhaled air.Administration, Inhalation: The administration of drugs by the respiratory route. It includes insufflation into the respiratory tract.Electron Spin Resonance Spectroscopy: A technique applicable to the wide variety of substances which exhibit paramagnetism because of the magnetic moments of unpaired electrons. The spectra are useful for detection and identification, for determination of electron structure, for study of interactions between molecules, and for measurement of nuclear spins and moments. (From McGraw-Hill Encyclopedia of Science and Technology, 7th edition) Electron nuclear double resonance (ENDOR) spectroscopy is a variant of the technique which can give enhanced resolution. Electron spin resonance analysis can now be used in vivo, including imaging applications such as MAGNETIC RESONANCE IMAGING.Lower Body Negative Pressure: External decompression applied to the lower body. It is used to study orthostatic intolerance and the effects of gravitation and acceleration, to produce simulated hemorrhage in physiologic research, to assess cardiovascular function, and to reduce abdominal stress during childbirth.Carbon: A nonmetallic element with atomic symbol C, atomic number 6, and atomic weight [12.0096; 12.0116]. It may occur as several different allotropes including DIAMOND; CHARCOAL; and GRAPHITE; and as SOOT from incompletely burned fuel.Muscle, Skeletal: A subtype of striated muscle, attached by TENDONS to the SKELETON. Skeletal muscles are innervated and their movement can be consciously controlled. They are also called voluntary muscles.Myoglobin: A conjugated protein which is the oxygen-transporting pigment of muscle. It is made up of one globin polypeptide chain and one heme group.Homeostasis: The processes whereby the internal environment of an organism tends to remain balanced and stable.Exercise Test: Controlled physical activity which is performed in order to allow assessment of physiological functions, particularly cardiovascular and pulmonary, but also aerobic capacity. Maximal (most intense) exercise is usually required but submaximal exercise is also used.Kidney: Body organ that filters blood for the secretion of URINE and that regulates ion concentrations.Microelectrodes: Electrodes with an extremely small tip, used in a voltage clamp or other apparatus to stimulate or record bioelectric potentials of single cells intracellularly or extracellularly. (Dorland, 28th ed)Baroreflex: A response by the BARORECEPTORS to increased BLOOD PRESSURE. Increased pressure stretches BLOOD VESSELS which activates the baroreceptors in the vessel walls. The net response of the CENTRAL NERVOUS SYSTEM is a reduction of central sympathetic outflow. This reduces blood pressure both by decreasing peripheral VASCULAR RESISTANCE and by lowering CARDIAC OUTPUT. Because the baroreceptors are tonically active, the baroreflex can compensate rapidly for both increases and decreases in blood pressure.Anesthetics, Intravenous: Ultrashort-acting anesthetics that are used for induction. Loss of consciousness is rapid and induction is pleasant, but there is no muscle relaxation and reflexes frequently are not reduced adequately. Repeated administration results in accumulation and prolongs the recovery time. Since these agents have little if any analgesic activity, they are seldom used alone except in brief minor procedures. (From AMA Drug Evaluations Annual, 1994, p174)Posture: The position or attitude of the body.
Nonlinear indicial response of complex nonstationary oscillations as pulmonary hypertension responding to step hypoxia. (1/1781)
This paper is devoted to the quantization of the degree of nonlinearity of the relationship between two biological variables when one of the variables is a complex nonstationary oscillatory signal. An example of the situation is the indicial responses of pulmonary blood pressure (P) to step changes of oxygen tension (DeltapO2) in the breathing gas. For a step change of DeltapO2 beginning at time t1, the pulmonary blood pressure is a nonlinear function of time and DeltapO2, which can be written as P(t-t1 | DeltapO2). An effective method does not exist to examine the nonlinear function P(t-t1 | DeltapO2). A systematic approach is proposed here. The definitions of mean trends and oscillations about the means are the keys. With these keys a practical method of calculation is devised. We fit the mean trends of blood pressure with analytic functions of time, whose nonlinearity with respect to the oxygen level is clarified here. The associated oscillations about the mean can be transformed into Hilbert spectrum. An integration of the square of the Hilbert spectrum over frequency yields a measure of oscillatory energy, which is also a function of time, whose mean trends can be expressed by analytic functions. The degree of nonlinearity of the oscillatory energy with respect to the oxygen level also is clarified here. Theoretical extension of the experimental nonlinear indicial functions to arbitrary history of hypoxia is proposed. Application of the results to tissue remodeling and tissue engineering of blood vessels is discussed. (+info)NADPH oxidase inhibition does not interfere with low PO2 transduction in rat and rabbit CB chemoreceptor cells. (2/1781)
The aim of the present work was to elucidate the role of NADPH oxidase in hypoxia sensing and transduction in the carotid body (CB) chemoreceptor cells. We have studied the effects of several inhibitors of NADPH oxidase on the normoxic and hypoxia-induced release of [3H]catecholamines (CA) in an in vitro preparation of intact CB of the rat and rabbit whose CA deposits have been labeled by prior incubation with the natural precursor [3H]tyrosine. It was found that diphenyleneiodonium (DPI; 0.2-25 microM), an inhibitor of NADPH oxidase, caused a dose-dependent release of [3H]CA from normoxic CB chemoreceptor cells. Contrary to hypoxia, DPI-evoked release was only partially Ca2+ dependent. Concentrations of DPI reported to produce full inhibition of NADPH oxidase in the rat CB did not prevent the hypoxic release response in the rat and rabbit CB chemoreceptor cells, as stimulation with hypoxia in the presence of DPI elicited a response equaling the sum of that produced by DPI and hypoxia applied separately. Neopterin (3-300 microM) and phenylarsine oxide (0.5-2 microM), other inhibitors of NADPH oxidase, did not promote release of [3H]CA in normoxic conditions or affect the response elicited by hypoxia. On the basis of effects of neopterin and phenylarsine oxide, it is concluded that NADPH oxidase does not appear to play a role in oxygen sensing or transduction in the rat and rabbit CB chemoreceptor cells in vitro and, in the context of the present study, that DPI effects are not related to NADPH oxidase inhibition. (+info)Continuous arterial P(O2) and P(CO2) measurements in swine during nitrous oxide and xenon elimination: prevention of diffusion hypoxia. (3/1781)
BACKGROUND: During nitrous oxide (N2O) elimination, arterial oxygen tension (PaO2) decreases because of the phenomenon commonly called diffusive hypoxia. The authors questioned whether similar effects occur during xenon elimination. METHODS: Nineteen anesthetized and paralyzed pigs were mechanically ventilated randomly for 30 min using inspiratory gas mixtures of 30% oxygen and either 70% N2O or xenon. The inspiratory gas was replaced by a mixture of 70% nitrogen and 30% oxygen. PaO2 and carbon dioxide tensions were recorded continuously using an indwelling arterial sensor. RESULTS: The PaO2 decreased from 119+/-10 mm Hg to 102+/-12 mm Hg (mean+/-SD) during N2O washout (P<0.01) and from 116+/-9 mm Hg to 110+/-8 mm Hg during xenon elimination (P<0.01), with a significant difference (P<0.01) between baseline and minimum PaO2 values (deltaPaO2, 17+/-6 mm Hg during N2O washout and 6+/-3 mm Hg during xenon washout). The PaCO2 value also decreased (from 39.3+/-6.3 mm Hg to 37.6+/-5.8 mm Hg) during N2O washout (P<0.01) and during xenon elimination (from 35.4+/-1.6 mm Hg to 34.9+/-1.6 mm Hg; P< 0.01). The deltaPaCO2 was 1.7+/-0.9 mm Hg in the N2O group and 0.5+/-0.3 mm Hg in the xenon group (P<0.01). CONCLUSION: Diffusive hypoxia is unlikely to occur during recovery from xenon anesthesia, probably because of the low blood solubility of this gas. (+info)Breathing patterns during slow and fast ramp exercise in man. (4/1781)
Breathing frequency (fb), tidal volume (VT), and respiratory timing during slow (SR, 8 W min-1) and fast (FR, 65 W min-1) ramp exercise to exhaustion on a cycle ergometer was examined in seven healthy male subjects. Expiratory ventilation (VE), pulmonary gas exchange (VO2 and VCO2) and end-tidal gas tensions (PET,O2 and PET,CO2) were determined using breath-by-breath techniques. Arterialized venous blood was sampled from a dorsal hand vein at 2 min intervals during SR and 30 s intervals during FR and analysed for arterial plasma PCO2 (PaCO2). PET,CO2 increased with increasing work rates (WRs) below the ventilatory threshold (VT); at WRs > or = 90% VO2,max, PET,CO2 was reduced (P < 0.05) below 0 W values in SR but not in FR.fb and VT were similar for SR and FR at all submaximal WRs, resulting in a similar VE. At exhaustion VE was similar but fb was higher (P < 0.05) and VT was lower (P < 0.05) in SR (fb, 51 +/- 10 breaths min-1; VT, 2590 +/- 590 ml) than in FR (fb, 42 +/- 8 breaths min-1; VT, 3050 +/- 470 ml). The time of expiration (TE) decreased with increasing WR, but there was no difference between SR and FR. The time of inspiration (TI) decreased at exercise intensities > or = VT; at exhaustion, TI was shorter (P < 0.05) during SR (0.512 +/- 0.097 s) than during FR (0.753 +/- 0.100 s). The TI to total breath duration (TI/TTot) and the inspiratory flow (VT/TI) were similar during SR and FR at all submaximal exercise intensities; at VO2,max, TI/TTot was lower (P < 0.05) and VT/TI was higher (P < 0.05) during SR (TI/TTot, 0.473 +/- 0.030; VT/TI, 5.092 +/- 0.377 l s-1) than during FR (TI/TTot, 0.567 +/- 0.050; VT/TI, 4.117 +/- 0.635 l s-1). These results suggest that during progressive exercise, breathing pattern and respiratory timing may be determined, at least at submaximal work rates, independently of alveolar and arterial PCO2. (+info)Electrocardiographic signs of chronic cor pulmonale: A negative prognostic finding in chronic obstructive pulmonary disease. (5/1781)
BACKGROUND: Chronic cor pulmonale (CCP) is a strong predictor of death in chronic obstructive pulmonary disease (COPD). The aims of this study were to assess the prognostic role of individual ECG signs of CCP and of the interaction between these signs and abnormal arterial blood gases. METHODS AND RESULTS: Two hundred sixty-three patients (217 men) with COPD, mean age 67+/-9 years, were grouped according to whether they had no ECG signs (group 1, n=100) or >/=1 ECG signs (group 2, n=163) of CCP and were followed up for 13 years after an exacerbation of respiratory failure. The median survival was significantly shorter in group 2 than in group 1 (2.58 versus 3. 45 years, respectively; Mantel-Cox test, 9.58; P=0.002). The Cox regression analysis identified S1S2S3 pattern, right atrial overload (RAO), and alveolar-arterial oxygen gradient (PAO2-PaO2) >48 mm Hg during oxygen therapy as the strongest predictors of death, with hazard rate (HR)=1.81 (95% CI, 1.22 to 2.69), HR=1.58 (95% CI, 1.15 to 2.18), and HR=1.96 (95% CI, 1.19 to 3.25), respectively. The median survivals of patients having both S1S2S3 pattern and RAO (n=14) and of patients having either S1S2S3 pattern or RAO (n=77) were 1.33 and 2.70 years, respectively (P=0.022). Group 2 patients had a 3-year survival of 18% or 53%, depending on whether their PAO2-PaO2 during oxygen therapy was or was not >48 mm Hg. CONCLUSIONS: Some ECG signs of CCP and PAO2-PaO2 >48 mm Hg during oxygen therapy qualified as a simple and inexpensive tool for targeting subsets of COPD patients with severe or very severe short-term prognosis. (+info)Spin-lattice relaxation of laser-polarized xenon in human blood. (6/1781)
The nuclear spin polarization of 129Xe can be enhanced by several orders of magnitude by using optical pumping techniques. The increased sensitivity of xenon NMR has allowed imaging of lungs as well as other in vivo applications. The most critical parameter for efficient delivery of laser-polarized xenon to blood and tissues is the spin-lattice relaxation time (T1) of xenon in blood. In this work, the relaxation of laser-polarized xenon in human blood is measured in vitro as a function of blood oxygenation. Interactions with dissolved oxygen and with deoxyhemoglobin are found to contribute to the spin-lattice relaxation time of 129Xe in blood, the latter interaction having greater effect. Consequently, relaxation times of 129Xe in deoxygenated blood are shorter than in oxygenated blood. In samples with oxygenation equivalent to arterial and venous blood, the 129Xe T1s at 37 degrees C and a magnetic field of 1.5 T were 6.4 s +/- 0.5 s and 4.0 s +/- 0.4 s, respectively. The 129Xe spin-lattice relaxation time in blood decreases at lower temperatures, but the ratio of T1 in oxygenated blood to that in deoxygenated blood is the same at 37 degrees C and 25 degrees C. A competing ligand has been used to show that xenon binding to albumin contributes to the 129Xe spin-lattice relaxation in blood plasma. This technique is promising for the study of xenon interactions with macromolecules. (+info)Randomised controlled trial of aminophylline for severe acute asthma. (7/1781)
OBJECTIVES: To determine whether children with severe acute asthma treated with large doses of inhaled salbutamol, inhaled ipratropium, and intravenous steroids are conferred any further benefits by the addition of aminophylline given intravenously. STUDY DESIGN: Randomised, double blind, placebo controlled trial of 163 children admitted to hospital with asthma who were unresponsive to nebulised salbutamol. RESULTS: The placebo and treatment groups of children were similar at baseline. The 48 children in the aminophylline group had a greater improvement in spirometry at six hours and a higher oxygen saturation in the first 30 hours. Five subjects in the placebo group were intubated and ventilated after enrollment compared with none in the aminophylline group. CONCLUSIONS: Aminophylline continues to have a place in the management of severe acute asthma in children unresponsive to initial treatment. (+info)Randomised trial of three doses of inhaled nitric oxide in acute respiratory distress syndrome. (8/1781)
BACKGROUND: Inhaled nitric oxide (iNO) is a potential therapeutic agent for the management of acute respiratory distress syndrome (ARDS). Concerns remain, however, regarding the potential toxicity from iNO and/or its oxidative derivatives and methaemoglobinaemia. AIMS: To determine the risk of toxicity from iNO, which includes worsening of lung injury, a prospective study evaluating the acute effects of three concentrations of iNO on gas exchange and haemodynamics in 12 children with ARDS was performed in a tertiary paediatric intensive care unit. INTERVENTION: iNO was administered for one hour at three concentrations (1, 10, and 20 parts per million (ppm)) in a random order of possible dosing schedules to avoid dose accumulation bias. Arterial blood gas, methaemoglobin concentrations, and haemodynamic parameters were obtained at baseline before commencement of iNO, at the end of each study hour, and after iNO was discontinued. Nitric oxide and nitrogen dioxide concentrations were continuously monitored during the study. RESULTS: iNO significantly improved the oxygenation ratio (Pao2/Fio2) from a mean (SEM) baseline of 11.9 (1.7) kPa to 20 (3.9) kPa, 24 (4.5) kPa, and 21.6 (3.9) kPa at 1, 10, and 20 ppm iNO, respectively. There was no significant difference in the improvement in oxygenation achieved between the three concentrations. Correspondingly, there was a significant improvement in oxygenation index (pre-iNO 28.3 (5) v post-iNO 18 (3) (1 ppm), 15 (3) (10 ppm), 16 (3) (20 ppm)). No toxicity from methaemoglobinaemia or nitrogen dioxide was seen during iNO administration. CONCLUSION: The results show that a low concentration of iNO (1 ppm) is as effective as higher concentrations (10 and 20 ppm) in improving oxygenation in children with ARDS and may be important in minimising toxicity during iNO use. (+info)
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Moles1
- The partial pressure formula is the product of the number of moles of a component of a substance divided by the total number of moles of the substance, multiplied by the barometric pressure. (reference.com)
Torr2
- Gas A is present in a 56 L bulb at a pressure of 213 torr. (jiskha.com)
- Gas B exerts a pressure of 683 torr in a 74 L bulb. (jiskha.com)
Concentration4
- Might be a silly question, but will there ever be an instance where partial pressure is given for one part of a chemical equation then the concentration is given for another part? (ucla.edu)
- The (n/V) is essentially concentration so you can convert from partial pressure to concentration this way. (ucla.edu)
- To convert between partial pressure and concentration you would use the ideal gas law, PV=nRT. (ucla.edu)
- To convert partial pressure to concentration, you would use the equation (n/V)=P/RT or conc. (ucla.edu)
Calculate3
- If the components of a pressure are given, you may calculate the partial pressures and add them to find the total pressure. (reference.com)
- Calculate the partial pressure from the information supplied to you in the problem and the aforementioned equation. (reference.com)
- Using the equation of partial pressures, insert the values and calculate the answer. (reference.com)
Gases1
- Given the normal composition of air, 78% dinitrogen, 21% dioxygen, 1% other gases, we can say quite categorically that the partial pressure of dioxygen in the atmosphere is approx. (socratic.org)
Equation4
- How do you solve a partial pressure equation? (reference.com)
- A partial pressure equation can be solved in more than one way. (reference.com)
- The total pressure is the sum of the partial pressures as shown in the following equation: Ptot = P1 + P2 + P3. (reference.com)
- These pressures can be found through the following equation: p = nRT/V. (reference.com)
Carbon2
- Our optical CO 2 sensors measure the partial pressure of carbon dioxide (pCO 2 ) in liquids. (presens.de)
- The measured signal correlates to the partial pressure of carbon dioxide. (presens.de)
Physiological1
- In normal physiological conditions, partial oxygen pressure is called physioxia. (tebu-bio.com)
Oxygen pressure4
- Why is the partial oxygen pressure of human tissues a crucial parameter? (uclouvain.be)
- In normal conditions, partial oxygen pressure (pO2) results in the balance between oxygen delivery and its consumption. (tebu-bio.com)
- Partial oxygen pressure in tissues varies widely, depending on their respective metabolic requirements and their functional status. (tebu-bio.com)
- Any alteration of tissue environment leading to a decrease in partial oxygen pressure is called hypoxia. (tebu-bio.com)
Mixture1
- In a gaseous mixture, the partial pressure of a gaseous component is the same as the pressure it would exert if that gas alone occupied the container. (socratic.org)
Total2
- If you are given a total pressure and one or more partial pressures, you may be able to simply subtract the partial pressures from the total pressure to find your solution. (reference.com)
- The total pressure is of course the sum of the individual partial pressures. (socratic.org)
Formula2
- What is the partial pressure formula? (reference.com)
- The partial pressure formula derives from Dalton's law of partial pressures. (reference.com)
Atmosphere1
- The partial pressure can be expressed using the atmosphere unit, abbreviated as atm. (reference.com)
Find1
- How do you find the partial pressure of oxygen? (socratic.org)
Component1
- The law states that the sum of the pressures of each component in a substance equals the pressure of the entire substance. (reference.com)
Container1
- An ideal gas is sealed within a container at a tempreture of 17 degree celcies and a pressure of 101KPa. (jiskha.com)
Normal1
- Lowering the oxygen partial pressure from 21% to 2.5% caused normal-term trophoblasts to reversibly modify their expression of genes associated with placental angiogenesis. (uclouvain.be)
Cell1
- Thus, low-oxygen partial pressure does not inhibit term-cytotrophoblast cell fusion and differentiation in vitro. (uclouvain.be)
Dalton's Law3
- The partial pressure formula derives from Dalton's law of partial pressures. (reference.com)
- And this gives us Dalton's Law or the Law of Partial Pressures. (coursera.org)
- When steam and hydrocarbon vapours are mixed together, the total pressure exerted is equal to the sum of their partial pressures (Dalton's Law). (eptq.com)
Atmospheric pressure16
- A liquid's atmospheric pressure boiling point corresponds to the temperature at which its vapor pressure is equal to the surrounding atmospheric pressure and it is often called the normal boiling point. (wikipedia.org)
- Note that at higher altitudes, the atmospheric pressure is less than that at sea level, so boiling points of liquids are reduced. (wikipedia.org)
- At the top of Mount Everest, the atmospheric pressure is approximately 0.333 atm, so by using the graph, the boiling point of Diethyl ether would be approximately 7.5 °C versus 34.6 °C at sea level (1 atm). (wikipedia.org)
- atmospheric pressure is usually closer to 101 kilopascal. (coursera.org)
- Lower atmospheric pressure. (study.com)
- a. 2HI(g) → H2(g) + I2(g) at atmospheric pressure. (jiskha.com)
- At a total atmospheric pressure of 1.00 atm, the partial pressure of CO2 in air is approximately 4.0×10−4 atm. (jiskha.com)
- 2- The earth's atmospheric pressure p is often modeled by assuming that the rate dpdhat Which p changes with the altitude above sea level is proportional to hp. (jiskha.com)
- The earth's atmospheric pressure, P, in terms of height above sea level is often modeled by an exponential decay function. (jiskha.com)
- GasExchange_BigIdea&WordList - atmospheric pressure. (coursehero.com)
- atmospheric pressure. (coursehero.com)
- The total pressure of the mixture is 192 kilopascals, which is about 1.9 times atmospheric pressure. (nagwa.com)
- The maximum partial pressure of oxygen we can get into the blood by breathing air at atmospheric pressure is about 12kPa (91.2mmHg), which you'll notice is quite a lot less than the 21kPa contained in the air itself. (freedive-earth.com)
- What is the value of normal atmospheric pressure? (answers.com)
- (answers.com)
- A mixture starts boiling when its vapor pressure exceeds the atmospheric pressure. (eptq.com)
Vapor17
- The higher the vapor pressure of a liquid at a given temperature, the lower the normal boiling point of the liquid. (wikipedia.org)
- The vapor pressure chart displayed has graphs of the vapor pressures versus temperatures for a variety of liquids. (wikipedia.org)
- As can be seen in the chart, the liquids with the highest vapor pressures have the lowest normal boiling points. (wikipedia.org)
- For example, at any given temperature, methyl chloride has the highest vapor pressure of any of the liquids in the chart. (wikipedia.org)
- It also has the lowest normal boiling point (-24.2 °C), which is where the vapor pressure curve of methyl chloride (the blue line) intersects the horizontal pressure line of one atmosphere (atm) of absolute vapor pressure. (wikipedia.org)
- Partial pressure is essentially the concentration of different components in the vapor above the liquid. (physicsforums.com)
- For example, the acetone vapor above liquid acetone has a higher pressure than the water vapor above liquid water, which has a much higher pressure than the copper vapor above solid copper. (physicsforums.com)
- A partial pressure sensor is disclosed which is suitable for determining the partial pressure of a gas or vapor in a thermally uncontrolled gas atmosphere over a large measurement range and with high measuring accuracy. (patentgenius.com)
- 9. The optical partial pressure sensor of claim 5 wherein said absorption of gas includes an absorption of water vapor. (patentgenius.com)
- Partial Saturated Vapor Pressure of Sodium Nitrite Over the System NaNO2-KNO3 Glazov, V. (deepdyve.com)
- The partial pressure of any vapor phase component is the mole fraction x total pressure. (eptq.com)
- Each component in a mixture exerts ist own vapor pressure, regardless of the other components present. (eptq.com)
- Vapor pressure increases with temperature. (eptq.com)
- The total vapor pressure of the mixture is the sum of the individual vapor pressure of each component in the mixture (proportional to their mole fractions). (eptq.com)
- Adding steam (water) is adding another vapor pressure component which contributes to the total vapor pressure of the mixture. (eptq.com)
- Mixing water vapor with the hydrocarbon in the flash zone reduces the pressure that the hydrocarbon is influenced by. (eptq.com)
- Thus, analytically, a higher vapor pressure would yield a lower density, which should yield a higher virtual temperature in turn. (wikipedia.org)
Temperature23
- If the total volume of gas collected is 5.25 L at a temperature of 25 [tex]^\circ {\rm C}[/tex] and a pressure of 734 torr, how many moles of gas was in the bicycle tire? (physicsforums.com)
- STP stands for standard temperature and pressure. (coursera.org)
- So, standard temperature and pressure. (coursera.org)
- So the temperature is 273.15 Kelvin and the pressure. (coursera.org)
- 3. The partial pressure sensor according to claim 1, wherein said temperature gauge is arranged between said substrate and said temperature regulation element. (patentgenius.com)
- 4. The partial pressure sensor according to claim 1, wherein said temperature gauge and said temperature-regulation element are integral component parts of said optical coating system. (patentgenius.com)
- The optimized growth temperature, the intensity ratios of the SBO (200) peak to the SBO (111) peak, and the crystallinities of SBO films increased with the sintering oxygen partial pressure. (mdpi.com)
- Reaction Temperature and Partial Pressure Induced Etching of Methylammonium Lead Iodide Perovskite by Trimethylaluminum. (americanelements.com)
- Here, the effects of reaction temperature and partial pressure of TMA on the mechanisms of TMA/CHNHPbI reactions are investigated. (americanelements.com)
- Our real time mass gain data and in situ mass spectrometry data show that the TMA/CHNHPbI reaction can either remove mass or accumulate mass onto CHNHPbI substrates, depending strongly on the reaction temperature and partial pressure of TMA. (americanelements.com)
- Reduction of the partial pressure of CO 2 at cool temperature also enhanced the activation state of Rubisco. (plantphysiol.org)
- At constant temperature CO2 gas is added to the mixture until the total pressure is 3.00 atm. (jiskha.com)
- Losev, V. 2004-10-13 00:00:00 The partial pressure of sodium nitrite in the system NaNO2-KNO3 was measured at 798, 823, and 848 K. The dependence of the logarithm of the NaNO2 pressure on inverse temperature is presented. (deepdyve.com)
- These data include AIR-SEA DIFFERENCE - PARTIAL PRESSURE (OR FUGACITY) OF CARBON DIOXIDE, Partial pressure (or fugacity) of carbon dioxide - atmosphere, Partial pressure (or fugacity) of carbon dioxide - water, SALINITY and SEA SURFACE TEMPERATURE. (data.gov)
- Boyle's law holds that in isothermal conditions (that is, a situation in which temperature is kept constant), an inverse relationship exists between the volume and pressure of a gas. (encyclopedia.com)
- Charles's law also yields a constant, but in this case the temperature and volume are allowed to vary under isobarometric conditions - that is, a situation in which the pressure remains the same. (encyclopedia.com)
- The initial reaction rate was found to be solely a function of temperature and CO2 partial pressure and was well described by the Langmuir Hinshelwood rate equation. (nwu.ac.za)
- Mercury at normal temperature and pressure is a liquid and will not hold a magnetic field - so it cannot be magnetized. (answers.com)
- As a side note the water dew point can be estimated from its partial pressure using something like Antoine's equation or steam tables (The dew point temperature is the temperature that corresponds to saturated steam conditions at the the steam partial pressure. (eptq.com)
- At a given temperature, more will flash if the pressure is reduced. (eptq.com)
- At a constant temperature, the amount of a given gas that dissolves in a given type and volume of liquid is directly proportional to the partial pressure of that gas in equilibrium with that liquid. (wikicalculator.com)
- of a moist air parcel is the temperature at which a theoretical dry air parcel would have a total pressure and density equal to the moist parcel of air. (wikipedia.org)
- The only variable quantity of the ideal gas law independent of density and pressure is temperature. (wikipedia.org)
Alveolar8
- Alveolar partial pressures of carbon dioxide and oxygen measured by a helium washout technique. (bmj.com)
- This was achieved by solving the Bohr equations for mean alveolar carbon dioxide and oxygen tensions (PACO2, PAO2) from known values of the dead-space:tidal volume ratio measured by helium washout, and from the mixed expired partial pressure of carbon dioxide and oxygen. (bmj.com)
- An encyclopedia entry for "A-ratio," which refers to the ratio of arterial oxygen partial pressure to alveolar oxygen partial pressure measuring oxygen transfer across the lung, is presented. (ebscohost.com)
- A dysproportional decrease in alveolar ventilation after sleep onset with a consecutive rise in arterial carbon dioxide partial pressure is called sleep-related hypoventilation, which. (ebscohost.com)
- A definition of the term "tracheal gas insufflation," which refers to a ventilatory technique to reduce accumulated carbon dioxide in the central airways and improve alveolar ventilation while decreasing ventilatory pressures and tidal volumes, is presented. (ebscohost.com)
- The alveolar-arterial oxygen partial pressure difference (AaDO2) and the arterial/alveolar oxygen partial pressure ratio (a/APO2) were compared for stability when inspired oxygen concentration (FIO2) changed. (ovid.com)
- Variations in alveolar partial pressure for carbon dioxide and oxygen have additive not synergistic acute effects on human pulmonary vasoconstriction. (ox.ac.uk)
- We independently controlled the alveolar partial pressures of carbon dioxide (Paco 2) and oxygen (Pao 2) to examine their possible interaction on human pulmonary vasoconstriction. (ox.ac.uk)
Chemistry2
- Published compositional data for glasses collected along the ridge were used to calculate pressures of partial crystallization and to examine variations in magma chemistry along the ridge. (osu.edu)
- This particular collection contains nine such videos, which cover topics in heat, pressure and states of matter, and are suitable for a high school or college course in Chemistry. (curriki.org)
Mole fraction6
- What is the mole fraction of Kr if the partial pressures of XE and Ar are 1.6 atm and 2.8 atm? (jiskha.com)
- In a gas mixture of He, Ne, and Ar with a total pressure of 8.40 atm, the mole fraction of Ar is ________ if the partial pressures of He and Ne are 1.50 and 2.00 atm respectively. (jiskha.com)
- The partial pressure of O₂ is equal to its mole fraction times the total pressure, which is equal to 0.251779 times 192 kilopascals. (nagwa.com)
- The partial pressure of nitrous oxide is equal to the mole fraction of nitrous oxide multiplied by the total pressure. (nagwa.com)
- The addition of steam reduces the mole fraction of hydrocarbons, and thus their partial pressure. (eptq.com)
- The hydrocarbon partial pressure is the mole fraction of hydrocarbon times total pressure. (eptq.com)
Molar1
- A gaseous mixture at a total pressure of 1.50 atm contains equal molar amounts of He, Ne, and Ar. (jiskha.com)
Oxygen in blood1
- The partial pressure of oxygen(PaO2) test is used to measure the pressure at which the oxygen in blood flows, more important to note is that the partial pressure of oxygen in the blood can be altered by very serious illnesses. (healthphreaks.com)
Concentrations2
- 1. The intramuscular oxygen partial pressure (pO2) in human gastrocnemius muscle was monitored during exercise and compared with metabolite concentrations reflecting the energy and the redox state in the tissue. (portlandpress.com)
- Using an ABA' design, the authors investigated the effects of Qi-training on blood gas concentrations with a 20 min control rest period (A), 1 h of Qi-training (B), and a 20-min rest period (A'). The blood partial pressures of oxygen (PO2) and carbon dioxide (PCO2), and oxygen content, oxygen saturation, and pH were significantly altered. (isharonline.org)
Venous13
- P bt O 2 , intracranial pressure (ICP), jugular venous oxygen saturation (S jv O 2 ), and cerebral perfusion pressure (CPP) were continuously monitored, and clinical outcomes were evaluated using the Glasgow Outcome Scale score. (dovepress.com)
- The purpose of this study was to determine the reproducibility of the indirect Fick method for the measurement of mixed venous carbon dioxide partial pressure (PvCO2) and venous carbon dioxide content (CvCO2) for estimation of cardiac output (Qc), using the exponential rise method of carbon. (ebscohost.com)
- Low central venous pressure (CVP) affects hemodynamic stability and tissue perfusion. (qxmd.com)
- Stroke volume variation in hepatic resection: a replacement for standard central venous pressure monitoring. (qxmd.com)
- Half clamping of the infrahepatic inferior vena cava reduces bleeding during a hepatectomy by decreasing the central venous pressure. (qxmd.com)
- Low central venous pressure reduces blood loss in hepatectomy. (qxmd.com)
- Randomized clinical trial comparing infrahepatic inferior vena cava clamping with low central venous pressure in complex liver resections involving the Pringle manoeuvre. (qxmd.com)
- The role of central venous pressure and type of vascular control in blood loss during major liver resections. (qxmd.com)
- Partial anomalous pulmonary venous connection (PAPVC) is one of the rare congenital cardiac diseases with a prevalence of 0.4-0.7% of autopsies. (clinicalimagingscience.org)
- The prevalence of a partial anomalous pulmonary venous connection is 0.2% in computed tomography (CT) among adults. (clinicalimagingscience.org)
- CT report database was searched for keywords of partial anomalous pulmonary venous connection, pulmonary hypertension, dilated right atrium (RA), and right ventricle (RV). (clinicalimagingscience.org)
- Partial anomalous pulmonary venous connection (PAPVC) is a rare congenital cardiac disease with a prevalence of 0.4%-0.7% in autopsies. (clinicalimagingscience.org)
- A CT database was searched for the following keywords: "Partial anomalous pulmonary venous connections," "pulmonary hypertension," "dilated right atrium (RA)," and "right ventricle (RV). (clinicalimagingscience.org)
Nitrogen5
- For example, given an ideal gas mixture of nitrogen (N2), hydrogen (H2) and ammonia (NH3): p = p N 2 + p H 2 + p NH 3 {\displaystyle p=p_{{\ce {N2}}}+p_{{\ce {H2}}}+p_{{\ce {NH3}}}} Ideally the ratio of partial pressures equals the ratio of the number of molecules. (wikipedia.org)
- What is the partial pressure of CO2(torr) in exhaled breathe at 37.0 degree C if the partial pressure of Oxygen is 116 torrr and that of nitrogen is 659 torr. (jiskha.com)
- If nitrogen gas added to the sample increases the total pressure to 1250 torr, what is the partial pressure in Torr of the Nitrogen added? (jiskha.com)
- In a gas mixture, the partial pressures are argon 393 mm Hg, neon 73 mm Hg, and nitrogen 119 mm Hg. (jiskha.com)
- Another whole set of problems is caused by the effect of increasing partial pressure of Nitrogen at depth as well… but that's another story. (freedive-earth.com)
Physiology3
- A partial pressure suit may affect human physiology, especially circulatory physiology. (iospress.com)
- It's a term that gets bandied around the freediving physiology literature all the time, but Partial Pressure is often poorly understood. (freedive-earth.com)
- Legeay, A, Houlihan, DFJ & Massabuau, J-C 2003, ' Influence of oxygen partial pressures on protein synthesis in feeding crabs ', American Journal of Physiology-Regulatory Integrative and Comparative Physiology , vol. 284, no. 2, pp. (elsevier.com)
Argon5
- This paper has discussed the structure and photoelectric properites of films dependence of sputtering argon partial pressure. (cnki.com.cn)
- Appropriate argon partial pressure is 0.5 Pa in this condition, the resistivity of the films is as low as 4.6×10 -4 Ω·cm and Hall mobility is 75 cm 2/(V·s). (cnki.com.cn)
- In visible range, the transmittance of the films is about 80% , in infrared range plasma resonance absorption wavelength is shorter with argon partial pressure decreased. (cnki.com.cn)
- XRD patterns indicate the X ray diffraction peaks of increase and peaks of decrease with argon partial pressure decreasing, which means the amount of crystal grain growing along increases. (cnki.com.cn)
- XPS spectra indicate that the density of the oxygen vacancies increases with the argon partial pressure decreased. (cnki.com.cn)
Reactant2
- Since it is the limiting reactant, the partial pressure of CO is zero after the reaction is complete. (yahoo.com)
- Keeping in mind that K = products/reactants, since K must remain a constant, the partial pressure of the product O2 must be higher to match the higher partial pressure of the reactant O3. (ucla.edu)
Solubility3
- Or indeed is partial pressure just an abstracted idea when looking at a liquid, that's to say the partial pressure is just mass dissolved divided by solubility - giving a partial pressure - but not in the real sense if pressure as we know it in terms of wall collisions? (physicsforums.com)
- Aqueous solubility of CO2 is 24.8 ml of CO2 per liter at 273K and a CO2 partial pressure of 3.6 atm. (wyzant.com)
- Thus, to determine the amount of oxygen in solution, one only has to multiply the partial pressure times the solubility , which at 37 degrees is equal to 0.03 ml O2/(liter blood x mm Hg). (washington.edu)
Monitoring the partial pressure of oxygen4
- The invention relates generally to sensors for monitoring the partial pressure of oxygen in various environments and more specifically relates to fiber-optic devices for monitoring the partial pressure of oxygen in medical applications. (justia.com)
- Another general type of optical device for monitoring the partial pressure of oxygen can be based on the use of ruthenium (II) complexes as luminescent sensors. (justia.com)
- The use of two fibers and/or a remote light source appears to be a requirement for most optical sensing devices for monitoring the partial pressure of oxygen. (justia.com)
- Therefore, a need exists to provide a miniaturized sensing system, for monitoring the partial pressure of oxygen, which is easily fabricated, is sufficiently responsive to small changes in the partial pressure of oxygen, can be operated using a single optical fiber in remote applications, and is not subject to the effects of membrane contamination such as deterioration of the accuracy of the sensor. (justia.com)
Decreases7
- Results from EDX show that with higher sulfur pressures the cracking along the ingot decreases, but at 2 bar these cracks are still present. (spie.org)
- because of butadiene gas consumed in reaction that,s why the pressure of htpb reactor decreases. (answers.com)
- pressure decreases inside the chest at the onset of inhalation. (answers.com)
- As your elevation increases, the air pressure decreases. (answers.com)
- The pressure gradient decreases. (answers.com)
- the partial pressure of O2 in the tissues decreases, creating a larger pressure graident for the movement of 02 from the blood into the tissues. (answers.com)
- Regular exercise typically decreases blood pressure. (answers.com)
Barometric3
- The partial pressure formula is the product of the number of moles of a component of a substance divided by the total number of moles of the substance, multiplied by the barometric pressure. (reference.com)
- Who invented the barometric pressure? (answers.com)
- The normal atmospheric or barometric pressure at sea level is around 76 cm of mercury. (answers.com)
20201
- Andrade E G, Punch L (June 26, 2020) Hybrid Use of Negative Pressure Therapy in the Management of Partial Wound Closure After Girdlestone Procedure. (cureus.com)
Atmospheres2
- Rodents with O(2)- and.NO-specific microelectrodes implanted adjacent to the abdominal aorta were exposed to O(2) at partial pressures from 0.2 to 2.8 atmospheres absolute (ATA). (isharonline.org)
- The partial pressure of oxygen (PO2) in the mix should never exceed 1.6 ATA (Atmospheres Absolute). (tdisdi.com)
Tidal6
- Value of measuring end tidal partial pressure of carbon dioxide as an adjunct to treadmill exercise testing. (ebscohost.com)
- Examines the value of measuring end tidal partial pressure of carbon dioxide. (ebscohost.com)
- We recorded the end-expiratory tidal partial pressure of carbon dioxide (Pet-CO2) as an indirect and continuous way to reflect the PaCO2. (medworm.com)
- We measured arterial and end-tidal partial pressures of sevoflurane in patients after induction of anesthesia to determine the existence and magnitude of the second gas effect. (asahq.org)
- Topic / Working Vocabulary List alveoli Bohr effect bronchi carbonic acid diaphragm* diffusion gas exchange gill heme group hemoglobin lung negative pressure breathing partial pressure random walk residual volume* respiratory distress syndrome surfactant tidal breathing trachea ventilation *Covered in assigned reading and homework rather than lecture. (coursehero.com)
- Mean arterial blood pressure, CPP, end-tidal CO2, and arterial oxygen saturation (pulse oximetry) were continuously recorded. (operativeneurosurgery.com)
Arterial blood5
- The Partial pressure of oxygen PaO2 is one of the parameters measured during the measurement of the Arterial blood Gas Test. (healthphreaks.com)
- Thus, in healthy people the partial pressures of oxygen and carbon dioxide in systemic arterial blood are the same as those in the alveoli. (washington.edu)
- Since the partial pressure of oxygen at sea level in normal systemic arterial blood is 100 mm Hg, the amount in solution is equal to 3 ml O2/liter blood. (washington.edu)
- The partial pressure of oxygen in arterial blood is approximately? (answers.com)
- The normal partial pressure of oxygen in arterial blood is 75-100 millimeters of mercury. (answers.com)
Gaseous mixture1
- In a gaseous mixture, the partial pressure of a gaseous component is the same as the pressure it would exert if that gas alone occupied the container. (socratic.org)
Pulmonary Artery4
- We chose to study the association between isolated PAPVC and volume overload, estimated systolic pulmonary artery pressure in a tertiary care center for cardiovascular diseases. (clinicalimagingscience.org)
- Of 54, 26 patients had volume overload of RA/RV or elevated estimated systolic pulmonary artery pressure. (clinicalimagingscience.org)
- In the present study, we examined the association between isolated PAPVC and volume overload and estimated systolic pulmonary artery pressure in a tertiary care center for cardiovascular diseases. (clinicalimagingscience.org)
- We hypothesized that isolated PAPVC involving vein drainage in a single lobe of the lung parenchyma is not a risk factor for volume overload on the right-sided cardiac chambers and increased estimated systolic pulmonary artery pressure. (clinicalimagingscience.org)
Systolic blood pr1
- Systolic blood pressure, the top reading of the reading, measures the pressure on the arterial walls while the heart undergoes systole. (answers.com)
Hemoglobin3
- Yu Wang, Song Hu, Konstantin Maslov, Yu Zhang, Younan Xia, and Lihong V. Wang, " In vivo integrated photoacoustic and confocal microscopy of hemoglobin oxygen saturation and oxygen partial pressure," Opt. (osapublishing.org)
- This curve was determined experimentally by equilibrating hemoglobin with various partial pressures of oxygen. (washington.edu)
- QUESTION: What is the percent saturation of hemoglobin if the partial pressure of oxygen is 40 mm Hg? (washington.edu)
Gradient6
- This study aimed to compare balloon volume and arterial pressure gradient, and analysed with intra-balloon pressure and balloon shape. (springer.com)
- The distal/proximal arterial pressure gradient and the intra-balloon pressures were also recorded. (springer.com)
- The partial pressure suit provides a pressure gradient in different parts of the body. (iospress.com)
- CuInS 2 single crystaLs of moderate size have been produced by the gradient freeze technique under different sulfur pressures. (spie.org)
- During each of these sixteen protocols Doppler echocardiography was used to evaluate cardiac output and systolic tricuspid pressure gradient, an index of pulmonary vasoconstriction. (ox.ac.uk)
- Mixed effects modelling delivered coefficients defining the interdependence of cardiac output, systolic tricuspid pressure gradient, ventilation, Paco 2 and So2. (ox.ac.uk)
Blood38
- Hi everyone, So I was thinking about how oxygen and CO2 are exchanged in the blood, and how a lot of this can be boiled down to differences in partial pressure. (biology-online.org)
- The simulation estimated the change of blood flow with the pressure level. (iospress.com)
- The increasing additional pressure on the abdomen and lower limbs block the blood flow to the lower limbs to avoid hypoxia in the most important tissues [ 10 ]. (iospress.com)
- At the same time, the peripheral blood pressure increases, the effective blood circulating in the body is reduced, and cardiac output is decreased [ 11 ]. (iospress.com)
- For specific analysis, phases of marked deterioration in systemic blood pressure and consecutive reductions in CPP were investigated. (operativeneurosurgery.com)
- The high partial pressure of oxygen in the lungs is pushing oxygen into the blood. (freedive-earth.com)
- In order to get more oxygen into the blood in this example, we'd have to increase the partial pressure of oxygen in the air and drive more in to the blood. (freedive-earth.com)
- That results in an increase in the Partial Pressure of oxygen in the blood too, as you might expect. (freedive-earth.com)
- Systolic pressure measures the maximum amount of pressure the blood exerts during a heart beat. (answers.com)
- Each time the heart contracts a sound is heard, a gauge on the sphygmomanometer measures the pressure that blood exerts during ventricle contraction. (answers.com)
- Blood pressure measures the pressure (force per area) on the arterial walls during the contraction and relaxation of the heart. (answers.com)
- The diastolic blood pressure - bottom reading - gives us the pressure on the arterial walls during diastole. (answers.com)
- While blood pressure would be high during exercise, it strengthens your heart and makes it healthier, therefore bringing your blood pressure closer to an ideal level. (answers.com)
- When determining the amount of oxygen in the blood, the first important point to establish is the partial pressure . (washington.edu)
- But while the partial pressures alone determine the direction a gas will diffuse , additional factors determine the amount of a gas in the blood . (washington.edu)
- my son is 4 years old what is a normal blood pressure for him. (answers.com)
- Normal human daily Blood Pressure Range can vary widely, so any single blood pressure monitor reading is not reliable. (answers.com)
- BP monitor readings must be taken at different times of day, to determine AVERAGE blood pressure levels over time. (answers.com)
- What could varying blood pressure readings be a sign of? (answers.com)
- It is totally normal for blood pressure readings to fluctuate throughout the day, even in healthy individuals. (answers.com)
- What normal blood pressure for 130 pound man? (answers.com)
- Do normal blood pressure readings change depending upon the person's age? (answers.com)
- A normal blood pressure is between 120 and 150. (answers.com)
- Blood pressure readings do change with age, as you normally start to develop heart problems (especially in men). (answers.com)
- You will often notice no signs of high blood pressure until your next trip to the doctor. (answers.com)
- What numbers represent normal blood pressure? (answers.com)
- Normal blood pressure is measured by two numbers that represent how much mercury is in your blood. (answers.com)
- A completely normal blood pressure reads: Below 120 / below 80. (answers.com)
- What are the names of the upper and lower blood pressure readings? (answers.com)
- Blood pressure is read in two parts, diastolic and systolic. (answers.com)
- It is documented as diastolic/systolic, example, a normal blood pressure is 120/80. (answers.com)
- What is the normal blood pressure for a 21 year old male? (answers.com)
- Normal blood pressure for an adult male is below 120 over 80. (answers.com)
- Is 110 70 a normal blood pressure? (answers.com)
- Is blood pressure 147 over 91 high? (answers.com)
- blood pressure at a normal range is 120/80, on average. (answers.com)
- Readings above this moves beyond the normal range towards hypertension (high blood pressure). (answers.com)
- that pressure on the vagus nerve causes changes to pulse rate and blood pressure and is dangerous in cases of carotid sinus hypersensitivity. (wikipedia.org)
Perfusion5
- In this experiment, 60% balloon volume was enough inflation to elevate central pressure allowing distal perfusion. (springer.com)
- The baseline pelvic pressure, the perfusion pelvic pressure (perfusion rates: 0.2 to 1.0 ml. per minute) and peristaltic waves were recorded after a resting period. (ovid.com)
- Negative pressure therapy (NPT) in open wounds has been shown to improve healing by augmenting angiogenesis, reducing edema and tension, and increasing tissue perfusion [1-. (cureus.com)
- Te purpose of a study was to compare brain PtiO2 with SjvO2 in severely head injured patients during phases of reduced cerebral perfusion pressure (CPP) to define a threshold in brain PtiO2 monitoring. (operativeneurosurgery.com)
- performed a post hoc analysis of prospectively collected data of patients on multimodal cerebral monitoring by intracranial pressure (ICP) and cerebral perfusion pressure (CPP) measurement as well as ptiO2 . (operativeneurosurgery.com)
Calculate the partial pressure2
- Some of the questions will require you to calculate the partial pressure as well. (study.com)
- Calculate the partial pressure of each gas in the 3L combined chamber. (yahoo.com)
Increases1
- Resuscitative endovascular balloon occlusion of the aorta (REBOA) increases proximal arterial pressure, but may also induce life-threatening distal ischemia. (springer.com)
Hydrogen1
- Babic, V., Geers, C., Jönsson, B. och Panas, I. (2017) Fates of Hydrogen During Alumina Growth Below Yttria Nodules in FeCrAl(RE) at Low Partial Pressures of Water . (chalmers.se)
Mixtures1
- This video introduces the notion of partial pressure in studying gas mixtures. (curriki.org)
PaO21
- So you see why the partial pressure of oxygen test is very important when trying to diagnose the effect of PaO2 on oxygen supply and circulation in the body during breathing difficulties. (healthphreaks.com)
Brain tissue3
- The aim of this study was to investigate the clinical significance and changes of brain tissue partial pressure of oxygen (P bt O 2 ) in the course of mild hypothermia treatment (MHT) for treating severe traumatic brain injury (sTBI). (dovepress.com)
- Roosen, Klaus 1998-11-01 00:00:00 AbstractOBJECTIVEWe assessed the technical and diagnostic reliability of partial pressure of oxygen (PO2) of brain tissue (P(ti)O2) monitoring. (deepdyve.com)
- Studies investigating multimodal cerebral monitoring including partial brain tissue oxygen monitoring (ptiO2) in neuro-intensive care patients during physiotherapy are completely lacking in the literature. (operativeneurosurgery.com)
Phases2
- This divide appears at pressures above ∼2 GPa in the natural system where garnet and pyroxenes are the principal residual phases in pyroxenites. (umn.edu)
- That means that the Partial Pressures in both phases remains the same. (freedive-earth.com)
Equals the pressure1
- The law states that the sum of the pressures of each component in a substance equals the pressure of the entire substance. (reference.com)
High partial pressure1
- A high partial pressure value means that the material is abundant and volatile. (physicsforums.com)
Moles of gas2
- pressure of gas a all of this expression if I know the number of moles of gas a. (coursera.org)
- Yes, in this case the partial pressures would be different because the moles of gas are different but the volume of the containers that they are in is the same. (ucla.edu)
Intracranial pressure1
- Intracranial pressure was monitored by means of an intraparenchymal catheter. (operativeneurosurgery.com)
Reaction2
- For a gaseous reaction, standard conditions are 298 K and a partial pressure of 1 atm for all species. (jiskha.com)
- Results of both water-slag and water-CO 2 -slag experiments after 72 h are consistent with a kinetics enhancement of the former reaction when a CO 2 partial pressure imposes a pH between 5 and 6. (frontiersin.org)
