Exacerbations of chronic obstrucAlveolar deadHypoventilationCarbon dioxideRespiratoryVenousOxygenationTissuesLungCapillariesPulmonaryShuntPartial pressurePhysiologicalDiffusionInertDifferencesDistributionPrimarilyConsumptionGeneratesMusclesTransportDeliveryRemovalChangeEffectsSignificantTherapyLevelsContributePatientsDead space
Exacerbations of chronic obstruc1
Alveolar dead2
- The significant increase in wasted ventilation (alveolar dead space) in the R group only may be secondary to the higher carbon dioxide tension, perhaps related to bronchodilatation. (atsjournals.org)
- Because there is no blood flow, no gas exchange is possible, and the region functions as alveolar dead space, or wasted ventilation. (clinicalgate.com)
Hypoventilation1
- Hypoxemia is generally attributed to one of four processes: hypoventilation, shunt (right to left), diffusion limitation, and ventilation/perfusion (VA/Q) inequality. (wikipedia.org)
Carbon dioxide2
- B, Corresponding variations in partial pressures of oxygen (P O 2 ) and carbon dioxide (P CO 2 ) in alveolar gas. (clinicalgate.com)
- During ventilation, respiratory mechanics and arterial oxygen and carbon dioxide levels change as conditions are altered, thus providing further sensory feedback to brainstem respiratory areas which imparts the respiratory continuum. (veteriankey.com)
Respiratory3
- Since then, Sassoon and colleagues ( 8 ) have supported this finding, whereas Dunn and colleagues ( 6 ) have found more evidence for a reduction in respiratory drive to ventilation. (atsjournals.org)
- The first section reviews the normal (gravity-determined) distribution of perfusion and ventilation, the major nongravitational determinants of resistance to perfusion and ventilation, transport of respiratory gases, and the pulmonary reflexes and special functions of the lung. (clinicalgate.com)
- Altogether, synchronized respiratory muscle contraction generates a breath which ultimately drives alveolar ventilation and blood gas regulation ( Figure 2.1 ) [7] . (veteriankey.com)
Venous4
- The multiple inert gas elimination technique (MIGET) is a medical technique used mainly in pulmonology that involves measuring the concentrations of various infused, inert gases in mixed venous blood, arterial blood, and expired gas of a subject. (wikipedia.org)
- Central venous and arterial pressures were measured by means of chronically implanted jugular venous and carotid catheters. (silverchair.com)
- Isovolemic exchange of blood with dextran caused no significant changes in arterial or central venous pressure, heart rate, capillary flow velocity, functional capillary density, or surface oxygen partial pressure during the 1-h observation period. (silverchair.com)
- A volume of Ringer's solution equal to four times of the amount of blood lost maintained arterial pressure and heart rate when central venous pressure was kept at predilution control values. (silverchair.com)
Oxygenation5
- The utilization of oxygen by working tissue is a process that involves three distinct steps-oxygenation, oxygen delivery, and oxygen consumption ( Figure 18.1 ). (musculoskeletalkey.com)
- Inspired oxygen diffuses across the alveolar-capillary membrane from the lungs into the blood (oxygenation). (musculoskeletalkey.com)
- Oxygenation occurs when inspired oxygen diffuses across the alveoli into the pulmonary capillaries. (musculoskeletalkey.com)
- To prove this hypothesis, the effects of isovolemic hemodilution (hematocrit 30%) with Ringer's lactate solution or dextran 60 on tissue perfusion and oxygenation were investigated in awake Syrian golden hamsters. (silverchair.com)
- In this model, volume replacement with artificial colloids yielded hemodynamic stability and adequate tissue oxygen supply, whereas administration of crystalloids alone jeopardized tissue perfusion and oxygenation. (silverchair.com)
Tissues4
- 1 We proposed that a different alignment may be preferable for clinicians in demonstrating its beneficial characteristics, enhancing both the "pick up" of oxygen despite cardiorespiratory disease and the "drop off" of oxygen to the tissues despite falling oxygen saturation (fig 1). (bmj.com)
- These characteristics result in (a) the pick up of oxygen by haemoglobin being maintained despite reduced oxygen tension, and (b) delivery of oxygen to the tissues being maintained despite progressively falling oxyhaemoglobin saturation. (bmj.com)
- Red blood cells then transport hemoglobin-bound oxygen throughout the body (oxygen delivery) and tissues extract oxygen for use in aerobic respiration (oxygen consumption). (musculoskeletalkey.com)
- [3] Another study on the effects of an isotonic fluid load (30% of plasma volume) demonstrated a preferential increase in the extracellular fluid of lung (14%), gastric fundus (15%), large intestine (21%), and skin (28%), suggesting that the perfusion of these tissues may be affected. (silverchair.com)
Lung2
- 7, 8 These effects may contribute to the reduction in lung volumes and decreased transfer factor observed with high flow oxygen. (bmj.com)
- The data produced by the MIGET is an approximation of the distribution of V A / Q {\displaystyle V_{A}/Q} ratios across the entire lung. (wikipedia.org)
Capillaries1
- However, tissue perfusion determined by counting perfused capillaries per terminal arteriole was reduced by 62%, and mean tissue oxygen partial pressure decreased from 19 to 8 mmHg. (silverchair.com)
Pulmonary4
- The potential adverse pulmonary effects of high flow oxygen therapy were recognised soon after its widespread use in clinical practice. (bmj.com)
- High flow oxygen was shown to result in worsening ventilation-perfusion mismatch due to absorption atelectasis and inhibition of reflex pulmonary vasoconstriction. (bmj.com)
- Perhaps the least recognised risk with high flow oxygen is that its use may lead to a delay in the ability to recognise and treat a progressive deterioration in pulmonary function. (bmj.com)
- The detailed mechanisms of oxygen-induced hypercapnia were examined in 22 patients during an acute exacerbation of chronic obstructive pulmonary disease. (atsjournals.org)
Shunt1
- The technique quantifies true shunt, physiological dead space ventilation, ventilation versus blood flow (VA/Q) ratios, and diffusion limitation. (wikipedia.org)
Partial pressure1
- Experiments were performed by using a chronic dorsal skinfold window giving access to skeletal muscle tissue (musculus cutaneus) with in vivo microscopy, quantitative video image analysis, and surface oxygen partial pressure electrodes. (silverchair.com)
Physiological1
Diffusion1
- The driving force for diffusion of oxygen across the alveolar-capillary membrane can best be understood by the alveolar gas equation. (musculoskeletalkey.com)
Inert2
- In this model, retention (R) is measured from the ratio P A / P v {\displaystyle P_{A}/P_{v}} . Stated mathematically: R = λ λ + V A / Q {\displaystyle R={\frac {\lambda }{\lambda +V_{A}/Q}}} From this equation, we can measure the levels of each inert gas retained in the blood. (wikipedia.org)
- Ventilation, cardiac output, and the distribution of ventilation-perfusion (V˙ a /Q˙ ) ratios were measured using the multiple inert gas elimination technique breathing air and then 100% oxygen through a nose mask. (atsjournals.org)
Differences1
- Although it has been shown repeatedly that either treatment regimen can restore intravascular volume and gross organ perfusion, no agreement has been reached regarding differences in sequelae, such as multiple organ failure or outcome. (silverchair.com)
Distribution1
- Moreover, a similar understanding exists for the relationship between the distribution of blood flow and the distribution of ventilation. (wikipedia.org)
Primarily1
- This type of exercise is supported primarily by aerobic metabolism, which requires oxygen to be present for the generation of energy from sources such as glucose, glycogen, and fat. (musculoskeletalkey.com)
Consumption1
- Paradoxically, high flow oxygen in excess of that required to relieve arterial hypoxaemia may cause a reversible decrease in oxygen consumption. (bmj.com)
Generates1
- In anaerobic metabolism, anaerobic glycolysis rapidly generates ATP from the breakdown of glucose without requiring oxygen. (musculoskeletalkey.com)
Muscles1
- In aerobic metabolism, the cardiopulmonary system must replenish oxygen in working muscles. (musculoskeletalkey.com)
Transport1
- Excessive amounts of Ringer's solution can impair oxygen transport because of decreased capillary flow and subsequently can impede wound healing. (silverchair.com)
Delivery4
- Regardless, the impaired oxygen delivery at the tissue level results in depressed cellular respiration and potential organ dysfunction. (bmj.com)
- In an exercising individual the cardiovascular system plays three important roles: the delivery of oxygen and nutrients to exercising muscle, the removal of waste by-products from exercising muscle, and the dissipation of generated heat through convection. (musculoskeletalkey.com)
- Thus, the delivery of oxygen to working tissue is dependent on the function of the lungs, the cardiovascular system, and red blood cells in order to meet the metabolic demands of the body ( 2 ). (musculoskeletalkey.com)
- The resulting tissue edema may interfere with nutritive capillary perfusion and oxygen delivery. (silverchair.com)
Removal2
- The most important mechanisms are considered to be a reduction in ventilation associated with removal of a hypoxic stimulus and increasing ventilation-perfusion (V˙ a /Q˙ ) inequality caused by release of hypoxic vasoconstriction ( 1 ). (atsjournals.org)
- Of the fatty acids, vitamins, are stored in the body and its removal through alveolar ventilation. (hybridnutrition.co.za)
Effects3
- High flow oxygen resulting in hyperoxia also has the potential to cause significant adverse cardiovascular effects with increased systemic vascular resistance and blood pressure, decreased cardiac output and reduced coronary, cerebral and renal blood flow. (bmj.com)
- 10- 14 These cardiovascular effects can potentially contribute to the worse outcomes observed with high flow oxygen therapy in myocardial infarction, 15 stroke, 16 neonatal resuscitation 17 and fulminant sepsis, 18 although the enhanced production of reactive oxygen species causing reperfusion injury may also play a role. (bmj.com)
- These adverse effects are not widely known and high flow oxygen is widely prescribed to breathless patients, regardless of the presence of arterial hypoxaemia. (bmj.com)
Significant1
- This study suggests that an overall reduction in ventilation characterizes oxygen-induced hypercapnia, as an increased dispersion of blood flow from release of hypoxic vasoconstriction occurred to a significant and similar degree in both groups. (atsjournals.org)
Therapy2
- The causes and precise pathophysiology of acute exacerbations are difficult to determine, so treatment is usually broadly based, encompassing imprecisely targeted bronchodilator, corticosteroid, and antibiotic therapy, supplemental oxygen, and physiotherapy. (atsjournals.org)
- in particular, the hypercapnia induced by oxygen therapy in some patients with COPD. (atsjournals.org)
Levels1
Contribute1
- Moreover, there are also "extrapulmonary" factors that can contribute to fluctuations in arterial PO2. (wikipedia.org)
Patients1
Dead space1
- The relative importance of a reduction in total ventilation and an increase in Bohr dead space (V d/Vt) in causing hyperoxic hypercapnia remains controversial. (atsjournals.org)