Airway Obstruction: Any hindrance to the passage of air into and out of the lungs.Intestinal Obstruction: Any impairment, arrest, or reversal of the normal flow of INTESTINAL CONTENTS toward the ANAL CANAL.Airway Resistance: Physiologically, the opposition to flow of air caused by the forces of friction. As a part of pulmonary function testing, it is the ratio of driving pressure to the rate of air flow.Ureteral Obstruction: Blockage in any part of the URETER causing obstruction of urine flow from the kidney to the URINARY BLADDER. The obstruction may be congenital, acquired, unilateral, bilateral, complete, partial, acute, or chronic. Depending on the degree and duration of the obstruction, clinical features vary greatly such as HYDRONEPHROSIS and obstructive nephropathy.Lung Diseases, Obstructive: Any disorder marked by obstruction of conducting airways of the lung. AIRWAY OBSTRUCTION may be acute, chronic, intermittent, or persistent.Forced Expiratory Volume: Measure of the maximum amount of air that can be expelled in a given number of seconds during a FORCED VITAL CAPACITY determination . It is usually given as FEV followed by a subscript indicating the number of seconds over which the measurement is made, although it is sometimes given as a percentage of forced vital capacity.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.Asthma: A form of bronchial disorder with three distinct components: airway hyper-responsiveness (RESPIRATORY HYPERSENSITIVITY), airway INFLAMMATION, and intermittent AIRWAY OBSTRUCTION. It is characterized by spasmodic contraction of airway smooth muscle, WHEEZING, and dyspnea (DYSPNEA, PAROXYSMAL).Laryngeal Diseases: Pathological processes involving any part of the LARYNX which coordinates many functions such as voice production, breathing, swallowing, and coughing.Spirometry: Measurement of volume of air inhaled or exhaled by the lung.Airway Remodeling: The structural changes in the number, mass, size and/or composition of the airway tissues.Vital Capacity: The volume of air that is exhaled by a maximal expiration following a maximal inspiration.Tracheal StenosisBronchi: The larger air passages of the lungs arising from the terminal bifurcation of the TRACHEA. They include the largest two primary bronchi which branch out into secondary bronchi, and tertiary bronchi which extend into BRONCHIOLES and PULMONARY ALVEOLI.Nasal Obstruction: Any hindrance to the passage of air into and out of the nose. The obstruction may be unilateral or bilateral, and may involve any part of the NASAL CAVITY.Lung: Either of the pair of organs occupying the cavity of the thorax that effect the aeration of the blood.Bronchial DiseasesRespiratory System: The tubular and cavernous organs and structures, by means of which pulmonary ventilation and gas exchange between ambient air and the blood are brought about.Bronchitis: Inflammation of the large airways in the lung including any part of the BRONCHI, from the PRIMARY BRONCHI to the TERTIARY BRONCHI.Pierre Robin Syndrome: Congenital malformation characterized by MICROGNATHIA or RETROGNATHIA; GLOSSOPTOSIS and CLEFT PALATE. The mandibular abnormalities often result in difficulties in sucking and swallowing. The syndrome may be isolated or associated with other syndromes (e.g., ANDERSEN SYNDROME; CAMPOMELIC DYSPLASIA). Developmental mis-expression of SOX9 TRANSCRIPTION FACTOR gene on chromosome 17q and its surrounding region is associated with the syndrome.Duodenal Obstruction: Hindrance of the passage of luminal contents in the DUODENUM. Duodenal obstruction can be partial or complete, and caused by intrinsic or extrinsic factors. Simple obstruction is associated with diminished or stopped flow of luminal contents. Strangulating obstruction is associated with impaired blood flow to the duodenum in addition to obstructed flow of luminal contents.Bronchial Hyperreactivity: Tendency of the smooth muscle of the tracheobronchial tree to contract more intensely in response to a given stimulus than it does in the response seen in normal individuals. This condition is present in virtually all symptomatic patients with asthma. The most prominent manifestation of this smooth muscle contraction is a decrease in airway caliber that can be readily measured in the pulmonary function laboratory.Plethysmography, Whole Body: Measurement of the volume of gas in the lungs, including that which is trapped in poorly communicating air spaces. It is of particular use in chronic obstructive pulmonary disease and emphysema. (Segen, Dictionary of Modern Medicine, 1992)Maximal Expiratory Flow-Volume Curves: Curves depicting MAXIMAL EXPIRATORY FLOW RATE, in liters/second, versus lung inflation, in liters or percentage of lung capacity, during a FORCED VITAL CAPACITY determination. Common abbreviation is MEFV.Bronchoscopy: Endoscopic examination, therapy or surgery of the bronchi.Pulmonary Ventilation: The total volume of gas inspired or expired per unit of time, usually measured in liters per minute.Bronchoconstriction: Narrowing of the caliber of the BRONCHI, physiologically or as a result of pharmacological intervention.Urinary Bladder Neck Obstruction: Blocked urine flow through the bladder neck, the narrow internal urethral opening at the base of the URINARY BLADDER. Narrowing or strictures of the URETHRA can be congenital or acquired. It is often observed in males with enlarged PROSTATE glands.Urethral Obstruction: Partial or complete blockage in any part of the URETHRA that can lead to difficulty or inability to empty the URINARY BLADDER. It is characterized by an enlarged, often damaged, bladder with frequent urges to void.Tracheal DiseasesBronchial Provocation Tests: Tests involving inhalation of allergens (nebulized or in dust form), nebulized pharmacologically active solutions (e.g., histamine, methacholine), or control solutions, followed by assessment of respiratory function. These tests are used in the diagnosis of asthma.Bronchodilator Agents: Agents that cause an increase in the expansion of a bronchus or bronchial tubes.Pulmonary Disease, Chronic Obstructive: A disease of chronic diffuse irreversible airflow obstruction. Subcategories of COPD include CHRONIC BRONCHITIS and PULMONARY EMPHYSEMA.Gastric Outlet Obstruction: The hindering of output from the STOMACH into the SMALL INTESTINE. This obstruction may be of mechanical or functional origin such as EDEMA from PEPTIC ULCER; NEOPLASMS; FOREIGN BODIES; or AGING.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.Total Lung Capacity: The volume of air contained in the lungs at the end of a maximal inspiration. It is the equivalent to each of the following sums: VITAL CAPACITY plus RESIDUAL VOLUME; INSPIRATORY CAPACITY plus FUNCTIONAL RESIDUAL CAPACITY; TIDAL VOLUME plus INSPIRATORY RESERVE VOLUME plus functional residual capacity; or tidal volume plus inspiratory reserve volume plus EXPIRATORY RESERVE VOLUME plus residual volume.Ventricular Outflow Obstruction: Occlusion of the outflow tract in either the LEFT VENTRICLE or the RIGHT VENTRICLE of the heart. This may result from CONGENITAL HEART DEFECTS, predisposing heart diseases, complications of surgery, or HEART NEOPLASMS.Tracheotomy: Surgical incision of the trachea.Laryngostenosis: Developmental or acquired stricture or narrowing of the LARYNX. Symptoms of respiratory difficulty depend on the degree of laryngeal narrowing.Residual Volume: The volume of air remaining in the LUNGS at the end of a maximal expiration. Common abbreviation is RV.Respiratory Mucosa: The mucous membrane lining the RESPIRATORY TRACT, including the NASAL CAVITY; the LARYNX; the TRACHEA; and the BRONCHI tree. The respiratory mucosa consists of various types of epithelial cells ranging from ciliated columnar to simple squamous, mucous GOBLET CELLS, and glands containing both mucous and serous cells.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.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)Lung Volume Measurements: Measurement of the amount of air that the lungs may contain at various points in the respiratory cycle.Larynx: A tubular organ of VOICE production. It is located in the anterior neck, superior to the TRACHEA and inferior to the tongue and HYOID BONE.Peak Expiratory Flow Rate: Measurement of the maximum rate of airflow attained during a FORCED VITAL CAPACITY determination. Common abbreviations are PEFR and PFR.Forced Expiratory Flow Rates: The rate of airflow measured during a FORCED VITAL CAPACITY determination.Dyspnea: Difficult or labored breathing.Laryngeal Edema: Abnormal accumulation of fluid in tissues of any part of the LARYNX, commonly associated with laryngeal injuries and allergic reactions.Albuterol: A short-acting beta-2 adrenergic agonist that is primarily used as a bronchodilator agent to treat ASTHMA. Albuterol is prepared as a racemic mixture of R(-) and S(+) stereoisomers. The stereospecific preparation of R(-) isomer of albuterol is referred to as levalbuterol.Maximal Expiratory Flow Rate: The airflow rate measured during the first liter expired after the first 200 ml have been exhausted during a FORCED VITAL CAPACITY determination. Common abbreviations are MEFR, FEF 200-1200, and FEF 0.2-1.2.Bronchoalveolar Lavage Fluid: Washing liquid obtained from irrigation of the lung, including the BRONCHI and the PULMONARY ALVEOLI. It is generally used to assess biochemical, inflammatory, or infection status of the lung.Respiratory Hypersensitivity: A form of hypersensitivity affecting the respiratory tract. It includes ASTHMA and RHINITIS, ALLERGIC, SEASONAL.Administration, Inhalation: The administration of drugs by the respiratory route. It includes insufflation into the respiratory tract.Pulmonary Emphysema: Enlargement of air spaces distal to the TERMINAL BRONCHIOLES where gas-exchange normally takes place. This is usually due to destruction of the alveolar wall. Pulmonary emphysema can be classified by the location and distribution of the lesions.Functional Residual Capacity: The volume of air remaining in the LUNGS at the end of a normal, quiet expiration. It is the sum of the RESIDUAL VOLUME and the EXPIRATORY RESERVE VOLUME. Common abbreviation is FRC.Tracheostomy: Surgical formation of an opening into the trachea through the neck, or the opening so created.Lacrimal Duct Obstruction: Interference with the secretion of tears by the lacrimal glands. Obstruction of the LACRIMAL SAC or NASOLACRIMAL DUCT causing acute or chronic inflammation of the lacrimal sac (DACRYOCYSTITIS). It is caused also in infants by failure of the nasolacrimal duct to open into the inferior meatus and occurs about the third week of life. In adults occlusion may occur spontaneously or after injury or nasal disease. (Newell, Ophthalmology: Principles and Concepts, 7th ed, p250)Epiglottis: A thin leaf-shaped cartilage that is covered with LARYNGEAL MUCOSA and situated posterior to the root of the tongue and HYOID BONE. During swallowing, the epiglottis folds back over the larynx inlet thus prevents foods from entering the airway.Tracheal NeoplasmsAerosols: Colloids with a gaseous dispersing phase and either liquid (fog) or solid (smoke) dispersed phase; used in fumigation or in inhalation therapy; may contain propellant agents.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).Laryngeal Masks: A type of oropharyngeal airway that provides an alternative to endotracheal intubation and standard mask anesthesia in certain patients. It is introduced into the hypopharynx to form a seal around the larynx thus permitting spontaneous or positive pressure ventilation without penetration of the larynx or esophagus. It is used in place of a facemask in routine anesthesia. The advantages over standard mask anesthesia are better airway control, minimal anesthetic gas leakage, a secure airway during patient transport to the recovery area, and minimal postoperative problems.Inhalation: The act of BREATHING in.Horse Diseases: Diseases of domestic and wild horses of the species Equus caballus.Mucus: The viscous secretion of mucous membranes. It contains mucin, white blood cells, water, inorganic salts, and exfoliated cells.High-Frequency Jet Ventilation: Respiratory support system used primarily with rates of about 100 to 200/min with volumes of from about one to three times predicted anatomic dead space. Used to treat respiratory failure and maintain ventilation under severe circumstances.Cough: A sudden, audible expulsion of air from the lungs through a partially closed glottis, preceded by inhalation. It is a protective response that serves to clear the trachea, bronchi, and/or lungs of irritants and secretions, or to prevent aspiration of foreign materials into the lungs.Bronchial Spasm: Spasmodic contraction of the smooth muscle of the bronchi.Airway Management: Evaluation, planning, and use of a range of procedures and airway devices for the maintenance or restoration of a patient's ventilation.Respiratory Sounds: Noises, normal and abnormal, heard on auscultation over any part of the RESPIRATORY TRACT.Pharynx: A funnel-shaped fibromuscular tube that conducts food to the ESOPHAGUS, and air to the LARYNX and LUNGS. It is located posterior to the NASAL CAVITY; ORAL CAVITY; and LARYNX, and extends from the SKULL BASE to the inferior border of the CRICOID CARTILAGE anteriorly and to the inferior border of the C6 vertebra posteriorly. It is divided into the NASOPHARYNX; OROPHARYNX; and HYPOPHARYNX (laryngopharynx).Sleep Apnea, Obstructive: A disorder characterized by recurrent apneas during sleep despite persistent respiratory efforts. It is due to upper airway obstruction. The respiratory pauses may induce HYPERCAPNIA or HYPOXIA. Cardiac arrhythmias and elevation of systemic and pulmonary arterial pressures may occur. Frequent partial arousals occur throughout sleep, resulting in relative SLEEP DEPRIVATION and daytime tiredness. Associated conditions include OBESITY; ACROMEGALY; MYXEDEMA; micrognathia; MYOTONIC DYSTROPHY; adenotonsilar dystrophy; and NEUROMUSCULAR DISEASES. (From Adams et al., Principles of Neurology, 6th ed, p395)Tongue DiseasesSleep Apnea Syndromes: Disorders characterized by multiple cessations of respirations during sleep that induce partial arousals and interfere with the maintenance of sleep. Sleep apnea syndromes are divided into central (see SLEEP APNEA, CENTRAL), obstructive (see SLEEP APNEA, OBSTRUCTIVE), and mixed central-obstructive types.Laryngocele: Congenital anomalous dilitation of the laryngeal saccule that may extend internally into the airway or externally through the thyrohyoid membrane.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.Bronchography: Radiography of the bronchial tree after injection of a contrast medium.Atropine Derivatives: Analogs and derivatives of atropine.Fiber Optic Technology: The technology of transmitting light over long distances through strands of glass or other transparent material.Plethysmography: Recording of change in the size of a part as modified by the circulation in it.Tomography, X-Ray Computed: Tomography using x-ray transmission and a computer algorithm to reconstruct the image.Croup: Inflammation involving the GLOTTIS or VOCAL CORDS and the subglottic larynx. Croup is characterized by a barking cough, HOARSENESS, and persistent inspiratory STRIDOR (a high-pitched breathing sound). It occurs chiefly in infants and children.Smoking: Inhaling and exhaling the smoke of burning TOBACCO.Laryngoscopy: Examination, therapy or surgery of the interior of the larynx performed with a specially designed endoscope.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: Act of listening for sounds within the body.Eosinophils: Granular leukocytes with a nucleus that usually has two lobes connected by a slender thread of chromatin, and cytoplasm containing coarse, round granules that are uniform in size and stainable by eosin.Ipratropium: A muscarinic antagonist structurally related to ATROPINE but often considered safer and more effective for inhalation use. It is used for various bronchial disorders, in rhinitis, and as an antiarrhythmic.Lung Compliance: The capability of the LUNGS to distend under pressure as measured by pulmonary volume change per unit pressure change. While not a complete description of the pressure-volume properties of the lung, it is nevertheless useful in practice as a measure of the comparative stiffness of the lung. (From Best & Taylor's Physiological Basis of Medical Practice, 12th ed, p562)Laryngismus: A disorder in which the adductor muscles of the VOCAL CORDS exhibit increased activity leading to laryngeal spasm. Laryngismus causes closure of the VOCAL FOLDS and airflow obstruction during inspiration.Hypopharynx: The bottom portion of the pharynx situated below the OROPHARYNX and posterior to the LARYNX. The hypopharynx communicates with the larynx through the laryngeal inlet, and is also called laryngopharynx.Maximal Midexpiratory Flow Rate: Measurement of rate of airflow over the middle half of a FORCED VITAL CAPACITY determination (from the 25 percent level to the 75 percent level). Common abbreviations are MMFR and FEF 25%-75%.Respiratory Muscles: These include the muscles of the DIAPHRAGM and the INTERCOSTAL MUSCLES.Sputum: Material coughed up from the lungs and expectorated via the mouth. It contains MUCUS, cellular debris, and microorganisms. It may also contain blood or pus.Trachea: The cartilaginous and membranous tube descending from the larynx and branching into the right and left main bronchi.Emphysema: A pathological accumulation of air in tissues or organs.Methacholine Chloride: A quaternary ammonium parasympathomimetic agent with the muscarinic actions of ACETYLCHOLINE. It is hydrolyzed by ACETYLCHOLINESTERASE at a considerably slower rate than ACETYLCHOLINE and is more resistant to hydrolysis by nonspecific CHOLINESTERASES so that its actions are more prolonged. It is used as a parasympathomimetic bronchoconstrictor agent and as a diagnostic aid for bronchial asthma. (From Martindale, The Extra Pharmacopoeia, 30th ed, p1116)Lung Diseases: Pathological processes involving any part of the LUNG.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.Tidal Volume: The volume of air inspired or expired during each normal, quiet respiratory cycle. Common abbreviations are TV or V with subscript T.Intubation: Introduction of a tube into a hollow organ to restore or maintain patency if obstructed. It is differentiated from CATHETERIZATION in that the insertion of a catheter is usually performed for the introducing or withdrawing of fluids from the body.Oscillometry: The measurement of frequency or oscillation changes.Polysomnography: Simultaneous and continuous monitoring of several parameters during sleep to study normal and abnormal sleep. The study includes monitoring of brain waves, to assess sleep stages, and other physiological variables such as breathing, eye movements, and blood oxygen levels which exhibit a disrupted pattern with sleep disturbances.Severity of Illness Index: Levels within a diagnostic group which are established by various measurement criteria applied to the seriousness of a patient's disorder.Cholestasis: Impairment of bile flow due to obstruction in small bile ducts (INTRAHEPATIC CHOLESTASIS) or obstruction in large bile ducts (EXTRAHEPATIC CHOLESTASIS).Respiratory Tract DiseasesMuscle, Smooth: Unstriated and unstriped muscle, one of the muscles of the internal organs, blood vessels, hair follicles, etc. Contractile elements are elongated, usually spindle-shaped cells with centrally located nuclei. Smooth muscle fibers are bound together into sheets or bundles by reticular fibers and frequently elastic nets are also abundant. (From Stedman, 25th ed)Cystic Fibrosis: An autosomal recessive genetic disease of the EXOCRINE GLANDS. It is caused by mutations in the gene encoding the CYSTIC FIBROSIS TRANSMEMBRANE CONDUCTANCE REGULATOR expressed in several organs including the LUNG, the PANCREAS, the BILIARY SYSTEM, and the SWEAT GLANDS. Cystic fibrosis is characterized by epithelial secretory dysfunction associated with ductal obstruction resulting in AIRWAY OBSTRUCTION; chronic RESPIRATORY INFECTIONS; PANCREATIC INSUFFICIENCY; maldigestion; salt depletion; and HEAT PROSTRATION.Respiratory Physiological Phenomena: Physiological processes and properties of the RESPIRATORY SYSTEM as a whole or of any of its parts.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.Hydronephrosis: Abnormal enlargement or swelling of a KIDNEY due to dilation of the KIDNEY CALICES and the KIDNEY PELVIS. It is often associated with obstruction of the URETER or chronic kidney diseases that prevents normal drainage of urine into the URINARY BLADDER.Vocal Cords: A pair of cone-shaped elastic mucous membrane projecting from the laryngeal wall and forming a narrow slit between them. Each contains a thickened free edge (vocal ligament) extending from the THYROID CARTILAGE to the ARYTENOID CARTILAGE, and a VOCAL MUSCLE that shortens or relaxes the vocal cord to control sound production.Cholestasis, Extrahepatic: Impairment of bile flow in the large BILE DUCTS by mechanical obstruction or stricture due to benign or malignant processes.Bronchioles: The small airways branching off the TERTIARY BRONCHI. Terminal bronchioles lead into several orders of respiratory bronchioles which in turn lead into alveolar ducts and then into PULMONARY ALVEOLI.Goiter, Substernal: An enlarged THYROID GLAND with at least 50% of the gland situated behind the STERNUM. It is an unusual presentation of an intrathoracic goiter. Substernal goiters frequently cause compression on the TRACHEA leading to deviation, narrowing, and respiratory symptoms.Histamine: An amine derived by enzymatic decarboxylation of HISTIDINE. It is a powerful stimulant of gastric secretion, a constrictor of bronchial smooth muscle, a vasodilator, and also a centrally acting neurotransmitter.Oropharynx: The middle portion of the pharynx that lies posterior to the mouth, inferior to the SOFT PALATE, and superior to the base of the tongue and EPIGLOTTIS. It has a digestive function as food passes from the mouth into the oropharynx before entering ESOPHAGUS.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.Ludwig's Angina: Severe cellulitis of the submaxillary space with secondary involvement of the sublingual and submental space. It usually results from infection in the lower molar area or from a penetrating injury to the mouth floor. (From Dorland, 27th ed)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.Respiratory Therapy: Care of patients with deficiencies and abnormalities associated with the cardiopulmonary system. It includes the therapeutic use of medical gases and their administrative apparatus, environmental control systems, humidification, aerosols, ventilatory support, bronchopulmonary drainage and exercise, respiratory rehabilitation, assistance with cardiopulmonary resuscitation, and maintenance of natural, artificial, and mechanical airways.Pharyngeal Muscles: The muscles of the PHARYNX are voluntary muscles arranged in two layers. The external circular layer consists of three constrictors (superior, middle, and inferior). The internal longitudinal layer consists of the palatopharyngeus, the salpingopharyngeus, and the stylopharyngeus. During swallowing, the outer layer constricts the pharyngeal wall and the inner layer elevates pharynx and LARYNX.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.Respiration Disorders: Diseases of the respiratory system in general or unspecified or for a specific respiratory disease not available.Pulmonary Heart Disease: Hypertrophy and dilation of the RIGHT VENTRICLE of the heart that is caused by PULMONARY HYPERTENSION. This condition is often associated with pulmonary parenchymal or vascular diseases, such as CHRONIC OBSTRUCTIVE PULMONARY DISEASE and PULMONARY EMBOLISM.Terbutaline: A selective beta-2 adrenergic agonist used as a bronchodilator and tocolytic.Horses: Large, hoofed mammals of the family EQUIDAE. Horses are active day and night with most of the day spent seeking and consuming food. Feeding peaks occur in the early morning and late afternoon, and there are several daily periods of rest.Dilatation: The act of dilating.Vocal Cord Paralysis: Congenital or acquired paralysis of one or both VOCAL CORDS. This condition is caused by defects in the CENTRAL NERVOUS SYSTEM, the VAGUS NERVE and branches of LARYNGEAL NERVES. Common symptoms are VOICE DISORDERS including HOARSENESS or APHONIA.Bronchoconstrictor Agents: Agents causing the narrowing of the lumen of a bronchus or bronchiole.Exhalation: The act of BREATHING out.Time Factors: Elements of limited time intervals, contributing to particular results or situations.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.Chronic Disease: Diseases which have one or more of the following characteristics: they are permanent, leave residual disability, are caused by nonreversible pathological alteration, require special training of the patient for rehabilitation, or may be expected to require a long period of supervision, observation, or care. (Dictionary of Health Services Management, 2d ed)Bronchiectasis: Persistent abnormal dilatation of the bronchi.Hypersensitivity: Altered reactivity to an antigen, which can result in pathologic reactions upon subsequent exposure to that particular antigen.Bezoars: Concretions of swallowed hair, fruit or vegetable fibers, or similar substances found in the alimentary canal.Apnea: A transient absence of spontaneous respiration.Dust: Earth or other matter in fine, dry particles. (Random House Unabridged Dictionary, 2d ed)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.Cricoid Cartilage: The small thick cartilage that forms the lower and posterior parts of the laryngeal wall.Nose: A part of the upper respiratory tract. It contains the organ of SMELL. The term includes the external nose, the nasal cavity, and the PARANASAL SINUSES.Carbon Dioxide: A colorless, odorless gas that can be formed by the body and is necessary for the respiration cycle of plants and animals.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)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.Aortic Arch Syndromes: Conditions resulting from abnormalities in the arteries branching from the ASCENDING AORTA, the curved portion of the aorta. These syndromes are results of occlusion or abnormal blood flow to the head-neck or arm region leading to neurological defects and weakness in an arm. These syndromes are associated with vascular malformations; ATHEROSCLEROSIS; TRAUMA; and blood clots.Eosinophilia: Abnormal increase of EOSINOPHILS in the blood, tissues or organs.Endoscopy: Procedures of applying ENDOSCOPES for disease diagnosis and treatment. Endoscopy involves passing an optical instrument through a small incision in the skin i.e., percutaneous; or through a natural orifice and along natural body pathways such as the digestive tract; and/or through an incision in the wall of a tubular structure or organ, i.e. transluminal, to examine or perform surgery on the interior parts of the body.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.Stents: Devices that provide support for tubular structures that are being anastomosed or for body cavities during skin grafting.Palate, Soft: A movable fold suspended from the posterior border of the hard palate. The uvula hangs from the middle of the lower border.Leukotriene Antagonists: A class of drugs designed to prevent leukotriene synthesis or activity by blocking binding at the receptor level.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).Epithelial Cells: Cells that line the inner and outer surfaces of the body by forming cellular layers (EPITHELIUM) or masses. Epithelial cells lining the SKIN; the MOUTH; the NOSE; and the ANAL CANAL derive from ectoderm; those lining the RESPIRATORY SYSTEM and the DIGESTIVE SYSTEM derive from endoderm; others (CARDIOVASCULAR SYSTEM and LYMPHATIC SYSTEM) derive from mesoderm. Epithelial cells can be classified mainly by cell shape and function into squamous, glandular and transitional epithelial cells.Insufflation: The act of blowing a powder, vapor, or gas into any body cavity for experimental, diagnostic, or therapeutic purposes.Acute Disease: Disease having a short and relatively severe course.Tongue: A muscular organ in the mouth that is covered with pink tissue called mucosa, tiny bumps called papillae, and thousands of taste buds. The tongue is anchored to the mouth and is vital for chewing, swallowing, and for speech.Tonsillectomy: Surgical removal of a tonsil or tonsils. (Dorland, 28th ed)Micrognathism: Abnormally small jaw.Ileal Diseases: Pathological development in the ILEUM including the ILEOCECAL VALVE.Work of Breathing: RESPIRATORY MUSCLE contraction during INHALATION. The work is accomplished in three phases: LUNG COMPLIANCE work, that required to expand the LUNGS against its elastic forces; tissue resistance work, that required to overcome the viscosity of the lung and chest wall structures; and AIRWAY RESISTANCE work, that required to overcome airway resistance during the movement of air into the lungs. Work of breathing does not refer to expiration, which is entirely a passive process caused by elastic recoil of the lung and chest cage. (Guyton, Textbook of Medical Physiology, 8th ed, p406)Failure to Thrive: A condition of substandard growth or diminished capacity to maintain normal function.Cyanates: Organic salts of cyanic acid containing the -OCN radical.Infant, Newborn: An infant during the first month after birth.Pneumonia: Infection of the lung often accompanied by inflammation.Masks: Devices that cover the nose and mouth to maintain aseptic conditions or to administer inhaled anesthetics or other gases. (UMDNS, 1999)Postoperative Complications: Pathologic processes that affect patients after a surgical procedure. They may or may not be related to the disease for which the surgery was done, and they may or may not be direct results of the surgery.Pulmonary Eosinophilia: A condition characterized by infiltration of the lung with EOSINOPHILS due to inflammation or other disease processes. Major eosinophilic lung diseases are the eosinophilic pneumonias caused by infections, allergens, or toxic agents.Rhinitis: Inflammation of the NASAL MUCOSA, the mucous membrane lining the NASAL CAVITIES.Adenoids: A collection of lymphoid nodules on the posterior wall and roof of the NASOPHARYNX.Hematoma: A collection of blood outside the BLOOD VESSELS. Hematoma can be localized in an organ, space, or tissue.Sinusitis: Inflammation of the NASAL MUCOSA in one or more of the PARANASAL SINUSES.Mucin 5AC: A gel-forming mucin that is primarily found on the surface of gastric epithelium and in the RESPIRATORY TRACT. Mucin 5AC was originally identified as two distinct proteins, however a single gene encodes the protein which gives rise to the mucin 5A and mucin 5C variants.Adenosine A1 Receptor Agonists: Compounds that bind to and stimulate ADENOSINE A1 RECEPTORS.Adenoidectomy: Excision of the adenoids. (Dorland, 28th ed)Hypoventilation: A reduction in the amount of air entering the pulmonary alveoli.Foreign Bodies: Inanimate objects that become enclosed in the body.Bronchial Neoplasms: Tumors or cancer of the BRONCHI.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.Constriction, Pathologic: The condition of an anatomical structure's being constricted beyond normal dimensions.Thyroid Cartilage: The largest cartilage of the larynx consisting of two laminae fusing anteriorly at an acute angle in the midline of the neck. The point of fusion forms a subcutaneous projection known as the Adam's apple.Ventilators, Negative-Pressure: Body ventilators that assist ventilation by applying intermittent subatmospheric pressure around the thorax, abdomen, or airway and periodically expand the chest wall and inflate the lungs. They are relatively simple to operate and do not require tracheostomy. These devices include the tank ventilators ("iron lung"), Portalung, Pneumowrap, and chest cuirass ("tortoise shell").Follow-Up Studies: Studies in which individuals or populations are followed to assess the outcome of exposures, procedures, or effects of a characteristic, e.g., occurrence of disease.Fenoterol: An adrenergic beta-2 agonist that is used as a bronchodilator and tocolytic.Hemoptysis: Expectoration or spitting of blood originating from any part of the RESPIRATORY TRACT, usually from hemorrhage in the lung parenchyma (PULMONARY ALVEOLI) and the BRONCHIAL ARTERIES.Respiratory Insufficiency: Failure to adequately provide oxygen to cells of the body and to remove excess carbon dioxide from them. (Stedman, 25th ed)Nebulizers and Vaporizers: Devices that cause a liquid or solid to be converted into an aerosol (spray) or a vapor. It is used in drug administration by inhalation, humidification of ambient air, and in certain analytical instruments.Jejunal Diseases: Pathological development in the JEJUNUM region of the SMALL INTESTINE.Pulmonary Gas Exchange: The exchange of OXYGEN and CARBON DIOXIDE between alveolar air and pulmonary capillary blood that occurs across the BLOOD-AIR BARRIER.Glottis: The vocal apparatus of the larynx, situated in the middle section of the larynx. Glottis consists of the VOCAL FOLDS and an opening (rima glottidis) between the folds.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.Tracheobronchomegaly: A rare and probably congenital condition characterized by great enlargement of the lumen of the trachea and the larger bronchi.Asthma, Exercise-Induced: Asthma attacks following a period of exercise. Usually the induced attack is short-lived and regresses spontaneously. The magnitude of postexertional airway obstruction is strongly influenced by the environment in which exercise is performed (i.e. inhalation of cold air during physical exertion markedly augments the severity of the airway obstruction; conversely, warm humid air blunts or abolishes it).Blood Gas Analysis: Measurement of oxygen and carbon dioxide in the blood.Arytenoid Cartilage: One of a pair of small pyramidal cartilages that articulate with the lamina of the CRICOID CARTILAGE. The corresponding VOCAL LIGAMENT and several muscles are attached to it.Laryngitis: Inflammation of the LARYNGEAL MUCOSA, including the VOCAL CORDS. Laryngitis is characterized by irritation, edema, and reduced pliability of the mucosa leading to VOICE DISORDERS such as APHONIA and HOARSENESS.Breath Tests: Any tests done on exhaled air.Positive-Pressure Respiration, Intrinsic: Non-therapeutic positive end-expiratory pressure occurring frequently in patients with severe airway obstruction. It can appear with or without the administration of external positive end-expiratory pressure (POSITIVE-PRESSURE RESPIRATION). It presents an important load on the inspiratory muscles which are operating at a mechanical disadvantage due to hyperinflation. Auto-PEEP may cause profound hypotension that should be treated by intravascular volume expansion, increasing the time for expiration, and/or changing from assist mode to intermittent mandatory ventilation mode. (From Harrison's Principles of Internal Medicine, 12th ed, p1127)Betamethasone Valerate: The 17-valerate derivative of BETAMETHASONE. It has substantial topical anti-inflammatory activity and relatively low systemic anti-inflammatory activity.Statistics, Nonparametric: A class of statistical methods applicable to a large set of probability distributions used to test for correlation, location, independence, etc. In most nonparametric statistical tests, the original scores or observations are replaced by another variable containing less information. An important class of nonparametric tests employs the ordinal properties of the data. Another class of tests uses information about whether an observation is above or below some fixed value such as the median, and a third class is based on the frequency of the occurrence of runs in the data. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed, p1284; Corsini, Concise Encyclopedia of Psychology, 1987, p764-5)