Also found in: Dictionary, Thesaurus, Legal, Financial, Encyclopedia, Wikipedia.
1. the substitution of one thing for another.
2. to substitute one thing for another.
gas exchange the passage of oxygen and carbon dioxide in opposite directions across the alveolocapillary membrane.
health care information exchange in the nursing interventions classification, a nursing intervention defined as providing patient care information to health professionals in other agencies.
impaired gas exchange a nursing diagnosis approved by the North American Nursing Diagnosis Association, defined as excess or deficit in oxygenation and/or carbon dioxide elimination at the alveolocapillary membrane (see gas exchange). Etiological and contributing factors include an altered oxygen supply, changes in the alveolar-capillary membrane, altered blood flow, and altered oxygen-carrying capacity of the blood. Defining characteristics include changes in mental status such as confusion, somnolence, restlessness, and irritability; ineffective coughing and inability to move secretions from the air passages; hypercapnia; and hypoxia. For specific medical treatments and nursing interventions, see airway clearance, ineffective; breathing patterns, ineffective; chronic airflow limitation; and anemia.
plasma exchange see plasma exchange.
gas carriagethe transfer of gases between an organism and the environment. In RESPIRATION, oxygen is taken in and carbon dioxide given out. Photosynthesis in plants complicates this system in that during the process carbon dioxide is required by the plant and oxygen given off (see COMPENSATION PERIOD). In plants and small animals such as PROTOZOANS and PLATYHELMINTHS, gas exchange occurs by DIFFUSION. In higher animals, special respiratory surfaces have been developed, for example, internal and external gills, lungs and trachea.
The process by which oxygen is extracted from inhaled air into the bloodstream, and, at the same time, carbon dioxide is eliminated from the blood and exhaled.
Mentioned in: Respiratory Failure
gas exchangein the animal kingdom, the uptake of oxygen and excretion of carbon dioxide, exchanged between the body and the environment aka respiratory gas exchange . In human physiology pulmonary gas exchange refers to the diffusion of oxygen from the gas phase in the lung alveoli, through the thin alveolar-capillary membrane, into solution in the pulmonary capillary blood, and of carbon dioxide in the opposite direction, both driven by partial pressure gradients. See also blood gases.
any elastic aeriform fluid in which the molecules are widely separated from each other and so have free paths.
see blood gas analysis.
gas bubble disease
a disease of fish in tanks in which the water is supersaturated with oxygen or nitrogen. Gas embolism develops in the gills. Air bubbles can be seen in the gills, eyes and under the skin and the fish show bizarre nervous behavior.
a cap of gas above fluid or solid contents in a hollow viscus, e.g. in a static rumen. Seen radiologically in distended intestinal loops in paralytical ileus.
gas edema disease
see blue wing disease.
gases move by simple diffusion in response to pressure differences; net diffusion occurs from areas of high pressure to areas of lower pressure irrespective of whether the gas is present as a gas or in solution or gases moving from gas to solution or vice versa. The rate of exchange of gases in body tissues, e.g. between alveolar space and erythrocyte, is influenced by many other factors, especially the diffusion distance and the solubility of the gas.
irritant gases, e.g. manure gas, cause pulmonary edema.
manure gas poisoning
see manure pit gas poisoning.
a gas that produces severe lacrimation by irritating the conjunctivae. See lacrimator.
relates to the efficiency of transport of gas, e.g. oxygen, by the patient as a whole. The efficiency of gas transport varies widely between normal individuals and between species, e.g. athletic breeds of horses and dogs have much faster gas transport systems than human athletes; the efficiency of gas transport in the individual depends largely on the rapidity of increase in minute ventilation, plus a similar rate of increase in cardiac output.
see crookes' tube.