hypoxia /hy·pox·ia/ (hi-pok´se-ah) reduction of oxygen supply to a tissue below physiological levels despite adequate perfusion of the tissue by blood.hypox´ic
hypoxia [hi-pok´se-ah]
hypoxia (hīpok´sē
),
anemic hypoxia that due to reduction of the oxygen-carrying capacity of the blood owing to decreased total hemoglobin or altered hemoglobin constituents.
histotoxic hypoxia that due to impaired use of oxygen by tissues.
hypoxic hypoxia that due to insufficient oxygen reaching the blood.
stagnant hypoxia that due to failure to transport sufficient oxygen because of inadequate blood flow.
| anemic hypoxia n. Hypoxia resulting from a decreased concentration of functional hemoglobin or a reduced number of erythrocytes. Also called anemic anoxia. |
hypoxia [hi-pok´se-ah]
diminished availability of oxygen to the body tissues; its causes are many and varied and includes a deficiency of oxygen in the atmosphere, as in altitude sickness; pulmonary disorders that interfere with adequate ventilation of the lungs; anemia or circulatory deficiencies, leading to inadequate transport and delivery of oxygen to the tissues; and finally, edema or other abnormal conditions of the tissues themselves that impair the exchange of oxygen and carbon dioxide between capillaries and tissues. adj., adj hypox´ic.
Signs and symptoms vary according to the cause. Generally they include dyspnea, rapid pulse, syncope, and mental disturbances such as delirium or euphoria. cyanosis is not always present and in some cases is not evident until the hypoxia is far advanced. The localized pain of angina pectoris due to hypoxia occurs because of impaired oxygenation of the myocardium. Discoloration of the skin and eventual ulceration that sometimes accompany varicose veins are a result of hypoxia of the involved tissues.
The treatment of hypoxia depends on the primary cause but usually includes administration of oxygen by inhalation (see oxygen therapy). In some vascular diseases, administration of vasodilators may help increase circulation, hence oxygen supply, to the tissues.
Signs and symptoms vary according to the cause. Generally they include dyspnea, rapid pulse, syncope, and mental disturbances such as delirium or euphoria. cyanosis is not always present and in some cases is not evident until the hypoxia is far advanced. The localized pain of angina pectoris due to hypoxia occurs because of impaired oxygenation of the myocardium. Discoloration of the skin and eventual ulceration that sometimes accompany varicose veins are a result of hypoxia of the involved tissues.
The treatment of hypoxia depends on the primary cause but usually includes administration of oxygen by inhalation (see oxygen therapy). In some vascular diseases, administration of vasodilators may help increase circulation, hence oxygen supply, to the tissues.
affinity hypoxia hypoxia resulting from failure of the hemoglobin to release oxygen to the tissues, as may occur with a left-shifted oxyhemoglobin dissociation curve.
anemic hypoxia hypoxia due to reduction of the oxygen-carrying capacity of the blood as a result of a decrease in the total hemoglobin or an alteration of the hemoglobin constituents.
circulatory hypoxia stagnant hypoxia.
histotoxic hypoxia that due to impaired utilization of oxygen by tissues, as in cyanide poisoning.
hypoxemic hypoxia (hypoxic hypoxia) that due to insufficient oxygen reaching the blood, as at the decreased barometric pressures of high altitudes.
stagnant hypoxia that due to failure to transport sufficient oxygen because of inadequate blood flow, as in heart failure.
hypoxia (hīpok´sē
),n low oxygen content or tension.
hypoxia, anemic,
n a type brought about by a reduction of the oxygen-carrying capacity of the blood because of a decrease in the complete blood counts or an alteration of the hemoglobin constituents.
hypoxia, anoxic,
n a type resulting from inadequate oxygen in inspired air or interference with gaseous exchange in the lungs.
hypoxia, histotoxic,
n a type resulting from the inability of the tissue cells to use the oxygen that may be present in normal amount and tension.
hypoxia, metabolic,
n a type resulting from an increased tissue demand for oxygen.
hypoxia, stagnant,
n a type resulting from decreased circulation in an area.
hypoxia
a broad term meaning diminished availability of oxygen to the body tissues.
Its causes are many and varied. There may be a deficiency of oxygen in the atmosphere, as in altitude sickness, or a pulmonary disorder that interferes with adequate ventilation of the lungs. Anemia or circulatory deficiencies can lead to inadequate transport and delivery of oxygen to the tissues. Finally, edema or other abnormal conditions of the tissues themselves may impair the exchange of oxygen and carbon dioxide between the capillaries and the tissues. The effect of hypoxia is to reduce the functional activity of tissues. The initial response may be one of temporarily increased activity. Terminally the tissue may be irreparably damaged.
anemic hypoxia
due to inadequate supply of hemoglobin in the blood.
cerebral hypoxia
may be acute or chronic causing either a tremor-convulsion syndrome or one of longer term weakness, ataxia, apparent blindness and lethargy.
fetal hypoxia
occurs as a result of deprivation of the fetus of oxygen during parturition, because it is delayed or the umbilical cord pinched off. Clinically there is weakness, imbecility, disinclination to suck, possibly hypothermia. Foals experience a much more violent, convulsive or dummy syndrome. See also neonatal maladjustment syndrome. Called also intrapartum hypoxia.
intrapartum hypoxia
see fetal hypoxia (above).
ischemic hypoxia
insufficient oxygen in tissues because of an inadequate blood supply.
stagnant hypoxia
inadequate supply of oxygen to tissues because of slow rate of passage of the blood through the tissues.
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