hypoxemia /hī′poksē″mē·ə/ [Gk, hypo + oxys, sharp, genein, to produce, haima, blood] , an abnormal deficiency in the concentration of oxygen in arterial blood. Symptoms of acute hypoxemia are cyanosis, restlessness, stupor, coma, Cheyne-Stokes respiration, apnea, increased blood pressure, tachycardia, and an initial increase in cardiac output that later falls, producing hypotension and ventricular fibrillation or asystole. Chronic hypoxemia stimulates red blood cell production by the bone marrow, leading to secondary polycythemia. Hypoxemia caused by decreased alveolar oxygen tension or underventilation improves with oxygen therapy. Hypoxemia resulting from shunting of blood from the right side of the heart to the left side without exchange of gases in the lungs is treated with bronchial hygiene and positive end-expiratory pressure. Also spelled hypoxaemia. Compare hypoxia. See also anoxia, asphyxia.
