ASPHYXIA (Gk. izacSuzFia, a stopping of the pulse, from a, a negat. a01.,;=tc, sphyxis, pulse). A condition brought about in oxygen-breathing animals when any obstacle prevents the en trance of air into the pulmonary vesicles, and unconsciousness or death occurs. Aquatic ani mals may be asphyxiated either by depriv ing the water they inhabit of oxygen, or im pregnating it with noxious gases. Asphyxia may develop by sudden strangulation, or gradu ally, as in close rooms with insufficient oxygen. When sudden strangulation occurs, there are at first a few seconds of quiet; then respiratory movements, both inspiratory and expiratory, follow rapidly, until in about a minute there are powerful convulsive movements of the chest, mainly expiratory. Exhaustion thus takes place, and the movements of respiration slowly cease; the blood-pressure falls; the right side of the heart becomes engorged with blood, and unconsciousness takes place in two or three minutes. In the early stages the face beeounes livid; later it becomes pale; the mucous membranes and skin become bluish, and the fine blood-vessels injected. Small hemorrhages
may occur. The heart, which at first beats strongly, becomes weaker and weaker, and final ly ceases to beat, and death occurs. In man, this occurs in from a minute and a half to five minutes. Some persons, no doubt, as the Cey lon divers, can by habit do without a fresh supply of air for a longer period; and some diving animals have an arrangement of blood vessels by which they are enabled to be under water for a long time. In the treatment of asphyxia, the cause must be removed imme diately, if possible.
Ordinary restorative measures may he employ ed with hopes of success at a very long period after apparent death. Some have recovered after being submerged in water for two hours.
The object of all methods is to supply fresh air to the lungs and to force the blood from the engorged right side of the heart—in other words, to supply an artificial respiration and an artificial circulation. Sec IlEsiquAriox,