Asphyxia means literally absence of pulse, but is the name given to the whole series of symptoms which follow stoppage of breathing and of the heart’s action. Drowning is one cause, but obstruction of the AIR PASSAGES may occur as the result of a foreign body or in some diseases, such as CROUP, DIPHTHERIA, swelling of the throat due to wounds or inﬂammation, ASTHMA (to a partial extent), tumours in the chest (causing slow asphyxia), and the external conditions of suﬀocation and strangling. Placing the head in a plastic bag results in asphyxia, and poisonous gases also cause asphyxia: for example, CARBON MONOXIDE (CO) gas, which may be given oﬀ by a stove or charcoal brazier in a badly ventilated room, can kill people during sleep. Several gases, such as sulphurous acid (from burning sulphur), ammonia, and chlorine (from bleaching-powder), cause involuntary closure of the entrance to the larynx, and thus prevent breathing. Other gases, such as nitrous oxide (or laughing-gas), chloroform, and ether, in poisonous quantity, stop the breathing by paralysing the respiration centre in the brain.
Symptoms In most cases, death from asphyxia is due to insuﬃciency of oxygen supplied to the blood. The ﬁrst signs are rapid pulse and gasping for breath. Next comes a rise in the blood pressure, causing throbbing in the head, with lividity or blueness of the skin, due to failure of aeration of the blood, followed by still greater struggles for breath and by general CONVULSIONS. The heart becomes overdistended and gradually weaker, a paralytic stage sets in, and all struggling and breathing slowly cease. When asphyxia is due to charcoal fumes, coal-gas, and other narcotic inﬂuences, there is no convulsive stage, and death ensues gently and may occur in the course of sleep.
Treatment So long as the heart continues to beat, recovery may be looked for with prompt treatment. The one essential of treatment is to get the impure blood aerated by artiﬁcial respiration. Besides this, the feeble circulation can be helped by various methods. (See APPENDIX 1: BASIC FIRST AID – Choking; Cardiac/respiratory arrest.)