2. The inspiration must be made of sufficient frequency.
3. The air is to be allowed a free exit from the lungs, so that the same air shall not be transmitted more than once.
4. The method of inflating the lungs must be simple, and easy of adoption; for as the interval of time, during which the artificial respiration can possibly be of any service, is very limited, it is important to avoid whatever may occasion the least delay.
Application of Heat.
There is perhaps no medium through which we can more successfully apply heat to the human body than that of the bath, because we can manage its application with precision; we know the exact degree of heat, and can avoid applying it in extremes; we, at the same time, can communicate it more rapidly, and more equally, than by any other means, and we are enabled to increase or diminish the temperature, by the addition of fresh portions of water, as circumstances may render it expedient.
Internal Exhibition of Stimulants.
The introduction of fluids into the stomach is not an easy process in many cases of suspended animation, as trismus is by no means an uncommon occurrence; where, however, the spasm of the jaw has subsided, the practitioner with a little address may by means of a flexible tube easily accomplish his object. Glysters will likewise furnish an easy mode of applying stimulants.
Electricity.
No sooner was the discovery made that galvanism is capable of exciting muscular contraction in animals apparently dead, than the physiological enthusiast seized it with avidity, and at once hailed it as the long desired influence that was to restore vigour to the enfeebled, and resuscitation to those that were in a state of suspended animation. It had been long known that muscles could be made to contract, by irritating the nerves belonging to them with the point of the scalpel, but not in a degree that remotely approached the vigorous contractions occasioned by the galvanic influence, whose stimulus seemed almost equivalent to that of volition. The sanguine expectations, however, which were thus very naturally excited, have ended in the most complete disappointment; and we are bound to confess that although galvanism is capable of exciting extraordinary contractions in the VOLUNTARY muscles, and of astonishing the multitude, yet its influence does not extend to those that are INVOLUNTARY. Bichat states distinctly that the involuntary muscles are beyond the reach of galvanism.[[69]] Mr. Brodie has frequently attempted to restore the heart’s action by the galvanic stimulus, in an animal dead from syncope, but never with success. The author of the present work may add, that he has attempted the same object by modifying the experiment in several different ways, but with no better success. But it may be said that, as galvanism will excite the contractions of the diaphragm, and other muscles of respiration, it may be made subservient to the purpose of producing artificial respiration: granted,—but it never can be made to act with the certainty, regularity, promptness, or convenience, which attend the operation of a common pair of bellows, nor even if it could, would any advantage be obtained which might not be equally insured by the use of this latter simple instrument. It is, moreover, questionable whether so powerful a stimulus may not produce a subsequent exhaustion of the muscular energy; such effect indeed would appear to have happened in the case related by Dr. Babington, where the asphyxia had been occasioned by the fumes of burning charcoal; “having passed,” says he, “a galvanic shock through the chest, the patient instantly, to our surprise, drew his breath deep; the muscles of the abdomen were seen to react, though feebly, while those of the face were slightly convulsed, and the eyelids were raised; at each successive application of this powerful agent, the respirations were more forcibly performed, and the stroke of the artery at the wrist rose in the same proportion. Having procured a bladder filled with oxygen gas, we caused it to be inspired, and we thought that it was followed by an increased activity of the powers of respiration and circulation; as the heat of the body was not deficient, we now sprinkled the face and chest with cold water, which also had the effect of rousing the dormant powers of sensation, as the respiratory muscles were uniformly thrown by it into action, though in a more feeble and interrupted manner than when we employed the galvanic influence. Having received a large supply of oxygen gas, we repeated the inhalation and the galvanic succussions alternately, through the chest and head, every half-hour, for three hours, when the galvanic influence was discontinued, as the heart, though uniformly excited by it, seemed in the intervals to act more feebly, and we were apprehensive that by exalting the action of one power continually, we might destroy that equilibrium of forces which is necessary to the maintenance of life.”[[70]]