[71] CHAPTER V—BRONCHOSCOPIC OXYGEN INSUFFLATION
Bronchoscopic oxygen insufflation is a life-saving measure equalled by no other method known to the science of medicine, in all cases of asphyxia, or apnea, present or impending. Its especial sphere of usefulness is in severe cases of electric shock, hanging, smoke asphyxia, strangulation, suffocation, thoracic or abdominal pressure, apnea, acute traumatic pneumothorax, respiratory arrest from absence of sufficient oxygen, or apnea from the presence of quantities of irrespirable or irritant gases. Combined with bronchoscopic aspiration of secretions it is the best method of treatment for poisoning by chlorine gas, asphyxiating, and other war gases.
Bronchoscopic oxygen insufflation should be taught to every interne in every hospital. The emergency or accident ward of every hospital should have the necessary equipment and an interne familiar with its use. The method is simple, once the knack is acquired. The patient being limp and recumbent on a table, the larynx is exposed with the laryngoscope, and the bronchoscope is inserted as hereinafter described. The oxygen is turned on at the tank and the flow regulated before the rubber tube from the wash-bottle of tank is attached to the side-outlet of the bronchoscope. It is necessary to be certain that the flow is gentle, so that, with a free return flow the introduced pressure does not exceed the capillary pressure; otherwise the blood will be forced out of the capillaries and the ischemia of the lungs will be fatal. Another danger is that overdistension causes inhibition of inspiration resulting in apnea continuing as long as the distension is maintained, if not longer. The return flow from the bronchoscope should be interrupted for 2 or 3 seconds several times a minute to inflate the lungs, but the flow must not be occluded longer than 3 seconds, because the intrapulmonary pressure would rise. A pearl of amyl nitrite may be broken in the wash bottle. Slow rhythmic artificial respiratory movements are a useful adjunct, and unless the operator is very skillful in gauging the alternate pressures and releases with the thumb according to the oxygen pressure, it is vitally necessary to fill and deflate the lungs rhythmically by one of the well known methods of artificial respiration. Anyone skilled in the introduction of the bronchoscope can do bronchoscopy in a few seconds, and it is especially easy in cases of respiratory arrest, because of the limp condition of the patient.
The foregoing applies to cases in which a pulmotor would be used, such as apnea from electric shocks, etc. For obstructive dyspnea and asphyxia, tracheotomy is the procedure of choice, and the skillful tracheotomist would be justified in preferring tracheotomy for the other class of cases, insufflating the oxygen and amyl nitrite through the tracheotomic wound. The pulmotor and similar mechanisms are, perhaps, the best things the use of which can be taught to laymen; but as compared to bronchoscopic oxygen insufflation they are woefully inefficient, because the intraoral pressure forces the tongue back over the laryngeal orifice, obstructing the airway in this "death zone." By the introduction of the bronchoscope this death zone is entirely eliminated, and a free airway established for piping the oxygen directly into the lungs.