The use of oxygen in emergency situations outside hospitals is limited by difficulties in supply. Low capacity cylinders (100-120 1) weigh 3-4 kg, and have cumbersome mechanisms for pressure and flow reduction. Disposable cylinders of oxygen from a chemical source create the possibility of the contents running out, and are fragile. Particularly when exposed to high pressures or temperature.
Mouth-to-mouth remains most rational and effective. Problems include aesthetic concern and exhaustion in rescuer. It is possible, however, to adapt a Brooke or a Safar airway for use with oxygen, by attaching a tube with tape near the proximal outlet of the airway. This apparatus has been tried on 4 patients during general anesthesia with thiopentone-succinylcholine-neuroleptics—for appendectomies using controlled ventilation with expired air with oxygen added. Tidal volumes of 350-500 ml of air/oxygen were delivered at a frequency of 6-8 breaths per minute. The nose was closed by a clip. Sellik's maneuver could prevent gastric inflation. The color of blood was normal, arterial pressure and pulse did not change, and skin was dry. No fatigue or other effects were reported by the anesthesiologist-“rescuer”. In outdoor use, where oxygen from a chemical source is used, the problems associated with the exothermic reaction can be limited by cylinder lagging with openings to disperse heat. A flow of O2 6-7 1/min is sufficient to support a critical situation. It allows O2 enrichment for mouth-to-mouth, mouth-to-mask, mouth-to-airway, or bag valve ventilation. Modest cost, and low weight allow large numbers to be stored for airport disasters, when resuscitation is performed on a large scale for many victims.