A Comparison of the Mouth-to-Mouth and Mouth-to-Airway Methods of Artificial Respiration with the Chest Pressure Arm-Lift Methods.

Safar P, Escarraga L, Elam JO New England Journal of Medicine 1958 Vol 258 Pages 671-677 OF HISTORICAL INTEREST

This article is the original comparison of the new mouth-to-mouth method of artificial respiration, with the then recommended Holger Nielsen and Silvester (Back and Chest Pressure, Arm-Lift) push-pull methods. Data was obtained during 27 experiments on anesthetized and paralyzed apneic adults, weighing between 49.9 and 95.2 kg. 164 untrained laymen and doctors served as operators... their degree of success being determined by the size of tidal volume delivered to the test subjects. When the push-pull methods were used, adequate tidal volumes could be delivered if the patients were intubated, however under field conditions (unintubated), trained operators were unable to move more than deadspace air in 13/16 subjects. Even with an oropharyngeal airway in place, these techniques often failed due to pharyngeal obstruction from flexion of the head or torsion of the neck. Following a demonstration of technique, these same 164 operators were then given sixty seconds to apply mouth-to-mouth ventilation. 87 of the operators also used the mouth-to-airway technique. With mouth-to-mouth and mouth-to-airway ventilation, tidal volumes greater than 1,500 ml. were produced in all subjects. Skin and mucous membranes remained pink and arterial oxygen saturation (measured in four experiments) remained between 97-100%, while end tidal carbon dioxide values (also measured in four patients) remained below the control level during 30 minutes of uninterrupted mouth-to-airway breathing. Mouth-to-airway breathing produced better pulmonary inflation and less gastric distension, and was more acceptable to the operators. The authors conclude that obstruction of the pharynx in the unconscious patient renders the ìpush-pull techniques ineffective in the majority of cases, and recommend that mouth-to-mouth and mouth-to-airway methods of artificial respiration be generally adopted.