described above, apneic oxygenation is inferior to extracorporal circulation using a heart-lung machine and is therefore used only in emergencies, short procedures, or where extracorporal circulation cannot be accessed. Use of PEEP valves is also an accepted alternative (5 cm H₂O in average weight patients and 10 cm H₂O significantly improved lung and chest wall compliance in morbidly obese patients).

In 1959, Frumin described