To the Editor.—The use of the Venturi oxygen injection technique in laryngoscopy should be of great interest to many endoscopists. In reading "Oxygen Injection in Suspension Laryngoscopy" by Barr et al in the June 1971 (Archives 93:606-609, 1971) two questions came to mind. (1) What are the real variations in pressure with this injector? (2) What would be the expected temporal changes in pH, Pco2, and Po2 following induction of general anesthesia, production of apnea and ventilation with 100% o2 for three minutes? The first question is raised because the time constant of an aneroid manometer is too large to measure the rapid fluctuations of pressure induced by this technique. The second question, asking what the control values would be in this experiment, led me to consult the literature.
Frumin et al,1 in 1959, maintained adequate oxygenation in apneic patients for over 30 minutes but
KARLAN MS. OXYGENATION. Arch Otolaryngol. 1971;94(5):481. doi:10.1001/archotol.1971.00770070727021