Effect of Apneic Oxygenation via Nasal Prong on Gas Exchange and Vital Signs during Fiberoptic Intubation under General Anesthesia

Abstract

A clinical study for the evaluation of the effect of apneic oxygenation by nasal prong during fiberoptic orotracheal intubation on gas exchange and vital signs has been done on the patients who received tympanomastoidectomy (ASA c1assfication 1 and 2, aged from 20 to 40). Among them, 22 patients were selected whose fiberoptic intubation lasted more than 3 but less than 4 minutes, to observe the changes of Pa02, PaC02, HR, and MAP. 11 patients who underwent fiberoptic orotracheal intubation in apneic state without oxygen administration (Group I) showed similar increases in vital signs to the other 11 patients who received apneic oxygenation (Group II). PaC02 increased more in Group I than in Group II, which was not statistically significant. The differences of Pa02 at 1 and 2 minutes between two groups after removal of oxygen mask and beginning of fiberoptic intubation, were not statistically significant but Group II showed a significantly lesser degree of decrease in Pa02 at 3 minutes. We might say that apneic oxygenation during fiberoptic intubation under general anesthesia is useful because it could delay the onset of hypoxia, thereby provide extra time for intubation. Therefore we could attempt intubation up to 3 minutes on the fully relaxed patient, if we give oxygen via nasal prong.