Discussion
SECONDARY, OBESE
This randomized control trial reveals that the SNHAP is longer in the morbidly obese population when the preoxygenation and induction of anesthesia are done using the RT/PPV combination compared to a traditional combination of RP/ZEEP. These results were substantiated by secondary outcome measures confirming that the RT/PPV combination was also associated with improvements in all oxygenation parameters assessed. Our results support the use the RT/PPV combination for the preoxygenation of morbidly obese patients undergoing generalized anesthesia.Preoxygenation in two different head-up positions (reverse Trendelenburg and beach-chair) has already been compared in the context of SNHAP optimization for the morbidly obese. In their preliminary study, Boyce et alConversely, using positive pressure ventilation during preoxygenation gave conflicting results on SNHAP in previous studies. Using PEEP [Interestingly, the increase in SNHAP found in this study is consistent with the hypothesis that the SNHAP directly correlates with patients’ FRC. Assuming that the FRC is composed of 90% oxygen at the end of the preoxygenation, the 465 mL difference in FRC previously observed between the RP/ZEEP and the RT/PPV groups would result in a difference of 418 mL in oxygen content between groups. Estimating a total body weight of 130 kg, a basal oxygen consumption (VOPatients in the RT/PPV group also improved other oxygenation parameters. Indeed, FetOThe mouthpiece and nose-clamp used in the present study is a clinical routine for pulmonary function testing. We used this technic in one of our previous studies in awake bariatric subjects and during a pilot study in the same context that the reported study (13). We observed a high tolerability with this device in a similar study population. We could speculate that the impact of this use was probably low in the results of this study.This study has several limitations. The increase of the oxygenation was achieved while changing operating table position [