We compared the resolution over time of pulmonary atelectasis after a laparoscopic procedure by performing computed tomography scans in two different groups of patients: 1 group had 10 nonobese patients, and in the other group there were 20 morbidly obese patients.

Sevoflurane preconditioning preserves myocardial and renal function as assessed by biochemical markers in patients undergoing coronary artery bypass graft surgery under cardioplegic arrest. This study demonstrated for the first time translocation of protein kinase C isoforms delta and epsilon in human myocardium in response to sevoflurane.

Application of positive end-expiratory pressure during induction of general anesthesia in morbidly obese patients prevents atelectasis formation and improves oxygenation. Therefore, this technique should be considered for anesthesia induction in morbidly obese patients.

Positive end-expiratory pressure (PEEP) applied during induction of anesthesia prevents atelectasis formation and increases the duration of nonhypoxic apnea in nonobese patients. PEEP also prevents atelectasis formation in morbidly obese patients. Because morbidly obese patients have difficult airway management more often and because arterial desaturation develops rapidly, we studied the clinical benefit of PEEP applied during anesthesia induction. Thirty morbidly obese patients were randomly allocated to one of two groups. In the PEEP group, patients breathed 100% O(2) through a continuous positive airway pressure device (10 cm H(2)O) for 5 min. After induction of anesthesia, they were mechanically ventilated with PEEP (10 cm H(2)O) for another 5 min until tracheal intubation. In the control group, the sequence was the same but without any continuous positive airway pressure or PEEP. We measured apnea duration until Spo(2) reached 90% and we performed arterial blood gases analyses just before apnea and at 92% Spo(2). Nonhypoxic apnea duration was longer in the PEEP group compared with the control group (188 +/- 46 versus 127 +/- 43 s; P = 0.002). Pao(2) was higher before apnea in the PEEP group (P = 0.038). Application of positive airway pressure during induction of general anesthesia in morbidly obese patients increases nonhypoxic apnea duration by 50%.

Application of positive end-expiratory pressure during the induction of general anesthesia prevents atelectasis formation. Furthermore, it improves oxygenation and probably increases the margin of safety before intubation. Therefore, this technique should be considered for all anesthesia induction, at least in patients at risk of difficult airway management during the anesthesia induction.