Perioperative ventilation strategy for obese patients--Meta-analysis

Abstract

Objective We conducted a systematic review of different perioperative ventilation mode on gas exchange and lung function for obese patients to identify the optimal strategy. Methods We collected data from the database of EBSCO, PubMed, Spring, Ovid, Wiley, Chinese National Knowledge Infrastructure, VIP network, Wanfang database. The gas exchange and lung function in obese patients accepted different ventilation mode during induction and after extubation, and different tidal volume during surgery were assessed. The Meta-analysis of the included randomized controlled trials(RCT) was conducted by RevMan 5.3 software. Results Twenty-four randomized controlled trials with a total of 946 patients were enrolled. ① During induction, head-up position prolonged the safe apnea duration compared with supine position(P<0.001). PaO2 increased in continues positive airway pressure(CPAP) group with autonomous respiration(P=0.005). Compared with the group without positive end expiratory pressure(PEEP), the safe apnea duration is long(P<0.001) and PaO2 is high(P<0.001) in intermittent positive pressure ventilation(IPPV) with PEEP group after transferring to mechanical ventilation. ② Large tidal volume with PEEP provided high oxygen index(OI)(P=0.02) compared with small tidal volume group, but caused large peak pressure (Ppeak) (P<0.001) at the same time. ③ PaO2 is high after extubation in non-invasive positive pressure ventilation(NIPPV) group compared with nasal catheter group(P=0.004). Conclusions The optimal ventilation strategy for obese patients is head-up position plus CPAP and IPPV with PEEP during induction, large tidal volume ventilation during surgery, and NIPPV after extubation. Key words: Obese; Anesthesia, general; Ventilation strategy; Tidal volume