Weber et al. Flow-controlled ventilation (FCV) improves regional ventilation in obese patients – a randomized controlled crossover trial. BMC Anesthesiol 2020;20(1):24

The workgroup of Prof. Schumann published the first randomized controlled trial on the effect of FCV during ventilation of obese and morbidly obese patients undergoing elective bariatric surgery. 23 patients were ventilated in a crossover design for seven minutes with FCV and VCV. Even after this short application of FCV, notable differences could be detected: With comparable respiratory variables, FCV improved lung recruitment, as demonstrated by a significantly reduced intraoperative loss of both end-expiratory lung volume (ΔEELV) and mean lung volume (ΔMLV) as compared to VCV (ΔEELV: FCV -126 ±207 ml; VCV -316 ±254 ml; p<0.001; ΔMLV: FCV: -108.2 ±198.6 ml; VCV -315.8 ±252.1 ml; p<0.001). These effects might be partially attributed to the increased mean tracheal pressure caused by the linearized pressure decline during FCV.

The authors conclude that ‘the recruitment effect (…) and the elevated P_mean during FCV may help prevent atelectasis and hypoxemia during mechanical ventilation in obese patients.’