Optimizing PEEP in Laparoscopic Bariatric Surgery Using Bedside Lung Ultrasound

"* a PEEP of 4 cmH2O will be used after intubation till 5 minutes after pneumoperitonium, and adjusted in a step wise approach after lung ultrasound by adding 2 cmH2O, repeating ultrasound 5 minutes after every change in peep till no lung collapse is detected by lung ultrasound with a maximal peep of 10 cmH2O, or if hemodynamic instability occurs.~* Lung ultrasound examination will be performed at a minimum three times in each patient; the first will be performed 1 min after starting mechanical ventilation of the lungs, 5 minutes after pneumoperitonium, 5 min after every peep increase in stepwise peep group and the last time at the end of the surgery.~We define anaesthesia-induced atelectasis to be significant if any region has a consolidation score of ≥ 2."