Effect of regular alveolar recruitment on intraoperative atelectasis in paediatric patients ventilated in the prone position: a randomised controlled trial

Background: Desaturation frequently occurs in infants after general anaesthesia in the prone position. We aimed to evaluate the effectof regular alveolar recruitment inpreventingatelectasis ininfantsandchildrenafter generalanaesthesia intheprone position. Methods: Children (<3 yr) undergoing general anaesthesia (>2 h) in the prone position were randomised to either receive regular alveolar recruitment or standardised care without recruitment. Ultrasound-guided alveolar recruitment was performed for both groups, and mechanical ventilation was started with a tidal volume of 6 ml kg(-1) and PEEP of 7 cm H2O. During mechanical ventilation, the intervention (regular recruitment) group received alveolar recruitment once per hour. Lung ultrasound was performed after inducing anaesthesia and each position change. The primary outcome was the incidence of significant atelectasis (defined by consolidation score >= 2 in any region) before extubation, as evaluated by lung ultrasound undertaken by an investigator masked to trial allocation. Results: Seventy-three children (regular recruitment: 37; standardised care: 36) were included in the analysis. Before the hourly intervention, atelectasis was similar between children randomised to regular alveolar recruitment or standardised care in both supine (83.3%, both groups; P>0.99) and prone positions (88.9% vs 91.9%; P=0.970). The incidence of atelectasis before extubation was lower in children receiving regular alveolar recruitment (8.1%), compared with 47.2% in children randomised to standardised care (absolute risk reduction: 39.1% [95% confidence interval: 20.6-57.6%); P<0.001). Conclusions: Regular alveolar recruitment reduced the incidence of atelectasis at the end of surgery in infants and children <3 yr undergoing general anaesthesia in the prone position.