Effects of an alveolar recruitment manoeuvre guided by lung ultrasound on anaesthesia-induced atelectasis in infants: a randomised, controlled trial.

Atelectasis occurs in the majority of children undergoing general anaesthesia. Lung ultrasound has shown reliable sensitivity and specificity for diagnosing anaesthesia-induced atelectasis. We assessed the effects of a recruitment manoeuvre on atelectasis using lung ultrasound in infants undergoing general anaesthesia. Forty infants, randomly allocated to either a recruitment manoeuvre group or a control group, received volume-controlled ventilation with 5 cmH2 O positive end-expiratory pressure. Lung ultrasound examination was performed twice in each patient, the first a minute after starting mechanical ventilation of the lungs and the second at the end of surgery. Patients in the recruitment manoeuvre group received ultrasound-guided recruitment manoeuvres after each lung ultrasound examination. The incidence of significant anaesthesia-induced atelectasis at the second lung ultrasound examination was less in the recruitment manoeuvre group compared with the control group (25% vs. 80%; p = 0.001; odds ratio (OR) 0.083; 95% confidence interval (CI): 0.019-0.370). The median (IQR [range]) lung ultrasound scores for consolidation and B-lines on the second examination were lower in the recruitment manoeuvre group compared with the control group; 6.0 (3.0-9.3 [0.0-14.0]) vs. 13.5 (11.0-16.5 [8.0-23.0]); p < 0.001 and 6.5 (3.0-12.0 [0.0-28.0]) vs. 15.0 (10.8-20.5 [7.0-28.0]); p < 0.001, respectively. The lung ultrasound scores for consolidation on the first and second examinations showed a negative correlation with age (r = -0.340, p = 0.008; r = -0.380, p = 0.003). We conclude that ultrasound-guided recruitment manoeuvres with positive end-expiratory pressure proved useful in reducing the incidence of anaesthesia-induced atelectasis in infants, although 5 cmH2 O positive end-expiratory pressure alone was not sufficient to eliminate it. In addition, the younger the patient, the more susceptible they were to atelectasis.