BackgroundThere is a high incidence of pulmonary atelectasis during paediatric laparoscopic surgeries. The authors hypothesised that utilising a recruitment manoeuvre or using continuous positive airway pressure may prevent atelectasis compared to conventional ventilation.ObjectiveThe primary objective was to compare the degree of lung atelectasis diagnosed by lung ultrasound (LUS) using three different ventilation techniques in children undergoing laparoscopic surgeries.DesignRandomised, prospective three-arm trial.SettingSingle institute, tertiary care, teaching hospital.PatientsChildren of ASA PS 1 and 2 up to the age of 10 years undergoing laparoscopic surgery with pneumoperitoneum lasting for more than 30 min.InterventionRandom allocation to one of the three study groups:CG group: Inspiratory pressure adjusted to achieve a TV of 5–8 ml/kg, PEEP of 5 cm H2O, respiratory rate adjusted to maintain end-tidal carbon dioxide (ETCO2) between 30-40 mm Hg with manual ventilation and no PEEP at induction.RM group: A recruitment manoeuvre of providing a constant pressure of 30 cm H2O for ten seconds following intubation was applied. A PEEP of 10 cm H2O was maintained intraoperatively.CPAP group: Intraoperative maintenance with PEEP 10 cm H2O with CPAP of 10 cm H2O at induction using mechanical ventilation was done.Outcome measuresLung atelectasis score at closure assessed by LUS.ResultsPost induction, LUS was comparable in all three groups. At the time of closure, the LUS for the RM group (8.6 ± 4.9) and the CPAP group (8.8 ± 6.8) were significantly lower (p < 0.05) than the CG group (13.3 ± 3.8). In CG and CPAP groups, the score at closure was significantly higher than post-induction. The PaO2/FiO2 ratio was significantly higher (p < 0.05) for the RM group (437.1 ± 44.9) and CPAP group (421.6 ± 57.5) than the CG group (361.3 ± 59.4) at the time of pneumoperitoneum.ConclusionApplication of a recruitment manoeuvre post-intubation or CPAP during induction and maintenance with a high PEEP leads to less atelectasis than conventional ventilation during laparoscopic surgery in paediatric patients.Trial registry.CTRI/2019/08/02058.