Background: Children are at risk for developing respiratory insufficiency and ventilatory failure after cardiac surgery. Thus, optimizing perioperative respiratory care is crucial to improve the outcome. We hypothesized that perioperative lung ultrasound (LUS) examination would benefit children undergoing cardiac surgery and assessed the feasibility and utility of it.
Methods: Pediatric patients (≤ 5 yr) scheduled for cardiac surgery under the diagnosis of acyanotic congenital heart disease were enrolled prospectively and randomized into either a control group or a LUS-RM group. Only the LUS-RM group received LUS examination 1 minute after starting mechanical ventilation. Both groups received LUS examination identically at the end of the surgery and once between postoperative 6-12 hours in the pediatric intensive care unit (PICU). In the LUS-RM group, ultrasound-­guided alveolar recruitment maneuver was performed after each LUS examination. The primary outcome was the incidence of intraoperative desaturation (SpO2≤95%). The secondary
outcomes included the incidence of postoperative desaturation and fever, the LUS scores,
intraoperative and postoperative ratio of arterial oxygen partial pressure to fractional inspired oxygen (PaO2/FIO2) from arterial blood gas analysis, the duration of mechanical ventilation, and the length of PICU stay.
Results: Among 122 enrolled pediatric patients, 120 were randomized into the control group (n=61) and the LUS-RM group (n=59). The incidence of intraoperative desaturation [36% vs 19%; P=0.041; OR 0.406; 95% CI: 0.176­0.939] and the incidence of postoperative desaturation [64% vs 27%; P<0.001; OR 0.210; 95% CI: 0.097­0.456] were higher in the control group compared to the LUS-RM group. The LUS scores were better in the LUS-RM group compared to the control group on the postoperative and ­PICU LUS examinations. Intraoperative and postoperative PaO2/FIO2 values were higher in the LUS-RM group than those of the control group. Although the length of the PICU stay did not show statistical difference between the groups, the duration of mechanical ventilation was shorter in the LUS-RM group [25.5 (24.6) vs. 38.2 (42.6); 95% CI of mean difference: 0.1 to 25.2; P=0.048].
Conclusions: Perioperative LUS examinations followed by recruitment maneuver proved useful in decreasing perioperative desaturation events, improving the LUS findings, and shortening the duration of mechanical ventilation in pediatric patients undergoing cardiac surgery.

Benefit of perioperative lung ultrasound in pediatric patients undergoing cardiac surgery: a randomized, controlled trial