Lung ultrasound evaluation of incremental PEEP recruitment maneuver in children undergoing cardiac surgery

Aim To explore the effect of incremental positive end‐expiratory pressure recruitment maneuver (iPEEPRM) in children with congenital heart diseases (CHDs) using lung ultrasound. Methods Thirty‐six children aged 3 months to 5 years scheduled for cardiac surgery participated. iPEEPRM was performed with PEEP stepwise increase (0‐5‐10‐15 cmH 2 O) and decrease at the same rate before and after surgery. Atelectatic areas, ultrasound scores, arterial oxygen pressure (PaO 2 ), and respiratory system dynamic compliance per kilogram body weight (CDyn/kg) were analyzed before and after iPEEPRM. The primary outcome is the incidence of atelectasis. Secondary outcomes are oxygenation, ventilation, CDyn/kg, and atelectasis area. Results iPEEPRM was successfully applied in 92% (33/36) children before surgery and 71% (24/34) children after surgery. The incidence of atelectasis was significantly reduced by iPEEPRM from 76% to 15% before surgery and from 92% to 38% after surgery, respectively ( P  < .001). Before surgery, iPEEPRM significantly reduced atelectatic areas and ultrasound scores: 32.5 (0‐128.1) mm 2 vs 0 (0‐0) mm 2 and 8 (3‐12) vs 2 (0‐4). PaO 2 and CDyn/kg were significantly increased after iPEEPRM: 243 (129‐275) mm Hg vs 278 (207‐323) mm Hg and 0.6 (0.4‐0.7) mL/cmH 2 O/kg vs 0.8 (0.6‐1.0) mL/cmH 2 O/kg. After surgery, iPEEPRM significantly reduced atelectatic areas and ultrasound scores: 45.7 (13.1‐115.8) mm 2 vs 0 (0‐34.7) mm 2 , and 9 (6‐12) vs 3 (0‐5). PaO 2 and CDyn/kg were also significantly increased after iPEEPRM. Conclusions iPEEPRM effectively reduced atelectasis, improved lung aeration, oxygenation, and CDyn/kg in children undergoing cardiac surgery.