The Stepwise Slow Titration of Positive End-Expiratory Pressure Before the End of General Anaesthesia Improves Lung Mechanics in Children: A Randomized Open Label Clinical Trial

Background: Intraoperative application of positive end-end-expiratory pressure (PEEP) is recommended in mechanically ventilated children since it improves lung mechanics. However, inadequate level of applied pressure can increase risk of barotrauma. Objectives: To assess the impact of titrated PEEP on lung mechanics in mechanically ventilated children under general anaesthesia. Methods: This was an open label, single Tertiary Centre randomized controlled clinical trial. The study population included 70 preschool children, ASA I and II, scheduled for orthopaedic, reconstructive, abdominal or urological surgery. Children with upper respiratory tract infection, allergic to chosen anaesthetics, cardiorespiratory comorbidities were excluded. Patients were randomly assigned either to receive intraoperative PEEP titration form 5 - 11 cmH2O 20 minutes before the end of anaesthesia (intervention group) or to be ventilated until the end of anaesthesia conventionally with a positive end-expiratory pressure of 3 cmH2O (control group). Main outcomes: changes in dynamic lung compliance (Cdyn), peak airway pressure (PIP), mean airway pressure (Paw) between groups at the end of surgery; changes in PIP and Paw during PEEP titration and desaturation in interventional group during PEEP titration. Results: Seventy preschool children were recruited and analysed. Intraoperative positive end-expiratory pressure titration improved Cdyn in the intervention group comparing to control (∆Cdy -3.2 vs. 0.63; P < 0.001). PIP and Paw were higher in interventional group (∆PIP -0.57vs. 0.11; P < 0.001, and ∆Paw -0.63 vs. 0.0; P < 0.001) and desaturation was not observed in interventional group. Conclusions: Stepwise titration of PEEP up to 11 cmH2O improves subsequent lung mechanics without causing of barotrauma.