Slow Positive End-Expiratory Pressure Titration During General Anesthesia with Muscle Paralysis Improves Lung Function Without Compromising Hemodynamic Stability in Preschool Children: A Randomized Control Clinical Trial

Mechanical ventilation impairs oxygenation and increases intrapulmonary shunt. Positive end-expiratory pressure (PEEP) slows derecruitment, improves lung function but can compromise hemodynamics.

To asses slow PEEP titration effect on intrapulmonary shunt, oxygenation and hemodynamics in preschool children on mechanical ventilation under general anesthesia.

This was a single tertiary care center an open-label, randomized parallel group controlled clinical trial. Study included 70 children, 3 - 7 years, ASA I and II, under general anesthesia for non-cardiothoracic surgery. Children were randomly allocated either to receive PEEP titration 5 - 11 cmH2O 20 minutes before the end of anesthesia (intervention group) or to be ventilated until the end of anesthesia with constant positive end-expiratory pressure of 3 cmH2O (control group). Main outcome measures were changes in oxygenation index (PaO2/FiO2) and alveolar-arterial gradient (P(A-a)O2) between and within groups and changes in systolic blood pressure (SBP), mean arterial pressure (MAP) and heart rate (HR) in interventional group during PEEP trial.

Seventy children were recruited and analyzed. P(A-a)O2 and PaO2/FiO2 improved in interventional group comparing to control as consequence of PEEP titration (ΔPaO2/FiO2 -30.3 vs. 0.52; P < 0.001; ΔP(A-a)O2 6.7 vs. -1.0; P < 0.001) and within interventional group before and after PEEP titration (PaO2/FiO2 522.0 vs. 552.3; P < 0.01; P(A-a)O2 20.1 vs. 13.3; P < 0.001). Hypotension and bradycardia were not documented.

Slow PEEP titration up to 11 cmH2O improves oxygenation, reduces intrapulmonary shunt without causing hemodynamic instability in preschool children during general anesthesia.