Pressure Support Ventilation Versus Continuous Positive Airway Pressure Ventilation with the ProSeal™ Laryngeal Mask Airway: A Randomized Crossover Study of Anesthetized Pediatric Patients

Continuous positive airway pressure (CPAP) and pressure support ventilation (PSV) improve gas exchange in adults, but there are little published data regarding children. We compared the efficacy of PSV with CPAP in anesthetized children managed with the ProSeal™ laryngeal mask airway. Patients were randomized into two equal-sized crossover groups and data were collected before surgery. In Group 1, patients underwent CPAP, PSV, and CPAP in sequence. In Group 2, patients underwent PSV, CPAP, and PSV in sequence. PSV comprised positive end-expiratory pressure set at 3 cm H2O and inspiratory pressure support set at 10 cm H2O above positive end-expiratory pressure. CPAP was set at 3 cm H2O. Each ventilatory mode was maintained for 5 min. The following data were recorded at each ventilatory modeETco2, Spo2, expired tidal volume, peak airway pressure, work of breathing patient (WOB), δ esophageal pressure, pressure time product, respiratory drive, inspiratory time fraction, respiratory rate, noninvasive mean arterial blood pressure, and heart rate. In Group 1, measurements for CPAP were similar before and after PSV. In Group 2, measurements for PSV were similar before and after CPAP. When compared with CPAP, PSV had lower ETco2 (46 ± 6 versus 52 ± 7 mm Hg; P < 0.001), slower respiratory rate (24 ± 6 versus 30 ± 6 min−1; P < 0.001), lower WOB (0.54 ± 0.54 versus 0.95 ± 0.72 JL−1; P < 0.05), lower pressure time product (94 ± 88 versus 150 ± 90 cm H2O s−1min−1; P < 0.001), lower δ esophageal pressure (10.6 ± 7.4 versus 14.1 ± 8.9 cm H2O; P < 0.05), lower inspiratory time fraction (29% ± 3% versus 34% ± 5%; P < 0.001), and higher expired tidal volume (179 ± 50 versus 129 ± 44 mL; P < 0.001). There were no differences in Spo2, respiratory drive, mean arterial blood pressure, and heart rate. We conclude that PSV improves gas exchange and reduces WOB during ProSeal™ laryngeal mask airway anesthesia compared with CPAP in ASA physical status I children aged 1–7 yr.