Comparing 3 ventilation modalities by measuring several respiratory parameters using the ProSeal laryngeal mask airway in children.

Study Objective: To determine quantitative differences in several routinely measured ventilation parameters using a standardized anesthetic technique and 3 different ventilation modalities in pediatric patients with a ProSeal laryngeal mask airway (PLMA).

Design: Randomized prospective study.

Setting: Pediatric hospital of a tertiary care academic medical center.

Patients: Thirty-three, American Society of Anesthesiologists classification 1-2, pediatric patients (12 months to 5 years).

Interventions: Three different ventilation strategies: spontaneous ventilation (SV), pressure support ventilation (PSV), and pressure-controlled ventilation (PCV) were randomly applied to patients who underwent a standardized mask induction with sevoflurane/oxygen and propofol 3 mg/kg and morphine 0.05 mg/kg administered intravenously followed by PLMA insertion. Patients were maintained on sevoflurane and N2O.

Measurements: We measured the differences in end-tidal CO2 (Etco2), tidal volume, and respiratory rate over time between SV, PSV, and PCV. These data were recorded at 5-minute intervals.

Main Results: Etco2 (mm Hg) was significantly higher in the SV vs PSV (P=.016) and vs PCV (P<.001). Tidal volume (mL/kg) was significantly lower in SV vs PSV (P<.001) and vs PCV (P<.001). Respiratory rate (breaths/min) was significantly higher in SV vs PSV (P<.001) and vs PCV (P=.005).

Conclusions: All 3 modes of ventilation using a PLMA were safely used. Our SV group was noted to have a significantly higher Etco2 when compared with PSV and PCV with a mean Etco2 over time in excess of 55 mm Hg. PSV and PCV were found to be more appropriate ventilation strategies to more optimally control Etco2 over time in these patients.