General anesthesia by mask with spontaneous ventilation during brief laparoscopic inspection of the peritoneum in...

We prospectively examined the cardiorespiratory changes seen with general anesthesia by mask with spontaneous ventilation during brief laparoscopic inspection of the peritoneum in children. Anesthesia consisted of isoflurane in 50% oxygen/air and a caudal epidural block. The patient was allowed to ventilate spontaneously without assistance. Baseline measurements of heart rate, systolic/diastolic blood pressure (BP), end-tidal CO2 (PETCO2), tidal volume, respiratory rate, and oxygen saturation were recorded every 1 min for 5 min before the start of laparoscopy and every minute during the laparoscopic procedure. A total of 20 patients were enrolled in the study, ranging in age from 15 to 80 months (mean 40.8 months) and in weight from 10.5 to 27 kg (mean 15.9 kg). The length of the laparoscopy varied from 3 to 18 min (mean 6.9 min). No significant changes (increase or decrease of 20% from baseline) of heart rate or BP occurred. Oxygen saturation remained at 98%-100% throughout the procedure in all patients. The baseline tidal volume before the start of laparoscopy was 6.27 +/- 1.9 mL/kg and increased to 7.3 +/- 2.2 mL/kg during laparoscopy (p = 0.01). The baseline respiratory rate was 27.7 +/- 7.0 breaths/min and increased to 33.5 +/- 7.2 breaths/min during laparoscopy (p = 0.0001). PETCO2 increased from a baseline value of 37.5 +/- 6.5 to 44.6 +/- 6.8 mm Hg (p = 0.0001). The increase in PETCO2 was 10 or greater in 3 patients and exceeded 50 mm Hg in 3 patients, with a maximum value of 66 torr.(ABSTRACT TRUNCATED AT 250 WORDS)