Effects of intraabdominal CO2 insufflation in the piglet

Adult intraabdominal surgery performed with the minimal-access technique has created a revolution in surgery. This technique has remained largely unused for pediatric surgical procedures because of concerns regarding its safety and efficacy. Presently, intraabdominal insufflation of CO2 is the preliminary step to performing minimal access surgery. In this study, an animal model was developed to determine the effects of intraabdominal CO2 insufflation in the infant. Eight piglets (4 to 6 kg; 14 to 19 days of age) were instrumented under fentanyl anesthesia to allow measurement of arterial blood pressure (BP), central venous pressure (CVP), heart rate (HR), cardiac index (CI), inferior vena cava pressure (IVCp), inferior vena cava flow (IVCf), mediastinal pressure (Mp), partial pressure of CO2 (PaCO2), and minute ventilation (VE) at baseline and during 1 hour of CO2 insufflation to a pressure of 15 mm Hg and again when ventilation was increased to control PaCO2 levels. Continuous recording of data allowed time-course analysis of 15-minute blocks to determine the rate of change of measured variables. A second group of 6 piglets (4 to 6 kg) underwent the same instrumentation, but their baseline values were compared with those during N2O insufflation to isolate the effects of increased intraabdominal pressure. During CO2 insufflation alone, PaCO2 increased by 31% (P < .0001). This increase occurred within the first 15 minutes of insufflation and then remained stable. The increase was likely the result of increased CO2 absorption from the peritoneal cavity because VE was unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)