Does laparoscopy adversely affect gas exchange and pulmonary mechanics in the newborn? An experimental study

Notwithstanding the clinical acceptability of pediatric laparoscopy, the physiological consequences of carbon dioxide (CO(2)) peritoneal insufflation on lung mechanics and gas exchange are not established. This study seeks to establish the affects of increased intraabdominal pressure (P ABD) from CO(2) insufflation on lung mechanics, the compliance of the respiratory system (CRS stat), and gas exchange. Ten anesthetized tracheostomized, and paralyzed rabbits (2.5-3.1 kg) were examined. Mechanical ventilation was established to produce normal ventilation (PaCO(2) 35-45 Torr). Continuous pulse, blood pressure (BP), and serial arterial blood gas measurements were obtained by femoral arteriotomy. The animals were examined at baseline conditions (P ABD = 0 mm Hg), at 2 levels of external compression (P ABD = 6 and 12 mm Hg, respectively), and at two levels of intraperitoneal CO(2) insufflation (P ABD=6 and 12 mm Hg, respectively). Increased P ABD, whether applied externally or by intraperitoneal insufflation, did not alter the CRS stat (ANOVA p = 0.557), nor systematically change the pH, PaCO(2) or PaO(2) (ANOVA p = 0.541, p = 0.545, p = 0.446, respectively). Neither BP nor pulse rate showed any change. Under conditions encountered during laparoscopy, P ABD of 0-12 mm Hg did not have a deleterious effect on ventilation and gas exchange in the ventilated and paralyzed small animal.