Background: Long-lasting minimally invasive procedures are increasingly used for children. However, the hemodynamic effects of a prolonged carbon dioxide (CO(2)) pneumoperitoneum (PP) on small infants are poorly understood and may differ from the effects on adolescents. This study aimed to detect and compare these effects in neonatal and adolescent pigs.
Methods: Six neonatal pigs weighing 5.6-6.4 kg and six adolescent pigs weighing 51-57 kg underwent a prolonged CO(2) PP of 180 min. Five neonatal pigs weighing 5.7-6.6 kg underwent sham PP as an additional control group. All the animals received crystalloid electrolyte solution at 10 ml/kg/h during the experiments. After CO(2) decompression, all the animals were monitored for a further 120 min. The end points of the study were mean arterial pressure (MAP), central venous pressure (CVP), and cardiac index (CI). The parameters were assessed after a 60-min resting phase (i.e., after initial placement of catheters in the jugular vein, the carotid artery, and the femoral artery four times during CO(2) PP and three times afterward.
Results: The comparison of neonates and adolescent pigs showed that neonates had a significantly more pronounced decrease in MAP during CO(2) PP (88.1 +/- 2.7% of baseline vs 95.1 +/- 1.6%; p < 0.05) and the recovery period (71 +/- 5.1% vs 86.4 +/- 1.4%; p < 0.05). Differences in CVP changes between the neonatal and adolescent pigs during and after CO(2) PP were not significant. For the neonates, the decrease in CI was most pronounced during the recovery period after decompression of the CO(2) PP and significantly less than in adolescents (84.3 +/- 3.3% of baseline vs 97.4 +/- 4.5%; p < 0.05). The neonates with sham PP did not show any significant MAP, CVP, or CI changes during the experiments.
Conclusions: A prolonged CO(2) PP induces hypotension and cardiac depression in neonatal but not in adolescent pigs. Thus, intensive monitoring during prolonged laparoscopic procedures and particularly afterward may be mandatory for neonates.