Hypercarbia is not the determinant factor of systemic arterial hypertension during carboperitoneum in laparoscopy

Laparoscopy performed with carboperitoneum in 30 women of infertility was studied to evaluate the changes of systemic blood pressure and end-tidal carbon dioxide (CO2) and their relationship. The patients were randomly divided into 2 groups. In group I (n = 15), the patient's respiration was set to maintain a nearly constant end-tidal CO2 by adjusting the minute ventilation. In group II (n = 15), the minute ventilation was kept constant to monitor the changes of end-tidal CO2. Perioperative measurements included end-tidal CO2, systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (HR) which were recorded the moment just before intra-abdominal CO2 administration and every 2 min thereafter for at least 10 min. The data showed that in both groups there were time-related changes of blood pressure with a maximum increase about 20-30% of baseline level found at 6 min later after the beginning of intra-peritoneal CO2 insufflation, and no significant change of HR was noted. The intergroup comparisons of SBP, DBP and HR were not statistically significant. With regard to end-tidal CO2 change in group II, it also appeared in a time-related fashion. A maximum increase was found 6 min later after the intra-abdominal CO2 administration. Our results disclosed that carboperitoneum during laparoscopy might consistently induce systemic arterial hypertension, and hypercarbia might not be the major determinant factor of hypertension.