The Effects of Co2 Pneumoperitoneum on End Tidal CO2 (ETCO2), Arterial Blood Pressure and Heart Rate During Laparoscopic Cholecystectomy Under General Anaesthesia

Abstract

Objective: To analyze the effects of CO2 pneumoperitoneum at 13 to 15 mmHg intra-abdominal pressure on end 
tidal CO2 (ETCO2), arterial blood pressure and heart rate during laparoscopic cholecystectomy under general 
anaesthesia with controlled mechanical ventilation.  
Design: Prospective Descriptive Study. 
Place and Duration of Study: The study was conducted at the department of anaesthesia Fauji Foundation Hospital 
Rawalpindi from August 2005 to September 2006. 
Patients and Methods: Fifty consecutive ASA grade-1 patients, 47 females, 3 males and aged 35-65 years 
undergoing laparoscopic cholecystectomy were included in the study. All patients received a standardized balanced 
anaesthetic in which 0.7 - 1 % isoflurane was used during maintenance. Ventilation was controlled and minute 
volume was kept at 100 ml/kg/min. Pneumoperitoneum was created with CO2 at a flow rate of 10 liter/min and 13 
to 15 mmHg intra abdominal pressure was maintained during the operation. End tidal CO2 (ETCO2), heart rate and 
non invasive systolic, diastolic and mean arterial blood pressure was recorded immediately before intra abdominal 
CO2 insufflation and then after 5 minutes interval during the period of CO2 pneumoperitoneum. Study period 
started immediately before intra-abdominal CO2  insufflation till about 60 minutes of surgical procedure.  
Results: The end tidal CO2 (ETCO2) levels progressively increased to reach a plateau 36mmHg 20 minutes after 
the beginning of intra abdominal CO2 insufflation. The end tidal CO2 (ETCO2) levels increased to 21 % of base 
line (from 30 to 36 mmHg) during CO2 pneumoperitoneum for laparoscopic cholecystectomy under controlled 
mechanical ventilation at minute volume 100 ml/kg/min. The systolic, diastolic and mean arterial blood pressure 
increased to 12% to 17% of the baseline during CO2 pneumoperitoneum at 13-15 mmHg intra abdominal pressure. 
There was no significant change in heart rate. 
Conclusion: CO2 pneumoperitoneum produces rise in end tidal CO2 (ETCO2) levels and hemodynamic alterations 
proportional to the increased intra abdominal pressure during laparoscopic surgery under general anaesthesia with 
controlled mechanical ventilation.