Evaluation of hemodynamic changes using different intra-abdominal pressures for laparoscopic cholecystectomy

Biliary diseases known since ages constitute major portion of digestive tract disorders world over. Among these cholelithiasis being the fore runner causing general ill health, thereby requiring surgical intervention for total cure. The study was undertaken in an attempt to compare the hemodynamic changes in patient undergoing laparoscopic cholecystectomy using different intra-abdominal pressures created due to carbon dioxide insufflation. The patients were randomly allocated to one of the three groups in which different levels of intra-abdominal pressures (8-10 mmHg,11-13 mmHg and 14 mmHg and above) were maintained. The base line parameters monitored were heart rate, non invasive blood pressur(systolic and mean)and end tidal carbon dioxide. All the parameters were monitored at various intervals i.e. Immediately during insufflation, 5 min, 10 min, 20 min, 30 min after CO2 insufflation and after every 10 min if surgery exceeds 30 min, at exsufflation,10 min after CO2 exsufflation. Patients were ventilated with Pedius Drager Ventilator keeping tidal volume 8-10 ml/kg and respiratory rate 12-14 breaths/min. During surgery patients were placed in reverse Trendlenburg position (head up) at 15 °. The results obtained were evaluated statistically and analyzed. Baseline characteristics were found to be comparable. Hemodynamic variables were reported as mean and standard deviation. Statistical significance among groups was evaluated using Analysis of Variance and unpaired student t test (two tailed). Inter-group comparisons were made using Bonferroni test. A p-value of <0.05 was considered as statistically significant. In all the three groups the mean heart rate (baseline 84.08 ± 12.50, 87.96 ± 15.73 and 86.92 ± 17.00 respectively) increased during CO2 insufflation and the rise in heart rate continued till exsufflation after which it decreased and at 10 min after exsufflation the heart rates were comparable with the baseline. The inter-group comparison of mean heart rate between I & III was statistically significant at 10, 20, 30 min after CO2 insufflation which continued at exsufflation and 10 min after CO2 exsufflation [p < 0.05]. The inter-group comparison between I & III showed statistically significant difference in systolic blood pressure at 10, 20, 30 min after CO2 insufflation, at exsufflation and 10 min after exsufflation [p = 0.0001] and mean arterial pressure at 5, 10, 20, 30 min after CO2 insufflation, at exsufflation and 10 min after exsufflation [p = 0.0001]. Comparison between Group I and Group III & between Group II and Group III showed highly significant statistical difference in EtCO2 immediately after insufflation and the same trend was seen till the completion of surgery and even 10 min after exsufflation [p = 0.001]. The conclusion drawn from the study was that laparoscopic cholecystectomy induces significant hemodynamic changes intraoperatively, the majority of pathophysiological changes are related to cardiovascular system and are caused by CO2 insufflation .A high intra-abdominal pressure due to CO2 insufflation is associated with more fluctuations in hemodynamic parameters and increased peritoneal absorption of CO2 as compared to low intraabdominal pressure so low pressure pneumoperitoneum is feasible for laparoscopic cholecystectomy and minimizes the adverse hemodynamic effects of CO2 insufflation.