Comparison of surgical pleth index guided analgesia with conventional analgesia during laparoscopic surgeries-a randomised controlled trial

Abstract

The Surgical Pleth Index (SPI) is a multivariate index derived noninvasively from finger plethysmographic signal. It has been demonstrated to correlate with surgical stress intensity. So, we examined these beneficial effects of SPI guided anaesthesia to determine the amount of intraoperative fentanyl consumption and haemodynamic stability in laparoscopic surgeries under general anaesthesia. After obtaining institutional ethical clearance and patient informed consent, A total of 100 Patients (20-65yrs) posted for laparoscopic surgeries under general anaesthesia were randomly allocated to the SPI and conventional analgesia group (50 patients each). In SPI group, SPI value >50; In conventional group, rise in heart rate(HR), mean arterial pressure (MAP) 20% above baseline were the criteria for fentanyl administration. Fentanyl 0.5 µg/kg is administered in each group for an event persisting for 5 min. Intraoperative fentanyl consumption, hemodynamic stability and postoperative pain for 1 hour were observed. Comparison analysis was performed for total intraoperative fentanyl consumption using t-test. Correlation analysis performed using the Pearson test and p- value <0.05 was considered significant.Total intraoperative fentanyl consumption was lower in SPI group than in the conventional group (108.30±21.84 µg vs 125.70±24.87 µg; p=0.0003) and it was statistically significant with good haemodynamic stability. Postoperative pain scores were comparable in both the groups. The postoperative fentanyl consumption in SPI group was 14.4 ± 1.7 µg and in conventional group was 19.4± 7.0 µg.Compared with conventional analgesia, SPI guided analgesia resulted in lower intraoperative fentanyl consumption and more stable haemodynamics.