An Entropy Based Observational Study to Assess the Dosage of Propofol required for Induction of Anaesthesia by Varying the Time Intervals between Fentanyl and Propofol Administration

Propofol is the preferred drug for the induction of anesthesia in many centers. However, its ubiquitous use is hampered by adverse effects. The rationale behind our study is to prove that whether the administration of an opioid drug before propofol induction, lowers the amount of propofol requirement for balanced anesthesia, and enhances hemodynamic stability. The present study intends to know the consequence of the differing time intervals between the administration of fentanyl and propofol on the dosage of propofol required to achieve induction of general anesthesia. In this observational study, 84 patients were included in the study. Patients who received propofol immediately after fentanyl injection were included in Group 1, whereas patients who received propofol at 3 min and 6 min after fentanyl injection, respectively, were grouped as Group 2 and Group 3. The total propofol required, the hemodynamic variations and the entropy values were recorded. SSPS version 25.09 (IBM) was used for statistical analysis. In this study, it was observed that there was a significant reduction in propofol requirement in Group 2 and Group 3 compared with Group 1. The incidence of hypotension was seen in about 42.9% of Group 1 when compared to Group 2 and 3, which was 28.6% and 17.8%, respectively. Furthermore, the entropy values in Group 3 were initially higher and later were comparable in all the groups. Our study concluded that as the duration between the administration of propofol and fentanyl increases, the hemodynamic stability also increases and there is no variation in the depth of anesthesia attained in the distinct study population.