A prospective randomized double-blind clinical study to compare the effect of nalbuphine versus fentanyl on attenuation of pressor response during endotracheal intubation and analgesic potential on patients under general anesthesia

Background:Laryngoscopy and orotracheal intubation often trigger a hemodynamic response, increasing catecholamines and potentially leading to higher morbidity. Fentanyl, with a high safety margin and rapid onset, and Nalbuphine, a mu receptor antagonist and k receptor agonist with minimal respiratory depression and a "ceiling effect," are commonly used to mitigate this response. Aim:This study compares the efficacy of Fentanyl and Nalbuphine in reducing the pressor response during laryngoscopy and intubation in patients under general anesthesia, monitored by Bispectral Index (BIS). It also evaluates total analgesic requirements, time to first rescue analgesic post-extubation (VAS score), and associated complications. Method:The study was a hospital-based, prospective, double-blind, randomized interventional trial registered under the Clinical Trials Registry - India (CTRI/2022/05/042731). The sample size of 70 patients (35 in each group) was calculated based on alpha error, study power, and the minimum clinically significant difference for MAP after induction. Patients aged 18-65 years with ASA grade I and II and body weight between 40-70 kg were included. Group A received Fentanyl, and Group B received Nalbuphine. Vital parameters were monitored during the surgery, and additional doses of the study drug were administered if the BIS score exceeded 60. Postoperative analgesic effect was evaluated by a blinded anesthesiologist. Results:The demographic characteristics of the study population were similar between the Fentanyl and Nalbuphine groups, as indicated by age, weight, sex, and ASA physical status, there was a statistically significant difference in systolic blood pressure, diastolic blood pressure, mean arterial pressure and heart rate post-intubation, with the Nalbuphine group demonstrating a greater increase compared to the Fentanyl group, which was significant at all time intervals.