A Study of the Effect of Varying Time Intervals between Fentanyl and Propofol on Propofol Requirement for Induction...

Propofol is widely used for the induction of general anesthesia but is associated with dose-dependent hypotension. Fentanyl, when administered before propofol, may reduce the propofol dose requirement and mitigate hemodynamic instability.

To evaluate the effect of varying time intervals between fentanyl and propofol administration on propofol dose requirement for induction and to assess associated hemodynamic responses.

This randomized controlled study enrolled 150 American Society of Anesthesiologists I-II patients aged 18-60 years scheduled for elective surgery under general anesthesia. Patients were allocated into three groups (n = 50 each): Group 1 received propofol immediately after fentanyl (2 μg/kg intravenous), Group 2 after 3 min, and Group 3 after 5 min. Propofol was titrated until loss of verbal response. Hemodynamic parameters were recorded at baseline, postfentanyl, during induction, and postintubation. Incidence of hypotension, movements, bucking, and vocalization were noted.

Group 3 required significantly less propofol (67.6 ± 16.36 mg) than Group 2 (104.6 ± 21.2 mg) and Group 1 (137.8 ± 12.41 mg) (P < 0.001). The incidence of hypotension was lowest in Group 3 (3%) compared with Group 2 (21%) and Group 1 (45%) (P < 0.001). Group 3 also showed better attenuation of the intubation response and fewer adverse movements.

Administering propofol 5 min after fentanyl significantly reduces induction dose requirements and improves haemodynamic stability during induction and intubation.