A Study to Assess the Efficacy of Different Doses of Propofol for Tracheal Intubation: A Randomized Clinical Trial.

Background: Tracheal intubation is usually facilitated by using a muscle relaxant to supplement drugs given for the induction of general anesthesia. Nondepolarizing muscle relaxants are also associated with the few disadvantages. Endotracheal intubation under volatile anesthetics without the use of muscle relaxants is possible, but it has disadvantages. Time available for intubation is much less when compared to the use of muscle relaxants. Considering the disadvantages of muscle relaxants and volatile agents in mind, there is a need for endotracheal intubation without muscle relaxants.

Objective: The objective of the study is to assess the efficacy of different doses of propofol for tracheal intubation - a randomized clinical trial.

Materials And Methods: A randomized study was conducted on 80 patients, comprising of 40 patients each. Patients of either sex were randomly allocated into Group P1 and Group P2 by computer-generated random numbers where Group P1 received 2 mg/kg propofol +3 μg/kg fentanyl and Group P2 received 4 mg/kg propofol +3 μg/kg fentanyl. SpO, heart rate, blood pressure (BP)- systolic BP, diastolic BP, and mean arterial pressure were recorded at 1 and 3 min after administration of study drugs were recorded. Intubating conditions were assessed modified Helbo-Hansen scoring system.

Results: The success rate of endotracheal intubation was 62.5% and 95% in propofol 2 mg/kg + fentanyl 3 μg/kg and propofol 4 mg/kg + Fentanyl 3 μg/kg, respectively. The total incidence of hypotension was 40% and 83% in propofol 2 mg/kg + Fentanyl 3 μg/kg and propofol 4 mg/kg + Fentanyl 3 μg/kg, respectively. The incidence of hypersensitivity was noted only in propofol 4 mg/kg + Fentanyl 3 μg/kg group and was 2.5%.

Conclusion: We conclude that endotracheal intubation is possible in premedicated adult American Society of Anesthesiologists by Grade I patients with receiving 3 μg/kg Fentanyl + 2 mg/kg or 4 mg/kg propofol for induction without muscle relaxants, and the intubating conditions are acceptable. We found that propofol 4 mg/kg + Fentanyl 3 μg/kg is the optimal dose required for intubation without the use of muscle relaxants.