Use of remifentanil and alfentanil in endotracheal intubation: a comparative study

Opioids, such as alfentanil, are used to facilitate endotracheal intubation without the use of neuromuscular blocking agents in patients undergoing elective surgery.

The goal of this study was to evaluate the endotracheal intubation conditions when remifentanil or alfentanil was used with propofol without the application of neuromuscular blocking agents.

One hundred American Society of Anesthesiologists (ASA) grade I patients scheduled for elective surgery were enrolled in this prospective, randomized, triple-blinded study. The patients were randomized to group A (alfentanil) or R (remifentanil). In group A, alfentanil (50 mcg/kg) was intravenously injected over 10 seconds, and after 45 seconds or at the occurrence of apnea, propofol (2 mg/kg) was intravenously injected over 5 seconds. Thirty seconds after the administration of propofol, laryngoscopy and endotracheal intubation were attempted. In group R, remifentanil (5 mcg/kg) was administered instead of alfentanil. Intubation conditions, including ease of laryngoscopy, patency of the vocal cords, jaw relaxation, limb movement (1-4 score), and also, demographic data were evaluated.

There were no demographic data differences between groups (age, weight, and sex). Further, laryngoscopy, jaw relaxation, and limb movement scores were similar in the R and A groups and there were no significant differences, but vocal cords were significantly more patent in group R than those in group A (P = 0. 028).

The results of this study showed that remifentanil, similar to alfentanil, provided excellent conditions for endotracheal intubation when used with propofol for the induction of anesthesia; however, remifentanil improved the patency of the vocal cords to a greater extent than alfentanil.