Alfentanil is comparable to remifentanil in preventing withdrawal movement following rocuronium injection

To evaluate and compare the efficacy and related side effects of alfentanil and remifentanil in preventing the withdrawal movement associated with rocuronium injection.

Prospective, randomized, blinded, placebo-controlled clinical trial.

Operating room of a university hospital.

115 ASA physical status I and II adult patients.

Patients were randomly allocated to one of three study groups. Group C received saline, Group A received alfentanil 10 microg/kg, and Group R received remifentanil one microg/kg, each in a volume of three mL. Treatments were injected over 30 seconds, followed by thiopental sodium. At 90 seconds after the start of the study drug injection, rocuronium 0.6 mg/kg was injected over 10 seconds.

Cough, breathholding, and thoracic muscle rigidity were observed while injecting the study drug. Each patient's response to the rocuronium injection was graded on a 4-point scale in a blinded manner.

During injection of the study drug, Group R showed a significantly higher frequency of cough than Group A (24% vs. 2%; P < 0.05). One Group R patient presented with apnea. Frequency of withdrawal movement in Groups A and R were significantly lower than that in Group C (6% and 0% vs. 63%; P < 0.0001) but there was no significant difference between the two groups.

When administered 90 seconds before rocuronium injection, alfentanil showed a comparable effect to that of remifentanil in attenuating rocuronium-associated withdrawal movement, and a lower frequency of side effects such as cough.