Half or more of patients have pain after rocuronium bromide (Zemuron®, Organon) injection, say the authors of a study comparing the efficacy of intravenous (IV) fentanyl with IV lidocaine as pretreatment. In fact, they noted withdrawal responses to rocuronium injection even after patients lost consciousness during induction of anesthesia.
Researchers from Malaysia randomly assigned 90 patients, 18 to 65 years of age, to three groups: one group of patients received 2 ml of IV fentanyl 50 mcg/ml, one group received 2 ml of preservative-free lidocaine 2%, and one group received placebo.
The incidence of withdrawal response after the rocuronium injection was 57% with placebo, 30% with lidocaine, and 7% with fentanyl. The researchers say the fact that fentanyl was better than lido-caine in this context is interesting, considering that other trials have found the opposite. The difference, they believe, is in timing. They administered fentanyl two minutes before induction, followed by the rocuronium injection, thus allowing adequate time for the onset of drug effect.
canadian pharmacy viagra
Pretreatment with opioids is effective only if adequate time is allowed for the onset of analgesia, whereas pretreatment with drugs with local anesthetic properties is effective when it is administered immediately before or with a venous occlusion technique.
The authors suggest combining IV fentanyl 2 mcg/kg and lidocaine 0.5-1 mg/kg, administering fentanyl (for its central analgesic action) two minutes before and lidocaine(for its peripheral analgesic action) immediately before the rocuronium.