Effects on Intubating Conditions of Pretreatment with Remifentanil before Administration of Cisatracurium

Cisatracurium provides superior hemodynamic stability with only minor release of histamine, and its metabolism via Hoffman elimination is independent of organ function. However, use of cisatracurium is limited because of reportedly slower onset and unsatisfactory intubating conditions. Many studies have shown that remifentanil might provide reliable intubating conditions; thus, we hypothesized that pretreatment with remifentanil before administration of cisatracurium might result in acceptable intubating conditions. Sixty healthy patients scheduled for elective surgery were enrolled and randomly divided into three groups: saline (Group I, n=20), remifentanil 0.5 µg/kg (Group II, n=20), and remifentanil 1.0 µg/kg (Group III, n=20). The anesthesia was induced with propofol 2.0 µg/kg given intravenously over 30 s followed by injection over 30 s of a different dose of remifentanil according to the study protocol. We examined the intubating condition by jaw relaxation, vocal cord state, and diaphragmatic response 90 s after administering cisatracurium. We also measured mean blood pressure, heart rate, and the onset time, which is the interval from the end of neuromuscular blocking agent administration until suppression of maximal T1 on a train-of four sequence. The mean values of the intubating condition after endotracheal intubation in Groups II and III were significantly lower than that in Group I (p<0.005), although the overall onset time of cisatracurium did not differ significantly between the three groups. Our results suggest that supplementation with remifentanil in an induction regimen with cisatracurium improves the quality of the intubating condition even though the onset time of cisatracurium is not shortened.