Rocuronium is a nondepolarizing muscle relaxants used for trying rapid-sequence intubation due to its relatively rapid onset of action and low side effects. Methods to further reduce the onset time of a muscle relaxant include increasing the dose of muscle relaxant, pretreatment for potentiating neuromuscular block of the muscle relaxants or increasing the cardiac output and muscle blood flow. The purpose of this study was to examine the pretreatment effect of combined lidocaine and ephedrine, as a pretreatment, on the onset time and intubation conditions of rocuronium-induced neuromuscular block in adults.

Sixty ASA physical stati 1 and 2 patients were randomly allocated to four groups. Normal saline 10 ml was administered to Group NS prior to induction, lidocaine (1.5 mg/kg) to Group L, ephedrine (70 µg/kg) to Group E, and combined lidocaine (1.5 mg/kg) and ephedrine (70 µg/kg) to Group LE. Anesthesia was induced with propofol (2.0 mg/kg) and rocuronium (0.6 mg/kg). Intubation was performed 45 seconds after the administration of rocuronium and the intubation conditions then evaluated. The change in the mean arterial pressure and heart rate were checked and compared during the peri-induction periods.

There were no differences in the hemodynamics between the four groups. The intubation conditions were graded as good to excellent in 33.3, 53.3, 66.7 and 93.3% of patients in NS, L, E and LE groups, respectively. The intubation conditions in group LE were significantly better than those in group NS (P < 0.05).

The above results demonstrated that pretreatment with a combination of ephedrine and lidocaine, following rocuronium, improves the tracheal intubation conditions.