To investigate the effects of different doses of cisatracurium pretreatment on succinylcholine-induced fasciculations.

Ninety patients scheduled for laparoscopic cholecystectomies were equally randomized into three groups to receive pretreatment of 0.005, 0.01, and 0.02 mg/kg cisatracurium, respectively. General anesthesia was induced 3.5 min later, train of four stimulation was monitored 4.5 min later, succinylcholine 1.5 mg/kg was injected 5 min later, and endotracheal intubation was implemented 6.5 min later. The side effects of cisatracurium, intensity of fasciculations, intubating conditions, time and extent to maximal depression of twitch and time for its recovery to 20% of control value, severity of myalgia at 24 h postoperatively, serum potassium before cisatracurium pretreatments, at intubating time, and 5 min after intubation were recorded.

Inclusion Criteria:

• American Standards Association (ASA) physical status I or II patients scheduled for elective laparoscopic cholecystectomies with tracheal intubation requiring general anesthesia;
• 20 - 65 years old;
• Without acid-base imbalance and electrolyte disturbance;
• With normal hepatic and renal function.

Exclusion Criteria:

• Patients with the contraindications associated with succinylcholine or cisatracurium;
• Patients taking drugs known to alter the action of neuromuscular blockers;
• Patients with a body mass index exceeding 30