RESUMO
In the patients at risk of aspiration, it is necessary to induce general anesthesia and intubate their trachea as rapid sequence. Succinylcholine is the only neuromascular blocker with short onset and ultrashort acting effect, therefore choice of drug is in rapid sequence induction of anesthesia. This drug has many advantages, including low cost, short onset, short duration of action, and profound muscle relaxation with no need to reversal of muscle relaxation. The most important side effects of this drug are fasciculation, postoperative myalgia and rise in serum potassium. We compared lidocaine with atracurium in preventing these side effects. The patients aged 20-50 years, in class one or two physical status [ASA], were randomly assigned either to group A or group B. Those in group A were given atracurium [0.05 mg/kg], 3 minutes before succinylcholine. Those in group B received lidocaine [1.5 mg/kg], 30 seconds before succinylcholine at induction of anesthesia. All patients in both groups received sodium thiopental [4 mg/kg] and succinylcholine 1.5 mg/kg at induction of anesthesia. We evaluated and recorded fasciculation and myalgia in two days after operation. We also measured serum potassium before induction and 5 minutes after succinylcholine injection. In order to control of post-operative pain, we used intravenous morphine or acetaminophen as either oral or suppository. 160 patients were studied. The occurrence and severity of fasciculation were the same in two groups [p>0.05]. There were less myalgia in group B in comparison with group A, one and two days after operation [p<0.05]. There were no significant changes in serum potassium in two groups. Lidocaine is as effective as atracurium in decreasing the occurrence and severity of fasciculation, following succinylcholine injection at induction of anesthesia. Lidocaine is more effective than atracurium in decreasing the occurrence and severity of myalgia