Evaluation of Tracheal Intubating Conditions and Serum Potassium Levels With Different Doses of Succinylcholine : A Prospective Randomized Comparative Study

Abstract

BACKGROUND: Utility of succinylcholine for rapid sequence induction is a common practice for more than last 50 years. The ED95 dose of succinylcholine is 0.3mg/kg. Regularly 2-3 times ED95 doses of non-depolarizing muscle relaxants are being used for tracheal intubation, but succinylcholine is being used traditionally in a dose of 1mg/kg which is more than 3.5 times ED95. However, according to the available literature evidence doses as small as 0.4mg/kg may also provide clinically acceptable intubating conditions with the possibility of earlier return of neuromuscular function which avoids critical hemoglobin desaturation in unanticipated difficult airway& CVCI situations. We did a study to evaluate the ease of tracheal intubation with low doses of succinylcholine in Indian population. AIM: To evaluate tracheal intubating conditions and serum potassium levels with different doses of succinylcholine. DESIGN: A prospective randomized double blind comparative study. METHODS: 80 patients belonging to ASA PS I&II were randomly divided into 4 groups A,B,C&D who received 0.5mg/kg,0.6mg/kg,0.7mg/kg& 1mg/kg of succinylcholine respectively. All the patients were pre-medicated with Tab. Alprazolam 0.25mg PO previous night and fentanyl 1mcg/kg 5min before induction, induced with sleep dose of thiopentone followed by administration of test drug. After 1min, 3yrs experienced anesthesiologist attempted tracheal intubation& assessment of intubating conditions were done using Cooper& colleagues criteria. N-M effects were monitored preoperatively and up to 3min after dug administration. Haemodynamic parameters& serum potassium were measured preoperatively, continued up to 5min& 1 hour after drug administration respectively. RESULTS: Clinical intubation cumulative scores in GROUP A were significantly different from other GROUPS (B, C, D) with (p<0.05) on ANOVA. N-M monitoring has revealed significant twitch height depression in Group D (p<0.05) at 60 sec after drug administration along with significant twitch height recovery in between the four groups (p<0.05). With Bonferroni multiple comparison test Group D is statistically different from Group A&B with no difference between Groups C&D. Haemodynamic monitoring and serum potassium levels were increased but not clinically significant. CONCLUSION: To conclude, 0.6mg/kg of succinylcholine can be attempted for rapid sequence induction as it provides equally good intubating conditions with early recovery.