Comparative evaluation of low dose succinylcholine against standard intubating dose in children

Background : Critical oxyhaemoglobin desaturation can occur if ventilation is unassisted with the conventional intubation dose of 1.0mgkg^-1 succinylcholine. We conducted this study to evaluate the role of low dose succinylcholine in producing acceptable intubating conditions during rapid tracheal intubation in paediatric patients and whether it leads to a lesser duration of apnoea. Patients & Methods: After IRB approval and parental consent, this prospective, randomized, double blind study included 60 patients (age 3-15 yrs). Patients received IV midazolam 0.05 mgkg-1 as premedication. Anaesthesia was induced with fentanyl 2 μgkg^-1 and propofol 3 mgkg^-1. Patient's respiration was then assisted with 1% halothane in 100% oxygen over 1 minute (denitrogenation). Patients were randomized to receive either 1 mgkg^-1 or 0.5 mgkg^-1 succinylcholine. Tracheal intubation conditions were graded 60s after succinylcholine administration. Patients were left apnoeic after succinylcholine injection till resumption of spontaneous breathing. Duration between succinylcholine injection to resumption of spontaneous breathing resumption was noted as duration of apnoea. Data were analyzed with chi-square test and student t test. P<0.05 was considered significant. Results : Intubating conditions were acceptable in 29/30 children in succinylcholine 1 mgkg^-1 group as against 28/30 children in succinylcholine 0.5 mgkg^-1 group (P=0.55). Duration of apnoea was significantly less in succinylcholine 0.5 mgkg^-1 group [114 (46) seconds] compared to succinylcholine 1 mgkg^-1 group [185 (45) seconds] (P=0.00). Conclusions : Succinylcholine 0.5 mgkg-1 provides clinically acceptable intubating conditions comparable to that of succinylcholine 1 mgkg^-1. Duration of apnoea with 0.5 mgkg^-1 succinylcholine was significantly less when compared with 1 mgkg^-1 succinylcholine.