Comparison Of Plasma Cholinesterase Levels And The Duration Of Suxamethonium Apnoea In Nigerian Adult And Paediatric Patients

Abstract

Background Plasma cholinesterase (butrylcholinesterase) is an enzyme of importance in the practise of anaesthesia due to its role in the metabolism of suxamethonium, and other anaesthetic related drugs. Deficiency of plasma cholinesterase has been associated with prolonged duration of suxamethonium apnoea. The study aimed to investigate the effect of varied levels of plasma cholinesterase on the duration of suxamethonium apnoea in anaesthetised patients and compare the effects in adults and children. Methods – One hundred healthy patients with the American Society of Anesthesiologists (ASA) physical status I and II scheduled for elective surgery under general anaesthesia requiring endotracheal intubation were studied. Pre-induction serum cholinesterase levels were estimated. Suxamethonium 2mg/kg was administered after induction of anaesthesia. After the administration of thiopentone, a Fisher and Paykel peripheral nerve stimulator (PNS) Model NS272 was applied to the ulnar nerve to determine onset and the duration of neuromuscular blockade. Results – Sixty-four adults and 36 children were studied. The mean cholinesterase level was 6573.29 ±2128.29 (ranged from 1227-14536) IU/L. The cholinesterase activity was similar in both children (7044.86 ±2448.81) IU/L and adults (6308.03 ±1894.19) IU/L p = 0.97. The mean onset time of suxamethonium was 37.83 ±9.49 seconds. This onset was similar in children and adults (p = 0.374). There was poor correlation between cholinesterase level and onset time (r = 0.031, p = 0.760). The mean clinical apnoea time was 5.88 ±2.00 minutes. Significant difference existed between adults (6.25 ±1.85 minutes) and children (5.22 ±2.06 minutes) p = 0.012. The mean PNS apnoea time was 8.17 ±3.14 minutes which was significantly shorter in children (6.73 ±3.59 minutes) than in adults (8.97 ±2.52 minutes) p<0.001. There was moderate inverse and significant correlation between cholinesterase level and PNS apnoea time (r = -0.423, p< 0.001), as well as clinical apnoea time (r = -0.461, p<0.001). There was a highly positive and significant correlation between clinical and PNS apnoea time (r = 0.876, p<0.001). The mean recovery time was 7.44 ±2.49 minutes which was significantly shorter in children (6.73 ±2.92 minutes) than in adults (7.86 ±2.13 minutes) p = 0.028. There was a moderate inverse and significant correlation between cholinesterase level and recovery time (r = -0.456, p<0.001). Conclusion – The duration of suxamethonium apnoea increased with low levels of plasma cholinesterase. Children exhibited significantly shorter apnoea and recovery times compared to adults.