Randomised, cross-over comparison of sevoflurane and ketamine-midazolam anaesthesia in children undergoing extracorporeal shock-wave lithotripsy

Introduction: The aim of this study was to assess the haemodynamic responses, adverse events and recovery characteristics associated with sevoflurane and ketamine-midazolam anaesthesia for paediatric extracorporeal shock-wave lithotripsy. Methods: Twenty children aged 2-11 years, who were undergoing two consecutive lithotripsy sessions at an interval of 4 weeks were enrolled and randomised to receive either inhalation or dissociative anaesthesia at their first session. The alternative anaesthesia protocol was used at their second session. Inhalation anaesthesia was induced with 8% sevoflurane and 70% N2O in oxygen; 10 mu g/ kg atropine and 2 mu g/ kg fentanyl were then administered. Anaesthesia was maintained with 2%-3% end-tidal sevoflurane and 70% N2O in oxygen via a laryngeal mask airway. Dissociative anaesthesia was induced intravenously with 10 mu g/ kg atropine, 0.05 mg/ kg midazolam, 1.5 mg/ kg ketamine and maintained with 0.5-1.0 mg/ kg ketamine. Haemodynamic parameters were recorded before and after induction, after the start of the procedure, and every 10 minutes thereafter. Postoperatively, the times to responding to command, sitting, ambulating, achieving an Aldrete score >= 9, and achieving a post-anaesthetic discharge score >= 9 were recorded. Results: Systolic and diastolic arterial pressures at all measurements throughout the procedure were higher with ketamine - midazolam than with sevoflurane ( P< 0.05). Heart rates were comparable between groups, except after induction and after start of the procedure in which they were higher with ketamine - midazolam ( P< 0.05). All recovery endpoints were achieved earlier with sevoflurane than with ketamine - midazolam ( P< 0.05). Nausea-vomiting incidences were similar in both groups. Conclusion: Sevoflurane and ketamine - midazolam both provided effective anaesthesia for paediatric lithotripsy. The recovery and discharge times were shorter after anaesthesia with sevoflurane compared with ketamine - midazolam in children undergoing lithotripsy.