Objectives: Numerous publications on sedation of and anaesthesia for diagnostic procedures in children prove that no ideal scheme is available. Therefore, we decided to study the protocol with midazolam and ketamine used by nonanaesthetists at our institution. The study aimed to establish the lowest effective starting dose of ketamine and to estimate a difference in the frequency of adverse reactions with or without the use of midazolam as premedication, with special stress on emergence reactions.
Methods: During 1 year we prospectively randomised children scheduled for gastrointestinal endoscopies to a first group with and to a second group without midazolam premedication. The starting ketamine dose was increased until the appropriate dissociative state was reached. Physiological functions were closely monitored and adverse reactions noted.
Results: The median age of 201 analysed patients (111 girls, 90 boys) was 8.2 years. The median starting dose of ketamine was 0.97 mg/kg (the group with midazolam premedication) and 0.99 mg/kg TT (without midazolam premedication). Laryngospasm was observed in 6 patients without statistical difference between the 2 groups. All of the adverse reactions were short lasting; they resolved by symptomatic treatment without complications. Emergence reactions during the observation period at the hospital occurred more often in the group sedated with ketamine without midazolam premedication (P = 0.02).
Conclusions: The sedation protocol with ketamine is safe and efficient. The starting dose of ketamine should be at least 1 mg/kg. There is an advantage to the use of midazolam as premedication before ketamine in paediatric patients because the frequency of emergence reactions in hospital was reduced compared with sole ketamine use.