The optimum bolus dose of remifentanil to facilitate laryngeal mask airway insertion with a single standard dose of propofol at induction in children

• Published in: Anaesthesia 2008-09, Vol.63 (9), p.954-958
• Main Authors: Kwak, H. J., Kim, J. Y., Kim, Y. B., Chae, Y. J.
• Format: Article
• Language: English
• Subjects: Airway management; Ambulatory Surgical Procedures; Anesthesia; Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Anesthesiology; Anesthetics, Combined - administration & dosage; Anesthetics, Intravenous - administration & dosage; Biological and medical sciences; Blood Pressure - drug effects; Child; Child, Preschool; Dose-Response Relationship, Drug; Female; Heart Rate - drug effects; Humans; Laryngeal Masks; Male; Medical sciences; Pediatrics; Piperidines - administration & dosage; Propofol - administration & dosage; Surgery
• ISSN: 0003-2409; 1365-2044
• DOI: 10.1111/j.1365-2044.2008.05544.x

Summary The purpose of this study was to determine the optimal bolus dose of remifentanil required for the successful insertion of the laryngeal mask airway during propofol induction in children without a neuromuscular blocking agent. Twenty‐six paediatric patients, aged 3–10 years, requiring anaesthesia for short ambulatory surgery were recruited. A predetermined bolus dose of remifentanil was injected over 30 s, followed by propofol 2.5 mg.kg−1 over 10 s. The bolus dose of remifentanil was determined by a modified Dixon’s up‐and‐down method, starting from 0.5 μg.kg−1 (0.1 μg.kg−1 as a step size). Laryngeal mask insertion was attempted 90 s after the end of remifentanil injection and the response of patients was classified as either ‘movement’ or ‘no movement’. The bolus dose of remifentanil at which there was a 50% probability of successful laryngeal mask insertion (ED50) during induction with 2.5 mg.kg−1 propofol was 0.56 (0.07) μg.kg−1 in children without a neuromuscular blocking agent. From probit analysis, the ED50 and ED95 of remifentanil were 0.52 μg.kg−1 (95% confidence limits, 0.42–0.62 μg.kg−1) and 0.71 μg.kg−1 (95% confidence limits, 0.61–1.40 μg.kg−1), respectively.