BACKGROUND: A commercially available target-controlled propofol infusion system, the 'Diprifusor'TM is used for the induction and maintenance of anesthesia in adults, not in children because the pharmacokinetics of propofol in children. We wondered whether it is safe to use the 'Diprifusor'TM in children weighing over 30 kg in clinical practice?

METHODS: Twenty unpremedicated children (8-15 yr, group 1) and sixty five unpremedicated adults (16-65 yr, group 2) scheduled for elective surgery were enrolled. After intravenous injection of fentanyl 1µg/kg, a propofol infusion was started at a target concentration of 4µg/ml using a 'Diprifusor'TM. We recorded the time to loss of eyelash reflex and effect site concentration at the time of loss of consciousness. Anesthesia was maintained with propofol-fentanyl-50% N2O-rocuronium. We also checked the effect site concentration at the time of eye opening to verbal command.

RESULTS: The effect site concentrations at loss of eyelash reflex were 1.19 ± 0.66µg/ml (group 1) and 0.96 ± 0.55µg/ml (group 2), and these were not significantly different between the two groups. But the effect site concentrations at eye opening were 1.66 ± 0.38µg/ml (group 1) and 1.47 ± 0.32µg/ml (group 2) which were significantly different (P <0.05).

CONCLUSIONS: 'Diprifusor'TM can be used safely in children weighing over 30 kg with a similar effect site concentration at loss of eyelash reflex as adults, but the effect site concentration at eye opening in children is slightly higher than that of adults.