Pharmacokinetics of lignocaine in children after infiltration for cleft palate surgery.

We have studied the pharmacokinetics of lignocaine in children after local infiltration for cleft palate surgery. After induction of anaesthesia, lignocaine 2.5 mg kg-1 with adrenaline 1:200,000 was injected into the palate. Blood samples were collected before and at 2, 5, 10, 15, 20, 30, 60 and 120 min after infiltration. Plasma concentrations of lignocaine were measured by a gas-liquid chromatographic technique. There were no signs of systemic toxicity on routine monitoring of the patients and the peak plasma concentrations were less than the accepted toxic values. Mean half-life was 72.9 (SEM 9.9) min, similar to that found previously in adults and children. However differences in mean clearance (24.6 (2.04) ml kg-1 min-1) and volume of distribution (0.80 (0.07) litre kg-1) were found between this and previous studies.