The effect of lidocaine on neutrophil respiratory burst during induction of general anaesthesia and tracheal intubation

Background and objective Respiratory burst is an essential component of the neutrophil's biocidal function. In vitro, sodium thiopental, isoflurane an d lidocaine each inhibit neutrophil respiratory burst. The objectives of th is study were (a) to determine the effect of a standard clinical induction/ tracheal intubation sequence on neutrophil respiratory burst and (b) to det ermine the effect of intravenous lidocaine administration during induction of anaesthesia on neutrophil respiratory burst. Methods Twenty ASA I and II patients, aged 18-60 years, undergoing elective surgery were studied. After induction of anaesthesia [fentanyl (2 mug kg(- 1)), thiopental (4-6 mg kg(-1)), isoflurane (end-tidal concentration 0.5-1. 5%) in nitrous oxide (66%) and oxygen], patients randomly received either l idocaine 1.5 mg kg(-1) (group L) or 0.9% saline (group S) prior to tracheal intubation. Neutrophil respiratory burst was measured immediately prior to induction of anaesthesia, immediately before and 1 and 5 min after lidocai ne/saline. Results Neutrophil respiratory burst decreased significantly after inductio n of anaesthesia in both groups [87.4 +/- 8.2% (group L) and 88.5 +/- 13.4% (group S) of preinduction level (P < 0.01 both groups)]. After intravenous lidocaine (but not saline) administration, neutrophil respiratory burst re turned towards preinduction levels, both before (97.1 +/- 23.6%) and after (94.4 +/- 16.6%) tracheal intubation. Conclusion Induction of anaesthesia and tracheal intubation using thiopento ne and isoflurane, inhibit neutrophil respiratory burst. This effect may be diminished by the administration of lidocaine.