INFLUENCE OF ADRENALINE ON MATERNAL PLASMA LEVELS AND PLACENTAL TRANSFER OF LIGNOCAINE FOLLOWING LUMBAR EPIDURAL ADMINISTRATION

Summary: The maternal and cord plasma concentrations of lignocaine have been determined following the administration of 20 ml 2 per cent lignocaine solution both with and without the addition of adrenaline 1/250,000. Forty-two patients were examined, 24 with adrenaline (Group 1) and 18 with adrenaline (Group 2). A significant difference (P>0.001) was found between Groups 1 and 2 in the maternal concentrations for those patients who were delivered either 11-22 min after injection or 23-30 min after injection but not for those patients delivered more than 30 min after injection. The effect of added adrenaline on the cord plasma lignocaine levels was much less than on the maternal plasma levels. Adrenaline had no effect on the ratio of cord venous plasma concentration at delivery and maternal plasma concetration, the mean value in the two groups being approximately 0.5. The addition of adrenaline 1/250,000 to lignocaine solutions administered epidurally increases the safety of the method for the mother but does not increase it for the neonate to the same extent. © 1969 John Sherratt and Son Ltd.