Plasma concentrations of catecholamines following adrenaline infiltration during gynaecological surgery.

High pressure liquid chromatography with electrochemical detection has been used to measure plasma catecholamine concentrations in six gynaecological patients undergoing halothane anaesthesia for cervical cone biopsy. Mean catecholamine concentrations before infiltration were 1.01 +/- 0.23 (SEM) nmol litre-1 (185 +/- 43 pg ml-1) for adrenaline, and 2.2 +/- 0.25 nmol litre-1 (364 +/- 41 (185 +/- 43 pg ml-1) for adrenaline, and 2.2 +/- 0.25 nmol litre-1 (364 +/- 41 pg ml-1) for noradrenaline. Following infiltration with 0.5% bupivacaine 15 ml with adrenaline 1:200 000, plasma adrenaline concentrations increased to a mean peak concentration of 18.6 +/- 3.7 nmol litre-1 (3.4 +/- 0.69 ng litre-1). The lack of sympathoneuronal response was confirmed by simultaneous measurements of plasma noradrenaline concentrations, which did not change significantly. The proportion of the injected adrenaline measured in the intravascular compartment was 21.8%. The significance of intravascular absorption of exogenous adrenaline is discussed in relation to the use of halothane anaesthesia and the concurrent injection of a local anaesthetic solution.