Carotid artery surgery. Local versus general anaesthesia as related to sympathetic activity and cardiovascular effects.

Arterial plasma catecholamines, blood pressure and heart rate were determined in 75 patients before, during and after carotid endarterectomy. Local anaesthesia given as a cervical block with skin infiltration containing 200 micrograms adrenaline was used in 28 patients (LA-group), general anaesthesia (nitrous oxide, fentanyl, isoflurane) with skin infiltration containing 200 micrograms adrenaline in 32 patients (GAs-group) and general anaesthesia without skin infiltration in 15 patients (GAo-group). In the LA-Group plasma noradrenaline (P-NA) levels were significantly higher during anaesthesia and surgery, with an increase from preanaesthesia levels (P less than 0.05). P-NA decreased from a preanaesthesia level in the GAo-group (P less than 0.01) but remained unaltered in the GAs-group. P-NA values in the GAo-group were lower than those of the GAs-group (P less than 0.001) following anaesthesia and surgery. Plasma adrenaline (P-A) increased in the LA- and the GAs-group and decreased in the GAo-group (P less than 0.001) following anaesthesia and surgery. In the LA-group P-A was similar before the skin incision and clamping but higher after declamping as compared to the GAs-group. Before the skin incision and thereafter P-A was lower in the GAo-group as compared to the other groups. There was a positive correlation between plasma catecholamines, on the one hand, and mean blood pressure and heart rate on the other. Two patients in the LA-, eight in the GAs- and seven in the GAo-group showed a hypotensive blood pressure reaction (SBP less than 100 mmHg; LA vs. GAo, P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)