[Comparison of changes in plasma catecholamines between general anesthesia and general anesthesia plus epidural block].

To investigate the stress-response during anesthesia-operation, 16 patients were allocated into either of two groups. Eight cases in Group A underwent an operation on the abdomen under general anesthesia, while the other eight cases in Group B were operated under general anesthesia plus epidural block. Plasma catecholamine levels were measured in all subjects during anesthesia operation procedure. A significant increase in the levels of plasma catecholamines was observed at 45 min after incision in Group A (1.82 +/- 0.48 vs. 0.94 +/- 0.19 ng/ml, P less than 0.05, paired t-test), while no change was seen in Group B during the whole procedure. The result may indicate that an operation on the abdomen rather than general anesthesia itself is responsible for the observed increase in plasma catecholamines level.