Abstract

Studies of plasma catecholamine levels during anesthesia and surgical stress revealed that responses to emotional stress are not blocked by regional anesthesia alone. Local anesthesia combined with intravenous diazepam, however, blocks both the emotional and physical stress responses associated with surgery.

The stress of intra-abdominal surgery is not blocked by clinical anesthetic levels of halothane. Low spinal anesthesia blocks afferent surgical stimuli without blocking efferent compensatory responses; i.e., while the block produces vasodilation of the blocked segments, there is a compensatory and essentially equal vasoconstriction above the block level resulting in little change in blood pressure.

Stress incurred in the recovery room can be just as pronouced as stress during the surgery. When early versus late recovery levels were compared, a drop in plasma catecholamine levels and mean arterial pressure occurred in the late recovery period (2 hours postsurgery) when anesthesia was decreasing and conscious pain increasing. Arterial blood pressure was found to correlate with the level of plasma norepinephrine and, hence, can be used clinically as an index of perioperative stress.