Circulatory, Plasma Catecholamine, Cortisol, Lipid, and Psychological Responses to a Real-Life Stress (Third Molar Extractions): Effects of Diazepam Sedation and of Inclusion of Epinephrine with the Local Anesthetic

We studied the circulatory, psychological, plasma catecholamine, cortisol, and lipid responses to a real-life stress--third molar extractions--in 21 patients and the effects of sedation with intravenous diazepam and of inclusion of epinephrine with the local anesthetic. Across all patients, the surgery was associated with significantly increased heart rate (25%), systolic blood pressure (13%) and cardiac output--as indicated using impedance cardiography (34%)--without a significant change in diastolic blood pressure. Plasma norepinephrine increased by 60% during the surgery in nonsedated patients. Diazepam sedation abolished the norepinephrine response to the surgery, without significantly affecting the heart rate or systolic pressure responses. Receipt of epinephrine with the local anesthetic resulted in a fivefold increase in mean plasma epinephrine 5 min after the injection, as well as increased cardiac output. The direct effect of epinephrine accounted for the cardiac output increase observed during the surgery. The results suggest the participation of the sympathetic nervous system in producing the circulatory responses to dental surgery. The elimination of sympathetic recruitment by diazepam-induced sedation, however, without concomitant reductions in heart rate or systolic pressure responses, suggests that other systems besides the sympathetic nervous system influence the circulatory response to this real-life stress.