Effects of diazepam premedication and epinephrine-containing local anesthetic on cardiovascular and plasma catecholamine responses to oral surgery.

The effects of diazepam premedication and administration of an epinephrine-containing local anesthetic on plasma catecholamine levels and cardiovascular parameters were evaluated prior to and during a minor surgical procedure, the removal of impacted third molars. Significant elevations in circulating epinephrine levels (203% above control) and cardiac output (30%) were seen in unsedated patients after administration of lidocaine with epinephrine before surgery, while no changes were seen after lidocaine alone. Unsedated patients had increased norepinephrine (24%) and epinephrine (57%) levels during surgery. Diazepam premedication decreased norepinephrine levels 29% below preoperative levels, followed by an increase during surgery to preoperative levels. These results indicate that intraoral injections of epinephrine-containing local anesthetics result in increased circulating epinephrine levels that are associated with cardiovascular changes and that diazepam premedication decreases plasma norepinephrine levels and attenuates the sympathoadrenal response to surgical stress.