[Adrenergic response during general anesthesia with propofol as maintenance agent]

To determine plasma catecholamine levels during the use of propofol for maintenance of anesthesia. We studied 20 randomly chosen patients undergoing elective orthopedic surgery under general intravenous anesthesia with propofol as the agent of maintenance along with pancuronium and fentanyl. Plasma concentrations of dopamine, noradrenalin and adrenalin were measured at the following times: baseline, after intubation and every 15 min during surgery. The levels obtained for the different samples were compared with baseline levels. At the doses used in our study, there were no significant differences in the way dopamine plasma levels varied. This was not the case with the other two hormones, however. Adrenalin levels were significantly higher at the first 3 extractions (post-intubation, 15 min and 30 min), and noradrenalin was significantly higher (p < 0.05) at all extraction times. Total intravenous anesthesia with propofol is associated with a significant increase in plasma concentrations of adrenalin and noradrenalin. Adrenalin returns to baseline levels 45 min after induction.