Alfentanil as an anesthetic induction agent--a comparison with thiopental-lidocaine.

Alfentanil (0.175 mg/kg) and a combination of thiopental (3-4 mg/kg) and lidocaine (1.5 mg/kg) during anesthetic induction were compared. Each was administered rapidly to eight patients with cardiovascular disease (average age, 64 yr), followed by succinylcholine (1.5 mg/kg) for laryngoscopy and intubation. Chest wall rigidity or flexor spasm of arm and jaw were seen transiently in 7 of 8 patients receiving alfentanil. Both drugs led to decreases in mean arterial pressure averaging 31 mm Hg (P less than 0.01). In patients given thiopental-lidocaine, intubation led to a 28 mm Hg (P less than 0.01) increase over control in arterial pressure and a 10 beats . min-1 increase in heart rate (P less than 0.01). In patients given alfentanil, after intubation arterial pressure returned to levels no different from control and the heart rate remained stable. Five of the patients given alfentanil required a single dose of naloxone (0.08-0.15 mg) to achieve a PCO2 less than 50 torr at the end of surgery. Rapidly administered alfentanil blunted the cardiovascular response to intubation but decreased arterial pressure as much as thiopental-lidocaine.