A controlled trial of the effects of esmolol on cardiac function.

We have examined the effects of two different bolus doses of esmolol hydrochloride (Brevibloc) on haemodynamic variables in a placebo-controlled, double-blind, randomized trial. Sixty healthy adult patients undergoing minor orthopaedic surgery were given a standardized general anaesthetic using a laryngeal mask airway. Heart rate (HR), mean arterial pressure (MAP), stroke volume (SV) and cardiac output (Q) were measured (the latter two by Doppler ultrasonography) every 1 min for 5 min after injection of either placebo or esmolol 100 mg or 200 mg. HR, MAP, SV and Q decreased significantly (P < 0.05) for both esmolol groups compared with placebo and, except for MAP, esmolol 200 mg had a greater effect than esmolol 100 mg (P < 0.05). Depression was maximal at 2 min after which recovery was observed but was still incomplete at 5 min.