Influence of intravenous clonidine in the cost of sevoflurane anesthesia for outpatient middle ear procedures.

BACKGROUND AND OBJECTIVES: Clonidine is an a2-agonist which decreases intravenous and inhalational anesthetics consumption. This study aimed at evaluating the cost-benefit ratio of preanesthetic medication with intravenous clonidine for general anesthesia with sevoflurane in outpatient procedures. METHODS: Forty five patients aged 15 to 52 years were included in this double-blind, randomized and placebo controlled study, and were distributed in 3 groups of 15: Group S (placebo), Group C3 (3 microg kg(-) clonidine) and Group C5 (5 microg kg(-1) clonidine). Anesthesia was induced with sevoflurane, alfentanil (30 microg kg(-1)) and pancuronium (0.08 mg kg(-1)). The following parameters were recorded: incidence of complications, halogenate consumption and anesthesia duration, as well as phase I and II recovery time. Cost analysis has considered direct and indirect costs. RESULTS: There were no differences among groups in demographics data, incidence of complications and phase I anesthetic recovery. Phase II anesthetic recovery was prolonged in Group C5 (p < 0.05). Sevoflurane consumption per minute of surgery was 0.54 +/- 0.14, 0.33 +/- 0.09 and 0.34 +/- 0.13 in Groups S, C3 and C5 respectively (p < 0.05). Costs were approximately 35% lower in the clonidine groups. CONCLUSIONS: Intravenous clonidine (3 microg kg(-1)) decreases sevoflurane consumption without prolonging phase I recovery. Although decreasing sevoflurane consumption, 5 microg kg(-1) clonidine prolongs phase II recovery, thus being inadequate for outpatient procedures.