Study objective: To evaluate the effects of the preoperative administration of clonidine by the oral, intramuscular (i.m.), or epidural routes, on isoflurane expense during total abdominal hysterectomy.
Design: Randomized, double-blind, placebo-controlled study.
Setting: University hospital.
Patients: 80 ASA physical status I and II patients scheduled for total abdominal hysterectomy.
Interventions: Patients were distributed into four groups of treatment: oral, i.m., epidural, and control. Each group received 300 microg clonidine according to the treatment group, plus placebo by the other routes. The control group received placebo by all three routes. Depth of anesthesia was evaluated by changes in blood pressure and heart rate over baseline values. Cost evaluation was based on three components: expense of isoflurane, cost of 300 microg of clonidine (tablets or ampoules), and the disposable material required to dispense clonidine to each group.
Measurements and main results: Groups were comparable regarding demographic data, duration of surgery, and time to discharge from recovery room. Postoperatively, none of the patients had recall of intraoperative events. Clonidine reduced isoflurane pharmacy cost by approximately 45%, regardless of the route of administration. However, when cost of clonidine and the disposable equipment used for its administration were taken into account, the cost of the epidural kit surmounted the savings in isoflurane expense.
Conclusion: In the patient population studied, premedication with 300 microg oral, i.m., or epidural clonidine, similarly and significantly reduced the expense of isoflurane during general anesthesia of an approximate duration of two hours. However, the cost of the epidural kit offsets the savings in isoflurane.