Continuous intravenous versus bolus parenteral midazolam: a safe technique for conscious sedation in plastic surgery

Abstract

Conscious intravenous sedation is a safe alternative method to general anaesthesia. We have used a technique of continuously titrated, as opposed to incremental boluses of, intravenous or intramuscular midazolam for conscious sedation, with tumescent adrenaline-lignocaine solution for local anaesthesia, routinely in 421 plastic surgical procedures between 1997 and 2000. All patients were American Society of Anesthesiologists (ASA) class I or II. Conscious sedation was administered through our protocol of continuously titrated doses of midazolam in dextrose saline. The operative field was injected subcutaneously with varying volumes of diluted lignocaine and adrenaline, depending on the anatomical region. Preoperative sedation was administered 1 h before the procedure in the form of an intramuscular injection of pethidine and promethazine (Phenergan). Intraoperatively, a subset of patients received up to four divided diluted doses of pethidine. A preoperative 4 h starvation period pronounced the effect of the sedative. No intraoperative conversions to general anaesthesia were needed, and no sedation complications occurred. No unplanned re-admissions secondary to nausea, prolonged drowsiness or pain were required. All patients who were treated using this technique had an uneventful postoperative course. Hospital stay was substantially shorter than following general anaesthesia, which provided a significant reduction in medical-care expenses and a faster return to work. In conclusion, conscious sedation administered by titrated intravenous midazolam is a well-tolerated, safe, consistent, predictable and effective anaesthetic choice for a variety of plastic surgical procedures, many of which would commonly be performed under general anaesthesia.