Cardiovascular reactions associated with the use of ketamine and epinephrine in plastic surgery.

Intravenous ketamine dissociation anesthesia combined with epinephrine solution infiltration may provoke serious tachyarrhythmias despite diazepam premedication and the use of minimal doses of both drugs. We use a dose of 0.5 mg of ketamine per kilogram of body weight to induce a short period of amnesia and analgesia, which enables us to infiltrate the operative field with lidocaine and epinephrine solution in a 1:200,000 or 1:400,000 concentration. In about 20% of the patients we encountered significant transient tachycardia and elevation of blood pressure, which required no treatment; however, in 2 of our patients, serious arrhythmias occurred that required drug conversions. Such a problem was not encountered with the use of epinephrine alone in patients without a predisposing condition, nor when ketamine in these small doses was used in other large series.