Journal of Clinical Case Reports

Ketamine as Adjunctive Anesthesia in Refractory Complex Regional Pain Syndrome Patients: A Case Series

Abstract

Schwartzman RJ, Samudralwar R, Getson P and Alexander GM

Complex regional pain syndrome most often follows peripheral soft tissue and nerve injury, fractures, and surgical procedures. The pain is out of proportion to the severity of the injury, spreads beyond a nerve or root territory and increases over time. In general, recommendations for anesthesia for these patients requiring surgery include sympathetic blockade or intravenous regional anesthesia as well as sympathetic blockade in conjunction with lidocaine. Quite often surgery for these patients seriously aggravates their condition. This is a retrospective evaluation of a case series of the use of ketamine as adjunctive anesthesia in twenty five refractory long standing complex regional pain syndrome patients. All patients met the International Association for the Study of Pain criteria for diagnosis. Ketamine was administered intravenously over four hours from the start of the procedure with midazolam and clonidine in addition to their standard anesthesia. At the end of the procedure, an additional dose of midazolam was administered. Lorazepam was used for restlessness if necessary for three nights after the procedure. All twenty five patients had no exacerbation of their symptoms and signs and no spread of their CRPS. This study supports the effective use of ketamine, midazolam and clonidine as adjunctive anesthesia in severe refractory CRPS patients undergoing a surgical procedure.