ABSTRACT: A474 NEUROLOGY 58 April 2002 (Suppl 3)
Recovery from Intractable Complex Regional Pain Syndrome Type I (RSD) under High-Dose Intravenous Ketamine-Midazolam Sedation
Ralph-Thomas Kiefer, Tuebingen, Germany, Peter Rohr, Saarbruecken, Germany, Klaus Unertl, Tuebingen, Germany, KarlHeinz Altemeyer, Saarbruecken, Germany, John Grothusen, Robert J. Schwartzman, Philadelphia, PA
OBJECTIVE: Complex Regional Pain Syndrome, type I, also known as Reflex SympathetIc Dystrophy is a very debilitating and very difficult pain syndrome to treat. New, more effective, therapeutic options are desperately needed.
BACKGROUND: Accumulating evidence points to the involvement of the central nervous system in CRPS-I / RSD. Functional and structural changes in central pain processing neurons (central sensitization) are thought to be important for initiating and maintaining chronic neuropathic pain of which CRPS I / RSD is a subset. Central sensitization may be a consequence of activity dependent N-Methyl-D-Aspartate (NMDA) receptor activation. Clinical evidence suggests a therapeutic value of NMDA-receptor antagonists in CRPS I / RSD.
DESIGN / METHODS: Six patients with CRPS I / RSD, that in each case was worsening in spite of aggressive treatment, were given the option of participating. After obtaining informed consent, and all risks were explained, each patient was admitted to the intensive care unit of the Department of Anesthesiology and Intensive Care Medicine, University of Tuebingen, Tuebingen, Germany, or the Department of Anesthesiology, Intensive and Emergency Medicine and Pain Therapy, Klinikum Saarbruecken, Saarbruecken, Germany. Each patient was given midazolam as repeated bolus until deep sedation was obtained. Continuous intravenous infusion of midazolam (0.15 mg/kg/hr, via central line) was accompanied by ketamine, starting at 3 mg/kg/hr on day 1, to 4 mg/kg/hr on day 2, to 5 mg/kg/hr on day 3, to 6 mg/kg/hr on day 4, and finally to 7 mg/kg/hr on day 5. On day 6 and 7 the ketamine dose was slowly tapered down. This was followed by tapering of the midazolam. Although ventilatory assistance was not needed in three of the patients, the other three were intubated preemptively as a precaution, due to concerns of possible aspiration.
RESULTS: To date six patients have received the treatment of high dose ketamine-midazolam sedation. All six patients tolerated the treatment well, there were no medical complications. All had excellent response initially with significant reduction in pain, both spontaneous and especially in touch evoked allodynia. To date, one patient has remained pain free for more than two years; one has remained pain free for 4 months so far. The two most recent patients have been pain free for 3 weeks so far. One patient has had some symptoms of neuropathic pain return after 3 months and one patient had all symptoms return after 1 month. To date five of the six patients treated have complete absence of allodynia, hyperalgesia and swelling in the effected areas.
CONCLUSIONS: High dose intravenous ketamine / midazolam sedation is a promising new therapeutic option in the treatment of intractable CRPS-I / RSD.
Disclosure: Ralph-Thomas Kiefer has nothing to disclose.