Evidence for the optimal management of acute and chronic phantom pain: a systematic review.

OBJECTIVES The objective was to examine the evidence to determine the optimal management of phantom limb pain in the preoperative and postoperative phase of amputations. METHODS Trials were identified by a systematic search of MEDLINE, review articles, and references of relevant trials from the period 1966-1999, including only English-language articles. Included trials involved a control group, any intervention, and reported phantom pain as an outcome. RESULTS Twelve trials were identified, including 375 patients whose follow-ups ranged in duration from 1 week to 2 years. Only three randomized, controlled studies with parallel groups and three randomized crossover trials were identified. Eight trials examined treatment of acute phantom pain, including epidural treatments (three trials), regional nerve blocks (three trials), treatment with calcitonin (one trial), and transcutaneous electrical nerve stimulation (one trial). Three trials demonstrated a positive impact of the intervention on phantom limb pain, but the remainder demonstrated no difference between the intervention and control groups. Four trials examined late postoperative interventions, including transcutaneous electrical nerve stimulation (two trials) and the use of Farabloc (a metal threaded sock) and ketamine (one trial each). With regard to late postoperative interventions, three of the four trials showed modest short-term reduction of phantom limb pain. There was no relation between the quality of the trial and a positive result of the intervention. CONCLUSIONS Although up to 70% of patients have phantom limb pain after amputation, there is little evidence from randomized trials to guide clinicians with treatment. Evidence on preemptive epidurals, early regional nerve blocks, and mechanical vibratory stimulation provides inconsistent support for these treatments. There is currently a gap between research and practice in the area of phantom limb pain.