Mannitol as salvage treatment for Complex Regional Pain Syndrome Type I

Abstract

Introduction Complex Regional Pain Syndrome Type I (CRPS I) is a continuation of symptoms and signs due to a pathological exaggerated reaction in an extremity of the human body after an injury or operation. Although the clinical picture of CRPS I in the majority of patients is well known, the underlying pathophysiology remains unclear. In the Netherlands, intravenous mannitol administration used as hydroxyl radical scavenger for patients who do not respond to conservative treatment of CRPS I is advocated but little evidence supports this salvage strategy. In this study the effect of mannitol as salvage medication was evaluated in a well-defined multimodal step-up treatment protocol. Patients and methods A consecutive group of 68 adult patients with persistent CRPS I was analysed, who underwent a total of 100 mannitol infusions. The effect of treatment was considered per sign and per symptom according to the Veldman et al. criteria for CRPS I. Results Overall improvement of CRPS I after mannitol treatment was successful in 24% after 1 week, and in 30% after 1 month. Mannitol treatment had some effect in patients with initially warm CRPS I in contrast to patients with cold CRPS I (OR = 6.30 with CI [2.37–16.75]). Also patients with CRPS I at the upper extremity had more benefit than patients with CRPS I at the lower extremity (OR = 3.26 with CI [1.34–7.93]). Poor results of mannitol treatment were associated with cold CRPS I ( p < 0.001), chronic CRPS I ( p = 0.04) and multiple mannitol treatments ( p = 0.04). Conclusion Mannitol did not significantly contribute to the overall success of treatment in patients with CRPS I. Patients, presenting with acute, warm CRPS I in the upper extremity may have some benefit.