Reflex sympathetic dystrophy: model of a severe regional inflammatory response syndrome.

The systemic inflammatory response syndrome (SIRS) and acute reflex sympathetic dystrophy syndrome (RSD) share clinical signs of severe inflammation, a protracted course, and a similar problem of impaired oxygen utilization. The difference is that SIRS patients have these signs and symptoms systemically and are severely ill in the intensive care unit (ICU), whereas acute RSD patients are in good health and their problems are limited to one extremity. Both conditions seem to be the result of an exaggerated inflammatory response. As RSD patients have a healthy contralateral extremity, they may be their own control in various flux studies. It is hypothesized that this situation is exquisitely suitable for studying the pathophysiology of severe inflammatory responses in humans. Only a few patients are required to perform studies of, for example, oxygen metabolism and cytokine or oxygen radical production. Assessment methods may be utilized, such as nuclear magnetic resonance spectroscopy, which cannot easily be performed in ICU patients.