181. HYPOTHERMIA IN COMPARTMENT SYNDROME

Abstract

Purpose: Compartment syndrome is a limb-threatening condition. Treatment is urgent decompression by fas-ciotomy. However, orthopedic surgeons are often confronted by a limb at risk for compartment syndrome, in which treatments to preserve tissue might be considered. Hypothermia has shown promise as a technique of maintaining tissue viability in transplant surgery, replant surgery and soft tissue injury. Cooling reduces microvascular dysfunction, inflammation and edema. This study was designed to determine whether tissue cooling might reduce muscle damage in the setting of elevated intracompartmental pressure. Purpose This study investigated the effect of hypothermia on tissue perfusion, viability and the inflammatory response in an animal model of elevated intracompartmental pressure. We hypothesize that hypothermia will preserve muscle tissue viability in an animal model of elevated intracom-partmental pressure.

Method: Twenty Wistar rats were randomized. Five animals had elevated intracompartmental pressure for 2 hours (CS). Five had elevated pressure and hindlimb cooling to 25oC (CS-HY). Five had hindlimb cooling to 25oC (HY) and 5 were control animals (C). All animals were anaesthesized for study. Core temperature was maintained over 30oC. Elevated ICP was maintained (30mmHg) using a saline infusion technique (groups CS and CS-HY). After 2 hours, fasciotomies were completed and intravital microscopy was used to measure tissue viability, microvascular perfusion and inflammation.

Results: The use of hypothermia reduced tissue damage by approximately 50% in the CS-HY group (8.2% injured cells) compared with the CS group (16.5% injured cells). There was no difference in capillary perfusion comparing the CS and CS-HY groups (p> 0.05). The number of adherent inflammatory cells was fewer comparing the CS-HY with the CS groups, but this did not reach statistical significance with the numbers available for study.

Conclusion: Hypothermia preserved tissue viability in an animal model of elevated intracompartmental pressure. Fasciotomy remains the gold standard treatment for established compartment syndrome. However cooling may be useful to preserve tissue viability in extremities that are at risk of developing compartment syndrome. The clinical utility of hypothermia for compartment syndrome requires further study.