Pathophysiology and mechanisms of compartment syndrome.

Compartment syndrome is a serious potential complication of trauma to the extremities. Increases in intracompartmental tissue pressure result from increases in fluid pressure plus the contributions of cells, fibers, gels, and matrices. The result is an increased venous pressure that lowers the arteriovenous pressure gradient, resulting in decreased local blood flow. While fasciotomy is the definitive treatment for an established compartment syndrome, preventive measures can be taken early to modify or halt the process. Tissue pressures are helpful in monitoring or establishing the diagnosis. However, their use requires a clear understanding of the pathophysiology of compartment syndrome for proper clinical correlation. Recent studies have suggested that determination of the difference between the mean arterial and compartmental pressures (delta P) is more useful than the absolute tissue-pressure measurement. This article reviews the pathophysiology and mechanisms of compartment syndrome.