Interstitial fluid flow as a factor in decubitus ulcer formation

Abstract

Decubitus ulcers form as a result of prolonged excessive external pressure on soft tissue. The mechanisms of ulcer formation are poorly understood. In this preliminary study, the effects of external pressure on interstitial fluid dynamics are analysed, using a simple mathematical model. Calculations revealed that an inverse relationship exists, between the intensity and duration of external pressure required for the interstitial fluid volume in the pressurized region to reach a given portion of its initial volume, which is similar to the experimentally observed relationship between the intensity and duration of external pressure required to produce threshold damage. The preliminary analysis suggests that interstitial fluid flow may play an important role in the ulcer formation.