The relationship between pressure ulcers and skin blood flow response after a local cold provocation

Objective: To study the relationship between an impaired blood flow response after a local cold stimulus, testing nerve regulation of the local blood flow response, and an increased risk of developing pressure ulcers. Design: An observational, longitudinal, prospective study. Setting: Dutch nursing home. Patients: Eighty-two newly admitted somatic nursing home patients, age 60 years and older. Intervention: A local cold stimulus (17°C) applied to the trochanter major. Main Outcome Measures: On admission, blood flow response to a local cold stimulus. As the stimulus was withdrawn, the temperature measured at the skin increased asymptotically toward the final temperature, T_fThe velocity of this rise was characterized by the time constant, τ, of the process. On admission, and weekly during a 4-week follow-up period, the presence or absence of pressure ulcers was verified. Results: The blood flow response time correlated significantly with the risk of developing pressure ulcers. The patients who developed pressure ulcers during the follow-up period had a significantly longer response time than the patients who did not. Conclusions: Malfunction of the nervous regulatory mechanisms of the local blood flow is partially responsible for an increased susceptibility to pressure ulcer formation.