Effects of local cooling on skin perfusion response to pressure: implications to pressure ulcer prevention

摘要

Pressure ulcers have long been an important healthcare issue in both acute and long-term care settings. Temperature is one of the extrinsic causative factors for this multi-factorial disease not yet fully explored. Previous animal studies revealed that skin cooling reduced the severity of ulceration compared to non-cooling. Cooling is also used widely in plastic surgery and organ transplants for tissue preservation. However, the underlying protective mechanism of local cooling remains unclear. Our study's objective was to measure the effect of cooling on tissue's response to pressure using skin perfusion response on human subjects. Reactive hyperemia is a normal protective physiological response occurring after vessel occlusion. Laser Doppler flowmetrey was used to measure cutaneous perfusion. We hypothesized that local cooling would reduce a rigid indenter induced post-ischemic reactive hyperemic response. Ten young healthy non-smokers were recruited into the study. A repeated measures design was used where all subjects were subjected to pressure with cooling to 25°C and pressure without cooling test sessions. Each test session contained five levels of pressure control: light contact (10 minutes), 60 mmHg (30 minutes), light contact (20 minutes), 150 mmHg (3 minutes), light contact (10 minutes). The cooling intervention was performed during the period of 60mmHg contact pressure. Our results showed a significantly attenuated peak perfusion response after 60mmHg (p=0.019) but not after 150mmHg (p=0.241) of pressure for the cooling session compared to the non-cooling. This study suggests that local cooling may protect skin from the harmful effects of prolonged pressure in this young healthy population. The study protocol would be modified to investigate populations at risk of pressure ulcers.