Effects of the magnitude of pressure on the severity of injury and capillary closure in rat experimental pressure ulcers.

Experimental pressure ulcers were successfully produced in the rat abdominal wall at 100 mmHg in our previous study. We hypothesized that injury is less severe when pressures are lower than 100 mmHg and explored a critical pressure in the production of pressure ulcers. At 70 and 60 mmHg, repeated compressions for 4 h daily for 5 consecutive days resulted in partial skin necrosis and eschar formation in the majority of rats, whereas skin injuries were absent or very mild in most of the rats at 50 mmHg.