Junko Niitsuma

Experimental study of decubitus ulcer formation in the rabbit ear lobe

An animal model of decubitus ulcer was created with the use of ear lobes of Japanese white rabbits. When the strength of the cyclic compressions and the duration of the cycles of compression and release are adjusted, the model successfully reproduced the four grades used to characterize decubitus ulcer. Compressions were recorded with video microscopy to continuously monitor the changes in tissue blood flow, in both the compressed and surrounding regions. This model is unique insofar as the blood-flow characteristics are clearly visible before, during, and after compression. Because long-term observation is possible in a living-body model, our study can easily be extended.

An analysis of skin temperature changes under pressure loading and relief by animal experiments

For immobile patients pressure sores are one of the most severe diseases. In this study we examined the skin temperature under pressure loading and relief by animal experiments. The results obtained show that the skin temperature of the ischemic area changed due to the same pressure loading and relief in different constant ambient temperature. In order to prevent pressure sores, it is therefore necessary not only to measure the pressure relief but to analyze the skin temperature under the pressure loading and relief.

Etiology of decubitus ulcers using an animal model - a comparison of blood flow measurement method between point analysis and two-dimensional analysis

The purpose of this study has been to clarify the effect of sustained compression on skin surface blood flow at the edema stage and flare in the initial phase of decubitus ulcer formation with the use of rabbit ears. Experimental protocol is compared between point analysis and two-dimensional analysis. For the point analysis, a laser Doppler perfusion monitoring probe is contacted with the skin surface continuously. For two-dimensional analysis, the scanning probe is not contacted with skin. The experimental phases are divided as follows: 1) initial (pre-compression), 2) edema, 3) compression and 4) release from compression. For the the point analysis, the blood flow rate has been measured continuously on a point from the initial phase to release from the compression phase. When the two protocols were compared, similar blood flow changes were observed. From results of two-dimensional analysis, during the compression phase and during release from compression, the blood flow rate in the peripheral part of the compressed area was found to change proportionately to the applied compressive load.

Etiology of decubitus ulcers using an animal model-an analysis of blood flow inhibition and recovery phenomena around compressed area

The purpose of this study has been to clarify an effect of ischemia on the causal mechanism in the initial phase of decubitus ulcer formation in rabbit ears. The experiment consisted of blood flow measurement during compression and during remission from compression. The compression protocol compares the single compression and repeated compression. The results showed that the blood flow rate changed in the peripheral zone of the compressed area on repeated compression. The investigations have yielded evidence to suggest the decubitus ulcers are due to the following causal factors: (1) localized ischemia in the compressed area; (2) skin surface blood flow from the rim of the compressed area to the surrounding zone.