Abstract
The present study aimed to identify factors and observe and classify skin changes in detail related to pressure ulcers caused by repeated use of unventilated masks during non-invasive positive pressure ventilation（NPPV）among healthy adults under identical fixation conditions as under actual usage conditions, mask fixation cannot be standardized and varies from patient to patient. Specifically, two mask types were placed on nine subjects at least twice. A single researcher ensured that masks were fitted in the same manner, and observed all survey contents. Cases in which similar skin changes were observed twice were regarded as mask-induced skin changes, and their relationship to the facial morphology and subjective assessment of the subject were analyzed. On the cheeks and forehead, skin changes in a pattern consistent with the mask configuration were observed；while on the nose, a distinct irregular pattern inconsistent with the mask configuration was observed. Moreover, the masks did not properly fit on the nose, indicating that using an ill-fitting mask or changes in the configuration of the mask itself may affect the pattern of skin changes. These findings indicate that the factors related to pressure ulcers caused by NPPV masks are not restricted to care-related factors, and that assessments of the device and its appropriate use are also important.
