Construction of an animal model for stage III pressure ulcer in guinea pigs

Background: The occurrence and development of pressure ulcers is a complex pathological process caused by a variety of reasons, coupled by the ethical and legal constraints. The relevant experiments cannot be directly done in the human body. Objective: To construct an animal model for stage III pressure ulcer in guinea pigs, which can provide evidence for studies on prevention, diagnosis, treatment and pathogenesis of pressure ulcer. Methods: According to the ischemia-reperfusion principle, stage III pressure ulcer was induced on the left trochanter of guinea pigs by exerting different pressures (6.65, 13.3, 19.95, 26.60, 33.25, 39.90 kPa). The model was evaluated based on general, pathohistological and behavioral observation. Results and Conclusion: Wound color and morphological features were similar among different groups, but appearing time was inversely proportional to the pressure size. Hematoxylin-eosin staining showed different degrees of histopathological injuries (6.65 kPa < 13.30, 19.95 kPa < 33.25, 39.90 kPa). When the pressure was 13.30 kPa, the pathohistological presence of the animal models was most similar to that of stage III pressure ulcer in the human body. Compared with the control group, the experimental groups had a significant difference in food intake, water intake and body mass changes from the control group (P < 0.01). With the increase in the pressure applied, the appearance, mental status, gait and temperament of guinea pigs became abnormal gradually. Stage III pressure ulcer model can be prepared under the pressure of 13.30 kPa on the left trochanter by the ischemia-reperfusion method, four cycles a day, 12 cycles in a row (3 days) followed by 5 days without treatment. This model can be used for long-term observation of the pressure ulcer study.