To investigate the distribution characteristics and risk factors associated with generalized subcutaneous edema in critically ill patients and the impact of the severity of subcutaneous edema on prognosis.

Semi-quantitative assessment of subcutaneous edema was performed at 36 sites in seven body parts of critically ill patients within 24 hours of admission to the Department of Critical Care Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine using convenience sampling, and the edema was classified into seven grades using the pressure depression test and according to the skin recovery time. Relevant clinical and laboratory data such as diagnosis, APACHE Ⅱ score, and organ function were also collected.

Binary logistic regression was used to screen for factors influencing the occurrence of subcutaneous edema in the whole body and susceptible parts, and the role of the severity of subcutaneous edema on prognosis. The median subcutaneous edema score at the 36 measurement sites was 0.61 (0.31, 0.78), with the highest incidence of subcutaneous edema in the abdominal wall (86.5%), with a degree of edema of 0.75 (0.5, 1.25). Logistic regression showed that APACHE Ⅱ score (＞15) and admission diagnosis (sepsis) were risk factors for the development of subcutaneous edema in the general and vulnerable parts of the body. In addition, total systemic subcutaneous edema score was a risk factor for death within the ICU stay of critically ill patients (odds ratio=1.03, 95% confidence interval: 1.00~1.06, P=0.038).

Critically ill patients have subcutaneous edema at different sites and to different degrees, which is characterized by a heterogeneous distribution throughout the body, is more likely to occur in the abdominal wall, and shows a gravity-dependent distribution. The severity of subcutaneous edema is associated with a poor prognosis in critically ill patients.