Persistent cool extremities as an independent predictor of adverse clinical outcomes among critically ill patients: a single-center retrospective observational study

Cool extremities representing impaired skin perfusion are a classical sign of shock. We evaluated associations between the presence and persistence of subjective cool extremities observed by caring nurses and clinical outcomes. We conducted a retrospective observational study in an Intensive Care Unit (ICU) at a university hospital in Japan. Patients were divided into two groups based on the presence or absence of subjective cool extremities during the first 24 hours of their ICU stay. We compared their characteristics and outcomes. In total, 2956 patients were analyzed. Patients with cool extremities were older, had higher severity Acute Physiology and Chronic Health Evaluation (APACHE III) scores, had higher in-hospital mortality (4.1% vs 18%, p<0.001), and had a higher prevalence of acute kidney injury requiring renal replacement therapy (2.1% vs 10%, p<0.001) as compared to patients without nurse-reported cool extremities. Multivariable logistic regression showed cool extremities persisting for ≥12 hours were significantly associated with in-hospital death (adjusted Odds Ratio, OR, 1.64) and acute kidney injury requiring renal replacement therapy (adjusted OR 1.82). Patients with subjective cool extremities were more severely ill and had poorer outcomes. Subjective skin temperature assessment may be useful to detect high-risk patients.