Association between hypothermia and hyperthermia and 28-day mortality in pediatric intensive care unit patients: a retrospective cohort study

Body temperature (BT) monitoring is critical for the management of critically ill patients, and numerous studies have demonstrated that abnormal BT in ICU patients is linked to adverse outcomes. However, evidence regarding the association between admission BT and 28-day mortality in pediatric intensive care unit (PICU) patients is limited. This study aims to clarify the association between admission BT and 28-day mortality in critically ill pediatric patients. This retrospective analysis utilized the pediatric intensive care (PIC) database, comprising 7,350 patients. The primary outcome was 28-day mortality, while 90-day mortality and in-hospital mortality were assessed as secondary outcomes. Multivariate Cox regression analysis and smooth curve fitting were used to evaluate the relationship between BT and mortality. Ultimately, the 28-day mortality rate in the PICU was 3.5%. Severe hypothermia (HR 1.89, 95% CI 1.35-2.63) and severe hyperthermia (HR 1.97, 95% CI 1.28-3.05) were identified as independent risk factors for 28-day mortality. Curve fitting analysis indicated a U-shaped correlation between BT and 28-day mortality (inflection point = 37.2 °C). Therefore, we conclude that the severity of temperature abnormalities at admission, whether hypothermia or hyperthermia, is directly associated with an increased risk of mortality in pediatric patients.