A retrospective study of clinical profile and outcomes of critically ill patients with heat-related illness

BACKGROUND AND AIMS: Heat-related illness (HRI) due to high ambient temperatures is a common feature during the Indian summer. HRI often results in Intensive Care Unit (ICU) admissions and are associated with significant morbidity and mortality. However, published report on the effects of HRI among the Indian population is lacking. This study was undertaken to identify the profile of patients admitted to ICU with clinical features of HRI and study their clinical outcomes. METHODS: This was a retrospective case series of patients admitted with features of HRI during the summer of 2012 in our multidisciplinary ICU. Data on demographics, co-morbid illness, admission severity of illness (Acute Physiology and Chronic Health Evaluation II [APACHE II]), organ failure scores (Sequential Organ Failure Assessment [SOFA]) and neuroimaging studies were collected. Outcome data studied included mortality, ICU length of stay (LOS), ventilator days and hospital LOS. Statistical analysis was performed using Student's t-test, Chi-square test and multivariate analysis. RESULTS: Twenty-six patients met the diagnostic criteria for HRI. Fifteen were males. The mean age was 53.12 ± 18.6 years. Mean APACHE II score was 19.6 ± 7.7 and mean SOFA score was 7.5 ± 2.6. The common presenting symptoms were fever with neurological impairment (100%) and gastrointestinal symptoms (30%). Major organ systems involvement include neurological (100%), renal (57%), hepatic (34%) and coagulation abnormalities (26%). Most common metabolic abnormality noted was hyponatraemia (73%). Magnetic resonance imaging findings suggestive of heat stroke were seen in 5 of 26 patients. Mortality rate was 34%. 8 of 17 survivors had residual neurological impairment. CONCLUSION: HRI carries a high mortality and significant neurological morbidity.