Hemodynamic and biochemical changes in therapeutic hypothermia treatment applied after cardiac arrest

Therapeutic hypothermia has been introduced as a critical intervention in patients with circulatory return after cardiac arrest. The main goal of this treatment modality is to preserve patients' neurological function without deficits and improve survival rates and quality of life. Our aim in this study was to further clarify the biochemical outcomes (changes) after therapeutic hypothermia, contributing to the improvement of treatment strategies and clinical outcomes. This study retrospectively included 174 patients aged 18 to 85 years who were exposed to therapeutic hypothermia for 24 hours or longer. Gender, age, diagnosis, day of discharge, neurologic sequelae, day of death if mortality was present, and whether vasopressor drugs were used during treatment were recorded in the intensive care unit. Biochemical parameters (glucose, urea, creatinine, alanine aminotransferase [ALT], aspartate aminotransferase [AST], albumin, calcium, sodium, potassium, pH, SPO2, C-reactive protein, Hb, neutrophils, lymphocytes, neutrophil-lymphocyte ratio, platelet-lymphocyte ratio) and Glasgow Coma Scale (GCS) values before (T1) and after 24 hours (T2) treatment were recorded. T1 GCS value measured in the intensive care unit was compared with the T2 GCS values, a significant difference (P < .05) was found between T1 and T2. Statistically significant decreases (P < .05) were observed in T2 (glucose, ALT, AST, albumin, calcium, potassium, and troponin) levels. In contrast, T2 (creatinine, urea, and sodium) levels increased (P < .05). In conclusion, in our study, statistically significant decreases were observed in glucose, ALT, AST, albumin, calcium, potassium, and troponin levels in patients treated with hypothermia. Increases in neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio suggest potential suppression of the immune response, which may increase susceptibility to infection. In contrast, creatinine, urea and sodium levels increased. In addition, pH values tended to increase towards normal limits. Large-scale and long-term studies are needed to better understand the effects of theropathic hypothermia on biochemical processes and clinical outcomes.