Assessment of mortality-associated laboratory and hemodynamicparameters in internal medicine ICU patients: A retrospective cohort from 2021 to 2023

Objective: This study aimed to comprehensively evaluate the demographic, clinical, and laboratory characteristics of patients admitted to the Internal Medicine Intensive Care Unit of Pamukkale University Hospital between January 2021 and December 2023. The primary goal was to determine the mortality rate and identify prognostic factors affecting mortality. Additionally, comorbidities, causes of ICU admission, and hemodynamic parameters such as timing of mechanical ventilation were analyzed. Methods: This descriptive, cross-sectional, retrospective cohort study was conducted between November 20, 2021, and November 20, 2023. A total of 766 patients over 18 years of age were included. Data collected on admission included complete blood count (WBC, neutrophil count, hemoglobin, platelet count, mean platelet volume, neutrophil-to-lymphocyte ratio, red cell distribution width), biochemical parameters (glucose, creatinine, blood urea nitrogen, lactate dehydrogenase, C-reactive protein, albumin, NT-proBNP, lactate, thyroid stimulating hormone, cortisol, procalcitonin), APACHE II score, gender, age, and comorbidities (such as diabetes mellitus, hypertension, hematologic or oncologic malignancies, neurological, cardiac, or renal diseases), as well as the day of intubation. Results: Among the 766 patients included, 326 were female and 439 were male, with a mean age of 68±14 years. Of 765 patients with available outcome data, 517 (67.6%) died, while 248 (32.4%) were discharged alive. To identify prognostic factors associated with survival, logistic regression analysis was performed. Red cell distribution width (RDW), platelet count (PLT), blood urea nitrogen (BUN), sex, cortisol, and lactate levels were found to be statistically significant predictors of mortality (p < 0.05). Other variables including LDH, albumin, CRP, procalcitonin, and NT-proBNP were not found to be significantly associated with survival (p ≥ 0.05). Conclusion: In this study, clinical and laboratory parameters associated with mortality were evaluated in patients admitted to the internal medicine intensive care unit. The most significant predictors of mortality included higher APACHE II score, lactate, cortisol, NT-ProBNP, BUN, LDH, RDW, procalcitonin levels, as well as lower hemoglobin, albumin, and platelet levels. Additionally, the presence of hematological malignancies and solid tumors was identified as an important factor contributing to increased mortality. These findings suggest that early identification of high-risk patients may allow for closer monitoring and more aggressive treatment strategies, potentially improving survival. Further large-scale, prospective studies are needed to validate these results and strengthen their prognostic utility in critical care settings. Key words: intensive care unit, mortality, prognostic factors, red cell distribution width, platelet count, lactate, cortisol, blood urea nitrogen, logistic regression, internal medicine, APACHE II score, and mechanical ventilation