Hematometabolic Fragility and Mortality in Delirium: A Prospective Clinical Study

INTRODUCTION: Delirium is a neuropsychiatric syndrome that significantly increases mortality and morbidity in critically ill patients. The aim of this prospective study is to identify parameters contributing to the etiology of delirium and to investigate biochemical and hematological factors that predict mortality risk in patients who develop delirium.
METHODS: This study, conducted between October 2022 and May 2023 at the Internal Medicine Intensive Care Unit of the Faculty of Medicine at Yüzüncü Yıl University, included 65 patients diagnosed with delirium and 69 patients forming the control group. The delirium diagnosis was made using the CAM-ICU (Confusion Assessment Method for the ICU). Intergroup parameter differences were determined using the Mann-Whitney U test, while independent predictors of survival were evaluated using a multivariate logistic regression model.
RESULTS: Calcium, magnesium, and glucose levels were low, while sodium levels were high in patients who developed delirium. No significant differences were observed in terms of age and gender distribution. According to logistic regression analysis, the independent predictors of mortality in the delirium group were hypocalcemia (OR=0.051; p=0.004) and elevated RDW-SD (OR=1.357; p=0.004). When the optimal threshold value of 53.0 determined by ROC analysis for RDW-SD was used, 100% mortality was detected in delirium patients with RDW-SD>53.0 and calcium<8.0.
DISCUSSION AND CONCLUSION: Based on these prospective data, RDW-SD and hypocalcemia were found to be strong, independent, and synergistic predictors of mortality in patients who developed delirium. Comprehensive evaluation of biochemical and hematological parameters may provide a new clinical perspective for early identification and risk prediction in critically ill patients who develop delirium.

Keywords: Delirium, RDW-SD, Hypocalcemia, Mortality, Critical illness, Hematometabolic fragility.