Association Between Disease Severity and Calcium Concentration in Critically Ill Patients Admitted to Intensive Care Unit.

BACKGROUND: Hypocalcemia is very common in critically ill patients admitted to ICU. However, its clinical importance and relation to patient's outcome during early days of ICU admission is questionable. Based on the mentioned problem, it seems that calcium assessment is highly important in these patients. The present study aimed at evaluating the relationship between different calcium concentrations (total/ionized/corrected) and disease severity in critically ill patients. METHODS: A total of 100 patients admitted to intensive care units of Imam Reza and Shohada hospitals during Feb 2014 and Apr 2016 were enrolled in this prospective trial. Concentrations of total, corrected, and ionized calcium and their relationship with APACHE score and disease severity were noted during the study. RESULTS: There was a strong and inverse correlation between disease severity and ionized calcium concentration (P < 0.001, r = -0.697). There was a medium and significant inverse correlation between disease severity and total calcium concentration (P < 0.001, r = -0.368). Weak and direct significant correlation was observed between disease severity and corrected calcium concentration (P 0.02, r = 0.232). CONCLUSIONS: A significant correlation was found between total and ionized calcium, but there was not any significant correlation between corrected and ionized calcium. Hypocalcemia is a predictor of disease severity and mortality. We recommend measuring ionized calcium concentration for patients admitted to ICU.