Relationship of on Admission Hypocalcaemia and Illness Severity as Measured by APACHE-II and SOFA Score in Intensive Care Patients'.

Introduction: Hypocalcaemia is very much prevalent in critically ill patients yet very less is known about its association with severity of illness. Acute Physiology and Chronic Health Evaluation (APACHE) and Sequential Organ Failure Assessment (SOFA) are two commonly used and validated scoring tool used to assess the severity of illness in critically ill patients.

Aim: To analyze the relation of on admission hypocalcaemia with severity of illness as measured by APACHE-II and SOFA scores.

Materials And Methods: After institute approval, 111 patients admitted during May to June 2016 were evaluated. Age, sex, on admission, ionized calcium (iCa0) levels, first day APACHE-II and SOFA scores were collected. Data were then divided in different classes based on iCa0 levels (i.e., normocalcaemic, mild, moderate and severe hypocalcaemic), APACHE-II and SOFA scores and their relationship was assessed using INSTAT software (GraphPad Software, Inc, La Zolla, CA, USA) with appropriate statistical tests.

Results: Seventy eight (70.27%) patients were having hypocalcaemia on admission (<1.15 mmol/L). The mean APACHE-II score of normocalcaemic patients were significantly (p<0.05) lower as compared to moderate and severe hypocalcaemic patients (15.57±6.85 versus 21.72±6.37 and 15.57±6.85 versus 22.34±7.53, respectively). The mean iCa0 level in patients with APACHE-II > 20 were significantly lower than patients with APACHE-II < 9 (0.88±0.26 versus 1.09±0.24, p <0.05) but the mean iCa0 level in patients with SOFA > 9 were not significantly lower than patients with SOFA < 4 (0.99±0.41 versus 1.04±0.23, p > 0.05). The relative risk of on admission hypocalcaemia across increasing illness severity was also not statistically significant. Both relative risk of mortality and length of ICU stay were higher in on admission moderate hypocalcaemic patients as compared to normocalcaemic but the difference was not statistically significant.

Conclusion: On admission, hypocalcaemia has inconsistent correlation with increasing illness severity in adult intensive care patients. iCa0 of 0.81-0.90 mmol/L appears to have maximum deleterious effect with regard to mortality and length of ICU stay.