[Influence of hypocalcemia on the prognosis of septic patients].

OBJECTIVE: To investigate the effect of serum calcium level on the prognosis of patients with sepsis.

METHODS: Clinical data of 119 patients with sepsis admitted to intensive care medicine (ICU) of the First Affiliated Hospital of the University of Science and Technology of China from January 2017 to October 2018 were retrospectively analyzed. Gender, age, and C-reactive protein (CRP), procalcitonin (PCT), serum calcium levels, acute physiology and chronic health evaluation II (APACHE II), sequential organ failure score (SOFA) within 24 hours of diagnosis, and 28-day mortality were collected. The patients were divided into the normal serum calcium group (serum calcium 2.00-2.67 mmol/L) and the hypocalcemia group (serum calcium < 2.00 mmol/L) according to their serum calcium level. The patients were divided into survival group and death group according to 28-day prognosis. Pearson correlation test was used to analyze the correlation between serum calcium level and clinical indicators. Receiver operator characteristic (ROC) curve was used to analyze the predictive value of serum calcium level on prognosis.

RESULTS: A total of 119 patients with sepsis were included, including 50 patients with normal serum calcium, with serum calcium level of (2.14±0.10) mmol/L; and 69 patients of hypocalcemia, and the incidence of hypocalcemia was 57.98%, with serum calcium level of (1.81±0.14) mmol/L. In the hypocalcemia group, except that the APACHE II score was significantly higher than that of the normal serum calcium group (25.59±5.52 vs. 22.28±4.89, P < 0.01), there was no significant difference in gender, age, CRP, PCT and SOFA score between the two groups. The 28-day mortality rate of the hypocalcemia group was significantly higher than that of the normal serum calcium group [78.26% (54/69) vs. 48.00% (24/50), χ2 = 10.45, P < 0.01]. The level of serum calcium in the death group was significantly lower than that in the survival group (mmol/L: 1.90±0.20 vs. 2.04±0.19), while the APACHE II score was significantly higher than the survival group (25.78±5.25 vs. 21.20±4.68), with statistically significant differences (both P < 0.01). There was a negative correlation between serum calcium level and PCT, APACHE II scores in patients with sepsis (r1 = -2.10, P1 = 0.04; r2 = -3.91, P2 < 0.01), but no correlation with CRP and SOFA score (r1 = 0.75, P1 = 0.46; r2 = -1.21, P2 = 0.23). The ROC curve analysis showed that the area under the ROC curve (AUC) for predicting the prognosis of sepsis patients with serum calcium level was 0.70 [95% confidence interval (95%CI) = 0.602-0.798], and the best cut-off value was 1.92 mmol/L, with the sensitivity was 52.56%, and the specificity was 82.93%.

CONCLUSIONS: The prognosis of sepsis patients with hypocalcemia is poor. Serum calcium level can be used as a predictor of prognosis in patients with sepsis.