The Clinical Significance Of Ionized Hypocalcemia In The Patients With Sepsis

ObjectivePrevious studies have shown that ionized hypocalcemia is common in the patientswith sepsis. The purpose of this study was to investigate possible causes ofhypocalcemia in critically ill patients with sepsis and evaluate its relationship with theseverity of disease and mortality in the intensive care unit.MethodsAdjusted serum ionized calcium and known factors influencing or reflectingcalcium homeostasis such as PTH and PCT were measured in 60 consecutive patientswith sepsis admitted to the ICU of Tianjin medical university general hospital during a12-month period. No patient had pancreatitis or other medical disorders typicallyknown to cause hypocalcemia. Severity of disease was assessed by the AcutePhysiology and Chronic Health Evaluation (APACHEâ…¡) during the first 24 h in theICU. It was calculated by mean of deviation of 12 physiological variables fromnormality plus correction for age and different chronic illnesses. And in-hospitalmortality was recorded. Among the septic patients there were 48 men and 18 womenand the mean age was 55±7 yeas old (SD). In a following prospective study,survivors(n=25) and non- survivors(n=35) were investigated with the discrepancyamong ionized calcium, PTH, PCT and APACHEâ…¡score. On the other hand, the abovedata should be analyzed between the patients with normal- and hypo-calcemia.Statistical analyses were performed with SPSS 13.0 for windows. Independent t testwere used to evaluate relationships between normally distributed variables andMann-Whitney U-test for non-normally distributed variables. Sex and the serum level of PCT differences are analyzed by chi-square test. Multiple stepwise regression isused to find the relationship between serum Ca²⁺ and its related indexes. Two-tailedsignificant levels were used. Results with P-values less than 0.05, were considered toindicate statistical significant.ResultsIn the present study, the prevalence of ionized hypocalcemia in septic patients was80%, and associated with the severity of disease. Serum calcium levels weresignificantly decreased in non-survivors compared with survivors(mean Ca²⁺0.96±0.08 vs. 1.07±0.06mmol/L, p＜0.05). Serum PTH levels were elevated in 50%of the septic patients and was not related to serum calcium level(p＞0.05), but showeda significant relationship to the APACHEâ…¡score (p＜0.05). Although serum PCTlevels were more pronounced with increasing severity of infection (p＜0.05), changesof serum ionized calcium concentration did not correlate with changes of serum PCTconcentration. (p＞0.05)ConclusionIonized hypocalcemia was most pronounced in sepsis, and associated with theseverity of disease. Serum PTH level elevated in the patients with sepsis. IncreasedPTH levels were associated with a poor outcome, but not related to serum calcium.PCT have been shown to be the most reliable diagnosis and prognostic markers ofsepsis, although as the calcitonin precursors, it has little influence to calciumhomeostasis.