Correlation of Serum and Ionized Calcium in Patients with Calcium Nephrolithiasis

Introduction: Pathogenesis of kidney stones includes many factors, whereas uroliths, as a generic term for kidney stones, are of a different composition. In pathogenesis of calcium urolithiasis hypercalcemia/hypercalciuria takes a significant place. Hypercalcemia exists when the serum calcium is of increased values, along with measurement and calculation of physiologically active calcium, when there are differences in the Ph of the blood or albumin. Goal: the goal of this research is to determine the correlation of values of the serum (CaS) and ionized calcium (Ca++) in patients with the calcium nephrolithiasis, whom have been established not to have hyperparathyroidism and malign diseases. Material and methods: the research was prospective and implemented at the Clinical Center in Banja Luka, at the Urology Clinic, in the period between 1st April 2012 – 1st January 2013 and it included 120 patients with the calcium lithiasis of the upper part of the urinary tract, divided into three age categories. Diagnosis of the calcium lithiasis of the upper part of the urinary tract was established on the basis of the ultrasonography of the urinary tract as well as native urinary tract/intravenous urography and chemical analysis of the stone in patients with spontaneous stone emission or after some of the methods for active removal of the stone. Chemical laboratory analysis of the serum and ionized calcium was done for all the patients, with 3ml of blood being taken for establishing the aforementioned parameters (1-2 ml of the serum) in vacuumed test tubes or glass tubes of capillary blood. Increased parathormone values (PHT) and history of malignity were excluding factors. Results: out of the 120 patients observed, Cs(S) had the value in the reference interval with most of them, that is, in 110 patients (91.7%). Those, whose value was out of the interval, are of an older age (all above 40). Average value of this parameter amounted to 2.3017, with an average difference (the standard deviation) of 0.11391. Observing the value of Ca++, the value within the reference interval was found in 106 patients (88.3%). Out of the remaining 14 patients, only two simultaneously had the value of Ca(S) out of the permitted interval. The majority of this group consisted of older patients (a half of those whose values were outside the interval was over 60). Average value of Ca++ amounted to 1.22 mmol/L with an average difference of 0.06454. In the 2 aforementioned patients, who simultaneously had increased values of CaS and Ca++, the blood Ph was within the referential value limits, which suggests that, in line with the hyporcalcemia definition, only 2 patients with nephrolithiasis, in the total sample of 120 patients of our research sample, could have had a true hypercalcemia. Conclusion: the biggest number of patients with the calcium urolithiasis, who do not have hyperparathyroidism and history of malign diseases, do not have a real hypercalcemia.