Calcium and albumin relationship in esrd

calcium and albumin relationship in esrd

calcium, chronic renal failure, ionized calcium, secondary .. The formula used in our laboratory for albumin correction differs slightly from the. Albumin-corrected calcium $ mg/dl and serum phosphorus. $ mg/dl were on dialysis, although such correction has been shown to be inaccurate in the. Calcium and phosphorus levels predict the risk for mortality among Serum albumin level affected the relationship between calcium and.

Blood for analysis of total and ionized calcium was drawn simultaneously.

calcium and albumin relationship in esrd

As ionized calcium is pH dependent, samples were analysed at the actual pH of the individual patient. For both methods, a similar number of patients were characterized as normocalcaemic.

According to present guidelines, the difference in calcium classification of patients might have clinical implications for the prescription of vitamin D, and on the choice of phosphate binders. SHPT is a result of hypocalcaemia, hyperphosphataemia, and reduced levels of 1,25 dihydroxyvitamin D3 [ 23 ], and is not only associated with renal bone disease but also with excess cardiovascular morbidity and mortality in these patients [ 145 ].

calcium and albumin relationship in esrd

Clinical guidelines for the treatment of disturbances in mineral and bone metabolism in patients with chronic kidney disease have recently been published [ 6 ]. The main factor for regulation of parathyroid hormone PTH secretion is the extra cellular ionized calcium concentration [ 23 ].

calcium and albumin relationship in esrd

In clinical guidelines, the target level for serum calcium is given as albumin-corrected total calcium concentration and no target level is given for the concentration of ionized calcium [ 6 ].

A variety of formulae have been proposed to permit calculation of the albumin-corrected total calcium or ionized calcium from the total calcium and protein concentration, but no data support the use of such algorithms [ 78 ].

calcium and albumin relationship in esrd

The sample collection and handling are crucial for an accurate measurement of ionized calcium [ 79 ]. We have evaluated the use of ionized calcium as opposed to albumin-corrected total calcium in an unselected group of patients in chronic haemodialysis. We hypothesized that the calcium classification of patients would be different in individual patients depending on the use of ionized- or albumin-corrected calcium levels. Subjects and methods We investigated all patients undergoing chronic haemodialysis in our department, 23 men and 11 women, median age range The median duration range in haemodialysis was All patients were dialyzed three times a week, 4—5 h per treatment, using a dialysate calcium concentration of 1.

All blood samples were collected midweek prior to next dialysis, and after the patient had been seated for at least 10 min. We hypothesized that our new formula would outperform the conventional formula.

Subjects and methods This experiment was divided into two parts following suggested guidelines for the development of clinical prediction rules [ 19 ]. The first was the derivation of a new formula for corrected serum calcium and second was the validation of the new formula in an independent data set. Patients and sample analysis Blood samples were collected from chronic stable HD outpatients at three tertiary care hospitals.

The validation set comprised patients from St.

Pitfalls of Measuring Total Blood Calcium in Patients with CKD

Samples were collected pre-dialysis on days of routine monthly biochemical testing. Arterialized venous blood was collected without a tourniquet from the patient's fistula or graft. If the patient had a tunnelled heparin-primed catheter, an initial sample of blood equal to or greater than the volume of the catheter was discarded to avoid contamination. All blood was collected in lithium heparin tubes.

The bromcresol purple BCP dye-binding assay was performed on fresh plasma for albumin measurements. Both total calcium and albumin were measured using the LX20 Beckman Coulter analyser.

Pitfalls of Measuring Total Blood Calcium in Patients with CKD

As physicians, we are more interested in the degree to which a patient deviates from the norm rather than whether a measure correctly dichotomizes a patient as being normal or abnormal. Thus, to assess the agreement between the gold standard and the various formulae we followed the methodology of Clase et al. ICCs were compared following methodology described by Donner et al.

We also present data on the number of patients who were misclassified for each of the formulae tested. All analyses were performed using SPSS