Nomogram for Estimating Diffusible Serum Calcium

Hanna, Ed A.; Nicholas, Henry O.; Chamberlin, James Allen

doi:10.1093/clinchem/10.3.235

Cited by 10 publications

(2 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, the exponent 3 / 4 or 0.75· is one of the most frequent exponents found in allometric equations to predict numerous biological phenomena [ 25 ]. Albumin [ 13 , 15 , 16 , 18 , 19 ] and ProtTot [ 10 , 11 , 12 , 13 , 14 , 17 ] are found in several Ca 2s+ -predicting equations. However, in this study, many equations containing them were discarded due to problems of multicollinearity and independence.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

New Predictive Equations for Serum Ionized Calcium in Hospitalized Patients

Antonio

2015

Med Princ Pract

View full text Add to dashboard Cite

Objective: To study a new and easy way to calculate equations to predict ionized calcium (Ca²⁺) for adult hospitalized patients with the usual laboratory and clinical parameters. Subjects and Methods: This retrospective observational study was conducted in a third-level university hospital. An initial learning cohort (cohort L: 269 patients) was selected to derive the new equations. These equations were tested in a validation of another cohort (cohort V: 146 patients). Patients selected were hospitalized adults who had simultaneous determinations of Ca²⁺ and serum total calcium (CaTot). They were classified using their estimated glomerular filtration rate (GFRe) into normal function, moderate and severe kidney dysfunction. Demographic and biochemical parameters, in addition to comorbidities, were collected from hospital databases. Nine published equations to predict Ca²⁺ and 2 widely used equations to predict corrected CaTot were also selected to be compared to newer equations for accuracy in detecting serum calcium alterations. New equations were derived by a multiple linear-regression analysis from patients in cohort L. Results: Three equations were derived containing the CaTot square root as the main independent variable. Equation 1: Ca²⁺ = 0.815 × CaTot^0.5. Equation 2: Ca²⁺ = 0.826 × CaTot^0.5 - 0.023 × renal function. Equation 3: Ca²⁺ = 0.813 × CaTot^0.5 - 0.006 × albumin^0.75 + 0.079. These equations performed better than published equations to predict Ca²⁺ when their error measures were analyzed in cohort V, even in special populations such as critically ill and very old patients. Conclusions: Three new equations predicting Ca²⁺ were derived requiring easily available clinical and laboratory parameters. They could be valuable in predicting hypocalcemia but are of limited use in hypercalcemia.

show abstract

Section: Discussionmentioning

confidence: 99%

“…Widely used equations to calculate corrected CaTot were also selected to compare the accuracy in detecting calcium alterations. Ten equations were found that were used as comparators [ 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 ]. They are shown in table 1 .…”

Section: Methodsmentioning

confidence: 99%