Limitations of calculated ionised calcium & adjusted calcium in critically ill patients: Time to consider measured ionised calcium
The Malaysian Journal of Pathology
;
: 385-394, 2020.
Article
in English
| WPRIM
| ID: wpr-876031
ABSTRACT
@#Introduction:
Ionised calcium is a good prognostic and diagnostic tool as opposed to total calcium in critical patients but is not available in most central laboratories and non-intensive care units. To date, four equations to calculate ionised calcium in critical patients have been published.Objectives:
(1) Evaluate the four published equations’ performance in estimating ionised calcium; (2) Determine the accuracy of calculated ionised and adjusted total calcium in classifying patients according to calcium states; and (3) Identify factors associated with hypocalcaemia in the critically ill population. Materials andmethods:
This is a cross-sectional study involving 281 critically ill patients aged 18-80 years of both genders in a Malaysian tertiary intensive care unit. Performance of the four equations was analysed using Bland-Altman difference plot and Passing Bablok regression analysis. Crosstabulation was conducted to assess classification accuracy. Mann-Whitney U or Pearson Chi-Square tests were performed to identify variables associated with hypocalcaemia.Results:
Calculated ionised calcium using all four equations significantly overestimated ionised calcium. Calculated ionised and adjusted total calcium had poor accuracies in classifying hypocalcaemic patients. pH was significantly higher in hypocalcaemics.Conclusion:
Calculated ionised and adjusted total calcium significantly overestimate ionised calcium in the critically ill. In this specific population, calcium status should only be confirmed with ionised calcium measured by direct ion-selective electrode (ISE).
Full text:
Available
Index:
WPRIM (Western Pacific)
Type of study:
Observational study
/
Prognostic study
/
Risk factors
Language:
English
Journal:
The Malaysian Journal of Pathology
Year:
2020
Type:
Article
Similar
MEDLINE
...
LILACS
LIS