Estimation Formulas for Ionized Magnesium in Critically Ill Children

Researchers from the National Center for Child Health and Development in Japan have developed predictive formulas for estimating ionized magnesium levels in critically ill children. The team used a prospective study of pediatric patients under 18 years of age who were admitted to a pediatric intensive care unit in a tertiary children's hospital. The study aimed to develop equations for estimating ionized magnesium levels based on molecules involved in acid-base regulation. The research resulted in three predictive equations that were tested on additional samples and demonstrated minimal error between measured and estimated values.

Key Takeaways:

• The study was conducted prospectively with pediatric patients under 18 years of age admitted to the pediatric intensive care unit in a tertiary children's hospital in Japan between July and August 2024.
• The researchers measured serum ionized magnesium levels using the Stat Profile Prime analyzer from Nova Biomedical, and concurrent blood samples were collected for ion analysis following the Stewart approach.
• Multiple regression analysis was utilized to develop an equation for estimating ionized magnesium levels, and the accuracy of the developed equations was further assessed using Bland-Altman analysis and weighted k coefficients.
• A total of 200 samples were analyzed, and Spearman's rank correlation coefficient between ionized magnesium and total magnesium concentrations was 0.915, indicating a strong and statistically significant association.
• Three predictive equations were developed using multivariate analysis, and these models were tested on another 86 additional samples, demonstrating minimal error between measured and estimated values.
• The study successfully developed an ionized magnesium estimation model using routinely measured clinical parameters.
• The research has potential implications for improving the assessment of magnesium homeostasis in critically ill children.

Statistics:

• 200 samples were analyzed in the study.
• Spearman's rank correlation coefficient between ionized magnesium and total magnesium concentrations was 0.915.
• Bland-Altman analysis demonstrated minimal error between measured and estimated values.
• Weighted k coefficients indicated high concordance between measured and estimated values.
• The study was conducted in a pediatric intensive care unit in a tertiary children's hospital in Japan between July and August 2024.

Sources:

• Clinical Biochemistry. (2025). Estimation formulas for ionized magnesium in critically ill children. 110962.
• National Center for Child Health and Development. (2025). Findings in Chemicals and Chemistry (Estimation formulas for ionized magnesium in critically ill children). Pediatrics Week, 420.