Objectives: To determine the pediatric reference ranges for iron, cortisol, CK, CKMB, and troponin I.
Methods: Iron and CK were measured on the Vitros analyzer (Johnson and Johnson) while CKMB, troponin I, and cortisol were measured on the Immuno I (Bayer Corp.). Pediatric reference ranges were determined on hospitalized patients using the Hoffmann approach.
Results: Pediatric reference ranges were obtained for iron (AM and PM) and cortisol (AM and PM). Ranges were also obtained for CKMB, troponin I, and total CK.
Conclusion: This work represents an expansion in our knowledge base on pediatric reference ranges. For iron, the 97.5th percentiles were significantly higher in the PM than in the AM. The diurnal fluctuation in 97.5th percentiles for cortisol was only 10-20%. Pediatric reference ranges for CKMB were not previously available and are important especially in the first year of life. The elevated Troponin I is found in the first year of life also represents new data.