Pediatric reference ranges for creatine kinase, CKMB, troponin I, iron, and cortisol

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 John son) while CKMB, troponin I, and cortisol were measured on the Immune I (Ba yer Corp.). Pediatric reference ranges were determined on hospitalized pati ents 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 t otal CK. Conclusion: This work represents an expansion in our knowledge base on pedi atric reference ranges. For iron, the 97.5th percentiles were significantly higher in the PM than in the AM. The diurnal fluctuation in 97.5th percent iles far 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 repr esents new data. Copyright (C) 1999 The Canadian Society of Clinical Chemis ts.