High-resolution pediatric reference intervals for 15 biochemical analytes described using fractional polynomials.

OBJECTIVES: Assessment of children's laboratory test results requires consideration of the extensive changes that occur during physiological development and result in pronounced sex- and age-specific dynamics in many biochemical analytes. Pediatric reference intervals have to account for these dynamics, but ethical and practical challenges limit the availability of appropriate pediatric reference intervals that cover children from birth to adulthood. We have therefore initiated the multi-center data-driven PEDREF project (Next-Generation Pediatric Reference Intervals) to create pediatric reference intervals using data from laboratory information systems. METHODS: We analyzed laboratory test results from 638,683 patients (217,883-982,548 samples per analyte, a median of 603,745 test results per analyte, and 10,298,067 test results in total) performed during patient care in 13 German centers. Test results from children with repeat measurements were discarded, and we estimated the distribution of physiological test results using a validated statistical approach (kosmic). RESULTS: We report continuous pediatric reference intervals and percentile charts for alanine transaminase, aspartate transaminase, lactate dehydrogenase, alkaline phosphatase, γ-glutamyl-transferase, total protein, albumin, creatinine, urea, sodium, potassium, calcium, chloride, anorganic phosphate, and magnesium. Reference intervals are provided as tables and fractional polynomial functions (i.e., mathematical equations) that can be integrated into laboratory information systems. Additionally, Z-scores and percentiles enable the normalization of test results by age and sex to facilitate their interpretation across age groups. CONCLUSIONS: The provided reference intervals and percentile charts enable precise assessment of laboratory test results in children from birth to adulthood. Our findings highlight the pronounced dynamics in many biochemical analytes in neonates, which require particular consideration in reference intervals to support clinical decision making most effectively.

Two site evaluation of the performance of a new generation point-of-care glucose meter for use in a neonatal intensive care unit.

BACKGROUND: Monitoring of blood glucose in neonatal intensive care unit (NICU) patients is important in maintaining normoglycaemia and reducing the risk of hypoglycaemia. Point-of-care testing (POCT) glucose meters provide short turnaround times but some have been reported to be affected by haematocrit interference and other biochemical or biological substances in their accuracy and performance. The aim of this study was to assess the performance of a new POCT glucose meter in a challenging preterm neonatal population. METHODS: The new Nova Biomedical StatStrip™ (Nova Biomedical) was tested on 159 heparinised whole blood samples from NICU patients obtained for blood gas analysis. Accuracy (bias) of the meter and analytical interferences were evaluated by comparing the results of the meter with the results of the blood gas analyser routinely used for glucose measurements in this NICU setting. RESULTS: The results of the StatStrip glucose meter correlated very well with the reference routine method across a wide glucose concentration range (13-389 mg/dL) and were not affected by the level of haematocrit, by sample pH or by medication. CONCLUSIONS: The StatStrip meter showed good clinical accuracy and performance for measuring and monitoring glucose levels in NICU patients, with special respect to preterm infants, and therefore can act as a perfect alternative to a blood gas analyser for measuring blood glucose in NICU patients.