# Evaluation of point-of-care hemoglobin testing vs. central laboratory measurements in neonates: a prospective study in neonatal intensive care unit

## TL;DR

This study compares point-of-care hemoglobin testing with lab results in neonates, finding good agreement for arterial-venous samples but discrepancies in capillary samples.

## Contribution

The study provides empirical evidence on the reliability of POC hemoglobin testing in neonates born after 28 weeks.

## Key findings

- POC testing showed no significant difference from lab results for arterial-venous samples.
- Capillary POC samples showed significantly higher hemoglobin levels than lab results.
- Bland-Altman analysis revealed a mean difference of 0.09 for arterial-venous and -0.41 for capillary samples.

## Abstract

Point-of-care (POC) testing for blood gas analysis is commonly used for neonates in the Neonatal Intensive Care Unit (NICU) to determine blood gases using small blood volumes. This helps reduce blood loss and speeds up treatment. However, many clinicians remain skeptical about the accuracy of POC hemoglobin results. Our study evaluated the agreement between POC testing and laboratory measurements of hemoglobin concentration in infants born at >28 weeks gestational age.

This prospective cohort study analyzed 187 paired blood samples from infants born after 28 weeks of gestation admitted to the NICU between July 2023 and December 2024. Hemoglobin levels from paired blood samples were measured using two different Methods: a POC gas analyzer and a laboratory analyzer. The laboratory analyzer (Sysmex XN-9100®) requires a minimum of 500 µL of blood, while the POC analyzer (ABL90 Flex Radiometer®) only needs 65 µL. A Bland-Altman plot was utilized for statistical analysis to assess the agreement between the two methods and to identify any systematic differences.

Of 197 eligible patients, 187 were enrolled in the study, with a mean gestational age of 36.6 weeks (± 3.2) at birth. There was no significant difference between the results from laboratory arterial-venous samples (16.14 g/dL) and POC testing (16.04 g/dL; p = 0.34). However, capillary samples from the POC testing showed significantly higher results (p = 0.01) than the laboratory results. The Bland-Altman plot revealed a mean difference of 0.09 for arterial-venous samples and −0.41 for capillary samples when comparing POC results with laboratory results.

Point-of-care testing for hemoglobin analysis using arterial-venous samples may be an alternative method for quantifying hemoglobin in neonates born at a gestational age >28 weeks. However, due to notable discrepancies between capillary POC results and laboratory results, it is essential to exercise caution when interpreting hemoglobin measurements obtained from capillary POC testing.