Quality in post-analytical phase: indirect reference intervals for erythrocyte parameters of neonates

This study aims to gain an estimation of the reference intervals for erythrocyte parameters of neonates in the venous blood, in their first day of life, aiming to achieve quality assurance in post-analytical phase according to the requirement of the ISO standard 15189:2007: Medical laboratories-particular requirements for quality and competence.

The study was performed on a group of 845 subjects selected from the laboratory database. The blood test was performed with the Nihon Celltac F automatic hematology analyzer. In order to find the reference interval, the Hoffmann indirect method was used to process the study group.

The results give the reference intervals for red blood cell (RBC=3.45-5.26×10(6)/μL), hemoglobin (HGB=12.5-19.48g/dL), hematocrit (HCT=37.18-55.65%), mean cell volume (MCV=99.63-111.92fL), mean corpuscular hemoglobin (MCH=33.55-39.28pg) and mean corpuscular hemoglobin concentration (MCHC=32.33-36.23g/dL), along with the corresponding confidence intervals.

Neonates are a special category of population to which the application of the direct method for determining the reference intervals is difficult and raises ethical issues. Thus, the indirect method is a reasonable alternative. The reported approach is easy to apply and accessible to any laboratory.