Usefulness of P(50,std) for the Diagnostic Work-up of Patients with Erythrocytosis.
10.15263/jlmqa.2018.40.1.46
- Author:
Sang Yong SHIN
1
Author Information
1. Department of Laboratory Medicine, Seoul Metropolitan Dongbu Hospital, Seoul, Korea. hypocra@naver.com
- Publication Type:Brief Communication
- Keywords:
Hill's equation;
P₅₀;
Polycythemia
- MeSH:
2,3-Diphosphoglycerate;
Blood Gas Analysis;
Chemistry, Clinical;
Humans;
Methods;
Oxygen;
Polycythemia*;
Reference Values
- From:Journal of Laboratory Medicine and Quality Assurance
2018;40(1):46-49
- CountryRepublic of Korea
- Language:English
-
Abstract:
High oxygen-affinity hemoglobin (Hb) variants and a 2,3-diphosphoglycerate (2,3-DPG) deficiency could cause congenital (familial) erythrocytosis. High oxygen-affinity Hb variants and a 2,3-DPG deficiency might result in low tissue oxygen tension left-shifted oxygen dissociation curves and reduction in the standard P₅₀ value (P(50,std), oxygen tension at which haemoglobin is 50% saturated). Hence, the P(50,std) value is considered while formulating diagnostic strategies for erythrocytosis. In this study, we established a reference range for P(50,std) using an International Federation of Clinical Chemistry and Laboratory Medicine-approved equation (Hill's equation) for individual single venous/arterial blood samples. Blood gas analysis results of 243 samples with oxygen saturation ranging from 40%–90% (Hb < 16 mg/dL) were selected. The reference range of P(50,std) was in the 2.5th–97.5th percentile, and was 25.9–27.3 mm Hg. Hill's equation is a simple approved method for evaluating the P(50,std) values. Only a single sample of venous or arterial blood and a blood gas analyser are required to obtain the P(50,std). Our study provides a useful tool for the diagnostic work-up of patients with erythrocytosis.
