EXTERNAL QUALITY ASSESSMENT


The use of POC analysers has grown significantly over the past 25 years, with the proportion rising from just 7% of analysers in 2001, to 43% in 2010, reaching 95% in 2023


do not allow for between instrument comparisons, due to matrix affects and the pO2


StatPearls Publishing; 2024 https://www. ncbi.nlm.nih.gov/books/NBK536919


binding properties of the


samples. The tonometered bovine haemolysate samples distributed on the annual Weqas pO2


accuracy study have


identical oxygen saturation characteristics to fresh whole blood. This provides commutable material that allows for instrument-to-instrument comparison for assessment of accuracy of pO2


.


Results from each annual distribution are reviewed and distributed to participants for information. The latest study, distributed in November 2024, confirms that pO2


methods in current clinical


use are accurate, even at very low pO2 concentrations.


References 1 Castro D, Patil SM, Zubair M,


Keenaghan M. Arterial Blood Gas. PPi


2 Cowley NJ, Owen A, Bion JF. Interpreting arterial blood gas results. BMJ. 2013;346:f16. doi:10.1136/bmj.f16


3 Severinghaus JW, Astrup PB. History of blood gas analysis. IV. Leland Clark’s oxygen electrode. J Clin Monit. 1986;2(2):125-139. doi:10.1007/ BF01637680


4 Werner J, Belz M, Klein K-F, Sun T, Grattan KTV. Fiber optic sensor designs and luminescence-based methods for the detection of oxygen and pH measurement. Measurement. 2021;178:109323. doi:10.1016/j.measurement.2021.109323


5 Thomas MA. An evaluation of the performance of blood gas analysis in the UK using tonometered haemolysate material. Clin Chim Acta. 2001 May;307(1-2):125–33. doi:10.1016/s0009- 8981(01)00443-0


Ceri Parfitt, R&D Clinical Scientist – Weqas Ceri Parfitt has recently joined the team at Weqas as a Clinical Scientist Specialist in EQA. With over 12 years’ experience in laboratory medicine, Ceri is responsible for overseeing research projects within Weqas, developing new EQA programmes and assisting with quality improvement initiatives.


Annette Thomas, Director – Weqas Annette Thomas is a Consultant Clinical Biochemist at Cardiff and Vale University Health Board with over 40 years’ experience in laboratory medicine, over 20 years of which has been as Director of Weqas, a well-respected International EQA provider and Reference Measurement Laboratory. Annette is also the National Clinical Lead for Point-of-Care Testing in Wales, a seconded position to NHS Wales Performance and Improvement, responsible for delivering the strategic plan for POCT.


Weqas operates as an independent organisation, hosted by Cardiff and Vale University Local Health Board, with over 50 years’ experience in delivering global Quality Assessment Programmes in laboratory medicine.


+44 (0) 2920 314750 contact@weqas.com www.weqas.com


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