POCT glucose meters should not be used to diagnose diabetes due to insufficient analytical precision (±15–20% error versus ±6% recommended for diagnosis) and susceptibility to user and environmental errors. They are suitable for self-monitoring and acute care management, but not for diagnostic purposes. Additionally, capillary whole blood (WB) glucose testing is unreliable in patients with poor perfusion, tissue edema, or hypoxemia, which can cause inaccuracies (e.g. pseudohypoglycemia) and lead to dosing errors. Given the potential limitations of POCT capillary WB glucose, use of venous or arterial samples is recommended for critically ill patients to ensure accurate glucose management.
Sources:
Diabetes Canada Clinical Practice Guidelines Expert Committee. Diabetes Canada 2018 Clinical Practice Guidelines for the Prevention and Management of Diabetes in Canada. Can J Diabetes. 2018; 42(Suppl 1):S1-S325.
Inoue S, et al. Accuracy of blood-glucose measurements using glucose meters and arterial blood gas analyzers in critically ill adult patients: systematic review. Crit Care. 2013;17(2):R48. PMID: 23506841.
Nichols JH. CLSI POCT17. Use of glucose meters for critically ill patients. Wayne, PA: Clinical and Laboratory Standards Institute. 2016.
Sacks DB, et al. Guidelines and recommendations for laboratory analysis in the diagnosis and management of diabetes mellitus. Diabetes Care. 2023;46(10):e151-e199. PMID: 37471273.