Point-of-Care versus Central Laboratory Testing: Accuracy, Reliability, and Clinical Utility for Hematologic, Electrolyte, and Metabolic Parameters

Abstract

Although Point-of-care testing (POCT) significantly expedites turnaround time in critical care, its analytical interchangeability with central laboratory testing (CLT) remains contested. This review evaluates the accuracy, reliability, and clinical utility of POCT compared to CLT for hematologic (haemoglobin, haematocrit), electrolyte (sodium, potassium), and metabolic (lactate) parameters.Observational evidence published from 2015 to 2025 was synthesized following a comprehensive search of major biomedical databases, including PubMed, Scopus, Embase, Web of Science, The Cochrane Library, CINAHL, LILACS, and Google Scholar. The comparative validity of blood gas analysers against laboratory auto-analysers was evaluated, with specific attention paid to high-acuity settings such as emergency departments, intensive care units, and perioperative environments.POCT demonstrated superior turnaround times compared to central laboratories. Analytically, electrolytes generally exhibited acceptable concordance, despite minor discrepancies arising from methodological differences. Conversely, haemoglobin and haematocrit frequently lacked interchangeability; POCT often overestimated haemoglobin and underestimated haematocrit, particularly during massive transfusions or conductivity shifts. Furthermore, lactate precision diminished at higher concentrations, increasing the risk of clinical misclassification.While POCT facilitates rapid therapeutic intervention, it is not universally interchangeable with CLT. Electrolytes are generally reliable for routine management; however, haemoglobin, haematocrit, and elevated lactate measurements require laboratory confirmation to prevent therapeutic errors. Consequently, POCT should serve as a complement to, rather than a replacement for, central analysis, with consistent analyser use recommended for serial monitoring.