Performance of New Roche Cobas Pulse Glucose Meter Against Potential Interfering Substances and Hematocrit Variations

Background: Point-of-care (POC) glucometers are essential for rapid blood glucose monitoring but are subject to interference and hematocrit variations. This study evaluated the analytical performance of the new Cobas Pulse glucometer against the Accu-Chek Inform II meter in the presence of N-acetylcysteine (NAC, 0.32-2.5 mmol/L), ascorbic acid (0.28-2.84 mmol/L), D-galactose (5.5-27 mmol/L), hemolysis (0.5-5 g/L hemoglobin), icterus (200-1600 μmol/L bilirubin), lipemia (2.5-15 g/L Intralipid), and hematocrit variations (20-60%). Methods: Interference testing followed CLSI EP07 guidelines using three whole blood pools with low (2.0-2.7 mmol/L), medium (4.5-7.4 mmol/L), and high (16.3-23 mmol/L) glucose levels. Interferents were spiked into these whole blood pools. Duplicate glucose levels were measured by 2 Pulse meters and 2 Inform II meters. The results were then assessed using the international standards, e.g., ISO 15197:2017 criteria (±15% or ±0.83 mmol/L). Results: Accu-Chek Inform II showed severe positive interference from galactose (up to 446.3%, p < 0.001), ascorbic acid (up to 98.8%, p = 0.002), and NAC (up to 61.4%, p = 0.001), exceeding ISO limits. Cobas Pulse demonstrated minimal interference (maximum biases: -3.7% for galactose, -4.4% for ascorbic acid, 7.7% for NAC, all p > 0.05). Both meters showed similar hematocrit-dependent bias (positive at 20-30%, negative at 50-60%) and acceptable performance for hemolysis, icterus (≤800 μmol/L), and lipemia. Conclusions: Compared to the Accu-Chek Inform II, the Cobas Pulse demonstrated greater resilience to interferences. Cobas Pulse meets strict accuracy standards (±10% for hospital use) with low interference, which makes it suitable for care of critically ill patients. The Cobas Pulse is more dependable for POCT across various clinical situations, supporting its role in critical care.