Effects of High-dose Intravenous Vitamin C on Point-of-Care Blood Glucose Level in Septic Patients: A Retrospective, Single-Center, Observational Case Series

Introduction: High-dose vitamin C (hdVC) is regarded as one of the essential adjunctive drugs for sepsis treatment. The present study aimed to deduce if hdVC could lead to erroneous testing results from the point-of-care glucose (POCG) measurement. Methods and materials: This retrospective, single-center, observational case series involved septic patients treated by hdVC and monitored their paired POCG and laboratory glucose (LG) level for statistical analysis. The Parkes Consensus Error Grid Analysis was used as clinical influence assessment for paired blood glucose values. Subgroup analyses were conducted to explore the affecting extent of POCG readings by different VC dosage and various renal function level respectively. Results: During the 3-year research period, 82 eligible septic patients who accepted at least three-day hdVC treatment were included in the current study. Compliance with ISO15197:2013 criteria was met in 30 (36.59%) paired values, which was far from the minimum criteria for accuracy. Subgroup analysis showed that worse renal function or higher VC dosage could lead to greater bias of POCG reading, but clinical risk would come forth scarcely while dealing with inaccurate POCG value. Conclusions: High-dose intravenous ascorbate acid infusion could interfere POCG measurement values and LG method is more recommended, although significant medical risk hardly appears when physicians alter clinical action based on unreliable POCG reading.