title: The effects of intravenous vitamin C on point-of-care glucose monitoring.
abstract: Ascorbic acid (vitamin C) decreases systemic inflammation and lowers fluid requirements after thermal injury; therefore it has been adopted in many burn centers as an adjunct to resuscitation. However, recent concerns have been expressed over clinically significant hypoglycemic events caused by vitamin C interference with the point-of-care (POC) glucose measurements. This case series presents a direct comparison of POC and laboratory reference glucose values in the patients receiving vitamin C infusion. Vitamin C was administered at 66 mg/kg/hour in seven patients with burns >30% TBSA. The baseline characteristics and burn characteristics were recorded. POC glucose measurements were made with a commonly used hand-held device, and the laboratory values were obtained using standard spectrophotometric methods. POC and laboratory glucose values drawn within the same hour were compared. Hemoglobin, which is known to cause interference in POC testing, was also recorded. All the patients demonstrated falsely elevated POC glucose values during and/or immediately after the infusion period, with discrepancies ranging from 10 to 200 mg/dl. These findings were irregular, unpredictable and unrelated to hemoglobin levels. The findings suggest an idiosyncratic reaction that cannot be easily corrected at the bedside using mathematical equations. POC glucose monitoring should be avoided during and after vitamin C therapy.
authors.affiliation: From the *Department of Surgery, Texas Tech University Health Sciences Center, Lubbock; and †UMC Health System, Lubbock, Texas.
authors.forename: Zach
authors.initials: Z
authors.lastname: Sartor
authors.forename: Jenna
authors.initials: J
authors.lastname: Kesey
authors.forename: Sharmila
authors.initials: S
authors.lastname: Dissanaike
mesh_terms: D000328:Adult; D000368:Aged; D001205:Ascorbic Acid / Q000627:therapeutic use*; D001786:Blood Glucose / Q000378:metabolism*; D002056:Burns / Q000097:blood* / Q000628:therapy*; D015331:Cohort Studies; D005260:Female; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D008875:Middle Aged; D019095:Point-of-Care Systems; D015203:Reproducibility of Results; D014815:Vitamins / Q000627:therapeutic use*
chemical_list: D001786:Blood Glucose; D006454:Hemoglobins; D014815:Vitamins; D001205:Ascorbic Acid