Authors: Stephenson E, Hooper MH, Marik PE
DOI:https://doi.org/10.1016/j.chest.2018.08.232
Abstract
PURPOSE: The use of intravenous vitamin C for sepsis is increasing. Vitamin C interferes with point-of-care (POC) glucose monitoring devices that use the glucose-dehydrogenase method of testing (e.g. Accu-Chek, Roche, Indianapolis, IN). Spuriously elevated POC glucose levels have been reported in patients with burns after large doses of vitamin C (in excess of 50g/day). The purpose of this study was to assess the accuracy of the Accu-Chek Inform II POC device (A-POC) in patients receiving the 1.5 g IV q 6 hourly dosing strategy of vitamin C in sepsis.
METHODS: This is a retrospective, observational, study conducted in our MICU (IRB approved). We reviewed the electronic medical record (EPIC, Verona, WI) of patients with sepsis who were treated with intravenous Vitamin C (iVC) and had an A-POC glucose and central laboratory glucose (CL-glucose) measurement within 15 minutes of each other. We recorded whether the paired glucose values were taken before or immediately after the iVC. Patients were stratified by renal function into a non-oliguric group (including AKI and CRRT) and oliguric patients including those with ESRD. Patients were classified as oliguric if they had urine output of < 500cc on the day of vitamin C administration.
RESULTS: We obtained 104 paired glucose measurements in 72 patients. 13 patients had ESRD/oliguria. The mean CL-glucose was 166.2 ± 67.2 mg/dl. The mean difference of A-POC and CL-glucose was 6.1 ± 1.6 mg/dl in the non-oliguric group (86 paired samples) while it was 25.2 ± 20 mg/dl in the oliguric/ESRD group (18 paired samples). We further analyzed the results according to the proximity of testing to the administration of vitamin C. In the non-oliguric group the glucose difference was 2.3 ± 8.4 prior (within 1 hour of infusion start time) to iVC (n=18) and 7.2 ± 16.4 (n=68) after (within 30 minutes after infusion completion time) iVC dosing. In the oliguric/ESRD group the glucose difference was 13.3 ± 14.0 mg/dl before iVC (n=3) and 27.6 ± 20.5 after iVC dosing (n=15). The mean baseline vitamin C level was 28 ± 14 umol/l (n=17).
CONCLUSIONS: In the majority of patients receiving standard iVC dosing the difference between the A-POC glucose and the CL-glucose was not significant. In patients with severe renal disease the A-POC glucose was on average 25 mg/dl higher than the CL-glucose. This difference was most marked immediately after iVC dosing.
CLINICAL IMPLICATIONS: This data suggests that in patients with severe kidney failure and those with ESRD on HD, POC blood glucose measurement the Accu-Chek Inform II device should be confirmed using the central laboratory. The accuracy of blood glucose measurement is dependent upon the chemistry of the POC device and the vitamin C serum level.[/fusion_text][fusion_text columns="" column_min_width="" column_spacing="" rule_style="" rule_size="" rule_color="" hue="" saturation="" lightness="" alpha="" content_alignment_medium="" content_alignment_small="" content_alignment="" hide_on_mobile="small-visibility,medium-visibility,large-visibility" sticky_display="normal,sticky" class="" id="" margin_top="" margin_right="" margin_bottom="" margin_left="" fusion_font_family_text_font="" fusion_font_variant_text_font="" font_size="" line_height="" letter_spacing="" text_transform="" text_color="" animation_type="" animation_direction="left" animation_color="" animation_speed="0.3" animation_delay="0" animation_offset="" logics=""]Keywords: vitamin C, glucose, glucose measurements, sepsis
