Reliability of point-of-care testing for glucose measurement in critically ill adults.
BACKGROUND
Glycemic control is increasingly being recognized as a priority in the treatment of critically ill patients. Titration and monitoring of insulin infusions involve frequent blood glucose measurement to achieve target glucose ranges and prevent adverse events related to hypoglycemia. Therefore, it is imperative that bedside glucose testing methods be safe and accurate.


OBJECTIVE
To determine the accuracy and clinical impact of three common methods of bedside point-of-care testing for glucose measurements in critically ill patients receiving insulin infusions.


METHODS
Prospective observational study.


METHODS
A 21-bed mixed medical/surgical intensive care unit of a tertiary care teaching hospital.


METHODS
Thirty consecutive critically ill patients who were vasopressor-dependent (n = 10), had significant peripheral edema (n = 10), or were admitted following major surgery (n = 10).


METHODS
Findings from three different methods of glucose measurement were compared with central laboratory measurements: (1) glucose meter analysis of capillary blood (fingerstick); (2) glucose meter analysis of arterial blood; and (3) blood gas/chemistry analysis of arterial blood. Patients were enrolled for a maximum of 3 days and had a maximum of nine sets of measurements determined during this time.


RESULTS
Clinical agreement with the central laboratory was significantly better with arterial blood analysis (69.9% and 76.5% for glucose meter and blood gas/chemistry analysis, respectively) than with capillary blood analysis (56.8%; p = .039 and .001, respectively). During hypoglycemia, clinical agreement was only 26.3% with capillary blood analysis and 55.6% and 64.9% for glucose meter and blood gas/chemistry analysis of arterial blood (p = .010 and <.001, respectively). Glucose meter analysis of both arterial and capillary blood tended to provide higher glucose values, whereas blood gas/chemistry analysis of arterial blood tended to yield lower glucose values.


CONCLUSIONS
The magnitude of the differences in the glucose values offered by the four different methods of glucose measurement led to frequent clinical disagreements regarding insulin dose titration in the context of an insulin infusion protocol for aggressive glucose control.
Kanji
Salmaan
S
Department of Pharmacy, The Ottawa Hospital, Ottawa, Canada.
Buffie
Jennifer
J
Hutton
Brian
B
Bunting
Peter S
PS
Singh
Avinder
A
McDonald
Kevin
K
Fergusson
Dean
D
McIntyre
Lauralyn A
LA
Hebert
Paul C
PC
D018806:APACHE; D000328:Adult; D000368:Aged; D001774:Blood Chemical Analysis / Q000379:methods*; D001786:Blood Glucose / Q000032:analysis*; D003422:Critical Care / Q000379:methods*; D016638:Critical Illness / Q000628:therapy*; D003920:Diabetes Mellitus / Q000097:blood / Q000175:diagnosis / Q000188:drug therapy; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D007328:Insulin / Q000008:administration & dosage; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000379:methods*; D019095:Point-of-Care Systems; D011237:Predictive Value of Tests
D001786:Blood Glucose; D007328:Insulin