ACCURACY OF REAGENT STRIPS IN DETECTING HYPOGLYCEMIA IN THE EMERGENCYDEPARTMENT

Study objective: Although reagent strips are commonly used, their reli ability to estimate blood glucose concentration and guide administrati on of dextrose solutions in the emergency department environment has n ot been proved. We determined the accuracy of visually interpreted rea gent strips (Chemstrip bG, Boehringer Mannheim Corp, Indianapolis, IN) and their ability to identify hypoglycemic patients in the ED. Method s: We conducted a prospective, nonrandomized blinded clinical study of the visual estimation of blood glucose values by ED personnel using C hemstrip bG reagent strips during a 4-month period. Simultaneously obt ained blood samples sent for laboratory glucose determination served a s controls. The study was con ducted at a large university hospital ED with an urban patient population. A convenience sample of 215 adult E D patients underwent serum glucose determination with data form comple tion. No study intervention was tested, although timing of administrat ion of dextrose solutions, if given, was recorded. Results: Hypoglycem ia was defined as a glucose concentration less than 60 mg/dL on standa rd laboratory analysis. Reagent strips identified 28 of 29 of these pa tients (sensitivity=97%), and 171 of 182 patients without hypoglycemia (specificity=94%, negative predictive value=99%) compared with contro l samples. The 1 false-negative reagent strip reading of 80 mg/dL was obtained from blood stored in a serum separator tube and had a laborat ory glucose value of 39 mg/dL. Eighty-seven percent of the reagent str ips were within +/- 60 mg/dL of the control value for the laboratory g lucose reference range less than 350 mg/dL. Conclusion: Visually inter preted Chemstrip bG reagent strips provide an acceptable estimation of blood glucose concentration in the ED and are highly sensitive in det ecting hypoglycemia.