Preliminary studies of diabetic decompensation assessed with bedside glucose-monitoring techniques

Blood glucose-monitoring techniques originally developed to aid outpatient management of diabetic patients are now being used to facilitate hospital care. However, applications in hyperglycemic patients have been limited because many glucose-oxidase strips and meters respond only to glucose values less than or equal to 400 mg/dl. We asked if prior dilution of blood samples would permit reliable estimations. Ten consecutive decompensated diabetic patients (age 35-73, glucose 506-879, HCO3 12-28) had blood glucose determinations done simultaneously by the hospital laboratory and by Chemstrip bG after dilution of heparinized blood 1:2 in saline. Thirty-one samples were obtained before and during insulin therapy. Correlations with laboratory glucose values were 0.95 with strips read by Accu-Chek meter and 0.90 read visually, both P less than 0.001. Average deviations from laboratory values were 7.9% with Accu-Chek and 12.9% with visual readings. Accu-Chek deviations averaged 9.6% for glucose greater than 700 mg/dl, and 6.9% for glucose greater than 400 mg/dl. Over the first hour of insulin therapy, glucose fell 150 +/- 30 mg/dl by Accu-Chek, comparable to 168 +/- 29 by laboratory measurement; the decrement by visual reading was 107 +/- 32, not significantly different. We conclude that dilution of blood samples with glucose greater than 400 allows reliable estimation of elevated values by home glucose-monitoring techniques. This approach is cost-effective and provides the rapid feedback needed for the management of critically ill patients.