ABSTRACT
OBJECTIVE: To evaluate the Ames Glucometer Elite glucose meter for use in point-of-care glucose testing in the neonatal intensive care unit. METHODS: An important part of our quality control program involves a weekly comparison of glucose values obtained with each of the seven Elite analyzers and the Beckman CX7 analyzer located in the central laboratory. Each "split" sample involves measurement of the glucose by using the Elite analyzer in a sample of blood obtained from a heel stick at the bedside, followed by bleeding ("milking") 150 to 200 microl (4 to 5 drops) of blood into a heparinized microcontainer. This process should take no longer than 1 to 2 minutes, whereupon the microcontainer is placed on ice and sent to the laboratory. The values obtained were compared by regression analysis. Imprecision of the Elite meter was estimated at four levels of blood glucose concentration and on a normal-level quality control sample used for a period of 4 months. RESULTS: Regression analysis between the glucose values obtained on the Elite meter and the CX7 meter revealed r = 0.93, p less than 0.0001, n = 188, Sy/x = 0.59 mmol/L, intercept = 0.47 +/- 0.14 mmol/L (1 SEM), and slope = 0.91 +/- 0.028 (1 SEM). When we switched to on-ice delivery of split samples to reduce metabolic activity during transport of the specimens to the laboratory, scatter about the regression line was decreased and the Sy/x was reduced to 0.45 mmol/L. Before the on-ice delivery of split samples, 24% of the Elite analyzer's results differed from those of the CX7 analyzer by more than 15%, whereas only 8% differed from those of the CX7 meter by more than 15% after on-ice delivery of split samples. Of 30 samples read as "Lo" by the Elite meter, 29 were less than 2.2 mmol/L on the CX7 meter, whereas only 1 was 2.2 mmol/L. The coefficients of variation taken as a measure of imprecision were less than 5% for the normal-level aqueous control and less than 5% for four heel-stick blood glucose levels. CONCLUSIONS: The Ames Glucometer Elite analyzer can be used with confidence in measuring heel-stick blood glucose concentrations at the bedside in the neonatal intensive care unit. Hypoglycemic blood samples are reliably detected. As with adults, meticulous technique should be followed to prevent filling defects, and all split samples should be analyzed promptly on the CX7 analyzer, with delivery to the laboratory on ice. Unlike previous generations of glucometers, the Elite meter has been well accepted by the neonatal nursing staff.
