Neonatal glucose determinations obtained from an umbilical artery catheter: evaluation for accuracy using an in vitro...

Accuracy of glucose values is crucial in the management of the critically ill neonate. Sampling for these values may be obtained from an umbilical artery catheter (UAC), but dextrose solutions infused through these catheters may contaminate samples obtained for glucose determination. An in vitro study was conducted to evaluate the effect of blood withdrawal amount and normal saline irrigation on the accuracy of glucose measurements obtained from a UAC. Methods included randomization of blood withdrawal amounts and irrigation with normal saline solution prior to obtaining the blood for glucose measurement. Two hundred and eighty glucose samples were obtained. Results revealed a significant difference between measured and baseline glucose values for all withdrawal amounts and varying flush volumes. This inability to approximate the baseline glucose values could mean that a UAC sample may not reflect the neonate's actual glucose value.