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

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 to avoid the trauma of a heelstick. The risk of dextrose contamination must be appreciated when utilizing the umbilical artery catheter as the sampling site. An in vitro study was conducted to evaluate glucose measurements from an umbilical artery catheter. Randomization of blood withdrawal increments and irrigation of a nondextrose-containing solution through the catheter was performed to minimize the risk of dextrose contamination. Repeated measures analysis of variance (ANOVA) revealed a significant difference between measured and baseline glucose for all withdrawal amounts and varying flush volumes. This inability to approximate the baseline glucose necessitates a need for further studies if the umbilical artery catheter is to be relied upon for glucose sampling.