University of Michigan
Department of Pediatrics
Evidence-Based Pediatrics Web Site

Question

• Does the method of blood collection from the UAC reduce the risk of intraventricular hemorrhage?

Clinical Bottom Lines

1. Multiple authors agree that blood collection from an umbilical artery catheter alters the cerebral hemodynamics (i.e. cerebral blood volume and oxygenation).
2. Authors disagree whether the velocity vs. the volume of collection makes a difference in these measurements.
3. This topic is in its infancy and it is unclear whether the endpoints measured affect intraventricular hemorrhage directly.
4. This may constitute a potentially better practice given that intraventricular hemorrhage is a serious complication of preterm delivery and methods to prevent it should be employed.

Summary of Key Evidence

1. Roll et al found statistically significant decreases in cerebral oxygenation and cerebral blood volume from baseline during UAC blood collection at 40 s and 80 s with sample volumes of 1.7 mL, but no statistical difference between the two different velocities. However, there was statistical significance between larger and smaller volumes (1.7 mL vs. 0.2 mL).¹
2. Previously, Schulz et al had demonstrated a statistical difference between 20-s vs. 40-s sampling times, thus concluding in that study that a slower velocity does reduce the hemodynamic changes.²
3. The two studies differ in that Schulz et al used older, more stable patients who were less likely to have IVH than earlier gestation neonates.

Additional Comments

• Intraventricular hemorrhage constitutes a serious cause of morbidity and mortality in neonates. It occurs in 60-75% of 500-750 gram neonates and 10-20% of 1,000-1500 gram neonates.
• According to Futagi et al, in those that experience any grade of hemorrhage, only 56.1% of these babies have normal neurodevelopmental outcome, with the rest having some degree of CP (22.4%), MR (10.2%) or borderline intelligence (11.3%). Severity of outcomes increased with higher grade of hemorrhage. Epilepsy occurred in 11.6% of infants with IVH.³
• These early studies show that blood collection from UACs affects the cerebral hemodynamics; whether this is due to volume or velocity is to be determined. Although no studies have been done on humans to directly correlate these changes with IVH, there is no extra cost to being cautious and sparing in our collection.
  

Citation

1. Roll C, Huning B, Kaunicke M, Krug J, Horsch Sl. Umbilical artery catheter blood sampling volume and velocity: Impact on cerebral blood volume and oxygenation in very-low-birthweight infants. Acta Paediatrica, 2006;95:68-73.
2. Schulz G, Keller E, Haensse D, et al. Slow blood sampling from an umbilical artery catheter prevents a decrease in cerebral oxygenation in the preterm newborn. Pediatrics 2003;111: e73-6.
3. Futagi Y, Toribe Y, Ogawa K, Suzuki Y. Neurodevelopmental Outcome in Children with Intraventricular Hemorrhage. Pediatr Neurol 2006;34: 219-24.

CAT Author: Rebecca Vartanian, MD

CAT Appraisers: Cynthia Chi, MD

Date appraised: September 20, 2006