Effect of umbilical arterial catheters on intestinal blood supply.

Umbilical arterial catheters in the high position reduce the lumen of the aorta and may thereby impair blood supply to the intestine. Thirty-two preterm and three term infants were studied with an umbilical arterial catheter by colour and duplex Doppler sonography. The diameter of the aorta at the level of the coeliac axis was measured to calculate the reduction of the cross-sectional area of the aorta by the catheter. Blood-flow velocities were measured in the coeliac axis, the superior mesenteric artery and the anterior cerebral artery before and after removal of the catheter. The umbilical arterial catheter reduced the cross-sectional area of the aorta by 3.4-27.2% (mean 10.1%). There was no difference between blood-flow velocities in the coeliac axis and the superior mesenteric artery before and after removal of the umbilical arterial catheter, indicating that the catheter did not impair blood supply to the intestine.