Umbilical artery catheterization in newborns. IV. Strain-gauge plethysmography for the diagnosis of catheter-related thrombo-embolism in the legs.

Strain-gauge plethysmography was performed shortly after withdrawal of the catheter in 48 of 49 newborn ifnats who had undergone umbilical artery catheterization. Plethysmorgraphy was used to find a noninvasive method for diagnosing catheter-related thrombo-embolism in neonates. The results were compared with the findings at aniography. The method permits simultaneous measurements of the systolic blood pressure and of the resting and submaximal blood flow in both legs. Nine infants howed angiographic signs of total or partial occlusion in one leg, and 8 of them were investigated with plethysmorgraphy. The systolic blood pressure was signifcantly reduced in ifants with total and/or partial occlusion, but the blood flow was reduced only in infants with total occlusion. The peak flow after sugrasystolic occlusion was significantly otener delayed in infants with thrombo-embolism in the leg.