Umbilical artery catheters: high, low, or no. Low positioning of umbilical-artery catheters increases associated complications in newborn infants. Randomized trial of umbilical arterial catheter position: clinical outcome. Umbilical artery catheterization in newborns. I. Thrombosis in relation to catheter type and position. The association of heparin exposure with intraventricular hemorrhage among very low birth weight infants.
nan We performed a randomized prospective study of the effect of placement position of umbilical-artery catheters on complication rates in high-risk newborn infants. A higher complication rate (31 of 40 vs. 13 of 33) (P less than 0.005) occurred in the group with the catheter tip at the third to fourth lumbar segment, as compared to those with the tip at the seventh to eighth thoracic segment, owing to more episodes of blanching and cyanosis of the extremities. There was no difference between groups in the rate of complications requiring catheter removal. Aortography revealed thrombosis in 21 of 23 patients studied, but there was no clinical evidence of impaired circulation. In retrospect, we found that, independently of catheter position, administration of antibiotics through the catheter was associated with an increased rate of complications (63 vs. 20 per cent). Umbilical-artery catheterization entails potential risks regardless of the position of the catheter; placement of the catheter with its tip at the seventh to eighth thoracic segment may be associated with fewer complications than at lower positions. In order to determine if umbilical arterial catheter position affects the incidence of necrotizing enterocolitis, clinical outcome was analysed in 308 infants whose umbilical arterial catheter had been randomly allocated to a high (n = 162) or a low (n = 146) position. Necrotizing enterocolitis was classified as suspected or confirmed; all renal, lower limb and local catheter complications were also recorded. High umbilical arterial catheters were in place for longer than low catheters, provided more samples and were removed as an emergency less often. Lower limb blanching and cyanosis were more common with low catheters. Eleven cases of confirmed necrotizing enterocolitis occurred in the "high" group and nine in the "low" group. One case of fatal aortic thrombosis was encountered in the high group. Positioning umbilical arterial catheters in a high position allowed longer functional use and did not increase the incidence of necrotizing enterocolitis. Seventy-one sick newborn infants, who had an umbilical artery catheterized, were randomized in one of four catheter groups: long end-hole-, short end-hole-, long side-hole- or short side-hole catheter. A long catheter means a high position of the catheter tip (Th6--11) and a short catheter a low position of the tip (L3--5). An angiography through the indwelling catheter in order to diagnose thrombosis was performed before the catheter was withdrawn. Dissection of the aorta and its brances was performed on infants who died. The total frequency of thromboses was 26%. There were no thromboses among infants with long end-hole catheters while infants with short end-hole catheters had thrombosis in 26%, long side-hole catheters in 33% and short side-hole catheters in 64%. Long end-hole catheters functioned better than the others. Only 6 of 16 infants with thrombosis had physical signs from the legs, while 12 infants without thrombosis had similar signs. To determine whether there is a relationship between exposure to heparin and an increased risk of intraventricular hemorrhage (IVH), we analyzed data from a cohort of infants who had been subjects in a randomized clinical trial of umbilical artery catheter placement. Data from 862 infants who survived the first 6 days of life were used for analysis. The incidence of IVH (grades 1 through 4) was 28.6%. The mean (SD) birth weight for infants with IVH was 954 gm (247 gm) compared with 1053 gm (253 gm) among infants without IVH (p < 0.01). The mean (SD) heparin intake among infants with an IVH was 83.5 units/kg/day (48.7) compared with 59.4 units/kg/day (48.7) among infants without an IVH (p < 0.01). With the use of logistic regression modeling to adjust for a number of potentially confounding variables, including fluid intake and birth weight, we observed an odds ratio for an IVH of 1.96 (95% confidence interval = 1.32, 2.91) for infants with second through fourth quartile intakes of heparin compared with that for infants with first quartile heparin intakes. Although we cannot rule out the possibility that the observations from this model may be confounded by factors associated with the severity of illness of the infant, these data support the findings of previous reports of an association between heparin exposure and the risk for an IVH.
There appears to be no evidence to support the use of low placed umbilical artery catheters. High catheters should be used exclusively.