Umbilical venous catheter insertion depth estimation using birth weight versus surface measurement formula: a randomized controlled trial

To determine if umbilical venous catheter (UVC) insertion depth estimated by surface measurement (SM) results in optimal catheter tip position on ultrasound as compared with formula using birth weight (BW).

In this randomized controlled trial, eligible infants were randomized to UVC insertion depth estimated by SM or BW method. We compared proportion of optimum UVC position on ultrasound read by neonatologist masked with group assignment.

UVC was inserted to estimated depth in 164 of 200 enroled infants. There was no difference in the proportion of correctly positioned UVCs between the groups (SM 33/82 (40.2%) vs BW 27/82 (32.9%), p = 0.33). Among BW < 1000 g, SM method had higher correctly positioned UVC (43.7% vs 22.5%, p = 0.07).

There was no difference in the rate of optimally positioned UVC tip between the two methods for estimating UVC insertion depth. However, SM method results in more optimal positioning of UVC tip among BW < 1000 g infants.