Objective: The study was aimed at comparing the accuracy in length of insertion of umbilical arterial catheter in all new born groups stratified according to weight, by using two different methods, that is, Wright et al./Case (Group I): (4 × Body wt (BW) (kg)) +7; Shukla et al./Control (Group II): (3 × BW (kg)) +9.
Study design: It was a randomized open label case control study in a Level III tertiary level Neonatal Intensive Care Unit over 9 months.
Result: The babies in both the groups were similar in relation to weight, gender, prematurity and weight subgroups. Under insertion was seen in 8% (4/50) of babies in group I and over insertion was seen in group II where it was 32.6% (16/49). There was a reduction of 82% abnormal insertions and repositioning by using the Wright's formula as compared with the Shukla's formula in preterm babies. Statistically significant reduction in repositioning was seen in all babies <1500 g in Group I and under insertion seen in 8% of babies in group I did not attain statistical significance (P=0.34).
Conclusions: There is no universal formula, which gives the accurate length of placement of an umbilical arterial catheter, but Wright's formula comes closer in neonates with different weight sub groups.