Femoral vein size in newborns and infants: preliminary investigation

Background: The femoral vein is an important site for central venous access in newborns and infants. The objectives of this study are to determine whe ther age or weight can be used clinically to predict the size of the femora l vein in newborns and infants, and to compare the size of the vein in each individual in both the supine and reverse Trendelenburg positions. Results: Analysis was done in 24 euvolemic individuals, each studied in bot h the supine and reverse Trendelenburg positions. Twelve of these individua ls were newborns and 12 were infants. We used two-factor analysis of varian ce to explore differences between groups and multiple linear regression ana lysis to estimate the strength of the relationship between variables. In th e infant group, there was a correlation between femoral vein diameter and w eight. There was no correlation between weight and vessel size in newborns. In both the newborn and infant groups, vessel diameter increased with subj ects in the reverse Trendelenburg position (P<0.01). Conclusion: Weight is predictive of femoral vein diameter in infants, but n ot in newborns, In infants, weight might serve as a more sensitive index fo r estimating size of the femoral vein in order to determine accurately the size of intravascular catheter appropriate for cannulation. The diameter of the femoral vein increases in the reverse Trendelenburg position compared with that in the supine position in both newborns and infants. A large pros pective study is required to validate these findings.