[II-JCKAP5-1-3] Diameter of the carotid, axillary, and femoral arteries in infants less than 2.5 kg of body weight.
Keywords:Arterial diameter, Neonatal intervention, Vascular ultrasound
Objectives: To evaluate the normative arterial diameter at each major arterial access site in infants with small body weights < 2.5 kg.Methods: Neonates admitted to our institutions without any hemodynamic burden were included in the study. Using a vascular ultrasound, the carotid (CA), axillary (AA), and femoral arterial (FA) diameters were measured. Results: Ninety-nine (49 males) patients with a median body weight (BW) of 1866g (556 to 2456) were enrolled and were divided into 4 groups depending on the BW [G1, 500-999g; G2, 1000-1499g; G3, 1500-1999g; G4, 2000-2499g]. The mean diameter of CA, AA, and FA was 2.3, 1.4, and 1.5 mm in G1, 2.5, 1.7, and 1.7 mm in G2, 2.7, 1.7, and 1.8 mm in G3, and 2.8, 1.9, and 1.9 mm in G4, respectively. No significant difference was seen between the AA and the FA diameter despite the CA being significantly larger than the other vessels. The arterial diameters significantly (all p-value < 0.001) related to the height (r = 0.49 in CA, r = 0.38 in AA, r = 0.52 in FA), BW (r = 0.50 in CA, r = 0.44 in AA, r = 0.48 in FA), and head circumference (r = 0.41 in CA, r = 0.41 in AA, r = 0.41 in FA). The vessel diameter above 1.6 mm, the smallest sheath outer diameter, was predicted based on the BW with an area under the curve (AUC) of 0.75, with cut off value of 1754 g for the AA and AUC of 0.75, in cut off value of 1668 g for the FA. The CA diameter was bigger than 1.6 mm in all cases.Conclusion: Arterial diameters correlated with the patient's body size. Under 1800 g of BW, femoral or axillary arterial access may better be avoided.