The primary objective of this study was to measure the width and depth of peripheral veins using bedside ultrasound in children younger than 3 years. Secondary objectives included the evaluation of other vein and patient characteristics that may affect intravenous (IV) site selection. Assessment of nursing preferences for peripheral IV site selection was performed.
Sixty children aged 0 to 3 years who presented to an urban pediatric emergency department were enrolled. Ultrasound measurements of the transverse diameter (width) and distance from the top of the vein to the skin (depth) were recorded. Upon examination, veins were categorized as visible, palpable, detectable only by ultrasound, or not detectable. Sixteen staff nurses rated the likelihood of successful IV placement among different peripheral veins.
The mean width of saphenous veins was significantly larger than that of hand veins (2.8 vs 1.8 mm, P < 0.0001). When comparing saphenous veins to antecubital veins, no significant difference was measured between the mean width (2.8 vs 2.8 mm). The mean depth of saphenous veins was significantly greater than those of hand veins (1.9 vs 1.4 mm, P < 0.0001) and antecubital veins (1.9 vs 1.6 mm, P = 0.019). Differences in visibility and palpability were observed between different vein types. Hand veins and antecubital veins were rated by the nursing staff as the most likely sites for successful IV placement, whereas saphenous veins were among the least likely (P < 0.0001).
In children younger than 3 years, the saphenous vein is larger than hand veins and is similar in size to antecubital veins, although marginal differences in depth exist. The sonographic findings of the saphenous vein and antecubital vein suggest that either should be considered a superior first choice for IV cannulation in this age group. Knowledge of these differences is important when choosing a site for peripheral IV placement. Future studies should evaluate peripheral IV success rates by vein type with or without ultrasound guidance.