[Ultrasound-guided peripheral venous puncture in patients with a poor venous status]

In the case of a poor peripheral venous status the use of conventional approaches is associated with several failed attempts, delay of treatment, increased pain and escalation to more invasive techniques. Ultrasound-guided venous access has become increasingly popular for difficult venous access; however, in German-speaking countries it has not yet become as popular as in English-speaking countries. First attempt success rates are high, but the factors contributing to the time needed for ultrasound-guided venous access are not well investigated. It is hypothesized that body mass index (BMI), vein diameter and depth contribute to the time needed for successfully establishing a peripheral vein access in patients with a difficult venous status.

This study included 68 patients with a poor venous status. After written consent was obtained patient characteristics were documented and upper extremity veins eligible for access were scanned with ultrasound with the aim of performing an ultrasound-guided venous access. The following time periods were documented: 1) first skin contact with the ultrasound probe, 2) time to identify an accessible vein, 3) time for venous access.

Of the patients 67 were successfully punctured by ultrasound-guided venous access, 65 at the first attempt and 2 at the second attempt. In one patient conventional venous access was obtained at the same time. A higher BMI was associated with a significantly shorter total puncture time (+1 BMI point ≙ -2.25 s) and a shorter vein identification time (+1 BMI point ≙ -1.82 s). A greater vein diameter correlated with a shorter total time (-14.23 s/mm) and a greater depth correlated with an increased total time (+1.65 s/mm).

A greater vein diameter and a higher BMI contribute to a shorter time period for ultrasound-guided venous access. Obese patients with difficult venous access may benefit from ultrasound-guided venous access, which could be explained by the imaging contrast with a higher proportion of subcutaneous fatty tissue.