Ultrasound-guided versus palpation-guided radial artery cannulation in patients with obesity: A randomized controlled...

Radial artery cannulation is often more difficult in patients with obesity because arterial landmarks may be less reliable and the vessel may be deeper from the skin surface. Whether ultrasound guidance improves cannulation outcomes in this subgroup remains uncertain.

In this prospective, single-center, randomized, assessor-blinded trial, adults with body mass index >30 kg/m² scheduled for elective laparoscopic sleeve gastrectomy and requiring radial artery cannulation were assigned to ultrasound-guided cannulation using a short-axis out-of-plane technique or to palpation-guided cannulation. The primary outcome was first-attempt success at the initially selected radial artery. Secondary outcomes included need for a second attempt, two-attempt success, cannulation time, failure at the initially selected artery, and vascular complications.

Of 130 patients assessed for eligibility, 126 were randomized and analyzed (63 per group). First-attempt success was higher with ultrasound guidance than with palpation guidance (57/63 (90.5%) vs 44/63 (69.8%); absolute risk difference, 20.6%; 95% CI, 6.7-33.9; p = 0.003). Fewer patients in the ultrasound group required a second attempt (6/63 (9.5%) vs 19/63 (30.2%); p = 0.003). Two-attempt success was also higher with ultrasound guidance (62/63 (98.4%) vs 52/63 (82.5%); absolute risk difference, 15.9%; 95% CI, 5.8-27.1; p = 0.002). Median cannulation time was longer with ultrasound guidance for first-attempt success (64.0 s (IQR, 45.0-98.5) vs 41.0 s (IQR, 26.1-58.0); p = 0.005). Overall vascular complications were less frequent in the ultrasound group (7/63 (11.1%) vs 21/63 (33.3%); absolute risk difference, -22.2%; 95% CI, -35.7 to -7.7; p = 0.003).

Among patients with obesity undergoing sleeve gastrectomy, ultrasound-guided radial artery cannulation increased first-attempt and two-attempt success and reduced vascular complications, although cannulation time was modestly longer. These findings support preferential use of ultrasound guidance when reliable first-site radial artery cannulation is clinically important.