Influence of arm position on the first pass success rates of ultrasound-guided infraclavicular axillary vein cannulation in spontaneously breathing patients: A randomised clinical trial

Background: Significant collapsibility during spontaneous respiration, deeper location, and smaller vein size are key challenging factors to safe infraclavicular axillary vein cannulation. Arm abduction reduces collapsibility, but interventional data supporting this observation is lacking. This study investigates the effect of neutral and abducted arm position on the first pass success rate of infraclavicular axillary vein cannulation in spontaneously breathing patients. Methods: One hundred and twelve patients were randomly assigned to two arm positions, neutral or abducted by 90° at the shoulder joint. Under ultrasound guidance, the infraclavicular axillary vein was cannulated using an in-plane approach. The primary outcome was the first pass success rate of guidewire placement in the infraclavicular axillary vein. The secondary outcome measures were the number of attempts for successful cannulation, failure rate, and catheter tip malposition. Results: Fifty-two patients in the neutral arm and fifty-six patients in the arm abduction group were compared according to the intention to treat analysis. The abducted arm position was associated with a higher first pass success rate (RR = 3.39, 95% CI = 1.47–7.85; p = 0.004) with fewer attempts (p = 0.005), lower failure rate (RR = 1.37, 95% CI = 1.16–1.61; p = 0.000) and lower catheter tip malposition (1.5 vs 15.8%; p = 0.012) when compared to the neutral arm position. Conclusion: Abducted arm position resulted in a significantly higher first pass success rate with a lower failure rate and catheter tip malposition during ultrasound-guided infraclavicular axillary vein cannulation in spontaneously breathing patients.