Ultrasound guidance in difficult radial artery puncture for blood gas analysis: A prospective, randomized controlled trial

BACKGROUND: Ultrasound (US) guidance has yet to prove its applicability in radial arterial blood gas analysis (ABGA) punctures. The main objective of our study was to compare the number of first-attempt successes (NFAS) for radial arterial puncture in difficult patients with or without US guidance. The Secondary aims were to compare the number of punctures (NOP), puncture time, and patient pain. METHODS: In this single-center, randomized controlled trial, patients who required a radial ABGA and in whom the arterial puncture was assessed as difficult (because of non-palpable radial arteries or two previous puncture failures by a nurse) were assigned to the US group or no-US (NUS) group (procedure performed by a trained physician). RESULTS: Thirty-six patients were included in the US group and 37 in the NUS groups. The NFAS was 7 (19%) in the NUS group and 19 (53%) in the US group. The relative risk of success in the US group was 2.79 (95% CI,1.34 to 5.82), p = 0.01. In the NUS and US groups, respectively, the median NOP was 3 [2; 6] vs. 1 [1; 2], estimated difference −2.0 (95%CI, −3.4 to −0.6), p < 0.01; the respective puncture time was 3.1 [1.6; 5.4] vs. 1.4 [0.6; 3.1] min, estimated difference −1.45 (95%CI, −2.57 to −0.39), p = 0.01; the respective median patient pain was 6 [4; 8] vs. 2 [1; 4], estimated difference −4.0 (95%CI, −5.8 to −2.3); p < 0.01. CONCLUSION: US guidance by a trained physician significantly improves the rate of success in difficult radial ABGA patients.