Fig 1.
Illustrations for two ultrasound-guided radial artery cannulation methods.
A. Conventional method (a) Confirmation of needle tip visualization in the centre of intra-arterial lumen on the ultrasound screen. After confirming that blood has been aspirated into the catheter hub, the needle is advanced slightly whilst reducing the puncture angle, and an external catheter was inserted into the artery. Then, after the inner guide needle is removed, the (b)and (c) process are performed sequentially if the blood return is not observed. (b) The outer catheter was withdrawn by applying negative pressure until the blood aspiration is observed again, (c)If blood aspiration continued, an outer- catheter is inserted into the artery. B. DNTP (dynamic needle tip positioning) method (a) The skin and radial artery are punctured, and the tip of the needle is seen in the centre of the intra-arterial lumen. (b) The probe is moved forward slightly until the needle tip disappears in the intra-arterial lumen. (c) The needle tip is slightly advanced tip of the needle. Repeat steps (a)-(c) 2 or more times to ensure that the entire catheter of the outer cannula is advanced into the artery.
Fig 2.
CONSORT flow diagram.
Table 1.
Patient characteristics.
Fig 3.
Kaplan–Meier curves for the overall catheterization success time.
D: Group D, dynamic needle tip positioning method. C: Group C, conventional short-axis method. Time(x-axis) is defined as the time from the start of ultrasound scanning during the first attempt to the appearance of an arterial waveform on the monitor. If cannulation was not successful with the assigned method after 10 min, it was defined as cannulation failure.
Table 2.
Study results.
Table 3.
Cannulation related complications.