Efficacy of catheterization of the distal radial artery in blood pressure monitoring and blood sampling: a randomized controlled clinical study

PURPOSE: The radial artery at the wrist (proximal radial artery) is the most common site for arterial catheterization, but catheterization may sometimes be difficult. The distal radial artery, located on the back of the hand, has been proposed as an alternative access site. METHODS: As a randomized controlled study, 120 anesthetized patients were randomly assigned to receive arterial catheterization either to the proximal radial artery (Group P) or to the distal radial artery (Group D) under ultrasound guidance. The primary outcome was the incidence of loss of normal arterial pressure waveform during wrist movement. Secondary outcomes included the success rate, the number of attempts at insertion, and the incidence of loss of intraoperative arterial waveforms and of failed blood sampling. RESULTS: There was no significant difference in the success rate of insertion (P = 0.36, 95% CI for difference: -13%-2%) and in the number of attempts at insertion (P = 0.19) between the groups. Loss of arterial waveform during wrist movement was significantly lower in Group D (3 patients (5%)) than in Group P (22 patients (37%)); P < 0.0001, 95% CI for difference: 18%-45%. No significant differences were observed in intraoperative waveform loss (P = 1.0, 95% CI for difference: -5%-9%) or blood sampling failure (P = 0.24, 95% CI for difference: -3%-19%) between the groups. CONCLUSIONS: The distal radial artery may be a useful alternative site to the proximal radial artery for catheterization, particularly in adult patients in whom positional change is required.