Effect of local warming for arterial catheterization in adult cardiac surgery: a randomized controlled trial

Background: The increase in internal diameter (ID) and cross-sectional area (CSA) may facilitate better arterial catheterization. Since an increase in body temperature can cause peripheral vasodilation, we aimed to determine if local warming of the radial artery (RA) catheterization site could improve the success rate of catheterization.Methods: This randomized, controlled study enrolled 160 patients aged >18 years who were scheduled for heart surgery. They were randomized into non-warming palpation (NP), non-warming ultrasonographyguided (NU), warming palpation (WP), and warming ultrasonography-guided (WU) groups. After induction, the baseline RA ultrasonography images were collected. In the warming groups (WP, WU), local warming was applied on the catheterization site. Before catheterization, the RA ultrasonography images were collected. The primary outcome was the first-attempt success rate. The secondary outcomes included the ID and CSA of the RA and overall complications.Results: Totally 152 adults were included in the analysis. The first-attempt success rates in each of the four groups were not significantly different (P=0.985). The rates in the non-warming (NP + NU) and warming (WP + WU) groups were also not different (P=0.827). Unlike non-warming group, the warming group had increased ID (3.34 +/- 0.78 vs. 3.02 +/- 0.73 mm; P<0.001) and CSA (6.9 +/- 2.8 vs. 5.8 +/- 2.4 mm(2); P<0.001) compared with baseline.Conclusions: Local warming for peripheral artery catheterization does not increase the first-attempt success rate in adults undergoing cardiac surgery; however, it can increase the ID and CSA of the RA and prevent vasospasm.