Effect of preoperative prolonged occlusion flow-mediated dilation on radial artery cannulation: A prospective randomized controlled trail.

Background: Radial artery catheterization is commonly used for continuous blood pressure monitoring, arterial blood gas analysis, and routine blood sampling during the perioperative period. However, the small diameter of the radial artery and potential complications make catheterization challenging. This study was aimed to investigate the efficacy and safety of preoperative prolonged occlusion flow-mediated dilation (PO-FMD) in enhancing radial artery catheterization.

Methods: A total of 144 patients scheduled for elective surgery requiring radial artery catheterization were enrolled in this study. Patients were randomly assigned to either the PO-FMD group or the sham PO-FMD group. For patients in PO-FMD group, the blood pressure was first measured, then inflated cuffs to 50 mmHg above the patients' systolic pressure and maintained for 5 min to induce radial artery dilation. The same procedure was performed for the sham PO-FMD group, except that the cuff was not inflated. Use an ultrasound machine to measure the diameter and depth of the radial artery at baseline, 5 min after the cuff was placed, and after catheter placement. The successful rate, numbers of attempt, durations, and complications of the cannulation were recorded.

Results: One hundred and thirty-one patients completed the trial and were included in final statistical analysis. The PO-FMD group showed a significant increase in radial artery diameter compared to sham PO-FMD group and baseline. After catheterization, this diameter remained stable in the PO-FMD group but decreased in the sham PO-FMD group. No significant differences in radial artery depth were observed between groups. Then, the first-attempt success rate for radial artery cannulation was 86% in the PO-FMD group, significantly higher than the 64% success rate in the sham PO-FMD group. In the PO-FMD group, both the duration of cannulation and the number of attempts were lower compared to the sham PO-FMD group. Additionally, complications related to radial artery cannulation, such as arterial spasm, loss of pulsation and occlusion, occurred less frequently in the PO-FMD group than in the sham PO-FMD group.

Conclusions: Our data suggested that the PO-FMD significantly increased and stabilized the radial artery diameter, improved the success rates of radial artery cannulation, shortens the time to successful catheterization, and decreases the incidence of cannulation-related complications.