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Updated: Mar 6, 2026

Ultrasound Assessment of Endothelial-Dependent Flow-Mediated Vasodilation of the Brachial Artery in Clinical Research
Published on: October 22, 2014
Effect of Periradial Administration of Papaverine on Radial Artery Diameter
P S Nagaraja1, Naveen G Singh1, N Manjunatha1
1Department of Cardiac Anaesthesia, Sri Jayadeva Institute of Cardiovascular Sciences and Research, Bengaluru, Karnataka, India.
Background:
Radial artery cannulation is a skillful procedure. An experienced anesthesiologist might also face difficulty in cannulating a feeble radial pulse.
Aim:
The purpose of the study was to determine whether periradial subcutaneous administration of papaverine results in effective vasodilation and improvement in the palpability score of radial artery.
Settings And Design:
Prospective, double-blinded trial.
Methodology:
Thirty patients undergoing elective cardiac surgery were enrolled in the study. 30 mg of papaverine with 1 ml of 2% lignocaine and 3 ml of normal saline were injected subcutaneously 1-2 cm proximal to styloid process of the radius. Radial artery diameter before and after 20 min of injection papaverine was measured using ultrasonography. The palpability of the radial pulse was also determined before the injection of papaverine and 20 min later. Patients were monitored for hemodynamics and any complications were noted.
Statistical Analysis Used:
Student's t-test for paired data.
Results:
Radial artery diameter increased significantly (P < 0.0001), and the pulse palpability score also showed statistically significant improvement (P < 0.0001) after periradial subcutaneous administration of papaverine. There was no statistically significant difference in heart rate, mean arterial blood pressure before and after papaverine injection. No complications were noted in 24 h of follow-up.
Conclusion:
Periradial subcutaneous administration of papaverine significantly increased the radial artery diameter and pulse palpability score, which had an impact on ease of radial artery cannulation essential for hemodynamic monitoring in cardiac surgical patients.
Related Concept Videos
Assessment of radial pulse
The radial pulse, located at the wrist, is often the preferred site for assessing peripheral pulse because of its accessibility and dependability. The process of determining the radial pulse involves several steps:
Assessment of apical radial pulse
The A-R pulse assessment involves simultaneous evaluation of the apical and radial pulses. When the apical and radial pulse rates vary, this assessment helps identify a pulse deficit.
Pre-Procedural Preparation
Peripheral Arterial Disease II: Clinical Manifestations and Diagnostic Evaluation
Sites for measuring blood pressure
The Brachial Artery: Primary Site for Blood Pressure Measurement

