Flow within radial artery remains unchanged after cannulation among patients undergoing abdominal surgery, finds study

The radial artery is commonly cannulated during the perioperative period and in critical care situations. Despite being invasive, this procedure offers real-time monitoring of arterial blood pressure, enabling clinicians and anesthesiologists to promptly assess and treat patients, as well as to obtain arterial blood samples for various diagnostic purposes such as blood chemistry, blood gas analysis, and coagulation management. Recent study evaluated the impact of arterial cannulation on flow in the radial artery and the ulnar artery in patients undergoing abdominal surgery. The primary outcome was to measure the resistive indices (RIs) before cannula insertion and 6 hours after decannulation, while the secondary outcomes included measuring the artery size by anteroposterior (AP) diameter at the insertion site and at a point 4 cm proximal to the insertion site in both the radial and ulnar arteries. The study included 96 patients and used peak systolic velocity (PSV) and end‑diastolic velocity (EDV) to derive RI using a linear ultrasound transducer.

Study Results

The results showed that the flow in the radial artery did not change following cannulation, and the resistive index (RI) and AP diameter at the insertion site and proximal to the insertion site were similar before and after cannulation. However, the peak systolic velocity (PSV) and anteroposterior (AP) diameter in the ulnar artery increased significantly after decannulation, indicating a compensatory increase in flow following radial artery decannulation. Subgroup analysis revealed that patients with cannulas retained for less than 24 hours showed increased end‑diastolic velocity (EDV) of the radial artery following decannulation, while those with cannulas retained for more than 24 hours showed an increase in PSV and AP diameter of the ulnar artery after decannulation. The study also considered other research findings and discussed the impact of different techniques of radial arterial cannulation on complications. The study acknowledged limitations, such as the inability to document decreased pulsatility of the radial pulse on ultrasound Doppler due to study design constraints and the lack of follow-up beyond 6 hours of decannulation. In conclusion, the study found that resistive indices and artery size in the radial artery did not change significantly following cannulation, while there was a compensatory increase in flow in the ulnar artery after decannulation. The study emphasized the need for further research to evaluate flow patterns at decannulation and extend the measurement period beyond immediate decannulation. Overall, the study provided insight into the impact of arterial cannulation on arterial flow in patients undergoing abdominal surgery and highlighted the need for further research in this area.

Key Points

- The study aimed to assess the impact of arterial cannulation on flow in the radial and ulnar arteries in patients undergoing abdominal surgery. It included 96 patients and measured resistive indices (RIs) before cannula insertion and 6 hours after decannulation, as well as artery size by anteroposterior (AP) diameter at the insertion site and proximal to it in both arteries, using peak systolic velocity (PSV) and end‑diastolic velocity (EDV) derived from a linear ultrasound transducer.

- The analysis of the results revealed that the flow in the radial artery did not change following cannulation, and the resistive index (RI) and AP diameter at the insertion site and proximal to it were similar before and after cannulation. However, there was a significant increase in peak systolic velocity (PSV) and anteroposterior (AP) diameter in the ulnar artery after decannulation, suggesting a compensatory increase in flow following radial artery decannulation.

- Subgroup analysis indicated that patients with cannulas retained for less than 24 hours showed increased end‑diastolic velocity (EDV) of the radial artery following decannulation, while those with cannulas retained for more than 24 hours showed an increase in PSV and AP diameter of the ulnar artery after decannulation.

- The study also acknowledged limitations, including the inability to document decreased pulsatility of the radial pulse on ultrasound Doppler due to study design constraints and the lack of follow-up beyond 6 hours of decannulation. - In conclusion, the study found that resistive indices and artery size in the radial artery did not change significantly following cannulation, while there was a compensatory increase in flow in the ulnar artery after decannulation. The study emphasized the need for further research to evaluate flow patterns at decannulation and extend the measurement period beyond immediate decannulation.

- Overall, the study provided valuable insight into the impact of arterial cannulation on arterial flow in patients undergoing abdominal surgery and highlighted the need for more comprehensive research in this area.

Reference -

Kumar L, Subramaniam R, Kartha PA, Thomas DE, Patel S, Kartha N. Does the resistive index of the radial artery change after arterial cannulation in patients undergoing abdominal surgery? A prospective observational study. Indian J Anaesth 2024;68:909‑14