Rajeev Narayan (San Antonio Health Center, San Antonio, USA) has presented at the American Society of Diagnostic and Interventional Nephrology (ASDIN) 19th Annual Scientific Meeting (17–19 February, Orlando, USA) to give his tips and tricks on distal radial artery cannulation. “There are many things that are exciting in the field of nephrology,” said moderator of the session Anil Agarwal (Veterans Administration Central California Health Care System, Fresno, USA), introducing Narayan and his talk’s topic, “but some of them are downright scary”. Narayan aimed to shed some useful light on the procedure.
“Basically,” Narayan said, “the more you do something, the better you get at it—so this talk is mainly for those who do not do [distal radial artery cannulation] as much.” Beginning with indications, Narayan said that the procedure was appropriate for haemodynamic monitoring, as well as access for maturation of percutaneous arteriovenous fistula and dialysis access procedures.
He then moved on to assessing the safety of the procedure for a patient, something for which he emphasised the value of the complete superficial palmar arch (SPA) and the deep palmar arch (DPA), making reference to a review by Marek Brzezinski (VA Medical Center, San Francisco, USA) et al from 2009. Using a modified Allen test (MAT), he advised clinicians to use the following instructions: “Make a fist for 30 seconds with occlusion of both radial and ulnar arteries. Open the hand and release ulnar artery.” Then, he said, if colour returns in 3–12 seconds, the patient will likely be able to tolerate radial artery occlusion. He also noted that if the patient can demonstrate a complete palmar arch with ultrasound or Doppler, this may be “better at predicting ischaemia to the hand with radial artery occlusion”. If the ulnar artery is not patent, he stressed, “I would avoid distal radial artery cannulation”.
Moving on to technique, Narayan implored his audience to remember “if nothing else” to cannulate above the level of the radial styloid. “We were all taught to cannulate at a 45 degree angle, but I do not really do that nowadays,” he added. “I come in at a much steeper angle nowadays and level off—I find that that is easier.” Another trick Narayan recommended that he said may not be appropriate for every situation but was “good to have in the back of your mind” was ulnar artery compression. For this, he said, the clinician carrying out the procedure should “use ultrasound to localise and compress the ulnar artery, sometimes [found] in the upper forearm”. This can, on occasion, cause dilation of the distal radial artery “just enough to assist in cannulation”.
Towards the end of the presentation, Narayan said that using a needle as a guide during cannulation. He noted that it can be used “under ultrasound to push through clots or calcifications into a better part of the artery prior to advancing the wire”. Additionally, he suggested cannulation should be performed “with haemostasis in mind”.
