Residual flow of the radial artery in the presence of an arterial catheter: A single-centre retrospective observational study.

Adhering to the current guidelines, especially using ultrasound to ensure a catheter/artery ratio of at least 45%, can help maintain preserved perfusion through the cannulated radial artery. Ulnar compensation appears to be crucial for maintaining good tissue perfusion and should always be evaluated before catheterisation. Therefore, further studies are warranted.