Technically speaking, a caudal has the highest risk of bleeding of any procedure, but there is no significant arterial blood supply in this area so any bleeding would be venous and therefore very low risk especially considering that if doing the procedure correctly, you wont be inserting the needle further than the space where there no longer is a thecal sac.I thought caudal was same as interlaminar in risk given you’re injecting into an enclosed space so I will have patient hold for both. FWIW I’ve been doing TFESI’s on thinners for the past few years because of what I had read here and Endres.