This is relevant to Question 14 from the second paper of 2004, and  Question 23 from the first paper of 2008:

"A large bore catheter for renal replacement therapy has been accidentally inserted into the carotid artery of a man with multiple organ failure (including a coagulopathy) due to systemic sepsis. The location of the catheter was only discovered after it had been sutured in place. List the potential complications, and outline how you are going to deal with this problem."

LITFL have a nice page on this topic.

Additonally, the BJMP has an article with a case report of precisely this sort of complication. The author has done a literature search, and presents a list of complications which have been reported in the papers in association with this problem:

Complications of accidental arterial large-bore cannulation

  • Haematoma formation
    • Airway obstruction
    • Cerebral venous outfow obstruction
    • Jugular venous thrombosis due to stasis
    • Haemomediastinum
    • Compromised cardiac function due to RV compression by down-tracking haematoma
  • Vascular injury
    • Pseudoaneurysm
    • Carotid dissection
    • Retrograde aortic dissection
    • Arteriovenous fistula
    • Occlusion by flap, catheter or thrombus
  • Cerebral injury
    • Ischaemic stroke
    • Atheroembolic stroke
    • Thromboembolic stroke
    • Air embolism
  • Peripheral neurological ijury
    • Compression damage to the vagus nerve
    • Compression damage to the phrenic nerve
    • Damage to the brachial plexus roots

Interestingly, having spoken to some of the vascular surgeons about such complications, the general opinion seems to be that if you have already dilated the artery and inserted the vas cath, the best thing you can do is suture it in position and leave it there until they arrive. Apparently that is somehow better than taking it out and then putting pressure on a carotid with a vas-cath-sized hole in it.

  • Prevent further complications
    • Keep the catheter in situ
    • Clamp the lumens
    • Label it clearly as "not for use"
    • Assess the urgency of removal and repair, i.e ischaemic stroke symptoms, ongoing bleeding, aortic dissection, known high grade carotid stenosis on the contralateral side, etc
    • Assess the extent of haematoma with imaging: ideally CT, but ultrasound may be enough
    • Correct any coagulopathy
  • Deal with the need for vas cath
    • ​​​​​​​Consider the placement of another vas cath into a venous structure at a different site, depending on the urgency for CRRT in this patient
    • Amend the CRRT protocol accordingly to expose this patient to minimal or no anticoagulation (i.e. use pre-dilution or citrate only)
  • Deal with the need to remove the vas cath
    • ​​​​​​​Determine the extent of the damage by combination of ultrasound, CT imaging and CXR (eg. to define the tip position)
    • Consult vascular surgeon to repair the carotid puncture, if that's all there is
    • Consult cardiac surgeon to repair any aortic arch damage
  • Deal with the consequences for staff and family
    • Debrief with the staff member who inserted the vas cath
    • Offer education and discussion to cover any knowledge gaps
    • Notify appropriate incident management body regarding the insertion
    • Commence the open disclosure process with the patient and family

References

Nair, Sanil, et al. "A case of accidental carotid artery cannulation in a patient for hemofilter: complication and management." British Journal of Medical Practitioners 2.3 (2009): 57-58.