The college has never really asked about this directly, in the sense of "What are the complications of angiography?"  However, there are plenty of questions which approach this topic indirectly. So indirectly that they were previously grouped under "complications of arterial access" in the Equipment section. 

  • Question 8 from the second paper of 2019 (a complication of radial arterial line insertion in a septic patient)
  • Question 25.3 from the first paper of 2011 invites the candidates to discuss the management of a completely trashed leg, as a complication of arterial access for a left heart study. 
  • Question 2a from the first paper of 2004 and the identical Question 29 from the first paper of 2006 go  further to discuss the diagnosis and management of a post-angiography retroperitoneal haematoma.
  • In a more direct fashion, Question 1 from the first paper of 2019 gave the candidates a scenario where a patient has become hypotensive following coronary angiography and angioplasty, asking for differentials and a management approach. 

Much of the practical information on arterial line insertion has migrated to the Cardiovascular and Procedural anatomy sections for the CICM Part I exam, and this brief entry is here to serve as an aide-memoire for the time-poor exam candidate. For peer-reviewed resources, Tavakol et al (2012) was used as the main resource for complications specific to coronary angiography

Complications of coronary angiography

Having a thing fidgeting around in your conorary artery is not without risk. 

  • Adverse reactions to anaesthesia
    • Local anaesthetic toxicity (i.e. inadvertent intravascular injection)
    • Cardiodepressant effects of general anaesthetic
    • Oversedation 
    • Resudial effects of general anaesthetic
  • Adverse reaction to the aspects of the angiography procedure
    • Contrast reaction (anaphylaxis)
    • Contrast-induced nephropathy
    • Adverse reaction to drugs in the drug-eluting stent
    • Heparin-induced thrombocytopenia
    • Abciximab-induced thrombocytopenia
  • Complications of vascular access - see below, but briefly:
    • Pain, thrombosis, infection
    • Haematoma, including haematoma of a lifethreatening volume (eg. retroperitonal) or in a lifethreatening location (eg. cardiac tamponade)
    • Air embolism
    • Cholesterol embolism
    • Accidental intra-arterial drug injection
    • Vessel damage, pseudo-aneurysm, arterial dissection, including aortic or coronary artery dissection
    • Arteriovenous fistula
  • Complications related to the underlying cardiac disease
    • Cardiac arrest and death
    • Brady or tachyarrhythmia
    • Myocardial infarction

Differential diagnosis of the shocked post-angiography patient

Question 1 from the first paper of 2019 asked for the differential diagnosis of a patient who is "hypotensive following coronary angiography and angioplasty". The only other information given to the candidates was that the patient is 60 years old, and male. 

The list of differentials can be divided into categories:

  • Complications of the anaesthetic
    • Anaphylaxis
    • Cardiodepressant effect of general anaesthetics
    • Local anaesthetic toxicity
  • Complications of the procedure
    • Cardiac tamponade
    • Coronary artery dissection or perforation
    • Aortic injury
    • Stent thrombosis
    • Retroperitoneal haematoma
    • Intestinal ischaemia due to cholesterol emboli
  • Complications of the underlying disease
    • Cardiogenic shock due to ischaemia
    • Brady or tachyarrhythmia
  • Unrelated catastrophic event
    • Pulmonary embolism
    • Sepsis

A short list of arterial vascular access complications

  • Pain
  • Thrombosis
  • Infection
  • Haematoma and nerve compression
    • median nerve compression (brachial)
    • retroperitoneal haematoma (femoral)
    • bowel perforation (femoral)
  • Air embolism
  • Accidental intra-arterial drug injection
  • Vessel damage may lead to stricture and prevent future AV fistula formation for haemodialysis
  • Pseudo-aneurysm
  • Arterial dissection
  • Arteriovenous fistula

Arterial cannulation complications in greater detail:

  • The risk of major complications is not influenced by the site of puncture.
  • There is no difference in complications when comparing ulnar artery cannulation to radial
  • There is no increased risk with brachial artery cannulation (the worst that happens seems to be a transient paraesthesia)
  • The risk of major complications is roughly 1 % for all sites.
  • The risk of thrombosis increases in parallel to the diameter of the catheter, as a proportion of the arterial lumen diameter.
  • A thrombosed artery takes up to 75 days to recanalize.
  • Arterial line related sepsis is very rare - occurring in 0.13% of cannulation events.
  • Risk of pseudoaneurysm is around 0.09 to 0.4%.
  • The Allen test has little predictive validity.

The arteries to avoid are:

  • Temporal (case report of cerebral thrombosis)
  • Posterior tibial (case report of amputation)
  • Dorsalis Pedis (poor accuracy in hypotension)

Unique complications according to site of cannulation:

  • Femoral artery insertion: retroperitoneal hematoma
  • Axillary artery insertion: brachial plexus injury
  • Brachial artery insertion: median nerve palsy due to compression by haematoma

Limb compromise after arterial puncture

Question 8 from the second paper of 2019  confronted the candidates with a pale ischaemic hand on the morning following a radial arterial line insertion, in a severely septic patient with meningogoccaemia. What are the potential causes, they asked.

The possibilities are:

  • Complication of line insertion
    • Possible complications which threaten limb perfusion include:
      • Mis-sized catheter (resulting in vessel occlusion)
      • Haematoma causing compression
      • Laceration causing vasospasm
      • Intimal dissection
      • Vessel  thrombosis
    • Distinguishing features:
      • Rapid onset
      • Evidence of multiple attempts
      • Pain and swelling at the insertion site
      • Dissection or thrombosis detected on angiography or ultrasonography of the affected limb
  • Complication of critical illness
    • Severe shock may give rise to poor limb perfusion
    • Distinguishing features:
      • Gradual onset
      • All limbs will be poorly perfused
      • Vasopressor requirements will be high
      • Angiography or ultrasonography of the affected limb will demonstrate normal patent vessels
  • Embolic phenomena
    • ​​​​​​​Due to 
      • Air embolism from the counterpressure set
      • Accidental administration of medications
      • Thrombi (from the line insertion site or from upstream, eg. in the context of AF)
      • Cholesterol emboli (also could be from line insertion)
      • Forgotten guidewire
    • Distinguishing features:
      • Rapid onset
      • History of drug administration or guidewire mismanagement
      • Vessel obstruction detected on angiography or ultrasonography of the affected limb

References

McGhee and Bridges Monitoring Arterial Blood Pressure: What You May Not Know (Crit Care Nurse April 1, 2002 vol. 22 no. 2 60-79 )

Scheer,Perel and Pfeiffer.Complications and risk factors of peripheral arterial catheters used for haemodynamic monitoring in anaesthesia and intensive care medicine. Crit Care. 2002; 6(3): 199–204.

Tavakol, Morteza, Salman Ashraf, and Sorin J. Brener. "Risks and complications of coronary angiography: a comprehensive review." Global journal of health science 4.1 (2012): 65.