Perioperative cardiovascular risk

Question 4 from the first paper of 2002 invites the candidates to discuss the perioperative management of a cardiac disease patient undergoing non-cardiac surgery.  The college model answer to this 2002 question refers to the "recently published" ACC/AHA guidelines. The 2014 reiteration of these guidelines is now available, which is a massive 50 page document.  The anaesthetic trainee will be abundantly familiar with these guidelines. For them, it must be bread and butter, luxuriously coated in the warmth of cuddly risk avoidance. For the intensivist however, anything reminiscent of anaesthetic preadmission clinics and preoperative risk assessments will be met with a mixture of revulsion and despair. In that spirit, the answer to Question 4 has been offered here in as brief a form as possible.

Preoperative assessment

  • Standard preoperative investigations including ECG, CXR, and bloods
  • Risk stratification, based on
    • Exercise tolerance (METs)
    • History of recent ischaemia
    • Stability of cardiac symptoms
  • High risk patients:
    • Exercise stress test: you need to pass it before surgery.
    • If this is failed for whatever reason, test for reversible ischaemia with a MIBI scan.
    • If there are areas of reversible ischaemia, angio and revascularisation should happen before the operation.
    • If there are no areas of reversible ischaemia and the patient has failed spectacularly in the EST, the degree fo cardiac disease makes them a poor candidate for surgery. Conservative options should be explored.   
  • Preoperative TTE and optimisation of LV function

Preoperative management

  • Control of hypertension
  • Control of arrhythmias
  • Management of antiplatelet agents for drug eluting stents:
    • Delay elective surgery until 4-6 weeks after bare metal stent insertion.
    • If possible, delay surgery until 180 days have passed.
    • Definitely delay for 180 days after a drug-eluting stent is placed months (assuming the clopidogrel is to be stopped)

Intraoperative management

  • Precautionary invasive monitoring, eg. arterial line / PA catheter
  • Maintenance of normotension
  • Epidural anaesthesia

Postoperative management

  • Monitoring in ICU/HDU, and possibly delayed extubation
  • postoperative support with vasopressors and inotropes

The college, in their 2002 model answer, recommended the use of perioperative beta-blockers to reduce the mortality and risk of MI in these patients. Unfortunately, they recommended this on the basis of some work by Don Polderman, which was discredted after he was fired from his academic position for widespread fraud. Later systematic reviews (eg. Wijeysundera et al, 2014), after performing pre- and post-fraud analysis, determined that beta-blockers actual"y increased perioperative mortality after Polderman's work was excluded from the data set. "Perioperative beta blockade started within 1 day or less before noncardiac surgery prevents nonfatal MI but increases risks of stroke, death, hypotension, and bradycardia" they somberly concluded. As such, the current guidelines do not recommend preoperative beta blockade.

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