General Medications

This covers perioperative management of medications, with the exception of:

Respiratory Medications

Inhaled bronchodilators:

  • Continue
    ↓ risk of post-operative respiratory complications.

Theophylline:

  • Withhold from day prior to surgery
    Multiple potential pharmacokinetic interactions.

Cardiac Medications

Alpha 2 agonists:

  • Continue if already taking
    Give parentally if will be NBM.

ACE-Is/A2RBs:

  • Generally withhold, however:
    • Favour continuing if for cardiac failure or poorly controlled hypertension to avoid exacerbation
    • Favour withholding if intraoperative hypotension likely or problematic
      If withheld, restart as soon as possible.

Beta-blockade:
* Continue if already taking * Consider starting: * If indicated and therapy can be initiated 2-4 weeks prior to surgery * In patients with known ischaemic heart disease or myocardial risk factors
* In patients with RCRI ⩾3 * If initiating, it is ideal to begin long enough in advance to evaluate safety and tolerability
* At least 2-7 days * ⩽1 day harmful

Calcium Channel Blockers:

  • Continue if already taking

Non-statin lipid-lowering agents:

  • Discontinue if taking
    May interfere with oral absorption of other medications, and contribute to myopathy.

Statins:

  • Should be continued
  • Consider initiation in patients:
    • Undergoing vascular surgery
    • Who have an indication and are undergoing elevated risk procedures

Diuretics:

  • Depends on indication:
    • For hypertension
      Withhold on morning of surgery.
    • For cardiac failure
      • Well controlled with stable volume state
        Withhold on morning of surgery.
      • Poorly controlled or previous problems with fluid overload
        Continue.

CNS Agents

Antidepressants:

  • SSRIs/SNRIs
    Generally continue, however:
    • May be ceased if substantial concern about bleeding
      Should be weaned off:
      • Over several weeks
      • With psychiatrist involvement
      • And consideration of starting an alternative anaesthetic regimen
  • MAO-Is
    Generally cease 2 weeks prior.
    • Risk of profound hypertension with indirect acting sympathomimetics
      Directly acting agents (noradrenaline, adrenaline, phenyephrine, isoprenaline) are safe when used judiciously.
    • May be continued if:
      • Anaesthetist comfortable with MAO-safe anaesthesia
      • Psychiatrist concerned about exacerbation of psychiatric disease with drug cessation
  • Lithium/Valproate
    Generally continue perioperatively due to concerns about exacerbating underlying disease. Ensure regular monitoring of:
    • Fluids
    • Electrolytes
    • Serum lithium levels
  • TCAs
    May be continued but:
    • Preoperative 12-lead ECG and intraoperative 5-lead ECG should be performed
      If ceased due to concerns about arrhythmia, should be tapered off 7-14 days prior to surgery.
    • Tramadol and meperidine should be avoided
    • Atropine or scopolamine may ↑ perioperative confusion

Endocrine Medications

OCP: * Consider ceasing 4 weeks prior if high VTE risk.

Thyroxine:

  • Should be continued perioperatively
  • Requires parental administration if cannot be resumed within 5-7 days perioperatively

Glucocorticoids:

  • Chronic glucocorticoid therapy may suppress the HPA axis and prevent an appropriate adrenal response to physiological stress
    In absence of glucocorticoids, endogenous cortisol release:
    • ↑ even with minor surgery or illness
      ↑ may be 5 to 50 times normal, depending on degree of insult.
    • May persist for days
      Normalise within 24 hours for small insults, and 5 days for larger insults.
  • Addition of “stress dose” steroids perioperatively is common practice, although lacks a strong evidence base
  • In general, patients:
    • Do not have HPA suppression with:
      • Prednisolone doses <5mg/day
      • Any dose of glucocorticoid for <3 weeks
    • Do have HPA suppression with:
      • Prednisolone doses >20mg/day
      • Evidence of Cushing’s syndrome
  • Stress-dosing varies on degree of surgical stress:
    • Minor stress
      Take usual steroid dose.
    • Moderate stress
      Take usual steroid dose, and supplement with:
      • 50mg Hydrocortisone IV pre-procedure
      • 25mg Hydrocortisone Q8H for 24/24
    • Severe stress
      Take usual steroid dose, and supplement with:
      • 100mg Hydrocortisone IV pre-procedure
      • 50mg Hydrocortisone Q8H for 24/24
      • Taper hydrocortisone dose by half each day until maintenance steroid dose reached

Complementary and Alternative Medicines

In general, ceasing all herbal/complimentary medicine 2 weeks prior is a safe approach.

Specific medications:

  • Ephedra
    Cease 24 hours prior; ↑ cardiac risk.
  • Garlic
    Cease 7 days prior; ↑ bleeding risk.
  • Ginkgo balboa
    Cease 36 hours prior; ↑ bleeding risk.
  • Ginseng
    Cease 7 days prior; ↑ hypoglycaemia.
  • Kava
    Cease 24 hours prior; pharmacokinetic interactions with anaesthetic agents.
  • St. John’s Wort
    Cease 5 days prior; multiple pharmacokinetic interactions.
  • Valerian root
    Tapered weeks pre-operatively; ↑ sedation with anaesthesia.
  • Echinacea
    ↑ Hypersensitivity.

References

  1. De Hert S, Imberger G, Carlisle J, et al. Preoperative evaluation of the adult patient undergoing non-cardiac surgery. Eur J Anaesthesiol. 2011;28(10):684-722.
  2. Duceppe E, Parlow J, MacDonald P, Lyons K, McMullen M, Srinathan S, et al. Canadian Cardiovascular Society Guidelines on Perioperative Cardiac Risk Assessment and Management for Patients Who Undergo Noncardiac Surgery. Canadian Journal of Cardiology. 2017 Jan 1;33(1):17–32.