Precautions for Patients on Steroids Undergoing Surgery

Since the 1940s synthetic corticosteroids (or steroids) have been developed for their anti-inflammatory and immunomodulatory effects. Patients on steroids who present for surgery may be at increased risk of complications because of:

• The adrenal suppression caused by steroid therapy.¹ This often poses the greatest risk and deserves particular attention. It is important for patients to be educated about the risk.² Steroid cards should be carried by patients taking steroids.
• The disease or condition which required them to take steroids. Corticosteroids are used in a wide variety of conditions. Some of these may also have attached risks for anaesthesia (those for example affecting lungs, neck joints or drug metabolism).
• Long term and other side effects of steroid therapy. These include:
  • Hypertension
  • Diabetes mellitus
  • Fatty liver
  • Susceptibility to infection
  • Osteoporosis
  • Avascular necrosis of bone
  • Skin sepsis
  • Electrolyte disturbance:hypokalaemia, metabolic alkalosis

There are pre-operative, per-operative and post-operative factors to be considered when assessing and managing these risks.

In normal healthy patients there is a prompt secretion of cortisol with the onset of surgery and secretion remains elevated for several days after surgery. Glucocorticoids are not stored and must be synthesised when required, for example during and after surgery. This response depends on the hypothalamopituitary axis which may be suppressed or unresponsive to stress when steroids have been taken.¹ Failure of cortisol secretion may result in the circulatory collapse and hypotension characteristic of a hypoadrenal or 'Addisonian' crisis.²

• Pre-operative considerations.
  • How much steroid has been taken and for how long? The degree of adrenal suppression depends on the dose and duration of steroid treatment. However the integrity of the adrenal response is not routinely tested and steroid cover or supplements are given according to the surgical stimulus (minor, moderate and major surgery).
  • Dosages of less than 5 mg prednisolone per day are not significant and no steroid cover is required.
  • 10 mg/day or more of prednisolone (or equivalent) is generally taken as the threshold dose for 'steroid cover'.
  • Steroid cover is required if taken within 3 months of the surgery. This is because adrenal suppression can occur after only a week and may take as long as 3 months to recover.³
• Per-operative considerations. Normal cortisol secretion is about 30 mg/day. The normal rise in plasma ACTH and hence cortisol is in response to the severity of surgery. The adrenals are capable of secreting about 300 mg/day (equivalent to about 75 mg of prednisolone) but output rarely exceeds 150 mg of cortisol/day even in response to major surgery.
• Post-operative considerations. The normal rise in cortisol secretion after surgery lasts about 3 days. In recent years doses used for steroid cover have been reduced⁴ because excessive doses cause adverse effects such as post-operative infection, gastrointestinal haemorrhage and delayed wound healing.⁵

Pre-operative assessment

This should focus on the history of steroid usage, routine examination (including blood pressure) and basic investigations including:

• FBC.
• U and Es.
• Blood glucose
• Liver function tests

Investigation for adrenal suppression is rarely done.¹ It is possible to assess this⁶ with:

• Serum and urinary cortisol
• Short synacthen test (SST) - more popular but interpret with care.⁶
• Insulin tolerance test
• CRH measurement

Peri-operative management

It is useful to summarise who should receive steroid cover for surgery (and during major illness):

• Patients on corticosteroids at a dose of 10 mg or more of prednisolone (or equivalent) daily (equivalent to Betamethasone 750 micrograms, Fluticasone 375 micrograms, Dexamethasone 6 mg, Hydrocortisone 20 mg, Methylprednisolone 4 mg daily).
• Patients who have received corticosteroids 10 mg daily within the three months preceding surgery.
• Patients on high dose inhaled corticosteroids (for example beclomethasone 1.5 mg a day).
• Patients who stopped their steroids more than 3 months ago or who are taking 5 mg or less require no steroid cover.

Peri-operative steroid cover

Note that infusion is now preferred to bolus (this avoids excessive doses of steroid with possible complications). Historically doses were even higher, further revision of doses may be recommended with further research, but for the moment empirical recommendations⁴ are:

• Minor surgery - 25 mg hydrocortisone at induction of anaesthesia and then resume normal medication postoperatively.
• Moderate surgery - Usual dose of steroids pre-operatively and then 25 mg of hydrocortisone intravenously at induction followed by 25 mg IV every 8 hours for 24 hrs. Usual pre-operative dose then continued.
• Major surgery - Usual dose of steroids pre-operatively, then a bigger 50 mg of hydrocortisone intravenously at induction followed by 50 mg Intravenously every 8 hours for 48-72 hrs. Continue this infusion until the patient has started light eating, then restart normal pre-operative dose.

Remember that patients receiving <10 mg of prednisolone or equivalent do not need steroid cover but should continue with their usual maintenance steroid dosage. Patients on long term steroids do not require supplementary steroid cover for routine dentistry or minor surgical procedures under local anaesthesia.⁷

There is a wide range of diseases for which corticosteroid treatment is commonly used. It is important to remember that these conditions may also carry risk for both anaesthesia and surgery. Examples of conditions likely to have a consequence for surgery and anaesthesia include:

• Asthma
• Rheumatoid arthritis
• Glomerulonephritis
• Idiopathic thrombocytopenic purpura
• Cerebral oedema
• Malignancies and chemotherapy

These conditions should be fully assessed pre-operatively.

There are many risks associated with long term steroid treatment and these should be borne in mind pre-operatively, per-operatively and post-operatively.