Acute Adrenal Insufficiency

Author(s): James Crane and Paul Carroll

Consider the diagnosis in any patient with unexplained hypotension and suggestive clinical features (Table 90.1). Acute adrenal insufficiency most commonly occurs as an acute exacerbation of an underlying chronic or subacute insufficiency, triggered by concomitant illness such as infection.

A high index of suspicion should be maintained in any patient with circulatory collapse particularly if not responsive to initial fluid resuscitation. Prompt recognition and glucocorticoid replacement may be a life-saving treatment in a critically unwell patient, and should not be delayed while awaiting test results.
Patients on long-term corticosteroid therapy (prednisolone >5 mg daily or equivalent for ≥4 weeks) are at risk of glucocorticoid insufficiency if steroids are abruptly withdrawn.
In secondary adrenal insufficiency (Table 90.2), haemodynamic compromise may not be accompanied by typical electrolyte disturbance as aldosterone is unaffected.

Priorities ⬆ ⬇

In the patient presenting with acute circulatory collapse and suspected adrenal insufficiency (Tables 90.1 and 90.2), the following goals should be achieved in the first hour of treatment:

Rapid assessment of airway, breathing, circulation and conscious level in a level 2 or 3 environment, with continuous monitoring of heart rate, blood pressure and oxygen saturation.
Airway management by competent staff if the airway is compromised or the Glasgow Coma Scale score is less than 8.
Supplemental oxygen if needed to maintain oxygen saturation >94%.
Intravenous access, with blood sent for urgent investigation (Table 90.3).
Fluid resuscitation with normal saline to correct the volume deficit.
Place a bladder catheter for monitoring of urine output.
Look for a MedicAlert^® or similar bracelet/necklace as this may reveal the diagnosis.
Give hydrocortisone 200 mg IV. Fludrocortisone is not required in addition, as this dose of hydrocortisone has sufficient mineralocorticoid action.
Give a broad-spectrum antibiotic after taking blood and urine for culture, in case the trigger is infection.
If the patient is well enough, take a detailed history for the symptoms of adrenal insufficiency and commonly associated disorders (Tables 90.1 and 90.2). Look for clinical signs, especially hyperpigmentation suggestive of elevated ACTH, to differentiate primary from secondary adrenal insufficiency. Hyperpigmentation is best seen over the palmar creases, knuckles, old scars and the oral mucosa.

Once stabilized, transfer the patient to an appropriate care area.

Further Management ⬆ ⬇

Outline

Steroid Replacement
Making the Patient Safe for Discharge
Confirming the Diagnosis
Determining the Cause

Steroid Replacement

If in doubt, hydrocortisone replacement should continue until adrenal sufficiency can be conclusively confirmed or excluded. In the acutely unwell patient, give hydrocortisone 50–100 mg 6-hourly IV or IM.
After treatment of any underlying concomitant illness and when the patient is feeling well, parenteral hydrocortisone can be stepped down to a double-physiological dose of oral hydrocortisone, or approximately 40 mg daily in divided doses. When completely recovered, physiological replacement can commence.
Mineralocorticoid replacement for primary adrenal insufficiency is normally achieved with a dose of fludrocortisone 50–200μgm PO once daily, and is started at 100μgm. Adequacy of dose can be assessed by an absence of clinical signs of hypovolaemia (e.g. postural hypotension) and normal electrolytes.

Making the Patient Safe for Discharge

Educating the patient on what to do in the presence of acute illness is of paramount importance and may be a life-saving intervention. Patient information resources can be found and reproduced free of charge at the website of the Addison's Disease Self-help Group, www.addisons.org.uk, and are based on the advice of an expert panel.
Patients should be advised to double their hydrocortisone dose in the presence of febrile illness (temperature >37.5°C), if on antibiotics or if undertaking very strenuous exercise. Patients should take 20 mg after vomiting and seek medical attention if vomiting more than once as parenteral hydrocortisone is likely to be required.
If a cause of permanent adrenal insufficiency is confirmed, the patient should be strongly advised to wear an identity bracelet to alert health-care professionals to their condition and potential need for immediate hydrocortisone in the event of an emergency.

Confirming the Diagnosis

When well, definitive determination of adrenal status can be sought. If primary adrenal insufficiency is suspected (ACTH elevated at presentation), a short Synacthen test is done (Table 90.4). Alternative investigations (e.g. an insulin stress test) may be necessary for secondary adrenal insufficiency; seek advice from an endocrinologist.

Determining the Cause

If primary adrenal insufficiency is confirmed, further investigations are required to elucidate the aetiology. The presence of adrenal autoantibodies suggests an autoimmune process that may be part of a polyglandular syndrome, and clinical features of other associated conditions should be sought (Table 90.2). Seek advice from an endocrinologist.
If secondary adrenal insufficiency is identified, a thorough search for a history of exogenous steroid is the first step. Inhaled and topical steroids can be absorbed systemically in sufficient quantities to result in adrenal insufficiency if stopped abruptly. Glucocorticoids are also found in commercially available skin-lightening creams and are a common cause of Cushing's syndrome (followed by adrenal insufficiency after cessation) in certain demographic groups.
In the absence of exogenous steroid, first-line investigations are directed at the pituitary gland. Seek advice from an endocrinologist.

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Information ⬇

Priorities ⬆ ⬇

Further Management ⬆ ⬇

Further Reading ⬆