Addisonian crisis

Emergency presentation with hypotension, hypoglycaemia and circulatory collapse due to acute glucocorticoid deficiency

Random cortisol

It is useful to send a random cortisol immediately in patients presenting acutely unwell before starting emergency glucocorticoid therapy. It is not necessary to perform a Synacthen test or other investigations as to possible underlying cause at this time.

Full blood count

This is a useful indicator of general health and underlying disease, and essential in the collapsed patient.

Macrocytosis may be seen with profound hypothyroidism, but may reflect undiagnosed pernicious anaemia.

Normocytic normochromic anaemia and eosinophilia may be seen with glucocorticoid deficiency.

Urea and electrolytes

Hyponatraemia is the most commonly seen abnormality.

Hyperkalaemia also usually occurs, though this can be deceptively normal in the patient who has been vomiting. 

Blood glucose levels

Patients with Addison's disease may well be hypoglycaemic. Monitor blood glucose levels at least 4 hourly.

Bone profile

Hypercalcaemia may occur with severe dehydration or with glucocorticoid deficiency.

Liver function test

Liver function should be tested at baseline and may be abnormal with congestive cardiac failure.

Thyroid function testing

Autoimmune thyroid dysfunction is commonly associated with Addison's disease. It is therefore prudent to check thyroid function at presentation, though a low TSH should be interpreted with caution in the acutely unwell patient.

Similarly, if glucocorticoid deficiency is the first presentation of pituitary disease, it is essential to document baseline pituitary function, although glucocorticoid replacement therapy takes precedence over all other treatments.  

Chest radiograph

Chest radiograph should be performed if there are any abnormal respiratory examination findings or there is a suspicioun of chest infection or malignancy. It may also reveal cardiomegaly and pleural effusions if there is coincident hypothyroidism.

Electrocardiogram

ECG must be performed in the collapsed or tachycardic patient.

Peaked T waves and arrythmias may occur with hyperkalaemia.

Bradycardia, decreased voltages, non specific St and T segment changes, varying degrees of heart block, a prolonged QT interval and J waves may all be present with myxoedema.

Septic screen: urine and blood cultures

A septic screen is usually worth performing in the collapsed patient looking for infections that might have precipitated the crisis.

Arterial blood gas analysis

This is not routinely required in the patient presenting with an obvious Addisonian crisis but may be indicated.