Lab Case 67 – Interpretation

5 year old critically unwell child who is hypotensive and tachycardic

1. Immediate priorities:

Concurrent Resuscitation and assessment

Check BSL – likely to be low

ivi access

2. Normal anion gap metabolic acidosis

hyperkalaemia

hyponatraemia

impaired renal function

3. Acute adrenal crisis – Addison’s disease

expect hypoglycaemia

4. This may be provoked either de novo, such as by adrenal hemorrhage, or in the setting of an acute event superimposed on chronic or inadequately treated adrenocortical insufficiency.

precipitants: stress factors such as infection, trauma, vomiting, diarrhoea, surgery or noncompliance with replacement steroids.

Causes of acute Addison disease:

  • Stress – Acute adrenal crisis precipitated by infection, trauma, surgery, emotional turmoil, or other stress factors may be the initial presentation of Addison disease in as many as 25% of cases.
  • Failure to increase steroids
    • in times of stress could precipitate an adrenal crisis.
    • Failure to adjust the replacement steroid dose in patients on cytochrome P450 enzyme-inducing medications such as rifampin and Dilantin also could precipitate an adrenal crisis.[32, 33]
  • Bilateral adrenal hemorrhage
    • This may be the cause of an acute adrenal crisis, and it may occur as a complication of bacterial infection with Meningococcus or Pseudomonas species, as in Waterhouse-Friderichsen syndrome.
    • It also may occur as a complication of pregnancy, anticoagulant therapy with heparin or warfarin, and as a complication of coagulopathies such as antiphospholipid syndrome (APS) in patients with systemic lupus erythematosus (SLE).
  • Bilateral adrenal artery emboli and bilateral vein thrombosis
    • This is a very rare cause of Addison disease but may occur in critically ill patients on heparin as a complication of heparin-induced thrombosis (HIT) or as a complication of other states that predispose to thrombosis.
    • It also may occur as a complication of radiographic contrast studies involving the adrenal glands.
  • Bilateral adrenalectomy for any reason
    • The surgical removal of a unilateral cortisol-producing adrenal adenoma in a patient with Cushing syndrome can cause an acute adrenal crisis from secondary adrenocortical insufficiency.
    • This is due to the atrophy of the normal adrenal cortex from lack of the stimulant effect of pituitary ACTH.

5.

Clinical Features:

History

Weakness, fatigue, poor appetite, weight loss

Prominent gastrointestinal symptoms may include nausea, vomiting, and occasional diarrhea

Dizziness with orthostasis due to hypotension occasionally may lead to syncope. This is due to the combined effects of volume depletion, loss of the mineralocorticoid effect of aldosterone, and loss of the permissive effect of cortisol in enhancing the vasopressor effect of the catecholamines

Myalgias and flaccid muscle paralysis may occur due to hyperkalemia

Other reported symptoms include muscle and joint pains; a heightened sense of smell, taste, and hearing; and salt craving.

Impotence and decreased libido may occur in male patients, especially in those with compromised or borderline testicular function

Female patients may have a history of amenorrhea due to the combined effect of weight loss and chronic ill health or secondary to premature autoimmune ovarian failure. Steroid-responsive hyperprolactinemia may contribute to the impairment of gonadal function and to the amenorrhea

Examination

Hyperpigmentation in sun exposed areas

Vitiligo

Presentation of acute Addison disease

Patients in acute adrenal crises most often have prominent nausea, vomiting, and vascular collapse. They may be in shock and appear cyanotic and confused.

Abdominal symptoms may take on features of an acute abdomen.

Patients may have hyperpyrexia, with temperatures reaching 105° F or higher, and may be comatose.

In acute adrenal hemorrhage, the patient, usually in an acute care setting, deteriorates with sudden collapse, abdominal or flank pain, and nausea with or without hyperpyrexia.

Physical

Physical examination in long-standing cases most often reveals increased pigmentation of the skin and mucous membranes, with or without areas of vitiligo.

  • Patients show evidence of dehydration, hypotension, and orthostasis.
  • Female patients may show an absence of axillary and pubic hair and decreased body hair. This is due to loss of the adrenal androgens, a major source of androgens in women.
  • Addison disease caused by another specific disease may be accompanied by clinical features of that disease.
  • Calcification of the ear and costochondral junctions is described but is a rare physical finding.

6. Give the patients steroids (and probably glucose) – do not delay steroids for investigation (see below)

Morbidity and mortality associated with Addison disease usually are due to failure or delay in making the diagnosis or a failure to institute adequate glucocorticoid and mineralocorticoid replacement

Consider antibiotics

Look for a cause

ICU admission

  • In acute adrenal crisis, where treatment should not be delayed in order to do the tests, a blood sample for a random plasma cortisol level should be drawn prior to starting hydrocortisone replacement.
    • A random plasma cortisol value of 25 mcg/dL or greater effectively excludes adrenal insufficiency of any kind. However, a random cortisol value in patients who are acutely ill should be interpreted with caution and in correlation with the circumstances of each individual patient. Random cortisol levels should also be interpreted cautiously in critically ill patients with hypoproteinemia (serum albumin < 2.5 g/dL). Approximately 40% of these patients will have baseline and cosyntropin-stimulated cortisol levels below the reference range even though the patients have normal adrenal function (as evidenced by the measurement of free cortisol levels). This phenomenon is because more than 90% of circulating cortisol in human serum is protein bound.
    • Cortisol is known to be elevated by stress, but exactly how high it should rise to constitute a normal response in times of severe stress is not known.
    • An abnormal test result should prompt a proper evaluation of the hypothalamic pituitary adrenal axis after the patient’s condition improves before committing a patient to lifelong steroid replacement.
    • In order to perform the ACTH stimulation test in this situation, the patient should be switched to dexamethasone and then tested 24-36 hours later. Dexamethasone does not interfere with the cortisol assay, as does hydrocortisone or prednisone. However, dexamethasone may interfere with interpretation of the random cortisol value drawn after dexamethasone already has been initiated. Dexamethasone also does not have any mineralocorticoid activity, which may be needed in patients with Addison disease.
      • In the setting of both adrenocortical insufficiency and hypothyroidism that requires treatment, corticosteroids should be given before thyroid hormone replacement to avoid precipitating an acute adrenal crisis.
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