168 Adrenal Crisis
Key Points• Adrenal crisis is an uncommon cause of shock.
• An inappropriate adrenal response may contribute to shock in patients with sepsis, trauma, myocardial infarction, and other conditions associated with extreme physiologic stress.
• The diagnosis of acute adrenal crisis may be challenging because the symptoms are often nonspecific (e.g., weakness, fatigue, gastrointestinal symptoms, abdominal, flank, or back pain).
• Laboratory findings include hyponatremia, hyperkalemia, hypoglycemia, lymphocytosis, and eosinophilia.
• Adrenal crisis may result from either primary adrenal insufficiency or secondary adrenal suppression as a result of exogenous steroids or from failure of the hypothalamic-pituitary-adrenal axis. In the latter, mineralocorticoid replacement is not necessary, but thyroid supplementation may be lifesaving.
• Emergency department management includes aggressive fluid resuscitation, correction of electrolyte abnormalities, maintenance of euglycemia, and administration of glucocorticoids and mineralocorticoids.
• Treatment should begin with initial suspicion of adrenal crisis, not at the time of laboratory confirmation. Interventions are indicated when the cause of the shock is obscure, the patient fails to respond to volume and pressors within 1 hour, or the diagnosis of adrenal insufficiency is confirmed.
Epidemiology
Most cases of primary adrenal insufficiency are autoimmune mediated, but other common causes include infection and hemorrhage. Onset is generally indolent, although acute adrenal crisis accounts for approximately 25% of all cases. Primary adrenal insufficiency has an estimated incidence of 50 per 1 million persons. Secondary insufficiency as a result of chronic glucocorticoid administration is more common than primary insufficiency in the United States; 2% of the population is estimated to have relative insufficiency that becomes manifested only at times of physiologic stress.1
Feedback Loops
Targets of Action
Mineralocorticoids act at the renal tubules to maintain Na+, K+, and water balance. Glucocorticoid subunits enter various cell nuclei and modify the expression of a wide range of genes in different organ systems (Table 168.1). Cortisol is capable of targeting the mineralocorticoid receptors at pharmacologic doses, although at physiologic levels it is converted to inactive cortisone on entering the kidney.
| FUNCTION/TARGET SYSTEM | ACTION |
|---|---|
| Metabolism |
Clinical Application
Adrenal insufficiency is classified as primary, secondary, or relative. Causes of primary insufficiency are numerous (Table 168.2). Secondary insufficiency is most commonly due to exogenous steroid withdrawal. Relative adrenal insufficiency occurs in individuals who may have normal glucocorticoid levels but exhibit an inadequate response of the hypothalamic-pituitary-adrenal axis to major stress.
| CAUSE | ASSOCIATED FACTORS |
|---|---|
| Autoimmune adrenal atrophy (80% of cases) | |
| Associated endocrinopathies | Hypoparathyroidism, hepatitis, type 1 diabetes mellitus, hypogonadism, hypothyroidism |
| Infections | Disseminated tuberculosis, cytomegalovirus, histoplasmosis, human immunodeficiency virus, candidiasis |
| Genetic diseases | Congenital adrenal hyperplasia, adrenoleukodystrophy, familial glucocorticoid deficiency |
| Metastatic malignancy or lymphoma | |
| Adrenal hemorrhage | |
| Infiltrative disorders | Amyloidosis, hemochromatosis |
| Drugs | Ketoconazole, suramin |
Presenting Signs and Symptoms
Patients with primary and secondary adrenal insufficiency typically have chronic complaints. Those with primary disease may exhibit weakness, fatigue, anorexia, nausea, vomiting, weight loss, hypotension, hyperpigmentation, hyponatremia, and hyperkalemia. The hyperpigmentation is initially generalized and later becomes evident in the mucous membranes, palmar creases, nail beds, and nipples. Gastrointestinal disturbances are present in about half of patients with postural symptoms. Salt craving is a less common complaint. Associated endocrinopathies may complicate the initial findings (see Table 168.2).
