Statistics and Incidences
Endogenous Cushing's syndrome is rare, with roughly 1.8 to 3.2 new cases per million people each year (StatPearls). It is about three times more common in women than men and usually appears between ages 25 and 40 (Endotext).
Causes
In about 70% of patients it comes from excess corticotropin and resulting adrenal cortex hyperplasia. In the other 30%, it comes from a cortisol-secreting adrenal tumor, usually benign.
Clinical Manifestations
Excess adrenocortical hormone changes multiple systems. Muscle weakness follows hypokalemia or loss of muscle mass from catabolism. The Cushing's triad shows up as buffalo hump (fat pads over the upper back), moon face (excess facial fat), and truncal obesity (fat pads through the trunk). Peptic ulcer develops from increased gastric acid and pepsin and decreased gastric mucus. Irritability and emotional lability swing from euphoria to depression and psychosis. Hypertension follows sodium and water retention. The immune system is compromised, with increased infection risk from decreased lymphocyte production and suppressed antibody formation.
Complications
Addisonian crisis. A patient treated by corticosteroid withdrawal, adrenalectomy, or pituitary tumor removal is at risk for adrenal hypofunction and addisonian crisis. Adverse effects of adrenocortical activity require monitoring fluid and electrolyte status through lab values and daily weights.
Assessment and Diagnostic Findings
Low-dose dexamethasone suppression test: give dexamethasone 1 mg orally at 11pm and draw a plasma cortisol at 8am the next morning; this usually confirms the diagnosis. Stimulation test: metyrapone blocks adrenal cortisol production and tests whether the pituitary and hypothalamus can detect and correct low plasma cortisol by raising corticotropin. Imaging with ultrasound, CT, or angiography localizes adrenal tumors and may find pituitary tumors. Electrolytes show increased serum sodium and decreased potassium. Blood studies show increased glucose, fewer eosinophils, and disappearance of lymphoid tissue.
Medical Management
Restoring hormonal balance may take radiation, drugs, or surgery. Pituitary-dependent Cushing's with adrenal hyperplasia and severe cushingoid features (psychosis, poorly controlled diabetes mellitus, osteoporosis, severe pathologic fractures) may need pituitary irradiation.
Pharmacologic therapy. Adrenal enzyme inhibitors (metyrapone, aminoglutethimide, mitotane, ketoconazole) reduce hyperadrenalism when the cause is ectopic ACTH secretion from a tumor that cannot be removed. Cortisol therapy is essential during and after surgery so the patient can tolerate the stress of removing the pituitary or adrenals.
Surgical Management
Transsphenoidal hypophysectomy is the treatment of choice for pituitary tumors and has an 80% success rate. Adrenalectomy is the treatment of choice in primary adrenal hypertrophy.
Nursing Management
Assessment. Take a history covering activity level and ability to do routine and self-care tasks. On exam, inspect the skin for trauma, infection, breakdown, bruising, and edema. Assess mental function: mood, responses to questions, awareness of environment, and depression.
Diagnosis. Major nursing diagnoses: risk for injury related to weakness; risk for infection related to altered protein metabolism and inflammatory response; self-care deficit related to weakness, fatigue, muscle wasting, and altered sleep; impaired skin integrity related to edema, impaired healing, and thin fragile skin; disturbed body image related to altered appearance, impaired sexual function, and decreased activity; and disturbed thought processes related to mood swings, irritability, and depression.
Planning and goals: decrease risk of injury and infection, increase self-care ability, improve skin integrity, improve body image, and improve mental function.
Interventions. Decrease injury risk with a protective environment to prevent falls and fractures, assist the weak patient in ambulating, and recommend foods high in protein, calcium, and vitamin D to limit muscle wasting and osteoporosis (refer to a dietitian). Decrease infection risk: avoid exposure to people with infections and assess frequently for subtle signs, since corticosteroids mask inflammation. Before surgery, monitor blood glucose and check stools for blood, since diabetes mellitus and peptic ulcer are common. Balance rest and activity: encourage moderate activity to prevent the complications of immobility, and plan rest periods in a quiet environment. Protect skin with meticulous care, avoid adhesive tape, assess skin and bony prominences often, and reposition frequently. Support body image by discussing how the changes affect self-concept and relationships; most physical changes reverse in time once the cause is treated, and weight gain and edema respond to a low-carbohydrate, low-sodium diet with high protein. Support thought processes by explaining the cause of emotional instability, helping the family cope with mood swings, reporting psychotic behavior, and encouraging the patient and family to verbalize feelings.
Monitoring complications. For adrenal hypofunction and addisonian crisis, watch for hypotension; rapid, weak pulse; rapid respirations; pallor; and extreme weakness, and note precipitants such as stress, trauma, or surgery. Give IV fluids, electrolytes, and corticosteroids before, during, and after surgery as indicated. Watch for circulatory collapse and shock in addisonian crisis and treat promptly. Monitor fluid and electrolyte status with labs and daily weight, and report blood glucose elevations. Acute adrenal crisis is life-threatening and occurs when cortisol is too low.
Teaching. Give Cushing's information verbally and in writing. Stress that stopping corticosteroids abruptly without medical supervision causes adrenal insufficiency and a return of symptoms, and that the patient must keep an adequate supply to avoid running out or skipping a dose, which can trigger addisonian crisis. Push dietary modifications for adequate calcium without raising the risk of hypertension, hyperglycemia, and weight gain. Teach the patient and family to monitor blood pressure, blood glucose, and weight. Stress wearing a medical alert bracelet and telling other providers about the diagnosis. Refer for home care to ensure a safe, low-stress environment, and emphasize regular medical followup and awareness of medication side effects.
Evaluation. The patient has a decreased risk of injury and infection, increased self-care ability, improved skin integrity, improved body image, and improved mental function.
Frequently Asked Questions
What is Cushing's syndrome? Cushing's syndrome is a cluster of clinical findings caused by prolonged exposure to excess cortisol, whether from an internal source such as a pituitary or adrenal tumor or from corticosteroid medication. Classic signs include central weight gain, a moon face, a buffalo hump, thin fragile skin, hypertension, and high blood glucose.
How common is Cushing's syndrome? Endogenous Cushing's syndrome is rare, with about 1.8 to 3.2 new cases per million people each year. It is roughly three times more common in women than men and usually appears between ages 25 and 40 (StatPearls).
What causes Cushing's syndrome? In about 70% of endogenous cases, excess corticotropin (often from a pituitary tumor) drives adrenal cortex hyperplasia; the other 30% come from a cortisol-secreting adrenal tumor, usually benign. Long-term corticosteroid therapy is the most common cause overall (Endotext).
How is Cushing's syndrome diagnosed? Screening relies on tests of cortisol excess such as the low-dose dexamethasone suppression test, late-night salivary cortisol, and 24-hour urinary free cortisol, followed by corticotropin levels and imaging (CT, MRI) to localize the source (StatPearls).
How is it treated? Treatment targets the cause. Transsphenoidal removal of a pituitary tumor is the treatment of choice for pituitary disease, and adrenalectomy treats primary adrenal tumors. Adrenal enzyme inhibitors such as metyrapone and ketoconazole lower cortisol when surgery is not an option, and cortisol replacement is given around surgery.
What is the most important nursing teaching point? Never stop corticosteroids abruptly. Tapering must be supervised, the patient should keep an adequate supply and never skip doses, and they should wear medical identification, since abrupt withdrawal can trigger a life-threatening addisonian crisis.
Discharge and Home Care Guidelines
Tell the patient and family that adrenal insufficiency and symptoms can recur if discharge orders are not followed. Do not stop corticosteroids abruptly without medical supervision, and always keep an adequate supply. Modify the diet for adequate calcium without raising the risk of hypertension, hyperglycemia, and weight gain. Teach the patient and family to monitor blood pressure, blood glucose, and weight. Emphasize regular medical followup, medication side effects, and wearing medical identification noting Addison's and Cushing's disease.
Documentation Guidelines
Document the patient's and caregiver's understanding of risks and safety concerns, availability and use of resources, recent or current antibiotic therapy, signs of infection, functional level and limitations, needed resources and adaptive devices, the plan of care and who is involved, the teaching plan, responses to interventions and teaching, specific actions and changes made, progress toward outcomes, and modifications to the plan.