CUSHING’S SYNDROME
Cushing's syndrome is a condition in which the plasma cortisol levels are elevated, causing signs and symptoms of hypercortisolism
Incidence Occurs 10 times more frequently in women than in men. Affects mostly women between 20 & 40 years of age.
Causes
Tumor arising in the cortex of one of the adrenal glands or a basophilic adenoma of the pituitary glands, involving an overgrowth of pituitary cells.
Pathophysiology
The normal feedback mechanisms that control adrenocortical function are ineffective, resulting in secretion of adrenal cortical hormones despite adequate amounts of these hormones in the circulation.
The manifestations are the result of excess hormones (glucocorticoids, mineralocorticoids and adrenal androgens) Excess of 1 hormone or all the hormones can occur, the predominant hormone secreted in excess (usually gluco corticoids) determines the predominant symptoms.
Clinical Manifestations
Manifestations caused by excess glucocorticoids:
1. Weight gain/obesity .
2. Heavy trunk, thin extremities,
3. "Buffalo hump" (fat pad) in neck and supraclavicular area.
4. Rounded face (moon face); plethoric, oily.
5. Fragile and thin skin, striae and ecchymosis, acne.
6. Muscles wasted because of excessive catabolism.
7. Osteoporosis-characteristic kyphosis, backache.
8. Mental disturbances mood changes, psychosis
9. Increases susceptibility to infections
Manifestations caused by excess mineralo corticoids
1. Hypertension
2. Hypertremia, hypokalemia.
3. Weight gain
4. Expanded blood volume
5. Edema
Manifestations caused by excess androgens:
1. Women experience virilism (masculinization)
a. Hirsutism-excessive growth of hair on the face and midline of trunk,
b. Breasts atrophy.
c. Clitoris enlargement
d. Voice-masculine
e. Loss of libido
2. If exposed in utero-possible hermaphrodite.
3. Males-loss of libido.
Diagnostic Evaluation
1. Serum sodium and blood glucose levels - increased
Serum potassium - decreased.
Blood eosinophils - reduced.
2 Excessive plasma cortisol levels
3. Elevated urinary 17 hydroxy corticoids and 17 ketogenic steroids [(24 hrs. urine sample)] [(the metabolites of cortisol and androgens)]
4. X-rays of the skull detect erosion of the sella turcica, by a pituitary tumor
5. Elevation of plasma ACTH in patients with pituitary tumors
6. Low plasma ACTH levels with adrenal tumor
7. CT scan and ultrasonography detect location of tumor
8. A low-dose dexamethasone suppression test may be conducted in which a low dose of dexamethasone, a potent synthetic glucocorticoid, is administered and plasma cortisol and urine 17-liydroxycorticosteroid levels are obtained. In patients with normal adrenal function, even low doses of the glucocorticoid will produce decreased cortisol and 17-hydroxycorticosteroid levels. In patients with bilateral adrenal hyperplasia or adrenal tumors, there will be no decrease in these levels.
Overnight DST, possibly with cortisol urinary excretion measurement.
a. Unsuppressed cortisol level in Cushing's syndrome caused by adrenal tumors.
b. Suppressed cortisol lev. I is Cushing's disease caused by pituitary tumor,
Management
Surgical and Radiation:
Tumor (adrenal or pituitary) is removed or treated with irradiation.
1. Cushing's syndrome in adults is transsphenoidal adenoidectomy or hypophysectomy (pituitary tumor).
2. Transfrontal craniotomy turcica when pituitary tumor has enlarged beyond sella
3. Hyperplasia of adrenals - bilateral adrenalectomy.
Replacement therapy post operatively:
1. Adrenalectomy patients requite a lifelong replacement therapy with the following:
a. A glucocorticoid-cortisone (Cortef)
b. A mineralocorticoid - Fludrocortisone (Florinet)
2. After pituitary irradiation or hypophysectomy, patient may require adrenal replacement plus thyroid, posterior pituitary and gonadal replacement therapy.
3. After transsphenoidal adenectomy, patient requires hydrocortisone replacement therapy for periods of 12-18 months and additional hormones if excessive loss of pituitary function has occurred
4. Protein anabolic steroids may be given to facilitate protein replacement; Potassium replacement is usually required.
Medical Management
If patient cannot undergo surgery, cortisol synthesis inhibiting medications may be used.
1. Mitotane [an agent toxic to adrenal cortex (DDT derivative) known as medical adrenalectomy. Nausea, vomiting, diarrhoea, somnolence and depression may occur with use of this drug.]
2. Metyrapone (Metopirone) to control steroid hypersecretion in patients [who do not respond to mitotape therapy).
3. Aminoglutethimide (Cytadren) [blocks cholesterol conversion to pregnenolone], effectively blocking cortisol production, [S/EGI disturbances, somnolence and skin rashes]
Complications
Possibility of recurrence in patients with adrenal carcinoma
Nursing Interventions
1. Assess skin frequently to detect reddened areas, breakdown, excoriations, infection or edema.
2 Handle skin and extremities gently [to prevent trauma] protect from falls by use of side rails, avoid use of adhesive tape [to reduce risk of trauma] to skin and [its removal]
3. Encourage the patient to turn frequently or to ambulate [to reduce pressure on bony prominences and areas of edema).
4. Use meticulous skin care [to reduce injury and breakdown]
5. Provide foods low in sodium to minimize edema formation.
6 Monitor Intake/Output & daily weights to evaluate fluid retention.
7. Assist with ambulation and hygiene when weak and fatigue
9. Encourage rest when fatigued. Encourage gradual resumption of activities as the patient gains strength.
10. Instruct the patient in correct body mechanics to avoid pain or injury during activities.
11. Use assistive devices during ambulation to prevent falls and fractures
12. Encourage foods high in K (bananas, orange juice, tomatoes) and administer K supplement as prescribed to counteract weakness R/T hypokalemia.
13. Encourage patient to verbalize concerns about illness, changes in appearance and altered role functions.
14. Identify disturbing situations to the patient and ways to avoid or modify them.
15. Answer questions about surgery.
16. Monitor closely for infection because glucocorticoids interfere with immune function, maintain aseptic technique, clean environment and good handwashing.
17. Monitor fluid I & O and urine specific gravity to detest DI caused by ADH deficiency after hypophysectomy
18. Instruct patient on lifetime hormone replacement therapy and the need to follow up at regular intervals [to determine if dosage is appropriate or to detect S/E].
19. Help patient prevent hyperglycaemia, and obesity by teaching a low-calorie, low-concentrated CHO and fat diet and to increase activity as tolerated.
20. Encourage diet high in calcium (dairy products, broccoli) and weight bearing activity to prevent osteoporosis caused by glucocorticoid replacement.
