Chapter 44

1. Chapter 44 Pituitary and Adrenal Disorders

2. Learning Objectives • Identify data to be collected for the nursing assessment of adrenal and pituitary function. • Describe the tests and procedures used to diagnose disorders of the adrenal and pituitary glands. • Describe the pathophysiology and medical treatment of adrenocortical insufficiency, excess adrenocortical hormones, hypopituitarism, diabetes insipidus, and pituitary tumors. • Assist in developing nursing care plans for patients with selected disorders of the adrenal and pituitary glands.

3. Hormone Functions and Regulation Released in response to body’s needs Responsible for reproduction, fluid and electrolyte balance, host defenses, responses to stress and injury, energy metabolism, and growth and development Endocrine system: maintain homeostasis Maintenance of physiologic stability despite constant changes in the environment

4. Hormone Functions and Regulation Feedback mechanisms Controls regulation of endocrine activity by either stimulating or inhibiting hormone synthesis and secretion Triggered by blood levels of specific substances May be positive or negative

5. The Pituitary Gland

6. Anatomy and Physiology Weighs approximately 0.6 g; located in the sella turcica, a small indentation in the sphenoid bone at the base of the brain Connected to the hypothalamus by the infundibular (hypophyseal) stalk Small and oval; diameter of about 1 cm

7. Figure 44-1

8. Anatomy and Physiology Anterior lobe Larger of the two lobes: accounts for 70% to 80% of the gland’s weight Called the adenohypophysis Secretes Growth hormone (GH), or somatotropic hormone Adrenocorticotropic hormone (ACTH) Thyroid-stimulating hormone or thyrotropic hormone Follicle-stimulating hormone Luteinizing hormone Prolactin, or lactogenic hormone Melanocyte-stimulating hormone

9. Anatomy and Physiology Posterior lobe The smaller lobe Also called the neurohypophysis Secretes Antidiuretic hormone (ADH), or vasopressin Oxytocin

10. Health History Present illness Slowed or accelerated growth, visual disturbances, headache, and changes in urine output, appearance, skin, and secondary sex characteristics Past medical history Brain tumors, pituitary surgery, head trauma, central nervous system infection, vascular disorders, chronic renal failure, hypothyroidism, and disease of the pancreas, liver, or bone Family history of diabetes insipidus

11. Health History Review of systems Fatigue, weakness, restlessness, or agitation Skin moisture and changes in body hair distribution Significant sensory changes such as blurred vision and diplopia (double vision) Changes in the breasts Chest pain, constipation, polyuria, changes in genitalia, sexual dysfunction, joint pain, abnormal sensations, edema, seizures, and intolerance of heat or cold

12. Health History Functional assessment Determine whether the patient has had sleep disturbances Usual diet; note the effects of symptoms on the person’s self-concept and usual activities

13. Physical Assessment Vital signs, height, and weight Skin for moisture and edema Inspect head and face for thickened lips, broad nose, and prominent forehead and jaw; test visual acuity Inspect the breasts for enlargement in men, atrophy in women, and nipple discharge Inspect and palpate the extremities for edema. Perform joint range of motion, noting any limitations or crepitus Test reflexes for slowness of response Male genitalia loss of hair; palpate for testicular atrophy

14. Age-Related Changes In healthy older adults, pituitary function remains adequate Increased ADH secretion impairs ability to concentrate urine, increasing risk of dehydration

15. Diagnostic Tests and Procedures Radiographic studies Conventional radiographs Computed tomographic (CT) scans MRI Cerebral angiography Laboratory studies Radioimmunoassay Enzyme-linked immunosorbent assay (ELISA) Hormone reserve activity also can be measured using a number of “suppression” or “stimulation” tests

16. Pituitary Disease

17. Figure 44-2

18. Disorders of the Pituitary Gland

19. Hyperpituitarism Etiology Pathologic state caused by excess production of one or more of the anterior pituitary hormones Common factor is presence of a pituitary adenoma Growth hormone and prolactin often in excess Overproduction leads to gigantism or acromegaly Overproduction of prolactin causes prolactemia

20. Figure 44-3

21. Figure 44-4

22. Hyperpituitarism Medical diagnosis Radiographic studies CT scans using a water-soluble dye MRI Laboratory studies Anterior pituitary hormone levels Dexamethasone suppression tests

23. Hyperpituitarism Medical treatment Drug therapy Somatostatin analogs, dopamine agonists, GH receptor antagonists, and octreotide (Sandostatin) Radiation Surgical management Hypophysectomy: surgical removal of the adenoma or of the pituitary

24. Figure 44-5

25. Hyperpituitarism Assessment Gigantism/acromegaly: energy level, height/weight, vital signs, contours of the face and skull, visual acuity, speech, voice quality, abdominal distention If surgery, determine what patient knows and expects Interventions Disturbed Body Image Activity Intolerance Chronic Pain Ineffective Therapeutic Regimen Management

26. Hyperpituitarism Postoperative nursing care Assessment Neurologic status and vision must be monitored closely with particular attention to level of consciousness, pupil size and equality, and vital signs Intake and output Inspect nasal packing Signs and symptoms of infection

27. Hyperpituitarism Postoperative nursing care Interventions Anxiety Impaired Sensory Perception Acute Pain and Impaired Oral Mucous Membrane Risk for Injury Excess Fluid Volume or Deficient Fluid Volume Risk for Infection

28. Etiology and Pathophysiology Dwarfism Inadequate secretion of growth hormone during preadolescence Attainment of a maximum height 40% below normal Causes hereditary or related to damage to the anterior portion of the pituitary gland Panhypopituitarism Growth has been completed and some pathologic process impairs the function of the pituitary

29. Hypopituitarism Signs and symptoms Depends on the stage of life which hormones are deficient Dwarfism Occurs early; person as short as 36 inches but with proportional physical characteristics Often have delayed or absent sexual maturation Accelerated pattern of aging, thus shorter life span

30. Hypopituitarism Signs and symptoms Panhypopituitarism Simmonds’ cachexia Muscle and organ wasting and disruptions of both digestion and metabolism Absence of ACTH affects ability to cope with stress Thyroid-stimulating hormone is depleted Decreased pigmentation of the skin Gonads may become atrophied

31. Hypopituitarism Medical diagnosis Health history, physical examination, diagnostic tests Conventional radiographs and CT scans Cerebral angiography Serum levels of pituitary hormones Medical and surgical treatment Deficient hormones are replaced as needed If caused by tumor, surgery, or radiation

32. Hypopituitarism Assessment Sense of well-being, energy level, appetite Changes in skin texture, body temperature, hair, and libido Determine whether there has been difficulty carrying out usual activities

33. Hypopituitarism Interventions Education important: disturbances in body image, sexual function, nutritional status, and fluid balance can be improved if patient follows the prescribed therapy Acknowledge patient’s feelings and encourage expression of concerns; refer to a mental health counselor if patient has difficulty dealing with the effects of the disease

34. Diabetes Insipidus (DI) Etiology Excessive output of dilute urine Nephrogenic DI Inherited defect: renal tubules do not respond to ADH, resulting in inadequate water reabsorption Neurogenic DI A defect in either the production or secretion of ADH Dipsogenic DI A disorder of thirst stimulation When patient ingests water, serum osmolality decreases, which causes reduced vasopressin secretion

35. Diabetes Insipidus Pathophysiology Antidiuretic hormone deficiency or inability of kidneys to respond to ADH results in the excretion of large volumes of very dilute urine Signs and symptoms Massive diuresis, dehydration, and thirst Malaise, lethargy, and irritability Medical diagnosis Health history, physical examination, and laboratory findings 24-hour urine output of greater than 4 L of fluid

36. Diabetes Insipidus Medical treatment Intravenous fluid volume replacement and vasopressors often required to maintain adequate blood pressure Neurogenic DI DDAVP (desmopressin acetate) Sodium intake restricted and thiazide diuretics prescribed

37. Diabetes Insipidus Assessment Thirst, change in urine appearance or volume, dizziness, weakness, fainting, and palpitations Hydration, including skin turgor, moisture of mucous membranes, pulse rate and quality, blood pressure, and mental status Intake and output, daily weights, urine specific gravity Interventions Deficient Fluid Volume Activity Intolerance Ineffective Therapeutic Regimen Management

38. Syndrome of Inappropriate Antidiuretic Hormone Etiology Water imbalance related to an increase in ADH synthesis or secretion, or both Pathophysiology When ADH is elevated despite normal or low serum osmolality, kidneys retain excessive water Plasma volume expands, causing the blood pressure to rise. Body sodium is diluted (hyponatremia), and water intoxication develops

39. Syndrome of Inappropriate Antidiuretic Hormone Signs and symptoms Weakness, muscle cramps or twitching, anorexia, nausea, diarrhea, irritability, headache, and weight gain without edema When the central nervous system is affected by water intoxication, the level of consciousness deteriorates Patient may have seizures or lapse into a coma

40. Syndrome of Inappropriate Antidiuretic Hormone Medical diagnosis Laboratory tests of serum and urine electrolytes and osmolality Radiographic studies of brain and lungs detect causative factors

41. Syndrome of Inappropriate Antidiuretic Hormone Medical treatment Acutely ill: hypertonic saline, very slowly over 4- to 6-hour period Restrict fluids to 800-1000 mL/day with high intake of dietary sodium Or administer normal saline with loop diuretics Patients who cannot adhere to fluid restriction with high sodium intake may be given demeclocycline or lithium carbonate

42. Syndrome of Inappropriate Antidiuretic Hormone Assessment Anorexia, nausea, vomiting, diarrhea, headache, irritability, and muscle cramps and weakness History of cancer, pulmonary disease, nervous system disorders, hypothyroidism, or lupus erythematosus Note prescription drugs the patient is taking Weight, intake and output, urine specific gravity Palpate the skin for moisture and edema Test muscle strength Seizures and muscle weakness, twitching, or cramps Describe mental status

43. Syndrome of Inappropriate Antidiuretic Hormone Interventions Risk for Injury Excess Fluid Volume Ineffective Therapeutic Regimen Management

44. The Adrenal Glands

45. Anatomy and Physiology A pair of small, highly vascularized triangular-shaped organs Located in the retroperitoneal cavity on the superior poles of each kidney, lateral to the lower thoracic and upper lumbar vertebrae Each weighs about 4 g and measures 3.3 cm Two parts: an outer portion called the cortex and an inner portion called the medulla

46. Anatomy and Physiology Medulla Constitutes 10% of the gland and contains sympathetic ganglia with secretory cells Stimulation of sympathetic nervous system: medulla secretes two catecholamines: norepinephrine (noradrenaline) and epinephrine (adrenaline) Function of these substances is adaptation to stress, as characterized by the “fight-or-flight response,” and maintenance of homeostasis

47. Anatomy and Physiology Cortex Comprises 90% of adrenal gland; the outer portion Considered part of the endocrine system Essential for maintaining many life-sustaining physiologic activities Cells organized into three distinct layers or zones Zona glomerulosa, zona fasciculata, and zona reticularis Hormones synthesized and secreted by cortex are steroids and consist of mineralocorticoids, glucocorticoids, and androgens or estrogens

48. Function of the Adrenal Glands Mineralocorticoids Produced by the zona glomerulosa Key in maintaining adequate extracellular fluid volume Renin, angiotensin, and aldosterone Renin produced by juxtaglomerular cells of renal afferent arterioles Release stimulated by decrease in extracellular fluid volume Renin acts on plasma proteins to release angiotensin I, which is catalyzed in the lung to angiotensin II Angiotensin II stimulates the secretion of aldosterone, which results in sodium and water retention

49. Function of the Adrenal Glands Glucocorticoids Produced by the zona reticularis and zona fasciculata Most abundant and potent is cortisol 92% of circulating cortisol bound to a plasma protein Cortisol has a permissive effect on other physiologic processes: the glucocorticoid must be present for other processes, such as catecholamine activity and excitability of the myocardium, to occur Control of carbohydrate, lipid, and fat metabolism, regulation of anti-inflammatory and immune responses, and control of emotional states

50. Function of the Adrenal Glands Sex hormones Adrenal androgens: class of steroids produced in the zona fasciculata and zona reticularis Primary function is masculinization Other sex hormones: estrogen and progesterone In men, these contribute little to reproductive maturation In women, however, estrogens are supplied by the ovaries and adrenal glands In postmenopausal women, the adrenal cortex is the primary source of endogenous estrogen