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Numerous etiologies of SIADH exist, with the most frequent cause

being small cell or oat cell carcinomas of the lung. Other etiologies

include the following'·15:

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AClITE CARE HANDBOOK FOR PIIYSICAL THERAPISTS

• Bacterial pneumonias, chronic obstructive pulmonary disease,

tuberculosis, lung abscesses

• Malignancies of the pancreas, duodenum, colon, lymphoid tissue, and thymus

• Medication side effects from anti psychotics, sedative-hypnotics,

diuretics, antihypertensives, analgesics, cardiac drugs, and antibiotics

• Head trauma, cenrral nervous system neoplasms

A mild condition of SlADH is usually asymptomatic. More severe

cases, however, can result in fluid and electrolyte imbalances, resulting

in interstitial edema from a lack of serum sodium. Many systems will

be affected by this edema, with the nervous system being most severely

involved. Manifestations can include any of the following: headaches,

nausea, confusion, increased blood pressure, peripheral edema, and

cerebral edema that leads to seizures and coma (in severe cases).l5

Management of SIADH may consist of any of the following: treatment of the underlying cause, fluid restriction, intravenous administration of sodium chloride solution, or administration of diuretics (furosemide).l5

Clinical Tip

The physical therapist should be aware of fluid restriction

guidelines for patients with SIADH, especially because

activity during physical therapy may increase the patient's

thirst. These guidelines are often posted at the patient's

bedside.

Hypopituitarism

There are numerous causes for primary (pituitary directly affected) or

secondary (hypothalamus or pituitary stalk affected) hypopituitarism.

The most common causes of primary hypopituiatarism are piruitary

neoplasms, such as pituitary adenomas and craniopharyngioma, and

ischemic necrosis occurring during the late stages of pregnancy (Sheehan's syndrome). Common causes of secondary hypopituitarism include hypothalamic tumors, cranial trauma, sarcoidosis, surgical

destruction of the pituitary stalk, or a combination of these.6•lJ,16.17

ENDDCR[NE SYSTEM

667

Symproms, physical findings, and management depend on the

extent of the disorder and the specific hormone and target cells

involved. Patients with complete pituitary hormone deficiency (panhypopituitarism) present with the following",[6:

• Hypogonadism

• Amenorrhea, regression of secondary sexual characteristics, and

infertility

• Dilutional hyponatremia

• Diabetes insipidus (OI)

• Short stature (in children)

• Hypothyroidism

• Glucocorticoid deficiency

Management of panhypopituitarism may consist of any of the following: replacement therapy or pituitary hormones, such as thyroxine, glucocorticoids, and GH for children; desmopressin for 01; androgen therapy for men; or estrogen therapy for women younger

than SO years of age. Management of other clinical sequelae of

hypopituitarism will be specific ro the involved areas.'I,[6

Diabetes Insipidus

01 involves the excretion of a large volume (i.e., greater than 30

ml/kg per day) of dilute urine (hyporonic polyuria). 01 may result

from hypothalamic, pituitary, renal, or psychogenic disorders;

however, most incidences of DI are described as idiopathic,6.ls

Piwirary DI involves the failure to synthesize or release vasopressin (AOH). Renal, or nephrogenic, OJ is a deficiency of vasopressin receptors in the renal collecting ducts. Psychogenic or dipsogenic OJ involves a large intake of fluid that may suppress

ADH secrcrion.7·8•1I,18

Signs and symproms of OJ may be transient or permanent and

include the following7,8,[6.[8:

• Polyuria, nocruria

• Thirst (especially for cold or iced drinks), polydipsia

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AClTfE CARE HANDBOOK FOR PHYSICAL THERAPISTS

• Dehydrarion

• Weighr loss

• Dry skin with decreased turgor

• Central nervous system manifestations (e.g., irritability, mental

dullness, ataxia, hyperthermia, and coma) if access to water is

interrupted

Management of neurogenic (hypothalamic or pituitary dysfunction)

Dl may consist of pharmacologic treatment, such as the following:

aqueous vasopressin or deamino-8-D-arginine vasopressin (Desmopressin), chlorpropamide (Diabinase), and clofibrate (Atromid-S).

Management of nephrogenic (renal) 01 may consist of diuretics

such as hydrochlorothiazide (HydroDIURIL), in combination with a

sodium-restricted diet.7·8•19

Adrenal Gland

Function

The adrenal gland has two distinct areas, the outer correx and the

inner medulla, that differ in their function and embryologic origin.- Table 11-7 summarizes the target sites and actions of the adrenal gland.

Adrenal and Metabolic Tests

Adrenal Tests

Evaluation of the adrenal cortical (glucocorricoids, androgens, and

mineralocorticoids) and medullary (epinephrine and norepinephrine)

hormones is described below. Anatomic investigation of the adrenal

glands may also be performed to diagnose possible adrenal dysfunction. Common methods to accomplish this are computed tomography scan (to identify adrenal tumors), radioisotope scan using seleno-cholesterol, ultrasound, arteriogram, adrenal venogram (allows measurements of hormone levels), and intravenous pyelogram (see Diagnostic Tests in Chapter 9).",20

ENDOCRINE SYSTE..\1

669

Table 1 1-7. Target Sites and Actions of Adrenal Gland Hormones

Hormone(s)

Target site(s)

Action(s)

Cortex

Mineralocorticoids

Kidney

Reabsorption of sodium and

(aldosterone)

water

Elimination of potassium

Glucocorticoids

Systemic

Metabolism of carbohydrate,

(cortisol)

protein, and fat

Response to stress

Suppresses immune responses

Anti-inflammarion

Sex hormones

Systemic

Preadolescent growth spurt,

(androgens.

affects secondary sex charprogesterone,

acteristics

and estrogen)

Medulla

Epinephrine

Cardiac and

Emergency functions

smooth muscle,

Stimulates the action of the

glands

sympathetic system

Norepinephrine

Organs innervated

Chemical transmitter subby sympathetic

stance

nervous system

Increases peripheral resistance

Sources: Data (rom BF Ful er. Anatomy and Physiology of the Endocrine System. In CM

Hudak, BM Gallo (cds), Critical Cllfe Nursing: A Holistic Approach (6th ed). Philadelphia:

Uppincort, 1994;875; and JV Corbcn (ed). L'lboratory Tests and Diagnostic Procedures

with Nursing Diagnoses (5th cd). Upper Saddle River, NJ: Prentice I-Iall l-le.'llth, 2000;391.

Clucocorlicoids

Glucocorticoids can be evaluated by testing serum and urine cortisol

levels, 24-hour urinary corticosteroids, or ACTH. Altered glucocorticoid levels can affect protein and carbohydrate metabolism.

•

Serum cortisol levels are measured by RIA, which is indicated for

diagnosing Cushing's or Addison's disease. For accuracy, notation should

be made as to the time of day the serum was drawn, because levels are