i bc27f85be50b71b1 (214 page)

Fastillg hypoglycemia occurs before eating and can be caused by an

insulin-producing islet cell tumor, liver failure, chronic alcohol ingesrion, GH deficiency, exrrapancrearic neoplasm, or leucine. Ir can also occur in infants with morhers who have diabetes.

Postprandial hypoglycemia occurs after eating and can be caused

by reactive hypoglycemia (inapptopriate insulin release afrer a meal),

early diabetes mellitus, or rapid gastric emptying.

Hypoglycemia can also be induced by external causes, such as

exogenous insulin or oral hypoglycemic overdose.6,s

Signs and symptoms of hypoglycemia may include the following:

•

Tachycardia and hypertension

•

Tremor, irritability, and swearing

•

Hunger

•

Weight changes

•

Headache

•

Menral dullness, confusion, and amnesia

•

Seizures

•

Paralysis and paresthesias

•

Dizziness

•

Visual disturbance

•

Loss of consciousness

Management of hypoglycemia may consist of any of the following:

glucose administration (fruit juice or honey); strict monitoring of

insulin and oral hypoglycemic administration; dietary modifications;

pharmacologic agents, such as glucagon, which is the first agent used

in emergency cases of hypoglycemia; diazoxide (Hyperstat) or streptozocin (Zanosar); surgery (e.g., subtotal pancreatectomy, insulinoma resection); or a combination of these.8,44

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ACUTE CARE HANDBOOK FOR PHYSICAL TIIERAPISTS

Parathyroid Gland

FUlIctioll

Parathyroid hormone (PTH) is the primary hormone secreted from

the parathyroid gland. The target sites are the kidneys, small intestine,

and bone. The primary function of PTH is to raise blood calcium levels by mobilizing calcium that is stored in bone, increasing calcium reabsorption from the kidneys, and increasing calcium absorption

from the small intestine.'·45

Parathyroid Tests

The primary measurements of parathryoid hormone are summarized

in Table 11-12. However, because PTH exerts its effects on the intes-

Table 11-12. Primary Tests Used ro Evaluate Parathyroid (PTH) Function

Test

Description

Serum calcium

Measurement of blood calcium levels indirectly

examines parathyroid function. Normally, low

calcium levels srimulate parathyroid hormone

secrerion, whereas high calcium levels could be

ref1ec-tive of high PTH levels.

Reference value for serum calcium is 8.5-J 1.0 mgldl

in adults.

Calcium levels can also be measured in the urine.

Reference value for urinary calcium is 50-300

mgldl.

Parathyroid hormone

Radioimmunoassays and urinalysis are lIsed to mea-

sure pararhyroid hormone levels. Reference value

is 10-60 pglml.

Sources: Data from WM Burch (ed). Endocrinology for rhe House Officer (2nd cd).

Balrimore: Williams & Wilkins, 1988; JV Corberr (cd). Laborarory Tesrs and Diagnostic Procedures with Nursing Diagnoses (5th cd). Upper Saddle River, NJ: Prentice Hall Health, 2000;167-176; and RA Sacher, RA McPherson,JM Campos (eds).

Widman's Clinicallmerpretarion of Laboratory Tests (11 th cd). Philadelphia: FA

Davis,2000j803-804.

ENDOCRINE SYSTEM

687

tines and kidneys, calcium metabolism can also be evaluated by testing gaStrointestinal and renal function. Please refer to Chapters 8 and 9, respectively, for a summary of diagnostic tests for the gastrointestinal and renal systems.

Paratllyroid Disorders

Hyperparathyroidism

Hyperparathyroidism is a disorder caused by overactivity of one or

more of the parathyroid glands that leads to increased PTH levels,

resulting in increased blood calciulll level, decreased bone mineralization, and decreased kidney function. This disorder occurs more frequently in women than in men. Radiation therapy is also a risk factor for developing this disorder46

Hyperparathyroidism can be classified as primary, secondary, or

tertiary. Primary hyperparathyroidism represents the most cases and

usually results from hyperplasia or an adenoma in the parathyroid

gland(s). Secondary hyperparathyroidism results from another organ

system disorder, such as renal failure, osteogenesis imperfecta, Paget's

disease, multiple myeiOlna, lymphoma, or bone metastases from primary breast, lung, or kidney tumors. Tertiary hyperparathyroidism occurs when PTH secretion is autonomous despite normal or low

serum calcium levels.6.23.47

The primary clinical manifestations of hyperparathyroidism

are hypercalcemia and hypercalciuria (calcium in urine). Hypercalcemia may then result in the following cascade of signs and symptoms23.4 6.47:

•

Bone demineralization and resorption (which causes skeletal

changes, such as dorsal kyphosis)

•

Backache, joint and bone pain, and pathologic fractures

•

Kidney stone formation, abdominal pain, and peptic ulcer disease

•

Nausea, thirst, anorexia, and constipation

•

Hypertension and dysrhythmias

•

Listlessness, depression, and paranoia

•

Decreased neuromuscular excitability

688

AC� CARE. HANDBOOK FOR I'HYSICAL TlIERAPISTS

Management of hyperparathyroidism may consist of any of the

followings.23"7 :

•

ParathyroidectOmy (partial or tOtal) is the preferred treatment

for patients with moderate to severe hypercalcemia.46-4S The use of

intraoperative, rapid PTH assay has been shown to be effective in

fully delineating the areas requiring resection, making for a safer

and more specific operative procedure.48

•

Pharmacologic inrervention with the following:

Parathyroid agents (e.g., calcitonin fCalcimar, CibacalcinJ)

Diuretic agents (e.g., furosemide I Lasix])

Phosphates

Bone resorption inhibitors (e.g., mithramycin IMithracinl

and gallium nitrate [Ganitel)

•

Fluid replacement

•

Dietary modification (a diet low in calcium and high in vitamin D)

Hypoparathyroidism

Hypoparathyroidism is a disorder caused by underactivity of one or

more of the parathyroid glands that leads to decreased PTH levels.

Decreased levels of PTH occur most commonly as a result of damage

to the parathyroid glands during thyroid or parathyroid surgery. Less

common causes may include radiation-induced damage, infiltration

by metastatic cells, and autoimmune dysfunction.23,47

Signs and symptOms of hypoparathyroidism may include the

following23:

•

Hypocalcemia

•

Increased neuromuscular irritability (tetany), painful muscle spasms

•

Tingling of the fingers

•

Laryngospasm

•

Dysrhythmias

•

Lethargy, personality changes

•

Thin, patchy hair; brittle nails; dry, scaly skin

•

Convulsions

•

Cataracts