Endocrine System GHOC

Vocational Nursing program 2nd semester 2016

Farahnaz Danandeh, BSN, MSN/Ed., RN

Behavioral Objectives- By end of this unit, the student will be able to: ● Describe the diagnostic tests used to determine endocrine gland dysfunctions

● Utilize the nursing process to define the nurse's role in assessment, implementation, and evaluation of patient care with disorders of thyroid, parathyroid, adrenal, and pituitary gland including the child, adolescent , and the elderly.

● Describe the use of pharmacologic agents in the endocrine disorders, as above.

● Compare and contrast the nutritional effects of hyper and hypothyroidism.

● Discuss dietary management for a patient with abnormal blood calcium

● Distinguish between Addison's disease and Cushing's disease . List types of foods used in treatment of each

● List important points in communication with and teaching patients with common endocrine disorders.

Actual concentration of hormoneAverage concentration of hormone

Feedback Control of Hormone ProductionFeedback circuits are at the root of most control mechanisms in physiology, and are particularly prominent in the endocrine system. Instances of positive feedback certainly occur, but negative feedback is much more common.

Negative feedback is seen when the output of a pathway inhibits inputs to the pathway. The heating system in your home is a simple negative feedback circuit. When the furnace produces enough heat to elevate temperature above the setpoint of the thermostat, the thermostat is triggered and shuts off the furnace (heat is feeding back negatively on the source of heat). When temperature drops back below the setpoint, negative feedback is gone, and the furnace comes back on. Feedback loops are used extensively to regulate secretion of hormones in the hypothalamic-pituitary axis. An important example of a negative feedback loop is seen in control of thyroid hormone secretion. The thyroid hormones thyroxine and triiodothyronine ("T4 and T3") are synthesized and secreted by thyroid glands and affect metabolism throughout the body.

Risk factors for Endocrine Disordersi. Hereditary

ii. Congenital

iii. Trauma

iv. Environmental

v. Secondary to other disorders

vi. Medications

Pituitary GlandAnterior section and posterior section

Anterior lobe is very important because is responsible for growth, maturation and reproduction.

Diagnostic tests including labs and other diagnostic studies

Labs: CBC, BMP, HORMONE levels, CORTISOL levels (am,Pm), ADH level in serum, blood TESTOSTERONE level, total THYROXINE in serum,...

Radiographs: CHEST, ABDOMEN, CT, MRI, …

Radionuclide studies: Radionuclide,Nuclear scan, Radioimmunoassay(determine the concentration of a substance in plasma,venous blood sample is ok. T3 determination by this technique for evaluating thyroid function)

Growth hormone deficiency may be present at birth. Growth hormone deficiency may be the result of a medical condition. Severe brain injury may also cause growth hormone deficiency.

Acromegaly is most often caused by a benign (non-cancerous) tumor of the pituitary gland that secretes excess growth hormone after adolescent, (overgrowth of tissues).

Gigantism is over secretion of GH prior to puberty,(overgrowth of bones).

Nanism is deficient production of GH prior to puberty, and or Growth hormone deficiency (GHD), also known as dwarfism or pituitary dwarfism

Sometimes, GHD can be associated with lower levels of other hormones such as ADH or vasopressin (which controls water production in the body), gonadotropins (which controls the production of male and female sex hormones), thyrotropin (which control the production of thyroid hormones), adrenocorticotropic hormone (which controls the adrenal gland and related hormones).

Treatment includes: Irradiation of pituitary gland and surgical intervention and medication such as, Bromocriptine mesylate and Somatostatin analogs.

The syndrome of inappropriate antidiuretic hormone (Excessive ADH) secretion (SIADH) is defined by the hyponatremia and hypo-osmolality resulting from inappropriate, continued secretion or action of the hormone despite normal or increased plasma volume, which results in impaired water excretion. The key to understanding the pathophysiology, signs, symptoms, and treatment of SIADH is the awareness that the hyponatremia is a result of an excess of water rather than a deficiency of sodium.

Causes: CNS disorders, chemotherapy, ADH production by some tumors, and overusing Vasopressin therapy for Diabetes insipidus

SymptomsNausea or vomiting, diarrheaCramps or tremorsDepressed mood,memory impairment, headacheIrritability, wt. gainHypertension due to H2O toxicityPersonality changes, such as combativeness, confusion, and hallucinationsSeizuresStupor or coma

TreatmentThe most commonly prescribed treatment for SIADH is fluid and water restriction. If the condition is chronic, fluid restriction may need to be permanent. Treatment may also include:∙ Certain medications that inhibit the action of ADH (also called vasopressin)∙ Surgical removal of a tumor that is producing ADH∙ Other medicines to help regulate body fluid volume I&O, daily wt, fluid restriction 500 - 1000 ml /day mental status, IV therapy such as hypertonic saline and Diuretics, also meds like demeclocycline and lithium carbonate...

Diabetes insipidus (die-uh-BEE-teze in-SIP-uh-dus, tasteless diabetes) is an uncommon disorder ( low ADH) characterized by intense thirst, despite the drinking of fluids (polydipsia), and the excretion of large amounts of urine (polyuria). In most cases, it's the result of your body not properly producing, storing or releasing a key hormone, but diabetes insipidus can also occur when your kidneys are unable to respond properly to that hormone. Rarely, diabetes insipidus can occur during pregnancy (gestational diabetes insipidus). Failure of tubular reabsorption of water.

Causes: head trauma, tumor of the gland, other tumors, after surgery by removing the gland partially.

The most common signs and symptoms of diabetes insipidus are: ∙ Extreme thirst ∙ Excretion of an excessive amount of diluted urine

Depending on the severity of the condition, urine output can range from 2 quarts (about 2 liters) a day if you have mild diabetes insipidus to 21 quarts (about 20 liters) a day if the condition is severe and if you're drinking a lot of fluids. In comparison, the average urine output for a healthy adult varies, but is in the range of 1.6 to 2.6 quarts (about 1.5 to 2.5 liters) a day. Other signs may include needing to get up at night to urinate (nocturia) and bed-wetting. Infants and young children who have diabetes insipidus may have the following signs and symptoms:

Think dilute for urine, so everything is decreased such as low PH, low osmolality, low SG, Na, K, and think concentrated for blood such as high Na, K, and high osmolality in serum, Radioimmunoassay: low ADH

cont. ∙ Unexplained fussiness or inconsolable crying ∙ Unusually wet diapers ∙ Fever, vomiting or diarrhea ∙ Dry skin with cool extremities, impaired skin turgor ∙ Delayed growth , SG in urine is very low and dilute∙ Weight loss , muscle pain and weakness, fatigue, postural hypotension, tachycardia

Causes

Central diabetes insipidus. The cause of central diabetes insipidus in adults is usually damage to the pituitary gland or hypothalamus, most commonly due to surgery, a tumor, an illness (such as meningitis), inflammation or a head injury. For children, the cause is often an inherited genetic disorder. In some cases the cause is unknown. This damage disrupts the normal production, storage and release of ADH.

Nephrogenic diabetes insipidus. Nephrogenic diabetes insipidus occurs when there's a defect in the kidney tubules — the structures in your kidneys that cause water to be secreted or reabsorbed. This defect makes your kidneys unable to properly respond to ADH. The defect may be due to an inherited (genetic) disorder or a chronic kidney disorder. Certain drugs, such as lithium and demeclocycline (a tetracycline antibiotic), also can cause nephrogenic diabetes insipidus.

Gestational diabetes insipidus. Gestational diabetes insipidus occurs only during pregnancy and when an enzyme made by the placenta — the system of blood vessels and other tissue that allows the exchange of nutrients and waste products between a mother and her baby — destroys ADH in the mother.

Tests and Diagnosis

Water deprivation test. This test confirms the diagnosis and helps determine the cause of diabetes insipidus. You'll be asked to stop drinking fluids several hours before the test so that your doctor can measure changes in your body weight, urine output and the concentration of your urine and blood when fluids are withheld, Also measure blood levels of ADH or administer synthetic ADH during this test. The water deprivation test is performed under close supervision in children and pregnant women to make sure no more than 5 percent of body weight is lost during the test.

Urinalysis

MRI

Genetic screening

Treatment

Central diabetes insipidus. Because the cause of this form of diabetes insipidus is a lack of antidiuretic hormone (ADH), treatment is usually with a synthetic hormone called desmopressin, ( DDAVP). You can take desmopressin as a nasal spray, as oral tablets or by injection. The synthetic hormone will eliminate the increase in urination. For most people with this form of the condition, desmopressin is safe and effective. If the condition is caused by an abnormality in the pituitary gland or hypothalamus (such as a tumor), cardiovascular and neuro check, avoid food with diuretic type of action like watermelon, wt monitoring and I&O and monitoring SG in urine, wearing medic-alert bracelet.

Neoplasms of the Pituitary gland● Overgrowth of Eosinophilic cells in the gland leads to Gigantism

● Overgrowth of basophilic cells can affect on adrenal glands and lead to Hyperadrenalism or Cushing's syndrome

● A chromophobic tumor can destroy the gland and result in Hypopituitarism.

Treatment is surgery and patient is in ICU for special care.

Hypopituitarism or panhypopituitarism is a complex medical condition associated with increased morbidity and mortality, requires complicated treatment regimens, and necessitates lifelong follow up by the endocrinologist. The causes, clinical features, and the management of hypopituitarism including endocrine replacement therapy

There are various causes of hypopituitarism in adults, pituitary adenoma or its treatment by surgery and/or radiotherapy is by far the commonest. treatment of this condition is hormone replacement or HRT. one of the hormone is being replaced is ADH and Vasopressin or DDAVP is a treatment of choice for this condition, along with other hormones such as cortisol, thyroxin, ...

Vasopressin overdose carries the risk of hyponatraemia, and hence sodium levels should be measured after starting treatment and whenever the dose is changed.