Acromegaly(Gigantism)

Source:  Acromegaly(Gigantism)    Tag:  gigantism treatment

Anterior pituitary gland produces Growth Hormone which stimulate the growth of bodily tissues. Hyperpituitarism, also called acromegaly and gigantism. It results in longitudinal growth of long bones. These children may grow as tall as 8 feet. In adults excessive Growth Hormone cause acromegaly. Because this develops after epiphyseal closure in adults, the bones are unable to grow longer. Instead, the bones increase in size and width.
 

Definition

Acromegaly is the overgrowth of the bones and soft tissues due to excessive secretion of the growth hormone.
Incidence
Acromegaly is uncommon; only three to four cases are diagnosed per million people each year. It develops very gradually and may not be recognized until it has been present for many years. hyperpituitarism occurs equally among men and women. The mean age at diagnosis is about 40-60 years.
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Causes

It is caused by prolonged, excessive secretion of growth hormone (GH). The most common cause of acromegaly is a benign tumour (adenoma) of the somatotroph cells, which produce growth hormone. These cells are within the anterior pituitary gland, located in the middle of the head just below the brain.
 

Pathophysiology

In adults excessive Growth Hormone cause overgrowth of bones and tissues. Because this develops after epiphyseal closure in adults, the bones are unable to grow longer. Instead, the bones increase in size and width. It results in structural changes of the skeletal system. It develops gradually, usually during the third and fourth decades of the life. Individuals experience enlargement of hands and feet. The fingertips develop a tufted or clubbed like appearance. The enlargement of bones and cartilage may cause mild joint pain to deforming, clipping arthritis.
Changes in physical appearance occur with thickening and enlargement of bony and soft tissue on the face and head. Enlargement of mandible causes jaw to jut forward. The paranasal and frontal sinuses enlarges. Enlargement of soft tissue around eyes, nose and mouth results in hoarsening of facial structures. Enlargement of tongue results in speech difficulties, and the voice deepens as a result of the hypertrophy of the vocal cords.
 
Overproduction of growth hormone -- Enlargement of viscera without increase in height -- fingertips develop a tufted or clubbed like appearance -- mild joint pain to deforming, clipping arthritis -- Enlargement of mandible -- The paranasal and frontal sinuses enlarges --- Enlargement of soft tissue around eyes, nose and mouth -- Change in facial structures
 
Clinical manifestations
Excessive growth of soft tissue, cartilage, and bone in the face, hands and feet.
Face and head — Facial features (nose, lips, ears, and forehead) become broader and larger the tongue enlarges, the space between the teeth increases, and the lower jaw grows, resulting in an under bite and extended lower jaw.
headache may be present.
Facial hair growth increases, which may be especially bothersome to women.
Throat — Excessive soft tissue growth of the throat and voice box can lead to a hoarse voice or sleep apnoea (a condition in which a person stops breathing temporarily during sleep, causing lowered levels of oxygen and disrupted sleep).
Hands and feet — The hands and feet enlarge, often requiring patients to wear larger sized rings, gloves, and shoes. Overgrowth of tissues in the wrist can compress nerves to the hands, leading to tingling or pain in the fingers (called carpal tunnel syndrome).
Skin — The skin may thicken, and skin tags may appear. Excessive sweating, even while resting, is common.
Bones — Overgrowth of the ends of bones can damage neighbouring cartilage and lead to arthritis.
Tumors — Patients with acromegaly have an increased risk of noncancerous (benign) tumors, especially if growth hormone levels are not controlled. Benign tumors of the uterus (fibroids) are more common in acromegaly. Polyps of the colon are more common, and can become cancerous if not surgically removed.
Heart — The incidence of heart disease is increased, likely due to enlargement of the heart muscle, which impairs functioning of the muscle (called cardiomyopathy). High blood pressure is more common in acromegaly. Some people have problems with their heart valves. Heart failure may occur if acromegaly is uncontrolled.
Diabetes — Higher blood glucose levels may be a direct result of excessive growth hormone production, which causes insulin resistance. Diabetes is more common in people with acromegaly, and people with previously diagnosed diabetes may require higher doses of medication.
Life expectancy may be reduced by approximately 10 years, especially when growth hormone levels are uncontrolled and diabetes and heart disease are present. Patients with controlled hormone levels generally have a normal life expectancy.
Diagnostic studies
· If acromegaly is suspected based upon a person's appearance, the diagnosis must be confirmed by measurement of IGF-1 and growth hormone levels. The blood level of IGF-1 can be determined in a single blood sample drawn at any time of day.
· Growth hormone must be measured by taking several samples of blood, drawn before and after drinking a glucose (sugar) solution. In acromegaly GH concentration do not fall.
· Plasma GH evaluation.
· MRI: Once excessive growth hormone secretion has been confirmed, magnetic resonance imaging (MRI) is indicated for identification, localisation ane determination of extension of the pituitary tumour.
· CT scanning may also be used to locate the tumour.
· A complete ophthalmologic examination, including visual fields to assess pressure of macroadenoma on optic nerves.
Treatment
Patients with acromegaly are treated to avoid the risk of complications, even if there are no obvious symptoms. The goal of therapy is to lower the level of growth hormone and IFG-1 in the blood. If therapy is successful, the soft tissue changes will regress over a period of several months and the risk of early death returns to normal. Sometimes, initial treatment is not entirely successful and additional treatment is needed.
There are three main forms of treatment: surgery, medications, and radiation therapy.
 
Surgery
Surgery offers the chance of a cure if the somatotroph adenoma can be completely removed. Surgery is also the first choice of treatment when the adenoma is very large and impairing or threatening vision.
During surgery, a small incision is made in the nose. The incision is extended through the sphenoid sinus, allowing the surgeon to visualize and remove the adenoma. An endoscope (a thin, lighted tube with a camera) may be used to ensure that the adenoma has been removed completely. Alternately, the entire procedure may be performed using the endoscope.
Surgery is usually effective in reducing growth hormone levels, although levels do not always return to normal. The chance that the growth hormone levels will be normal after surgery is directly related to the size of the adenoma before surgery. The levels of growth hormone and IGF-1 will return to normal in about eighty percent of people with small adenomas (less than 1 cm [0.5 inch]). On the other hand, only about 30 percent of people who have larger adenomas that extend beyond the pituitary will have normal hormone levels after surgery.
If the adenoma is completely excised, the blood GH level falls to normal within hours after surgery and the blood IGF-1 level returns to normal within weeks to months.
Medications
There are three classes of medications used to treat acromegaly:
  • Somatostatin analogs (octreotide or lanreotide)
  • Dopamine agonists, especially cabergoline
  • Growth hormone receptor antagonist (pegvisomant)
Somatostatin analogs — Somatostatin analogs inhibit secretion of growth hormones from the growth hormone-secreting cells of the pituitary.
Ø Octreotide (Sandostatin) is made in short-acting and long-acting forms. The short-acting form is given three times a day by injection, and the long-acting form is given every four weeks by injection.
Ø Lanreotide (Somatuline) is available in a long-acting form that is injected every four weeks.
These medications can be used as an initial treatment, especially when an adenoma is too large to remove completely with surgery. They can also be used as secondary treatment for people who have remaining adenoma tissue and an elevated blood growth hormone concentration after transsphenoidal surgery.
· Growth hormone receptor antagonist — Growth hormone receptor antagonists block the effects of growth hormone by binding to the hormone receptor, decreasing IGF-1 production and thereby decreasing growth effects. Pegvisomant (Somavert®) is given daily by injection.
· Dopamine agonists — Dopamine agonists may inhibit growth hormone secretion and therefore decrease IGF-1 levels, although they are not usually as effective as other classes of medications. They can be taken orally and may be more convenient than other forms of treatment.

Radiation therapy

Radiation therapy has been used for many years for treatment of pituitary adenomas, including somatotroph adenomas. Radiation can be delivered in one of several ways:
A linear accelerator
A cobalt source (gamma radiation)
A cyclotron (proton beam)
Radiation can be given as a single large dose or in multiple smaller doses. Whatever the source and number of doses, the radiation is directed stereotactically (three-dimensionally) to the adenoma by a computerized program.
Radiation therapy is usually effective in stopping or even reversing adenoma growth, and in decreasing growth hormone and IGF-1 production. However, the decline in growth hormone secretion (and clinical improvement) is very slow. Even 10 to 15 years after radiation, only a small percentage of patients achieve a normal blood growth hormone level.
Complications of treatment
The chance of serious complications, such as worsening of vision, hormonal imbalance, meningitis, nasal leakage, or very rarely, death, is less than 5 percent. The chance of damage to the pituitary gland is about 7 percent; Within 10 years after treatment, about 50 percent of patients treated with pituitary radiation develop a deficiency of one or more pituitary hormones, including the hormones that control the thyroid gland, adrenal glands, and ovaries or testicles.
 

Nursing diagnosis

1. Disturbed body image related to enlargement of body parts as manifested by enlarged hands, feet and jaw.
2. Disturbed sensory perception related to enlarged pituitary gland as manifested by protrusion of eye balls .
3. Fluid volume deficit related to polyuria as manifested by excessive thirst of the patient.
4. Disturbed sleeping pattern related to soft tissue swelling as manifested by verbalization of the patient about insomnia.
5. Anxiety related to change in appearance and treatment as manifested by verbalization of the patient about body appearance.
6. Ineffective coping related to change in appearance as manifested by verbalization of negative feeling about the change in appearance.
7. Knowledge deficit regarding development of disease and treatment as manifested by repeated questions by the patient regarding disease and treatment.
Interventions
1. Disturbed body image related to enlargement of body parts as manifested by enlarged hands, feet and jaw.
o Assess the body changes of the patient.
o Give psychological support.
2. Disturbed sensory perception related to enlarged pituitary gland as manifested by protrusion of eye balls.
o Assess the sensory perception status of the patient
o Administer medications if ordered
3. Fluid volume deficit related to polyuria as manifested by excessive thirst of the patient.
o Assess the fluid and electrolyte status of the patient.
o Provide more oral fluids to the patient.
o Administer IV fluids if ordered.
4. Disturbed sleeping pattern related to soft tissue swelling as manifested by verbalization of the patient about insomnia.
o Assess the sleeping pattern of the patient.
o Provide comfortable position to the patient.
o Provide calm and quiet environment.
5. Anxiety related to change in appearance and treatment as manifested by verbalization of the patient about body appearance.
o Assess the anxiety level of the patient
o Explain the patient about progressive features of the disorder
o Divert the attention of the patient by talking.
6. Ineffective coping related to change in appearance as manifested by verbalization of negative feeling about the change in appearance.
o Assess the coping ability of the patient.
o Provide psychologic support to the patient.
7. Knowledge deficit regarding development of disease and treatment as manifested by repeated questions by the patient regarding disease and treatment.
o Assess the knowledge level of the patient regarding features and treatment of the disorder.
o Explain the patient about progressive features of the disorder.
o Clarify patient’s doubts and questions regarding hyperpituitary disorder.

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