dependent edema

edema /ede·ma/ (ĕ-de´mah) an abnormal accumulation of fluid in intercellular spaces of the body.edem´atous

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angioneurotic edema  angioedema.

cardiac edema  a manifestation of congestive heart failure, due to increased venous and capillary pressures and often associated with renal sodium retention.

cytotoxic edema  cerebral edema caused by hypoxic injury to brain tissue and decreased functioning of the cellular sodium pump so that the cellular elements accumulate fluid.

dependent edema  edema in lower or dependent parts of the body.

edema neonato´rum  a disease of premature and feeble infants resembling sclerema, marked by spreading edema with cold, livid skin.

pitting edema  that in which pressure leaves a persistent depression in the tissues.

pulmonary edema  diffuse edema in pulmonary tissues and air spaces due to changes in hydrostatic forces in capillaries or to increased capillary permeability, with intense dyspnea.

vasogenic edema  cerebral edema in the area around tumors, often due to increased permeability of capillary endothelial cells.

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dependent edema

n.

A detectable increase in extracellular fluid volume localized in a dependent area such as a limb, characterized by swelling or pitting.

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dependent edema

Etymology: L, de, from, pendere, to hand; Gk, oidema, swelling

a fluid accumulation in the tissues that is influenced by gravity. It is usually greater in the lower part of the body than in the part above the level of the heart.

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edema [ĕde´mah]

the accumulation of excess fluid in a fluid compartment. Formerly called dropsy and hydrops. adj., adj edem´atous. This accumulation can occur in the cells (cellular edema), in the intercellular spaces within tissues (interstitial edema), or in potential spaces within the body. Edema may also be classified by location, such as pulmonary edema or brain edema; types found in certain locations have specific names, such as ascites (peritoneal cavity), hydrothorax (pleural cavity), or hydropericardium (pericardial sac). Massive generalized edema is called anasarca. Classification by location does not indicate whether the edema is cellular or interstitial or occupies a potential space (for example, brain edema may be either cellular or interstitial). Edema can be caused by a variety of factors, including conditions that affect osmotic pressure, such as hypotonic fluid overload, which allows the movement of water into the intracellular space, or hypoproteinemia, which decreases the concentration of plasma proteins and permits the passage of fluid out of the blood vessels into the tissue spaces. Other factors include poor lymphatic drainage; conditions that cause increased capillary pressure, such as excessive retention of salt and water and heart failure; and conditions that increase capillary permeability, such as inflammation.

Edema formation. With trauma, increased capillary permeability and dilation cause leaking into tissue space. Initially clear, exudate in the tissue space becomes more viscous with an increase in plasma protein. From Copstead and Banasik, 2000.

alveolar edema pulmonary edema in the alveoli, usually with hypoxemia and dyspnea.

brain edema cerebral edema.

cardiac edema a manifestation of congestive heart failure, due to increased venous and capillary pressures and often associated with renal sodium retention.

cellular edema edema caused by the entry of water into the cells, causing them to swell. This may occur because of decreased osmolality of the fluid surrounding the cells, as in hypotonic fluid overload, or increased osmolality of the intracellular fluid, as in conditions that decrease the activity of the sodium pump of the cell membrane, allowing the concentration of sodium ions within the cell to increase.

cerebral edema swelling of the brain caused by the accumulation of fluid in the brain substance. It may result from head injury, stroke, infection, hypoxia, brain tumors, obstructive hydrocephalus, and lead encephalopathy; it may also be caused by disturbances in fluid and electrolyte balance that accompany hemodialysis and diabetic ketoacidosis. The most common type is vasogenic edema, which may result from increased capillary pressure or from increased capillary permeability caused by trauma to the capillary walls. Cellular edema may occur in ischemia or hypoxia of the brain. Because the brain is enclosed in the solid vault of the skull, edema compresses the blood vessels, decreasing the blood flow and causing ischemia and hypoxia, which in turn result in further edema. Unless measures are taken to reverse the edema, destruction of brain tissue and death will result.

dependent edema edema of the lowermost parts of the body relative to the heart; it is affected by gravity and position, so that the lower limbs are affected if the individual is standing, but the buttocks are affected if the individual is supine.

generalized edema edema that is caused by poor venous return; it is not localized by the effects of gravity, in contrast to dependent edema.

interstitial edema

1. edema caused by the accumulation of fluid in the extracellular spaces of a tissue.

2. pulmonary edema in the interstitial tissues; there is dyspnea but no hypoxemia.

edema neonato´rum sclerema neonatorum.

nonpitting edema edema in which pressure does not leave a depression in the tissues, such as in cellular edema. See also pitting edema.

pedal edema swelling of the feet and ankles.

peripheral edema edema affecting the extremities; seen in heart disease, Crohn's disease, and amyloidosis.

pitting edema edema in which external pressure leaves a persistent depression in the tissues (see pitting); it occurs because the pressure pushes the excess fluid out of the intercellular spaces in the tissue. See also nonpitting edema.

pulmonary edema diffuse extravascular accumulation of fluid in the tissues and air spaces of the lung due to changes in hydrostatic forces in the capillaries or to increased capillary permeability. It is most often symptomatic of left ventricular heart failure, but can also be a complication of mitral stenosis, aortic stenosis, altitude sickness, acute hypertension, volume overload during intravenous therapy, or reduced serum oncotic pressure, as in patients who have nephrosis, cirrhosis, or hypoalbuminemia.

During the initial stage of pulmonary edema, patients may complain of restlessness and anxiety and the feeling that they are getting a common cold. Other signs include a persistent cough, slight dyspnea, and intolerance to exercise. On auscultation, rales can be heard over the dependent portion of the lung. As fluid continues to fill the pulmonary interstitial spaces the dyspnea becomes more acute, respirations increase in rate, and there is audible wheezing. The cough becomes productive of frothy sputum tinged with blood, giving it a pinkish hue. Eventually, if the condition persists, the patient becomes less responsive to stimuli as levels of consciousness decrease. Ventricular arrhythmias develop and breath sounds diminish. In some patients these phases are telescoped as the pulmonary edema develops rapidly and the final stages of respiratory insufficiency are evident in a very short period of time.

Treatment is aimed at enhancing gas exchange, reducing fluid overload, and strengthening and slowing the heart beat. To accomplish these goals the patient is often given oxygen by mask or through mechanically assisted ventilation. Drug therapy includes diuretics to remove excess alveolar fluid and morphine to relieve anxiety and reduce the effort of breathing. Administration of other medications depends on the cause of the edema, as well as what other problems the patient may be having.

vasogenic edema that characterized by increased permeability of capillary endothelial cells; the most common form of cerebral edema.

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edema (edē´m),

n the accumulation of fluid in the tissues or in the peritoneal or pleural cavities. Primary factors favoring edema are increased capillary hydrostatic pressure (increased venous pressure), decreased osmotic pressure of plasma (hypoproteinemia), decreased tissue tension and lymphatic drainage, increased osmotic pressure of tissue fluids, and increased capillary permeability. Additional renal and hormonal factors are important. Clinical manifestations may consist of a steady weight gain or localized or generalized swelling.

Eczema.

edema, angioneurotic

(an´jēōnerto´ik),
n See angioedema.

edema, cardiac,

n an edema caused by venous congestion in association with congestive heart failure; tends to appear first in such dependent parts as the legs.

edema, dependent,

n an edema that changes its position with the posture of dependent parts (e.g., edema of the legs in progressive heart failure).

edema of glottis

(glot´is),
n an edema caused by fluid accumulation in the soft tissues of the larynx. The condition, usually inflammatory, may result from an infection, injury, allergy, or inhalation of toxic substances.

edema, periorbital

(per´ēor´bitl),
n an edema of the eyelids in association with local injury, allergic reactions, hypoproteinemia, trichinosis, and myxedema.

Periorbital edema.

edema, pitting,

n a persistent indentation of the skin when pressure is applied to an edematous area.

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edema

an abnormal accumulation of fluid in the cavities and intercellular spaces of the body.

Edema can be caused by a variety of factors, including hypoproteinemia, in which a lowered concentration of plasma proteins decreases the osmotic pressure, thereby permitting passage of abnormal amounts of fluid out of the blood vessels and into the tissue spaces. Some other causes are poor lymphatic drainage, increased capillary permeability (as in inflammation), and congestive heart failure. See also anasarca, ascites, hydrothorax, hydropericardium and anatomically located edemas, e.g. brain, corneal, pulmonary edema.

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angioneurotic edema

see angioedema.

cardiac edema

is part of the syndrome of congestive heart failure. It comprises 'bottle jaw', jugular vein engorgement, edema of the brisket and underline, and ascites, hydrothorax and hydropericardium. See also congestive heart failure.

dependent edema

edema affecting most severely the lowermost parts of the body.

edema disease

1. in pigs a highly fatal disease of young pigs in the weaner and grower age groups characterized by incoordination, a hoarseness of voice, weakness, flaccid paralysis and blindness. Edema of the eyelids, face and ears is diagnostic but is seldom visible on clinical examination. The course is short, often less than 24 hours, and many pigs are just found dead. The disease is caused by the opportunistic proliferation of specific serotypes of Escherichia coli in an intestinal environment brought about by a change to a diet more dense in carbohydrates. These have pilus attachment antigens that allow attachment of the organism to the small intestines and produce a verotoxin (VT2e) which produces an increase in vascular permeability in the target vessels in the CNS with resultant neurological disease. Called also gut edema, bowel edema.

2. in goats a disease caused by Mycoplasma F38; a fatal cellulitis.

gravitational edema

see dependent edema (above).

gut edema

see edema disease (above).

hepatic edema

edema is a common accompaniment of hepatic disease because of the decline in production of plasma proteins and a fall in the blood's hydrostatic pressure. Ascites may occur independently because of portal hypertension when there is severe liver disease and obstruction to blood flow in the portal vein.

hypoproteinemic edema

caused by insufficient production of albumin or excess loss through a protein losing enteropathy. See hepatic edema (above), Johne's disease, proliferative enteropathy, type II ostertagiasis.

laryngeal edema

see laryngeal edema.

leg edema

a disease of market age turkeys of unknown cause and characterized by edema of the legs and focal muscle necrosis.

low-pressure edema

noncardiogenic pulmonary edema. See acute respiratory distress syndrome.

edema neonatorum

edema of the newborn. See lymphatic vessel obstruction.

pitting edema

edema in which pressure by the clinician's finger leaves a persistent depression in the tissues.

subcutaneous edema

may be generalized and constitute anasarca. Local areas of edema occur in such other conditions as angioedema and urticaria, edematous plaques in dourine and infectious equine anemia, and in purpura hemorrhagica.

vasogenic edema

that characterized by increased permeability of capillary endothelial cells; the most common form of brain edema.