Section III Common Symptoms edema

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Section III Common Symptoms(edema)

• Dr. Zhuoren Lu
• First Hospital
• Xian Jiaotong University

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B. Edema1. Definition
Edema is an excessive collection of fluid in the
interstitial space. anasarca (dropsy) body
edema ascites fluid located to peritoneal
cavity hydrothorax (pleural fluid or effusion)
fluid located to the pleural space.2. Etiology
Edema results when increased hydrostatic
pressure, decreased oncotic pressure or disrupted
capillary permeability allows fluid to shift from
the intravascular to the extravascular space.

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• Interstitium
  _______
• tissure pressure? oncotic pressure?
  _______ Lymphatics
• ?????????????????????????
• Capillary hydrostatic pressure? oncotic
  pressure?
• ?????????????????????????

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• (1) Generalized edema Commonly results from
  increased capillary hydrostatic pressure in
  congestive heart failure (cardiac edema), renal
  failure (renal edema) with excess sodium and
  water retention, expansion of intravascular
  volume by large volumes of fluid at a rate faster
  than kidney can excrete.
• (2) Localized edema It is often due to increased
  capillary hydrostatic pressure in chronic venous
  insufficiency (deep vein thrombophlebitis). Less
  commonly, localized edema results from chronic
  lymphangitis, because the fluid return from the
  interstistium to the intravascular space is
  impaired by disrupted or obstructed lymphotics,
  or after lymph node resection.

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• (3) Decreased oncotic pressure When serum
  proteins are reduced (malnutrition, protein loss
  via kidney, liver dysfunction), there is
  insufficient oncotic pressure within the
  intravascular space to hold the fluid there.
• (4) Disruption of capillary endothelium
  increased vessel permeability and leakage of
  protein and fluid from the intravascular space to
  the extravascular space, for example immunologic
  injury with hypersensitivity (generalized edema),
  infection, burn injury, trauma (localized edema).

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3. Characterizing the edema

• (1) Cardiac edema congestive heart failure as a
  cause, generally most noticeable in the evening
  and firstly found in the lower extremity with
  pitting edema (pretibial).
• (2) Renal edema renal disease with abnormal salt
  retention as a possible cause.
• Palpebral swelling occurs in the morning during
  the early stage of renal diseases.
• Edema develops more rapidly to generalized edema
  than cardiac edema does.