EDEMA Leyi Gu Renal Division, Renji Hospital

DEFINITION Expansion of the interstitial （间质） fluid volume. Weight gain precedes overt edema Massive and generalized edema is called anasarca （全身性水肿） Pitting ( 压凹性 ) and non-pitting ( 非压凹性 ) edema Schroth BE, JAAPA

Edema Pitting edema Non-pitting edema

Anatomy and pathophysilolgy 1/3 of total body water is extracellular space, and 2/3 is intracellular space; Extracellular space is composed of the intravascular plasma volume (25%) and the extravascular interstitial spaces (75%);

Starling’s law: Extravascular and intravascular hydrostatic pressurs; Differences in oncotic pressures within the interstitial space and plasma; The permeability of the blood vessel wall. Anatomy and pathophysilolgy Vascular system Interstitial space Hydrostatic pressure （流体静水压） Hydrostatic pressure Colloid oncotic pressure (tissue tension) （胶体渗透压） Colloid oncotic pressure

Reduced Plasma Osmotic Pressure Albumin is the serum protein MOST responsible for the maintenance of colloid osmotic pressure A decrease in osmotic pressure can result from increased protein loss or decreased protein synthesis

Capillary Damage Damage to the capillary endothelium Increase its permeability and permits the transfer of protein into interstitial compartment Injury agents Drugs Viral/bacterial agents Thermal/mechanical trauma Immune Responsible for inflammatory edema Nonpitting localized redness and tenderness

Clinical Causes of Edema Systemic edema Congestive heart failure Cirrhosis Nephrotic syndrome/other hypoalbuminemia Drug-induced Idiopathic Localized edema Venous/lymphatic obstruction

Systemic Edema Congestive heart failure

Congestive heart failure Left-sided heart failure: shortness of breath with exertion and when lying down at night (orthophea, 端坐呼吸 ) －－ pulmonary edema Right-sided heart failure: swelling in the legs and feet －－ peripheral edema The physician examining a patient who has congestive heart failure with fluid retention looks for certain signs: pitting edema; rales in the lungs, a gallop rhythm and distended neck veins.

Systemic Edema

Nephrotic Syndrome/Hypoalbuminemic states The primary alteration: decreased colloid oncotic pressure protein loss in the urine severe nutritional deficiency protein loss enteropathy congenital hypoalbuminemia liver cirrhosis Promotes fluid move into the interstitium Causes hypovolemia salt/water retention activation RAA axis etc

Idiopathic Edema Diurnal alterations in weight occurring with orthostatic retention of sodium and water Increase in capillary permeability fluctuate in severity aggravated by hot weather Reduction in plasma volume in this condition with secondary activation of the RAA system

Drug-induced edema Nonsteroidal anti-inflammatory drugs Antihypertensive agents Direct arterial/arteriolar vasodilators Calcium channel antagonists a-Adrenergic antagonists Steroid hormones Glucocorticoids Anabolic steroids Estrogens Progestines Cyclosporine Growth hormone Immunotherapies Interleukin 2 OKT3 monoclonal antibody

Localized edema Inflammation Venous/lymphatic obstruction Chronic lymphangitis Resection of regional lymph nodes Filariasis ( 丝虫病 )

Diagnosis Of particular importance is excluding major organ system dysfunction, especially cardiac, liver, and renal dysfunction. Ask questions such as the following: Do the rings on your fingers get tight? Have you had to let your belt out? Have your clothes or shoes gotten too tight? Pay special attention to the patient’s medications; Also, obtain a thorough dietary history, paying careful attention to the patient’s dietary sodium intake, total daily fluid intake;

Physical examination & Diagnostic testing In addition to the standard physical examination, chart the patient’s weight and note general appearance, paying special attention to the edema with respect to location, symmetry, pitting or nonpitting appearance, tenderness, and associated skin changes. Assess the severity of edema with a method such as the four-point scale (+1, slight, to +4, very marked) ; Including a chemistry panel and urinalysis to evaluate renal and liver function and albumin levels to assess nutritional status. Consider measuring the thyrotropin level to rule out hypothyroidism. In cases where screening for a cardiac etiology is required, an ECG and chest radiograph may be helpful in assessing cardiac function.

Differential diagnosis Heart failure Renal diseases Cirrhosis Nutritional origin Idiopathic Others

Differential diagnosis Heart Failure Edema initially occurs at lower part of the body (lower extremities) symmetric location The presence of heart diseases cardiac enlargement gallop rhythm dyspnea basilar rales venous distention hepatomegaly Noninvasive tests may be helpful echocardiography radionuclide angiography

Differential diagnosis Renal diseases Mainly due to hypoabluminemia and salt/water retention Associated with hematuria, proteinuria, hypertention and impaired renal functional Characteriastic of edema of renal origin: puffiness of the face prominent in the periorbital areas

Differential diagnosis Cardiac/Renal disease Renal Cardiac Location onset from the face, onset from the lower periobital areas part of the body Progression progress quickly progress slowly Identity soft and mobile relatively solid, less mobile Other signs proteinuria signs of heart failure: hypertension cardiac enlargement impaired renal venous distention functional test hepatomegaly

Differential diagnosis Liver diseases (cirrhosis) Clinical evidence of hepatic disease jaundice spider angiomas ascites Ascites refractory to the treatment Edema may also occur in other parts of the body due to: Hypoalbuminemia increased intraabdominal pressure impede venous return from the lower extremities

Differential diagnosis Idiopathic edema Exclusive in women periodic episodes accompanied by abdominal distention

Differential diagnosis Other Causes of Edema Hypothyroidism (myxedema, 粘液水肿 ) periorbital puffiness nonpitting Exogenous hyperadrenoncortism Pregnancy Estrogens angioneurotic

Approach to the patient Generalized Localized or Heart Liver Kidney Venous obstruction Lymphatic obstruction

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