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 2005 11
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%);
Anatomy and pathophysilolgy
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.
• Vascular system
Hydrostatic pressure
（流体静水压）
Colloid oncotic pressure
（胶体渗透压）
Interstitial space
Hydrostatic pressure
(tissue tension)
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
Localized edema
• Congestive heart failure
• Cirrhosis
• Nephrotic syndrome/other
hypoalbuminemia
• Drug-induced
• Idiopathic
• 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
liver cirrhosis
congenital hypoalbuminemia
• 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
Cyclosporine
Growth hormone
Immunotherapies
Interleukin 2
OKT3 monoclonal antibody
Progestines
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
Location
onset from the face,
periobital areas
Progression progress quickly
Identity
soft and mobile
Other signs
proteinuria
hypertension
impaired renal
functional test
Cardiac
onset from the lower
part of the body
progress slowly
relatively solid, less
mobile
signs of heart failure:
cardiac enlargement
venous distention
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
Heart
Liver
Kidney
Generalized
or
Venous obstruction
Lymphatic obstruction
Localized
Thanks for your attention