9. edema Flashcards
Edema
Is the collection of excess fluid in the interstitial space and body cavities
Causes
Increase in net fluid flux (Jv) + Lymphatic obstruction
Lymphatic obstruction
Erysipelas, elephantiasis, inflammatory breast cancer, lymphadenectomy or radiation, neoplasms and lymphatic malformations
Erysipelas
Superficial cutaneous Cellulitis caused by S.pyogenes
elephantiasis
Filarial lymphadenitis caused by Wuchereria bancrofti and Brugia malayi
Inflammatory breast cancer
Peau d’ orange
Increase in vascular permeability(Kf)
Inflammation,
infections (sepsis),
burn,
anaphylaxis
and bleomycin
Increase in oncotic pressure in interstitial space(πi)
Myxoedema due glycosaminoglycan (chondroitin sulfate and hyaluronic acid)
Hypothyroidism and Hyperthyroidism.
Decrease in oncotic pressure in vasculature (πc)
Hypoalbuminemia due to malnutrition (kwashiorkor),
Protein-losing gastroenteropathies malabsorption,
liver cirrhosis and
nephrotic syndrome
Increase in capillary hydrostatic pressure(Pc)
Impaired venous return; CHF, Constrictive pericarditis, Ascites (liver cirrhosis), Venous obstruction (DVT) and External pressure due to a mass
Arteriolar dilatation; Heat and Neurohumoral dysregulation
Classification of edema based on the distribution and extent of involvement
Localized edema is limited to a small area, E.g, organ-specific edema, elephantiasis, edema of DVT, allergic laryngeal edema and localized inflammatory edema
Generalized edema (Anasarca) may involve the entire body
eg (CHF, nephrotic syndrome and nutritional deficiency)
Based on the composition of the fluid
Transudate fluid that results from an imbalance in hydrostatic and osmotic pressures across the blood vessels
and
exudate a fluid that contains a higher protein content and is often associated with inflammation or tissue injury.
Consequences of edema
Increase in the diffusion distance for oxygen, nutrients and toxic by-products Compromise cellular function
Pulmonary edema 2 types
cardiogenic- left side heart failure
non cardiogenic - injury to lung parenchyma or vasculature of the lung like ARDS, pneumonia
Renal edema characteristic
Appears first in loose connective tissue eg, the eyelids (periorbital edema)
