The decrease in plasma osmotic pressure is the cause of edema in?
High-Yield Explanation
• Following conditions can cause edema :-
1) The increased hydrostatic pressure of capillaries : It causes an increase in outward driving force. It may be due to impaired venous return e.g. in CHF or DVT.
2) Decreased plasma osmotic pressure of capillaries: It causes decreases in inward driving force. It results from Hypoproteinemia.
When total plasma protein is below 5 gm/dl (normal 6-8gm/dl) or albumin is below 2.5 gm/dl (normal 3.5-5 gm/dl) edema takes place.
Conditions causing hypoproteinemia are a nephrotic syndrome, liver cirrhosis, protein-losing enteropathy, and PEM.
3) Defective removal of interstitial fluid by lymphatics: It is due to lymphatic obstruction, which may be inflammatory, neoplastic, post-surgical and post-irradiation.
4) Increased vascular permeability: It occurs in acute and chronic inflammation, and during angiogenesis (new vessels are leaky).
5) Sodium (salt) and water retention: It causes expansion of plasma volume (hydrostatic pressure) and dilution of plasma proteins (↓ osmotic pressure).
The conditions responsible for this type of edema are ARF, acute glomerulonephritis, renal hypoperfusion, and increase renin angiotensin aldosterone system (RAAS) activity.