edema-1.kmu lecture 2024....;.............

By abid.......

1. EDEMA MISS MARIA SAJJAD

2. EDEMA Abnormal or excessive fluid accumulation in interstitial tissue spaces is called EDEMA Excess fluid in the body tissue extravascularly Extravascular fluid refers to all the fluid outside of the blood vessels and includes lymph, cavity fluids etc Swelling caused by too much fluid trapped in the body tissue/interstitial tissue spaces/cavities called EDEMA

3. Excess fluid in the body either Intracellular edema Extracellular edema (interstitial or body cavity)

4. 60% of body weight is water 2/3of body water is intracellular 1/3 of bodywater is extracellular mostly interstatial 5% of body water is in plasma Extracellular fluid in two portion Vascular compartment Interstitial compartment

5. Classification

6. Transudates result from an imbalance of oncotic and hydrostatic pressures. whereas exudates are the result of inflammatory processes of the pleura and/or decreased lymphatic drainage.

7. Generalized Notice swelling and puffiness in different parts of body GENERALIZED EDEMA  In this case the edema involves more than 1 part of the body simultaneously . It is commonly due to cardiac, hepatic, renal or endocrine causes . Abdomen , arms,legs,face,feet etc

8. Localized In particular part or organ of a body  LOCALIZED EDEMA  It means that the edema is localized to a specific region of the body . It is commonly due to venous/lymphatic causes, allergy and inflammation.

9. Mechanisms of Edema Edema results from increased movement of fluid from the intravascular to the interstitial space or decreased movement of water from the interstitium into the capillaries or lymphatic vessels.

10. The mechanism involves :  Increased capillary hydrostatic pressure.  Decreased plasma oncotic pressure. Increase blood vessel wall permeability i.e inflammation Obstruction of fluid clearance in the lymphytic system 5. Sodium +water retention (Change in water retaining property of tissue)

11. Hydrostatic pressure: HP HP forces fluid out of the capillary . In plasma (90% fluid or water) is present. Apply pressure outward is called Hydrostatic pressure. E.g if there is Hole in the pen liquid will come out side due to pressure. HP increase—water apply pressure on blood vessels

12. Oncotic pressure Oncotic pressure ,or colloid osmotic pressure is a type of osmotic pressure induced by plasma proteins. Pressure due to protein present in plasma. Protein keep fluid inside vessels, retain water in vessels . If OP dec ---–fluid can not retain ----come in interstitial spaces

13. In general the opposing effects of vascular HP and Plasma COP are the major factors that govern movement of fluid between vascular and interstitial spaces. Normally the exit of fluid into interstitium from the arteriolar end of the microcirculation is nearly balanced by inflow at the venular end. A small residual amount of excess interstitial fluid is drain by lymphatics.

14. Fluid exchange Capillary to Tissue Fluid Exchange Capillaries are where fluids, gasses, nutrients, and wastes are exchanged between the blood and body tissues by diffusion. Capillary walls contain small pores that allow certain substances to pass into and out of the blood vessel.

15. Fluid exchange between body compartments At the arteriole end of a capillary, oxygen is being delivered to the intestinal fluid-tissue cell, like essential nutrients such as amino acids and glucose .

16. At the arteriole end of a capillary balance between HP 32 ( millimetres of mercury ,mmHg) and OP 25mmHg is the HP 7mmHg which is outward driving force so that small quantity of fluid and solute leaves the vessels to entre in interstitial space. Either increase capillary pressure or diminished oncotic pressure can result in increase interstitial fluid.

17. At the venular end of a capillary balance between HP 12mmHg and OP 25mmHg is the OP 13mmHg which is inward driving force so that fluid and solute re enter the plasma.

18. Increased capillary hydrostatic pressure Rise in HP at the venular end of the capillaries which in normally low to a level more than plasma oncotic pressure. Fluid come in interstitial spaces or come out of capillaries Minimal/NO reabsorption of fluid at venular end-----EDEMA

19. Increase HP in which conditions Generalized increase in venous pressure with resultant systemic edema, occurs most commonly in Congestive heart failure ( Effecting right ventricular cardiac function). Venus Return- ---heart can not pump blood properly----come back in heart---Venus return---less blood accumulate in veins—HP increase—fluid outside from vein.

20. Localized increase in intravascular pressure may result from impaired venous return e.g secondry to deep vein thrombosis in the lower extremities with edema restricted to the affected Legs.

21. Venous obstruction Venous obstruction is partial or complete occlusion(blockage) of the lumen of a vein . Hinder blood flow from legs to heart-----Vein blockage Back flow of blood----HP Increase -----cause EDEMA Diseases causes Venous obstruction Deep vein thrombosis  ( DVT ) occurs when a blood clot (thrombus) forms in one or more of the deep veins in the body, usually in the legs. Pelvic tumor Abdominal tumor

22. 2. Reduced plasma Osmotic pressure Reduced Albumin synthesis in liver/protein malfunction Fall in plasma oncotic pressure Net movement of fluid into interstitial EDEMA

23. This can result from excessive loss of or reduced synthesis if Albumin the serum protein most responsible for maintaining colloid osmotic pressure Important cause of Al loss is Nephrotic syndrome (Leaky glomerular capillary wall) Reduced Al synthesis occurs in L iver disease e.g Cirrhosis

24. Heart cant pump blood ---kidney receive less blood ( Hypoperfusion of kidney) Kidney activate RAAS system Water retention (kidney cant remove water) In plasma Albumin is present(keep water inside) Albumin hold water in capillaries so cant move outside

25. If Albumin is less----Oncotic pressure will be less-----water comes outside the capillaries EDEMA

26. 3. Lymphatic Obstruction Impaired lymphatic drainage Localized lymphedema Drainage system remove excess fluid from body tissues and return to blood stream. Subsystem 1. circulatory system 2. Immune system Circulatory system bring oxygen and nutrient to body tissue and remove waste.

27. Lymphatic system pick extra fluid and send to circulatory system Normally interstitial fluid in tissue drain by lymphatic system. If lymphatic obstruct due to any surgery/lymph nodes remove Fluid accumulate in interstitial area, cant drain----- Lymphedema Axilary lympnodes remove in Carcinoma breast. Filariasis ( Edema in lower extremity and external genitalia)

28. 4. Sodium and water retention Capillaries loss blood Reduction in blood volume in capillaries called HYPOVOLEMIA EDEMA

29. Salt retention may also be the primary cause of edema. Increase salt with accompanying water ,cause both increased hydrostatic pressure and diminished vascular colloid osmotic pressure. Salt retention may occur with any acute reduction of renal function e.g acute renal failure.

30. 5. INFLAMMATION Capillary endothelial injury by toxin/histamine/drugs Endothelial gape increase capillary permeability to plasma protein Plasma oncotic pressure decrease EDEMA

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