MICROCIRCULATION-EDEMA

SUMMARY

1. Edema is defined as the abnormal accumulation of fluid in the extravascular space.

2. Transudate: due to imbalances of hydrostatic Starling forces. Exudate: due to increased capillary permeability. The exudate is rich in protein & fibrinogen.

CAUSES
3. Reduced colloid osmotic pressure: as occurs in hypo-proteinaemic states such as malnutrition, malabsorption & nephrotic syndrome

4. Increased hydrostatic pressure: as occurs in heart failure, DVT, abnormal retention of salt & water

5. Increased capillary permeability: as occurs in inflammatory processes; factors involved: histamine, 5-HT, platelet-activating factor (PAF), PGE₂, C5_a

6. Lymphatic occlusion by malignant or infective processes

Reference(s)

Barrett, K.E., Barman, S.M., Boitano, S., Brooks, H.L., Weitz, M., Brian Patrick Kearns, Ganong, W.F. and Mcgraw-Hill Education (Firm (2016). Ganong’s review of medical physiology. 25th ed. New York: Mcgraw Hill Education.
Hall, J.E. and Hall, M.E. (2020). Guyton And Hall Textbook Of Medical Physiology. 14th ed. S.L.: Elsevier - Health Science.
West, J.B. and Luks, A.M. (2021). West’s Pulmonary Pathophysiology. Lippincott Williams & Wilkins.