Edema - MBBS Block 2 PDF

Edema AP DR. MIE MIE SEIN MBBS BLOCK 2  Learning Outcomes 1. Define oedema. (C1) 2. Classify oedema. (C2) 3. Describe the pathogenesis of the different types of oedema. (C2) 4. Correlate the clinical significance of serious complications of oedema. (pu...

Edema AP DR. MIE MIE SEIN MBBS BLOCK 2  Learning Outcomes 1. Define oedema. (C1) 2. Classify oedema. (C2) 3. Describe the pathogenesis of the different types of oedema. (C2) 4. Correlate the clinical significance of serious complications of oedema. (pulmonary oedema, papilloedema, cerebral oedema) (C4) 5. Describe pulmonary oedema. (C2) 6. Differentiate between transudate and exudate. (C4) Manipal University College Malaysia 2  Edema Definition: Abnormal accumulation of fluid in the tissue spaces (edema) or body cavities (effusion). Manipal University College Malaysia 3  Classification Generalized edema Local edema 1. Cardiac edema 1. Acute inflammatory edema 2. Renal edema 2. Hypersensitivity (allergic) edema 3. Nutritional edema 3. Edema of venous obstruction 4. Protein losing enteropathy 4. Lymphatic edema 5. Hepatic edema 6. Myxoedema 7. Unexplained edema Manipal University College Malaysia 4  60% of body weight – water 2/3 – intracellular Remainder– extracellular compartments mostly the interstitium Manipal University College Malaysia 5  Pathogenesis of edema Edema occur Increase in intravascular hydrostatic pressure A fall in colloid oncotic pressure in plasma An impairment in the flow of lymph Renal retention of salt and water Manipal University College Malaysia 6 Lymphatics Normally, hydrostatic and osmotic forces are nearly balanced so that there is little net movement of fluid out of vessels. Many different pathologic disorders are associated with increases in capillary hydrostatic pressure or decreases in plasma osmotic pressure that lead to the extravasation of fluid into tissues. Lymphatic vessels remove much of the excess fluid, but if the capacity for lymphatic drainage is exceeded, tissue edema results. Source: Robbins and Cotran Pathologic basis of disease Manipal University College Malaysia 7 I. Increased Hydrostatic Pressure Impaired venous return Congestive heart failure Constrictive pericarditis Ascites (liver cirrhosis) Venous obstruction or compression :Thrombosis, External pressure (e.g mass) Arteriolar dilation Heat Neurohumoral dysregulation Manipal University College Malaysia 8  II. Reduced Plasma Osmotic Pressure (Hypoproteinemia) Protein-losing glomerulopathies (nephrotic syndrome) Liver cirrhosis (ascites) Malnutrition Protein-losing gastroenteropathy III. Lymphatic Obstruction Inflammatory Neoplastic Postsurgical Post-irradiation Manipal University College Malaysia 9  IV. Sodium Retention Excessive salt intake with renal insufficiency Increased tubular reabsorption of sodium Renal hypoperfusion Increased renin-angiotensin-aldosterone secretion V. Inflammation Acute inflammation Chronic inflammation Angiogenesis Manipal University College Malaysia 10  Terminology Anasarca- generalized edema producing marked swelling of subcutaneous tissue Hydrothorax-abnormal accumulation of fluid in pleural cavity (Pleural effusion) Hydropericardium-abnormal accumulation of fluid in pericardial cavity (pericardial effusion) Hydroperitoneum-abnormal accumulation of fluid in peritoneal cavity (ascites) Manipal University College Malaysia 11  Morphology of edema (due to underlying cause) Cardiac edema - mainly due to congestive cardiac failure - Dependent edema- subcutaneous edema of lower parts of the body or sacral edema Renal edema 1.Acute glomerulonephritis 2.Nephrotic syndrome 3.Chronic glomerulonephritis - Periorbital edema and pitting edema Manipal University College Malaysia 12  Renal edema Periorbital edema Manipal University College Malaysia 13  clinical significance of serious complications of oedema Manipal University College Malaysia 14  Pulmonary edema Causes 1.Left ventricular failure 2.Renal failure 3.Adult respiratory distress syndrome 4.Pulmonary infections 5.Hypersensitivity reactions Manipal University College Malaysia 15  Gross The lungs are 2-3 times larger Edema is confined to lower lobes For advanced cases, all lobes may be involved On section, free escape of frothy serosanguinous fluid presenting a mixture of air, edema fluid & extravasated red cells Histology Edema fluid first accumulate about septal arteries with widening of septa Then, proteinaceous fluid escapes into alveolar spaces, marked by a granular pink coagulate within spaces Manipal University College Malaysia 16  Gross Pulmonary edema Manipal University College Malaysia 17  Histology Granular pink coagulate Septa Manipal University College Malaysia 18  Papilloedema Papilledema is the swelling of the part of the optic nerve inside the eye (optic disc) due to raised intracranial pressure typically in bilateral disc edema optic nerve is typically swollen and hyperemic Manipal University College Malaysia 19  Brain edema ( Cerebral edema) Localized – at sites of injury, abscess or neoplasm Generalized – encephalitis, hypertensive crisis, obstruction to venous flow Gross- brain is swollen with narrowing of sulci and flattening of gyri, on section – white matter may appear soft and gelatinous, peripheral gray matter is widened, ventricles are compressed Manipal University College Malaysia 20  Brain Edema Iron deficiency anaemia widened gyri with flattened surface sulci are narrowed Manipal University College Malaysia 21  Major herniations of the brain Manipal University College Malaysia 22  Clinical significance (effects of edema) Subcutaneous edema In cardiac and renal failure signals the underlying disease, impair wound healing & impair clearance of infection Pulmonary edema Impaired normal ventilatory function Fluid collect in alveolar septa around capillaries and impede oxygen diffusion Edema fluid in alveolar spaces creates a favourable environment for bacterial infections Edema of brain increased ICP-headache, projectile vomiting & convulsive seizure Serious and rapidly fatal, brain substance can herniate through the foramen magnum, brain stem vascular supply can be compressed, can injure the medullary centres and death Papilloedema is precious clinical signs of an increased intracranial pressure. Vision problems are not common initially, but may include short flickers of gray vision, blurred or double vision, and decreased field of vision or ability to see colors. Manipal University College Malaysia 23  Differences between transudate and exudate Features Exudate Transudate Definition Oedema associated with increased vascular Filtrate of blood or plasma; no increased in permeability permeability Nature Inflammatory edema Non-inflammatory edema Protein content 1. High (more than 4g/dl) 1. Low (less than 3 g/dl) 2. has high fibrinogen 2. Mainly albumin, low fibrinogen Specific gravity High (more than 1.018) Low ( less than 1.015) LDH High Low Fluid LDH/serum LDH ratio is>0.6 Fluid LDH/serum LDH ratio is