Hemodynamic disorders for Pathology Students

Hemodynamic disorders pathology

1. Hemodynamic Disorders AHMAD ULLAH LECTURER ANESTHESIA

2. Hemodynamic Disorders When blood passes through capillary, there is little net movement of substances into the tissues This movement is disturbed by pathologic conditions – edema The integrity of blood vessels is compromised by trauma Hemostasis prevents bleeding, if inadequate – hemorrhage Inappropriate clotting (thrombosis) or migration of clots (embolism) can obstruct blood vessels, causing ischemic cell death (infarction)

3. Increase Tissue Fluid Volumes Hyperemia Congestion Edema Decrease Tissue Blood Flow Hemorrhage Thrombosis Embolism

4. HYPEREMIA An active process of increased in inflow of blood volume in a tissue due to arteriolar dilation Increased blood flow ------- Due to arteriolar dilatation Tissues appear red (erythematous) and warm due to oxygenated blood. e.g. Sites of inflammation or exercising muscles Associated with capillary dilatation Increased inflow leads to erythema Active hyperemia is generally a beneficial physiological response ( e.g to meet metabolic demand or in inflammatory )

5. CONGESTION It is the medical conditions that arise due to an abnormal accumulation of fluid, typically blood or other bodily fluids, in tissues or organs. This condition often results from an imbalance in the circulatory system and can lead to a range of health issues.

6. Types of Congestion 1) Venous Congestion : This occurs when blood flow out of a particular area is impaired, leading to an accumulation of blood. It can be due to: Heart Failure : The heart's reduced ability to pump blood effectively leads to a backlog in the veins, particularly in the lungs (pulmonary congestion) or systemic circulation (systemic venous congestion). Deep Vein Thrombosis (DVT) : Blood clots in deep veins, often in the legs, can obstruct blood flow and cause congestion. Chronic Venous Insufficiency : A condition where veins have trouble sending blood from the legs back to the heart, leading to swelling and discomfort.

7. 2) Pulmonary Congestion : Specifically related to the lungs, this occurs when fluid accumulates in the lung tissues and alveoli. Common causes include: Left-Sided Heart Failure : When the left side of the heart fails to pump effectively, fluid backs up into the lungs. Pulmonary Edema : A condition where excess fluid collects in the lung tissues, often due to heart failure or acute respiratory distress.

8. 3) Hepatic Congestion : This is when blood backs up in the liver due to: Right-Sided Heart Failure : Impaired pumping from the right side of the heart can lead to fluid buildup in the liver. Cirrhosis : Liver scarring can obstruct blood flow through the liver, causing congestion.

9. 4) Portal Hypertension : Increased blood pressure in the portal venous system can lead to congestion in the spleen and other abdominal organs. It is often associated with liver disease, especially cirrhosis.

10. Pathophysiology: Impaired Blood Flow : Congestion often results from problems in blood flow, either due to obstructive conditions like thrombosis or due to heart failure where the heart's pumping capacity is diminished. Increased Hydrostatic Pressure : When blood flow is obstructed, pressure increases in the veins, pushing fluid out into surrounding tissues. Fluid Accumulation : The fluid that accumulates in tissues can lead to edema, which is swelling due to excess fluid.

11. Symptoms: Symptoms of congestion pathology vary depending on the affected area but can include: Swelling : Often in the legs or abdomen. Shortness of Breath : Especially if the lungs are affected. Pain or Discomfort : In the areas where fluid accumulates. Fatigue : Due to reduced efficiency of the heart or other organs.

12. Edema Water makes 60% of body weight 2/3 intracellular 1/3 extracellular Most in interstitium and very small amount in plasma Edema refers to accumulation of extra fluid within tissues interstitium Usually in lower limb , but also involve the entire body Old age and pregnant women are more likely to get edema

13. Effusion Fluid accumulations in body cavities is known as effusions Pleural cavity – hydrothorax Pericardial cavity – hydro pericardium Peritoneal cavity – ascites Severe swelling of subcutaneous tissues – Anasarca

14. Pathogenesis Fluid movement b/w vascular and interstitium is control by two opposing pressures: Vascular hydrostatic pressure – fluid, tends to outflow Colloid osmotic pressure – plasma proteins, tends to inflow Hydrostatic pressure at arteriolar end is slightly high Osmotic pressure at venular end is slightly elevated These pressure allow only a small net outflow of fluid into the interstitial space, drained by lymphatic vessels

15. Pathogenesis Imbalance in these pressures cause increased movement of fluid (transudate) into the interstitium – edema High hydrostatic pressure Low osmotic pressure

16. Etiologies Increased Hydrostatic Pressure Reduced Plasma Osmotic Pressure Lymphatic Obstruction Sodium Retention Inflammation

17. Mechanism Increased Hydrostatic Pressure Caused by disorders that impair venous return Local increases in IV pressure DVT in the lower extremity – local edema distal to affected leg CHF – Generalize increases in venous pressure – systemic edema

18. Factors increasing hydrostatic pressure: Reduced cardiac output Low output results in renal hypoperfusion – stimulate RAAS, Inducing sodium and water retention

19. Mechanism Reduced Plasma Osmotic Pressure Caused by reduction of plasma albumin concentrations Albumin make ½ of total plasma protein Albumin lost – Nephrotic syndrome – leak glomerulus, loss of albumin in urine – generalized edema Synthesizes in inadequate amounts – liver cirrhosis and protein malnutrition

20. Mechanism Lymphatic Obstruction Compromises resorption of fluid from interstitial spaces into the blood Edema due to lymphatic obstruction is called lymphedema Results from a localized obstruction due to inflammation, neoplasia, surgery

21. Mechanism Sodium Retention Excessive retention of salt (with water) increase hydrostatic pressure (expansion of IV volume) and reducing plasma osmotic pressure Diseases that compromise renal function Glomerulonephritis and acute renal failure (low GFR) Hyperaldosteronism – heart failure stimulating RAAS

22. Mechanism Inflammation Increased vascular permeability Exudation occur which increased osmotic pressure in interstitium Protein in interstitium exert osmotic pressure and attract more and more fluid

23. Signs Swelling Skin that hold a dimple or pit after being hold or pressed Shiny skin Enlarge abdomen Sudden weight gain Severe leg pain, feel heavy and difficult to walk Ulcer may developed on the skin – impair blood flow

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