Haemostasis and Haemodynamic Disturbances Ι PDF

Haemostasis and Haemodynamic Disturbances Ι Dr. MAHA ELTINGARI We are Going to Discuss the Following 2         Oedema (OR edema) Hyperaemia & congestion Overview of normal haemostasis Haemorrhage Thrombosis Embolism Infarction Shock Haemostasis and Haemodynamic Disturbances 1 3 Oedema Haemos...

Haemostasis and Haemodynamic Disturbances Ι Dr. MAHA ELTINGARI We are Going to Discuss the Following 2         Oedema (OR edema) Hyperaemia & congestion Overview of normal haemostasis Haemorrhage Thrombosis Embolism Infarction Shock Haemostasis and Haemodynamic Disturbances 1 3 Oedema Haemostasis and Haemodynamic Disturbances 1 4 Before going into discussion of oedema, we need to clarify the following points:  Body fluid compartments  Normal microcirculation Haemostasis and Haemodynamic Disturbances 1 Fluid Compartments 5 In a 70 kg weight adult male there are:  40 liters of total body water  25 liters of intracellular fluid  15 liters of extracellular fluid divided into: 12 liters of interstitial fluid 3 liters of intravascular fluid (plasma) Haemostasis and Haemodynamic Disturbances 1 Note the following facts.. 6    Intracellular and extracellular fluid compartments are separated by the semipermeable plasma membrane. Distribution of fluid between these two compartments depend on water movement to maintain equal osmolarity (simple diffusion) Sodium is the main cataion of the extracellular fluid. Haemostasis and Haemodynamic Disturbances 1 7   The interstitial fluid is normally an ultrafiltrate of plasma, i.e. it contains all the contents of plasma except proteins. Oncotic pressure (or colloid osmotic pressure) is the pressure exerted by plasma proteins across vessel wall. Haemostasis and Haemodynamic Disturbances 1 Normal Microcirculation 8 At the arteriolar end:  Hydrostatic pressure is greater than the plasma oncotic pressure Fluid leaves the vascular compartment into interstitial compartment Haemostasis and Haemodynamic Disturbances 1 Normal Microcirculation 9 At the venular end:  Plasma oncotic pressure is greater than the Hydrostatic pressure Fluid returns into the vessel  Fluids that couldn’t be retained at the venular end reenter the vascular compartment through lymphatics Haemostasis and Haemodynamic Disturbances 1 Normal Microcirculation 10 Haemostasis and Haemodynamic Disturbances 1 EDEMA Increased fluid in the interstitial tissue spaces   Fluid may also accumulate in body cavities: 1. Hydrothorax 2. Hydropericardium 3. Hydroperitoneum is also called Ascites Massive generalized edema is called Anasarca Definitions.. 12 Oedema refers to fluid accumulation in the interstitial space.  Fluid accumulation in the body cavities is named: Pericardium pericardial effusion Peritoneum Ascitis Pleural space pleural effusion  Haemostasis and Haemodynamic Disturbances 1 Oedema in Heart Failure 13 Haemostasis and Haemodynamic Disturbances 1 Causes of Oedma 14      Increased hydrostatic pressure Decreased plasma oncotic pressure Lymphatic obstruction Sodium and water retention inflammation Haemostasis and Haemodynamic Disturbances 1 Increased Hydrostatic Pressure 15 Can be:  Localized (local obstruction) or  Generalized (heart failure) Haemostasis and Haemodynamic Disturbances 1 Decreased Plasma Oncotic Pressure 16   Due to decreased plasma proteins (albumen in particular). Causes: Nutritional (e.g. Kwashiorkor).and malabsorption. Liver disease (decreased synthesis) Increased loss (renal or intestinal disease) Haemostasis and Haemodynamic Disturbances 1 Lymphatic Obstruction 17 Examples:  Infection (e.g. Filariasis in Elephantiasis)  Tumor permeation. E.g. breast peau d orange (i.e. orange like)  Postirradiation  Postsurgical  Primary lymphatic channel tumor (lymphangiosarcoma) Haemostasis and Haemodynamic Disturbances 1 Sodium and Water Retention 18 Occurs in:  Some renal diseases.  Congestive cardiac failure. Pathophysiologic Categories of Edema I. Increased Hydrostatic Pressure II. Reduced Plasma Oncotic Pressure III. Inflammation IV. Others Lymphatic Obstruction Water and Sodium Retention Oedema Finger pressure over edematous subcutaneous tissue leaves a finger-shaped depression, so-called pitting edema 20 Haemostasis and Haemodynamic Disturbances 1 Lymphoedema Non pitting edema(Elephantiasis 21 Haemostasis and Haemodynamic Disturbances 1 22 Generalized edema. Kwashiorkor Haemostasis and Haemodynamic Disturbances 1 Edema Fluid Transudate Cause High hydrostatic pr. Protein content Low Exudate Inflammatory High Specific gravity 1.020) Inflammatory cells Absent Rich 24 Hyperaemia & congestion Haemostasis and Haemodynamic Disturbances 1 Definitions 25    Hyperemia and congestion both indicate a local increased volume of blood in a particular tissue. Hyperaemia is the active increase in blood flow Congestion is the passive engorgement of a tissue with blood due to obstruction to venous outflow. Haemostasis and Haemodynamic Disturbances 1 Differences 26 I have considered hyperaemia and congestion together, despite they are dissimilar, in order to clarify the difference between them: 1. Hyperaemia is active while congestion is passive. 2. In hyperaemia blood flow increases but in congestion blood flow decreases. Haemostasis and Haemodynamic Disturbances 1 27 3. In hyperaemia the involved organ is reddened (full of oxygenated blood) while in congestion the tissue is bluish (full of deoxygenated blood) Haemostasis and Haemodynamic Disturbances 1 Hyperaemia 28 Haemostasis and Haemodynamic Disturbances 1 Congestion 29 Haemostasis and Haemodynamic Disturbances 1 hyperaemia 30    Can be localized or generalized. Localized e.g. inflammation, ischaemic tissue after removal of an obstruction Generalized: Paget’s disease of bone Haemostasis and Haemodynamic Disturbances 1 hyperaemia 31 Haemostasis and Haemodynamic Disturbances 1 Congestion 32    Can be localized or generalized Often coexists with oedema Morphologically the organ is bluish, with dilated vascular spaces. With chronicity, there will be parynchemal cell loss, fibrosis and haemosidernladen macrophages Haemostasis and Haemodynamic Disturbances 1 Congestion 33 Haemostasis and Haemodynamic Disturbances 1 HEMORRHAGE Is extravasation of blood from vessels into the extravascular space. Hemorrhage can be external or can be confined within a tissue; any accumulation is referred to as a hematoma. 35 Overview of Normal Haemostasis Haemostasis and Haemodynamic Disturbances 1 Definition of Haemostasis 36  Is the maintenance of the blood in its fluid state (clot-free state) inside the vascular tree and solidification of blood (localized hemostatic plug) in case of injury to prevent excessive blood loss. Haemostasis and Haemodynamic Disturbances 1 37 Normal haemostassis is an interplay between three components:  Endothelial cells  Platelets  Coagulation system Haemostasis and Haemodynamic Disturbances 1 Role of Endothelial Cells 38    Have anti-coagulant (i.e. prevent clotting) and procoagulant (i.e. enhance clotting) properties Anticoagulant: Anti platelet effect (prostacyclin) Anticoagulants (e.g. Antithrombin III) Fibrinolytic properties Procoagulant materials are also stored in endothelial cells and released upon vascular injury.. Haemostasis and Haemodynamic Disturbances 1 Pro- & Anti-Thrombotic Properties of Endothelium 39 Haemostasis and Haemodynamic Disturbances 1 Role of Platelets 40   Formation of the primary haemostatic plug. Substances stored in platelets granules (called α granules and dense granules) enhances coagulation and platelet aggregation. Haemostasis and Haemodynamic Disturbances 1 Platelets Adhesion 41 Haemostasis and Haemodynamic Disturbances 1 The Coagulation System 42     The coagulation cascade consists of enzymes found inactive in plasma They are synthesized by liver, platelets and endothelium They are activated sequentially.. The end result being conversion of soluble fibrinogen into the insoluble fibrin 3 pathways: extrinsic, intrinsic and common Haemostasis and Haemodynamic Disturbances 1 The Coagulation Cascade 43 44 Haemorrhage Haemostasis and Haemodynamic Disturbances 1 45   Haemorrhage is the loss of blood into extravascular space. It can be lost into the exterior of the body or can be internal bleeding (inside the body) Haemostasis and Haemodynamic Disturbances 1 46 Internal bleeding can be:  Subcutaneous  In a soft tissue or organ (haematoma)  Into a body cavity Haemostasis and Haemodynamic Disturbances 1 47 Subcutaneous bleeding is named according to its size:  1-2 mm petechiae  3-5 mm purpura  Larger ecchymosis Haemostasis and Haemodynamic Disturbances 1 48 Bleeding into a cavity:  In a joint is called haemarthrosis  Pericardial cavity is called haemopericardium Haemostasis and Haemodynamic Disturbances 1 Consequences of Blood Loss 49    chronic bleeding (e.g. peptic ulcer) may result in Iron deficiency anaemia Acute bleeding if massive may lead to shock Massive bleeding might be: Into a large body cavity (e.g. pelvic) Into the GIT Outside the body Haemostasis and Haemodynamic Disturbances 1