Fluid & haemodynamic disorders

1. Fluid & haemodynamic disorders Ischemia & Infarction DR SHASHIDHAR

2. ISCHAEMIA • Deficient blood supply to part of a tissue • Complete • Partial • ETIOLOGY • Cardiac • Arterial • Venous

3. Cardiac causes • Heart block • Ventricular arrest • Fibrillation

4. Arterial causes • Thrombosis, embolism • Vasospasm • Arteriosclerosis • Ligature • Torsion • Hypothermia • TAO • Torniquet • Tight bandage

5. Venous causes • Mesentric vein thrombosis • Cavernous sinus thrombosis • Varicose veins of legs • Strangulated hernia • Intussusception

6. Factors determining severity • Anatomic pattern of blood supply • General & CV status • Rapidity • Degree of occlusion

7. Effects result from • Hypoxia • Inadequacy of nutrients • Inadequate clearance of metabolism and thus accumulation

8. Effects are • Not adequate to withstand exertion  angina intermittent claudication • Cellular changes  cloudy swelling, fatty change, atrophy replacement fibrosis • Sudden death  cardiac/ cerebral

9. INFARCTION • Process of localised area of tissue necrosis resulting from circulatory insufficiency • It is the result of ischemia • Causes: Arterial Lumen: Thrombus / Embolus wall: vasospasm, atheromatous plq, TAO compression : Tumor Venous :Lumen -Thrombus/ Embolus compression- Tumor

10. Factors – outcome • Type of vascular supply Dual – Lung, liver , forearm End-arterial – Kidney , spleen • Rate of occlusion – slow : unlikely • Vulnerability : neurons> myocardial cells • Oxygen content: anemia or cyanosis

11. CLASSIFICATION : • Colour: pale / red • Age: recent / old • Infection: bland / septic

12. White / pale • Arterial • Solid Organs • End – Arterial Red/ Hemorrhagic • Venous • Loose textured tissue . Eg lung • Dual supply

13. Morphology • White infarcts: heart , kidney , spleen wedge shaped margins – well defined pale color • Red / hemorrhagic infarct : Dual : Lung, liver collateral : small intestine, brain margines- sharp , red to purple

14. INFARCTION wedge shaped

18. Old infarct : fibrosed, shrunken

19. Morphology • Microscopy : • coagulative necrosis of affected part {cerebral : liquefacive} • Hemorrhage • Peripheral inflammation, initially neutrophils, subsequently macrophages and fibroblasts • Necrotic area replaced by fibrous scar tissue dystophic calcification

20. In cerebral : liquefactive necrosis  gliosis • Microglial cells distended by fatty material = called gitter cells

21. Thank you