Hemodynamics Flashcards

Question

Thrombosis

Answer 1

The formation of a solid mass from circulating blood elements in the intact circulation. Normal role for thrombus formation is to plug defects produced by everyday activities in the vessel walls. Thrombus formation occurring within circulation at sites of no injury or relatively mild injury

Answer 2

Hemostasis is a precisely orchestrated physiologic process that occurs at the site of vascular injury and culminates in the formation of a blood clot to prevent or limit the extent of bleeding. -vascular wall -platelets -coagulation

Answer 3

Endothelial integrity is the most important factor. Abnormalities of procoagulants or anticoagulants can tip the balance in favor of thrombosis. Abnormal blood flow (stasis or turbulence) can lead to hypercoagulability directly and indirectly through endothelial dysfunction.

Answer 4

Most important factor 1. injury exposes VWF(platelet bindding site) -> increase tissue factor 2. Inflammation -> increase plasminogen activator inhibitor (pro) -> decrease anticoagulant factors. 3. platelet adhesion 4. clots are rich in platelets

Answer 5

Turbulence can cause direct injury to endothelial cells, while pockets of stasis allows platelets and leukocytes to come in contact with endothelium. contribute to abnormal BF: Atherosclerotic Plaques -> turbulent flow across plaque which can damage the fibrous cap covering the atheroma, causing bleeding and exposing subendothelial collagen causing platelet adhesion and therefore thrombus formation over the ulcerated atherosclerotic plaque. This is the pathogenesis of acute myocardial infarction. Aneurysmsv-> aortic aneurysms cause blood to settle within the dilated lumen. Loss of blood flow in the aneurysm predispose to stasis and clot formation. Atrial or Ventricular Fibrillation -> ineffective contraction and emptying of left atrium or ventricle causing stasis of blood and clot formation within the heart chamber.

Answer 6

Abnormally high tendency of activation of the clotting cascade in blood. Very important risk factor for venous thrombosis.

Answer 7

Most common cause of hereditary thrombosis and most commonly presents with veinous thromboses such as deep vein thrombosis (DVT). Factor V Mutation produces a factor V that is resistant to inhibition by Protein C, a natural anticoagulant. Note: PT, PTT are normal in this condition

Answer 8

- A single-nucleotide substitution (G to A) in the 3′-untranslated region. The result is increased transcription of prothrombin and increased levels of prothrombin in the blood. Clinically there’s an increased risk of veinous thromboses.

Answer 9

Antithrombin inhibits Factors IIa (Thrombin) and factor Xa. Note: PT, PTT are normal in this condition.

Answer 10

Loss of inhibition of Factor Va and Factor VIIIa. Warfarin inhibits factor II, VII, IX, X, Protein C and Protein S. Protein C and Protein S have shorter half lives than factors II, IX and X, therefore treatment with warfarin causes a transient procoagulant state presenting with skin necrosis in patients with protein C and protein S deficiency.

Answer 11

Paler than venous thrombi seen in heart and aorta seen in other smaller arteries coronaries, carotids, femoral, mesenteric

Answer 12

Takes shape of the vessel redder than arterial thrombus superficial veins rarely embolize deep veins -> embolize

Answer 13

- pain, tenderness, features of necrosis such as blue/black discoloration. - Venous thrombi: swelling, pain, tenderness, pitting edema, warm and discolored due to congestion (limb). - aterial thrombi: Infarct (e.g. Myocardial infarct) Slow – ischemia, atrophy, fibrosis, collateral vessel formation (e.g. Stable angina, limb claudication); pale and cold ( Venous embolize to lung usually arterial embolize to organs/tissue or lower extremeity

Answer 14

detached mass that is carried in the blood from point of orgin to a distant site, can cause infarction or dysfunction. most common emboli come from the heart then to the lower extremities or brain Most emboli were part of a dislodged thrombus

Answer 15

Common origin is from the deep leg veins to the lungs major contributor to death in hospital, when they first get out of bed. Massive -> sudden obstruction of 60%/sudden death Major -> medium occlusion dyspnea, pain/ infarction of 10% minor -> small vessels obstructed/ asymptomatic

Answer 16

arterial circulation emboli originates from the heart (80%) aorta from plaques venous circulation from atrial septal defect (paradoxical) Can lead to infarction due to embolization brain lower extremities and bowel

Answer 17

Trauma to bone, subcutaneous tissue, burns → fat globules enter the circulation by rupture of the marrow vascular sinusoids or rupture of venules Mechanical blockage - Globules enlarge in circulation, platelets adhere Biochemical injury – Free fatty acids are released from adipose tissue in the circulation and are toxic to endothelial cells – DIC, clogged pulmonary and systemic capillaries. Pulmonary insufficiency, neurologic symptoms, anemia, thrombocytopenia * Symptoms appear 1-3 days after injury – sudden onset of tachypnea, dyspnea, tachycardia, petechiae * Neurologic symptoms- irritability, restlessness, progression to delirium, coma

Answer 18

Air embolisms usually form via venous circulation due to lower pressure. Arterial circulation has more pressure and is less likely to get air. 150L can cause death -> obstructive shock -> prevents outflow of blood from RV. Tx with placing them on the left lateral decubitus so air embolism will rise to right lateral wall

Answer 19

Deep diving without Caissons chamber deeper than 10m. 02 and N2 dissolve in high amount in tissue due to pressure -> sudden resurface -> releases 02 and N2 -> 02 is reabsorbed but N2 bubbles out rupturing tissue and forming embolism. -> Platelets adhere to N2-> aggravate ischemia- Treat with slow decompression chamber

Answer 20

rare sudden event after labor-> Squames, hair, meconium in mother’s pulmonary vessels Usually fatal due to DIC or diffuse alveolar injury

Answer 21

autopsy finding small dislodged fragments of plaques that obstruct end of arteries rarely clinical symptoms

Answer 22

Found in small pulmonary vessels are cardiac resuscitation autopsy finding not the cause of death

Answer 23

Ischemic necrosis caused by occlusion of arterial supply or venous drainage in tissue 99% of infarcts are from embolism or thrombosis can be caused by anything that occludes the artery or vein

Answer 24

little bleeding solid organs like kidney, spleen, heart arterial occlusions

Answer 25

large amount of bleeding into organ tissues with dual supply (lungs) venous occlusion

Answer 26

1. nature of vascular supply. single or dual? 2. rate of development. Sudden or slow? 3. Tissue vulnerability. brain or muscle? 4. Oxygen carrying capacity. anemia increases chances

Answer 27

Dual blood supply will lessen chances of infarct Collateral circulation -> more anastomoses the lessly likely risk of infarction.

Answer 28

Pulmonary emboli with compromised bronchial circulation -> infarction Pulmonary emboli with healthy circulation -> no infarction.

Answer 29

Embolism is most common cause from mural thrombi Thrombotic occlusions found in areas of carotid or middle cerebral artery.

Answer 30

Coronary atherosclerosis with superimposed thrombosis left anterior descending most common; coagulation necrosis pale scar increase cardiac enzymes severe chest pain