Hemorrhage

Hemorrhage, thrombosis, and embolisms are all examples of altered ________

Hemostasis

Define Hemorrhage

Escape of blood from the cardiovascular system (can be internal or external)

Hemorrhage from a tear in the blood vessel or heart is called what?

Hemorrhage by Rhexis

Define Hemorrhage by Diapedesis, what causes it?

• Bleeding from a small defect

  • Caused by increased permeability in the vasculature

If a patient has bleeding diathesis, what does that mean?

They have an increased tendency to hemorrhage (aka more prone to bleeding)

What type of damage or dysfunction do these lesions indicate?

• The lesions are small foci of hemorrhage on mucosal surfaces and skin

• They indicate platelet defects

Define Thrombocytopenia and Thrombocytopathy

• Decreased # of circulating platelets

  • <200 × 10⁹

• Defective platelet function

If a patient has

• History of bleeding

• Normal Platelet counts

• Abnormal platelet function tests

• A defect in adhesion

• Defect in release of granules from platelets

• Defect in aggregation

What type of platelet disorder does this describe?

Thrombocytopathy

In general, large hemorrhages or hematomas in the absence of trauma suggest a _________ disorder

Coagulation

What are the two ways that coagulation disorders can be acquired?

• Inherited (rare)

• Acquired (more common)

Animals with a coagulation defect may have ________ clotting times, what are the 2 ways we test for clotting time?

• Prolonged

• PT (prothrombin time) and aPTT (activated partial thromboplastin time)

Acquired coagulation defects can results from a ____ in the production of coagulation factors

Decrease

Vitamin _ deficiency and ____ failure will cause decreased production of coagulation factors, which results in an inability of the animal to perform coagulation

• Vitamin K

• Liver failure

What is disseminated Intravascular Coagulation (DIC)

• Sudden onset of widespread thrombosis in the microcirculation

• Pathological activation/disequilibria of hemostasis

• Increased use of Coagulation factors

  • Excessive clotting throughout the body

What are some potential causes of DIC?

• Severe burns

• Heat stroke

• Systemic viral disease

• Shock

• Malignant neoplasia

• Heartworm

• Pancreatitis

Tissue factor is released from tissue when it is ______, it triggers coagulation

Damaged

What are the 2 ways that DIC causes hemorrhage?

1. Depletion of clotting factors → Hemorrhage

2. Activation of plasmin → Fibrinolysis → FDPs → Inhibition of clot formation → Hemorrhage

DIC is associated with excess ______ production, it can be caused by ________ activation/ _________ of hemostasis

• Thrombin

• Pathological

• Disequilibrium

Define subdural/epidural hemorrhage

• Blood accumulation beneath/above the dura

Define Hematoma

• Hemorrhage enclosed within a tissue

• Extravascular 3-dimensional blood clot

Define Hemopericardium

• Blood in the pericardial sac

  • Can be acute/chronic (tissue will appear red because blood is an irritant)

T/F: Hemopericardium can lead to cardiac tamponade

True

Define Cardiac Tamponade

• Compression of the heart due to accumulation of blood in the pericardial sac

If an animal has cardiac tamponade, which side of the heart would be more affected, if at all?

• The right side since it is less muscular than the left

Define Hemothorax

Blood in the thorax (pleural cavity)

Define Hemoabdomen (Hemoperitoneum)

Blood in the abdomen (peritoneal cavity)

T/F: Clotting of blood is a good indicator of chronicity

False, blood clots can break down post-mortem

Define Hemarthrosis

Blood in the joint spaces

Define Hemoptysis

Coughing blood from the lungs or airways

Define Epistaxis

Bleeding from the nose

Define Hematemesis

Vomiting up blood

What is the difference between Hematochezia and Melena?

• Hematochezia

  • The presence of fresh blood in the stool (red color, indicates lower G.I bleed)

• Melena

  • Presence of tarry blood in the stool (black blood, indicates upper G.I bleed)

Define petechia(e), where is it most commonly observed?

• Pinpoint hemorrhages (1-2mm)

• Most common in the skin, mucosa, and serosa

Define Purpura

• 3mm-1cm hemorrhages

• Most common in the skin, mucosa, and serosa

Define Ecchymosis (Ecchymoses)

• hemorrhages larger than 1cm

• Often blotchy and irregular

Define paint brush hemorrhage

• Hemorrhage, which looks like red paint was applied with a brush

Define Suffusive hemorrhage

Area of hemorrhage larger than ecchymoses and contiguous (sharing a common border; touching)

What type of hemorrhage is this?

Suffusive Hemorrhage

What type of hemorrhage is this?

Petechia(e)

What type of hemorrhage is this?

Purpura

What type of hemorrhage is this?

Ecchymosis/Ecchymoses

What type of hemorrhage is this?

Paint Brush Hemorrhage

Define Agonal Hemorrhage

Petechiae and ecchymoses that are associated with terminal hypoxia (bleeding associated with dying cells)

The arrest of hemorrhage occurs as a result of _______

Hemostasis

The resolution of hemorrhage depends on the amount of hemorrhage, what are the two ways hemorrhage can be arrested?

1. Resorption

   1. Only small amounts

2. Organization

   1. Larger amounts

   2. Breakdown and removal of RBCs by macrophages

What makes up an organizing hematoma?

• Center contains fibrin and RBCs that are phagocytosed by macrophages

• Outside is composed of vascularized fibrous tissue

Define Thrombosis

Inappropriate activation of hemostasis resulting in the formation of a solid mass (thrombus) within the blood vessels or heart

Define Thrombus

An aggregate of platelets, fibrin, and other blood elements (RBCs/WBCs) formed on the endothelial surface

What is Virchow’s Triad?

• A theory that explains three main factors that can lead to blood clots, or thrombosis

  • Hypercoagulability: When blood is more likely to clot

  • Stasis: When blood flow is abnormal

  • Endothelial injury: When the lining of blood vessels is damaged

What are the 3 main locations that thrombi can be found int he cardiovascular system?

1. Blood vessels

2. Cardiac Chambers

3. Cardiac Valves