Chapter 3: Hemodynamic Disorders, Thromboembolism, and Shock Flashcards
This is the active process of increasing blood volume within tissues. It is done by arteriolar dilation, causes tissue erythema (redness), and results from inflammation or exercise.
Hyperemia
This is the passive process of increasing blood volume within tissues. It is done by decreasing venous outflow, causes tissue cyanosis (blue), and results from venous obstruction.
Congestion (congestive heart failure, DVT (deep vein thrombosis), testicular torsion)
This this type of congestion is characterized by alveolar capillary engorgement, edema, and hemorrhage.
Acute pulmonary congestion (Acute respiratory distress syndrome (ARDS))
This type of congestion is characterized by the alveolar septa becoming fibrotic and the presence of alveolar macrophages and hemosiderin (“heart failure cells”)
Chronic pulmonary congestion (congestive heart failure (CHF))
This type of congestion is characterized by a “nutmeg liver”, steatosis, fibrosis (cirrhosis), hemorrhage, and necrosis.
Congestive hepatophy (hepatic congestion (CHF)
This is an abnormal accumulation of interstitial fluid within tissues or cavities.
Edema
What are the two opposing forces involved in fluid balance?
- Hydrostatic pressure: BP, pushes H2O out
- Osmostic pressure: plasma proteins, pulls H2O in
An increase in this type of pressure is characterized by an increased intravascular pressure most likely caused by impaired venous return.
Hydrostatic pressure
This is determined by plasma proteins, specifically albumin. It can be caused by a decrease in albumin production (cirrhosis, hepatitis) or increased loss of albumin (nephrotic syndrome).
Reduced plasma osmotic pressure (leads to generalized edema)
What are some additional causes of edema?
- Lymphatic obstruction (lymphedema)
- Retention of sodium
- Inflammation
What are the features of edema?
- It can occur in any tissue
- Decrease in wound healing
- May indicate pathology (inflammation, left ventricular failure, renal failure, cerebral edema)
This type of edema is characterized by transudate (protein-poor) fluid and no osmosis.
Pitting edema
This type of edema is characterized by exudate (protein-rich) fluid and osmosis.
Non-pitting edema
This term is used to describe an extravasation of blood from vessels. External or internal bleeding.
Hemorrhage
This term is used to describe an accumulation of blood within tissue.
Hematoma
How is the severity of hemorrhage determined?
- The extent and site of it
- Rate and volume of blood lost
This type of hemorrhage is often found in people with decreased platelets and Vitamin C. The areas are often 1-2 mm large.
Petechiae
This type of hemorrhage is caused by trauma, vasculitis, fragile vessels, or Kaposi sarcoma (AIDS). The areas are often 3-5 mm large.
Purpura
This type of hemorrhage often starts off with a reddish/blue color due to the presence of hemoglobin, transitions to a greenish color as hemoglobin is broken down into bilirubin, and then a yellowish color as bilirubin is broken down into hemosiderin. The areas are typically 1-2 cm large.
Ecchymosis
This term is used to describe clot formation inside a vessel.
Thrombosis
What three factors compose virchow’s triad?
Endothelial injury, abnormal blood flow, and hypercoagulability
These types of thrombi occur at the site of injury and grows against the flow of blood. They can result in infarction.
Arterial thrombi
These types of thrombi occur at the site of stasis and grow in the direction blood flow. They can result in congestion, tenderness, and pitting edema.
Venous thrombi
These types of thrombi occur on the heart valves and can either be sterile or infective (bacteria, fungi).
Vegetations
What are some factors that contribute to an acquired version of clotting disorders?
Smoking, pregnancy, obesity, irregular heart valves, immobilization, trauma/surgery, etc.
What are some inherited mutations that result in coagulation disorders?
- Factor V (decreases antithrombotic)
- Prothrombin (increases thrombotic)
This term is used to describe an obstruction of a vessel by a thrombosis.
Thromboembolism
This is a detached intravascular mass, which travels throughout the system until it becomes lodged and occludes a vessel.
Embolism (clinically silent and lethal)
What are some examples of solid, liquid, and gaseous emboli?
Solid: fat (marrow), plaque debris, tumor fragment
Liquid: amniotic fluid (labor)
Gaseous: nitrogen (decompression/caisson disease), air (needle)
This condition is due to an embolic occlusion of a pulmonary artery. 95% are caused by deep vein thrombosis in the femoral vein.
Pulmonary embolism
What are some risks of pulmonary emboli?
- Previous pulmonary emboli
- Bedrest
- Burns
- Surgery (knee, hip)
Systemic thromboemboli are within what system? Arterial or Venous?
Arterial system
80% of systemic thromboemboli arise from what type of thrombi?
Cardiac mural (wall) thrombi
What are some other causes of systemic thromboemboli?
- Aortic aneurysm
- Atheromas (any artery)
What is the fate of thrombi?
They enlarge (propagation), embolize, dissolve, organize (ingrowth of cells), and recanalization
This term is used to describe emboli which cross from the venous system to the arterial system.
Paradoxical embolism
What are some origins of paradoxical emboli? What can they cause?
Origins:
- Originates as a deep vein thrombosis
- Crosses to the arterial system through Atrial or ventricular septal defect
Results in stroke
This term is used to describe vascular occlusion, which can eventually lead to ischemia and necrosis.
Infarction
What is the severity of infarction determined by?
- Rate
- Tissue type
- Collateral blood supply
What are the categories of infarction?
- Red (hemorrhagic): organs which have collateral blood supplies
- White (anemic): organs which do not have collateral blood supplies
These cells produce platelets.
Megakaryocytes
What is the traditional definition of shock?
Peripheral vasoconstriction
This is the common final pathway for mortal injury. Causes can be hemorrhage, trauma, burns, myocardial infarction, pulmonary embolism, and sepsis.
Shock
This category of shock is characterized by the heart failing to pump blood to the rest of the body. Caused by myocardial infarction, arrhythmia, and cardiac tamponade.
Cardiogenic shock
This category of shock is characterized by a loss of blood/plasma. Caused by hemorrhage, severe burns, dehydration.
Hypovolemic shock
Both cardiogenic and hypovolemic shock cause traditional signs and symptoms of shock, which are…
Cyanosis (cool/clammy) and sympathetic nervous system stimulation
What are the traditional features of shock?
- Cyanosis
- Decreased urine output
- Increased respiratory rate
- Decreased level of conciousness
- Hypotension
- Release of aldosterone
- Constriction of splanchnic vessels
This type of shock is characterized by a systemic immune reaction and is often due to infection.
Septic shock
This type of shock is characterized by a depression of the medulla or SNS ganglia, severe vasodilation, syncope, and bradycardia. It is most often a result of CNS trauma, spinal anesthesia, and adverse drug reactions.
Neurogenic shock
This type of shock is characterized by severe vasodilation and bronchoconstriction and is most often a result of allergies (IgE-mediated).
Anaphylactic shock
What are some treatments for shock?
- Defibrillation, CPR, limit blood loss, I.V. fluid replacement
- Elevate legs, increase fluid volume, vasoconstrictive meds
What are the stages of progressive, multiorgan failure?
1) Nonprogressive: compensatory mechanisms
2) Progressive: hypoperfusion, anaerobic metabolism
3) Irreversible: severe cell/tissue damage
