Hemodynamic Derangements And Intro To Atherosclerosis

Front 1

What are hemodynamic disorders?

Back 1

Hemodynamic disorders are characterized by disturbed perfusion that results in organ and cellular injury.

Front 2

Name 6 examples of hemodynamic derangements.

Back 2

1. Bleeding
2. Congestion and edema
3. Shock
4. Arterial thrombi, emboli and infarcts
5. Venous thrombi, emboli and infarcts
6. Atherosclerosis

Front 3

Define "hemorrhage."

Back 3

Hemorrhage is a discharge of blood from the vascular compartment to the exterior of the body or into Non-vascular body spaces.

Front 4

Name 5 things that can cause hemorrhage.

Back 4

1. Trauma
2. Congenital defects
3. Vessel wall defects
4. HTN
5. Coagulopathy

Front 5

What are the 3 classifications of hemorrhage?

Back 5

1. Petechium
2. Purpura
3. Ecchymosis

Front 6

What is petechium?

Back 6

a pinpoint (1-2mm) capillary hemorrhage in the skin or elsewhere, usually in conjunction with underlying systemic disease such as coagulopathy or vasculitis

Front 7

What is purpura?

Back 7

a diffuse superficial hemorrhage in the skin, up to 1cm in diameter, usually in conjunction with underlying systemic disease

Front 8

What is an ecchymosis?

Back 8

A superficial skin hemorrhage greater than 1cm in diameter, AKA a bruise

Front 9

Name 3 examples of things that can cause petechiae.

Back 9

--Septic shock
--Anoxia
--Rocky Mountain Spotted Fever

Front 10

What are splinter hemorrhages?

Back 10

Splinter-shaped hemorrhages in the nailbeds that occur with bacterial endocarditis.

Front 11

What is active hyperemia?

Back 11

An augmented supply of blood to an organ, usually physiologic, e.g. from exercise.

Front 12

What is passive hyperemia?

Back 12

AKA congestion, it is the engorgement of an organ by venous blood, usually from left heart failure, which in turn leads to right heart failure.

Front 13

What is cardiac cirrhosis?

Back 13

Cardiac cirrhosis is centrilobular fibrosis and scarring of the liver caused by chronic severe congestive heart failure.

Front 14

What are the 5 features of cerebral edema?

Back 14

1. Brain weight increases 20-40%
2. Gyri are swollen
3. Sulci disappear
4. Cranial space is filled
5. Intracranial pressure forces brainstem and midbrain to herniate into foramen magnum

Front 15

What is shock?

Back 15

A condition of profound hemodynamic and metabolic disturbance characterized by the failure of the circulatory system to maintain adequate perfusion of vital organs

Front 16

What are the 3 stages of shock?

Back 16

1. Initial: vital organs ok, vasoconstriction, fluid retention by kidney failure
2. Progressive: hypoxia for vital organs, lactic acidosis
3. Irreversible: leads to death

Front 17

Name the 7 major causes of shock.

Back 17

1. Hypovolemia from fluid loss
2. Obstruction to blood flow (e.g. pulmonary embolus)
3. Cardiogenic (low cardiac output)
4. Neuropathic
5. Anaphylactic
6. Endocrine failure
7. Septic

Front 18

What causes of fluid loss could cause hypovolemic shock?

Back 18

--hemorrhage, either internal or external
--burns
--severe vomiting
--internal effusions

Front 19

What could cause cardiogenic shock?

Back 19

--P.E.
--cardiac tamponade
--M.I.
--severe cardiac arrhythmias
--severe congestive failure with low output

Front 20

What could cause shock from endocrine failure?

Back 20

--panhypopituitarism
--adrenal failure

Front 21

Name the 4 common features of shock.

Back 21

1. Reduced venous return
2. Decreased cardiac output
3. Tissue hypoxia
4. Commonly affected organs include: brain, lung, kidneys, liver, heart, and adrenals

Front 22

What are the early and late signs of shock in skin?

Back 22

Early: pale and cold
Late: cyanotic due to increased proportion of reduced-state Hb

Front 23

What are the early and late signs of shock in kidneys?

Back 23

Early: low urine output
Late: Acute tubular necrosis

Front 24

What are the early and late signs of shock in GI tract?

Back 24

Early: absent bowel sounds
Late: mucosal necrosis

Front 25

What are the early and late signs of shock in Lungs?

Back 25

Early: tachypnea
Late: alveolar necrosis

Front 26

What are the early and late signs of shock in liver?

Back 26

Early: fatty change
Late: centrilobular necrosis

Front 27

What are the early and late signs of shock in brain?

Back 27

Early: unresponsive
Late: coma

Front 28

What are the early and late signs of shock in heart?

Back 28

Early: tachycardia
Late: myocardial necrosis

Front 29

Describe the morphologic changes in the brain during shock.

Back 29

The extent of injury depends on the intensity and duration of injury. The brain experiences hypoxic encephalopathy, or brain damage, and complete anoxia for 3-5 minutes causes death with no apparent morphological changes at autopsy. For less severe hypoxia, short durations cause necrosis of neurons and Purkinje cells, and long durations cause laminar necrosis known as "watershed infarcts."

Front 30

Describe the morphologic changes in the kidneys during shock.

Back 30

After the inital period of low urine output, the kidney undergoes acute tubular necrosis, involving the proximal tubules, and begins producing a high volume of dilute urine, followed by oliguria (decreased urine production) and anuria. Complete recovery is possible under the proper conditions.

Front 31

Describe the morphologic changes in the GI tract during shock.

Back 31

The GI tract experiences patchy segmental necrosis of the stomach and superficial hemorrhagic necrosis of the intestinal mucosa. As long as the smooth muscle surrounding the GI tract remains intact, however, with no infarction or perforation, then complete recovery is possible.

Front 32

Describe the morphologic changes in the heart during shock.

Back 32

During shock, the heart undergoes subendocardial necrosis and hemorrhage, the formation of zonal lesions and hypercontraction of myocytes adjacent to the intercalated discs.

Front 33

Describe the morphologic changes in the adrenals during shock.

Back 33

The adrenal glands undergo lipid depletion in their cortical cells and increased steroid hormone production.

Front 34

Describe the pathogenesis of septic shock.

Back 34

Septic shock is usually caused by gram-negative bacilli, who produce the endotoxin LPS. LPS causes monocytes to release massive amounts of TNF-a into the circulation, which causes generalized vasodilation, intravascular coagulation, endothelial damage and capillary exudation. The overall effect is hypotension, ARDS and multiple organ failure.

Front 35

What are some of the causes of ARDS?

Back 35

--shock, frequently caused by M.I.
--septicemia (presence of bacteria or toxins in the blood)
--oxygen toxicity
--inhaled toxic fumes or gases
--trauma

Front 36

Name the 5 symptoms of ARDS.

Back 36

1. Tachypnea
2. Dyspnea
3. Cyanosis
4. Loss of lung compliance
5. Respiratory failure

Front 37

What is "shock lung?"

Back 37

Shock lung describes the histological appearance of lung tissue after undergoing shock. It features diffuse alveolar damage, interstitial edema, necrotic pneumocytes lining the alveoli, and the formation of hyaline membranes.

Front 38

What is a "chylous effusion?"

Back 38

A chylous effusion is a body cavity filling with lymph fluid because of a blockage in the lymphatic system.

Front 39

What does pulmonary edema resulting from cardiogenic shock look like?

Back 39

Grossly, the lobular appearance of the edema produces a light lines-on-dark X-ray pattern. Histologically, alveoli are filled with a pale, faintly eosinophilic transudate, and septal capillaries are congested.

Front 40

What is "acute tubular necrosis?"

Back 40

A.T.N. is damage to the kidney that occurs as a complication of shock. Epithelial cells of the proximal tubules undergo coagulative necrosis, and the kidney becomes pale, soft and floppy with an indistinct cortico-medullary juntion.

Front 41

Describe what happens during the initial, reversible phase of shock.

Back 41

There is peripheral vasoconstriction from ANS stimulus and adrenal catecholamines. Arterio-venous shunts open and blood goes from the splanchnic circulation to the heart and brain. The pH across capillary beds decreases, and the blood is diluted because interstitial fluid moves into the vessels to replace blood loss.

Front 42

Describe what happens during the critical phase of shock.

Back 42

There is a continued decrease in blood pressure and volume. Despite maximum peripheral vasoconstriction, there is decreased capillary perfusion, endothelial hypoxia and sludging and clotting of blood.

Front 43

Describe what happens during the final, irreversible phase of shock.

Back 43

Arteriolar vasodilation causes pooling and stagnation of blood. The increased capillary hydrostatic pressure leads to interstitial edema. There is decreased function of vital organs, metabolic acidosis, and death.

Front 44

What is "arteriosclerosis?"

Back 44

Arteriosclerosis is a generic term that describes thickening and hardening of the arteries. It can be because of old age, HTN, and Monckeberg's medial cacific sclerosis, in which medium-to-small caliber arteries get ring-like calcifications in their medial layer.

Front 45

What is "atherosclerosis?"

Back 45

Atherosclerosis is a disease of large and medium-sized arteries in which accumulations of smooth muscle cells and lipids within the intima of the vessels cause irregular thickening and narrowing of the wall.

Front 46

Name the 8 major risk factors for atherosclerosis.

Back 46

1. Age
2. Male gender
3. Family history
4. Genetic abnormalities
5. Hyperlipidemia
6. HTN
7. Smoking cigarettes
8. Diabetes

Front 47

Name some minor risk factors for atherosclerosis.

Back 47

--obesity
--physical inactivity
--stress
--homocysteine
--high carbohydrate intake
--alcohol
--lipoprotein A
--trans-fats
--postmenopausal estrogen deficiency
--chlamidia pneumoniae

Front 48

Name 5 frequent sites of severe atherosclerosis.

Back 48

1. Abdominal aorta/iliac arteries
2. Proximal coronary arteries
3. Thoracic aorta/femoral/popliteal arteries
4. Internal carotid arteries
5. Vertebral/basilar/middle cerebral arteries

Front 49

Name 4 complications of atherosclerosis.

Back 49

1. Luminal narrowing
2. Thrombus on plaque
3. Bleed into plaque
4. Aneurysm