Test 2 Flashcards
What type of shock results from pump failure of the heart? Most often SECONDARY to an infarction that destroys a large part of the functioning myocardium.
Cardiogenic Shock
In Cardiogenic Shock, the loss of contractile elements decreases the ability of the heart to pump blood which leads to what?
Arrhythmia (similar consequences may result from myocarditis, valvular heart disease or CHF)
The loss of circulatory volume results in?
Hypovolemic Shock
What 2 things mentioned in the slides can hypovolemic shock be attributed to?
- massive hemorrhage
2. water loss due to burns, vomiting, or diarrhea
In hypovolemic shock, you have the loss of vascular tone and pooling of blood in dilated peripheral blood vessels. What are 2 other causes of this mentioned in class?
- Anaphylactic shock -> caused by exposure to an allergen
2. Neurogenic stimuli -> pain caused by trauma or spinal cord injury
The major cause of Septic Shock?
Severe G- endotoxin (LPS) bacteremia (shock resulting from the spread of bacteria from a severe localized infection into the bloodstream)
What is currently the most common cause of death in ICUs?
Septic Shock
What are 6 examples of G- bacteria that can cause septic shock?
- E. coli
- Proteus
- Serratia
- Pseudomonas
- K. pneumoniae
- Bacteroides
Once LPS binds to macrophages, what 3 things does the macrophage release?
- TNF alpha
- IL-1
- MMP
What is defined as a state of hypoperfusion of tissues with blood which results in tissue hypoxia and multiple organ failure.
Shock
_______: freely moveable, intravascular mass that is carried from one anatomic site to another by blood
Embolism
__________: Fragments of thrombi carried by venous or arterial blood. Accounts for most the emboli in clinical practice.
Thromboemboli
Infected ______ give rise to septic emboli. Classified on basis of the _________ through which they are carried.
Thrombi
Vessels
______ ______: these include fat emboli that occur after bone fracture and _____ ______ emboli caused by the entry of amniotic fluid into the uterine veins during delivery
Liquid Emboli
Amniotic Fluid
_____ _____: an air embolism can be produced by injecting air into veins. Air is liberated under pressure, as in decompression sickness
Gaseous Emboli
What happens to cause a solid particle emboli?
Cholesterol crystals detach from atherosclerotic plaques or tumor cells, or bone marrow emboli, or bullets
Venous emboli originate where?
Where do they typically lodge?
Originate in veins
Lodge in Pulmonary artery
_______ emboli are venous emboli that reach the ______ circulation through the _____ _____ or an interventricular septal defect that can cause symptoms similar to those of an ______ emboli (including infarction)
Paradoxical
arterial
foramen ovale
arterial
Where do arterial emboli originate?
The left atrium or ventricle, aorta and the major arteries
How can an arterial emboli cause infarction?
carried by arterial blood, the embolism can occlude the peripheral arteries
What 2 things are found with true bone marrow emboli in the lungs at time of autopsy?
- Hematopoietic cells
2. Fat
What forms a meshwork of thin filaments that bind together the cellular elements of the blood seen in a thrombus. (adhesion molecules)
Fibrin (polymerized fibrinogen)
What are the 4 fates of a thrombus?
- Lysis and resolution
- Organization -> inflammatory cells to granulation tissue to collagen
- Recanalization
- Embolism
What is another name for heart failure cells?
Alveolar “hemosiderin-laden” macrophages
What does chronic passive congestion of the lungs lead to?
formation of edema and extravasation of the RBCs into the alveoli which are taken up by alveolar macrophages and the hemoglobin is degraded into a brown (hemosiderin) pigment which, which accumulates in the lysosomes of macrophages -> heart failure cells are formed
How do venous emboli become pulmonary emboli?
venous emboli typically originate in the deep veins of the lower extremities and are carried by venous blood to the vena cava through the right atrium and ventricle and then into the pulmonary artery
What is the name of an emboli that straddles the branching of an artery blocking both branches? -Often lethal bc they prevent the entry of blood into the lungs and cause acute anoxia.
Saddle Embolus
amniotic fluid and air emboli may also block pulmonary circulation
What emboli is usually a direct result of trauma with fat (from bone marrow) entering ruptured capillaries at the site of the fracture.
Fat Embolism - usually appears 1-3 days after injury
What is the most severe form of fat embolism syndrome?
Seen in the lungs with respiratory failue (ARDS)
-also with numerous fat globules within microvasulature
What 4 things happen when a fat emboli reaches the brain?
- Cerebral edema
- Red petechiae
- microinfarcts
- fat globules form in microvasculature