Shock

Question 1

Definition of shock?

Answer 1

Acute generalized failure of the circulatory system resulting from blood volume that is too low to fill the vascular system or insufficient cardiac output

Question 2

General characterization of shock?

Answer 2

Hypotension + Hypoperfusion –> Impaired perfusion+Hypoxia

Question 3

BP =

Answer 3

CO X Peripheral Resisitance (PR)

Question 4

Three causes of shock?

Answer 4

Decreased Cardiac Fxn
Decreased Blood Volume
Decreased Peripheral resistance

Question 5

Causes of decreased peripheral resistance

Answer 5

Systemic inflammation (Septic Shock)
Systemic mast cell activation (Anaphylaxis)
Systemic loss of vascular tone (Neurogenic shock)

Question 6

End result of shock

Answer 6

Cellular Hypoxia
Failure to transport CO2, Toxic substances away from cells
Cell Death/Tissue Dysfunction

Question 7

Five types of shock

Answer 7

Cardiogenic
Hypovolemic/Hemorrhagic
Spetic
Anaphylactic
Neurogenic

Question 8

Causes of cardiogenic shock

Answer 8

Myocardial infarction
Ventricular arrythmias
Cardiac tamponade
Saddle Embolism

Question 9

Causes of hypovolemic shock?

Answer 9

Hemorrhage, Burns, Dehydration

Question 10

What is septic shock?

Answer 10

Systemic inflammatory reaction from bacteremia with an organism expressing LPS or LOS

Question 11

What is Systemic Inflammatory Response Syndrome (SIRS)?

Answer 11

LPS activation of macrophages, endothelial cells. Overproduction of inflammatory cytokines and mediators. Decreased PR, BV loss throughout the peripheral.

Question 12

Most common cause of mortality in ICU

Answer 12

Septic Shock

Question 13

Central feature of Septic Shock

Answer 13

LPS activation of inflammation

Activated endothelial cells, monocytes, macrophages, and compliment

Question 14

What do activated endothelial cells in septic shock do? (Molecular)

Answer 14

Decrease production of tissue factor pathway inhibitor (TFPI) and thrombomodulin

Question 15

How does LPS activate Monocytes/Macrophages?

Answer 15

LPS/LPS BP complex binds CD14 on cell surface.
Signalling mediated thru TLR4, NFkB transcription
Cytokine storm
Triggers NO release and systemic inflammatory effects

Question 16

Effects of Endothelial cell activation?

Answer 16

Increased vascular permeability, adhesion molecule expression. Inhibition of anti-coagulation properties. Switch to pro-coagulation phenotype.

Question 17

Describe initial stages of sepsis.

Answer 17

Widespread systemic inflammatory response
systemic vasodilation, diminished contractility.
Widespread adhesion + capillary damage.
Coagulation and DIC

Question 18

Describe the later stages of sepsis.

Answer 18

Burned out inflammatory and immune responses.

Immune hypo-reactiveness and immune paralysis

Question 19

What happens in the non-progressive stage of shock?

Answer 19

Compensatory mechanisms maintain cardiac output and blood pressure, perfusion of vital organs.

Question 20

Examples of compensatory mechanisms that play a role in the non-progressive stage of shock

Answer 20

Baroreflexes
Sympathetic NS, Catecholamine release
Renin-Angiotensin Axis
ADH
Tachy, Peripheral Vasoconstriction, Pallor
H2O Conservation

Question 21

What happens in the progressive phase

Answer 21

Anerobic Glycolysis –> Metabolic Acidosis –> low pH retards vasomotor response –> arterial dilation –> blood pooling in microvasculature –> decreased CO

Question 22

What happens in the irreversible phase of sepsis?

Answer 22

Survival not possible
Lysosomal Enzyme release
NO synthesis causes low myocardial contractility
Ischemic bowel and release of gut bacteria into bloodstream

Question 23

Most commonly seen symptoms of hypovolemic and cardiogenic shock

Answer 23

Hypotension
Weak, Rapid Pulse
Tachypnea
Cool, Clammy, Cyanotic Skin

Question 24

Most commonly seen symptoms of septic shock

Answer 24

Warm, Flush skin from peripheral vasodilation

Question 25

Most commonly seen symptoms of anaphylaxis

Answer 25

Bronchoconstriction and Edema | Urticaria

Question 26

Which two kinds of shock are most reversible?

Answer 26

Hypovolemic and Anaphylactic

Question 27

Which is least reversible?

Answer 27

Cardiogenic

Question 28

What is DIC?

Answer 28

Sudden or insidious development of numerous fibrin thrombi within the microvasculature. Consumption of clotting components later leads to widespread hemorrhaging.

Question 29

Mechanism of DIC

Answer 29

Rapid consumption of platelets, prothrombinen, f, actors V, VIII, X, platelets and fibrin. Fibrin --> Anoxia/Hypoxia --> Coagulation Necrosis No platelets --> Hemorrhage

Question 30

Synonym for DIC

Answer 30

Consumption Coagulopathy

Question 31

Pathologic findings of DIC

Answer 31

Widespread Fibrin Thrombi Diffuse Circulatory Insufficiency Brain, Lungs, heart, Kidneys Inc. D Dimer and Hemorrhage

Question 32

Difference between Septic Shock vs. DIC

Answer 32

- Degree of Activation of Endothelial Cells - Degree of activation of coagulation cascade - Severe septic shock --> DIC

Question 33

Clinical Settings to look for Shock in.

Answer 33

Sepsis, Trauma, Malignancy, Obstetric calamities, vascular abnormalities, hepatic failure, severe toxic or immunologic reactions

Question 34

Severe toxic or immunologic reactions associated with shock

Answer 34

Snake Bites Transfusion reactions Recreational drugs