Shock Flashcards
List the types of shock?
1.Hypovolemic Shock
2. Cardiogenic Shock
3.Distributive shock
4.Obstructive Shock
Describe the steps in shockthat lead in death ?
- Decrease Tissue Perfusion
- Decrease in cellular respiration
- Local tissue Hypoxia
- Cell & Mitochondria death
- Multi -Organ Failure
- Death
What is the effect of decreased tissue perfusion in shock?
Homeostasis is lost.
-No O2 for mitochondrial electron transport chain
-Mitochondrial death – release of dAMPs
-Systemic response to Inflammation
Increase cardiac output (HR & SV)
Peripheral vasoconstriction (
SVR)
Arteriolar vasoconstriction away
from non-vital organs ( urine
output)
Mobilization of blood from
venules
Build-up of pyruvate (lactate) in
Kreb’s cycle = Metabolic Acidosis
Compensatory Mechanism Failure
Failure of pre-capillary sphincters
Capillary endothelial damage / membrane pump failure
How is mitochondria related to bacteria ?
Both bacteria and mitochondria release associated molecular patterns.
Mitochondria -Damage AMPs
Bacteria -Pathogen AMPs
Innate immune system recognizes both the same = initiates INFLAMMATION
What are the stages of shock and describe them?
1.Compensated (Pre-shock-
2.Decompensated -Compensatory mechanism becomes overwhelmed (Shock)
3. End-organ Dysfumction
Describe the Pre-shock/Compensated stage?
Appropriate compensatory mechanisms are still homeostatic
-Tachycardia
-Modest change in BP
Describe the decompensated stage of shock?
Signs & Symptoms of organ dysfunction
Symptomatic tachycardia
Dyspnea
Restlessness
Hypotension
Oliguria
Cool clammy skin
Describe End -organ dysfunction stage?
1.Irreversible organ damage
2.Multi-organ failure (anuria, acute renal failure, acidemia, recalcitrant hypotension)
3.Obtundation, coma, death
Describe the compensation phase that occurs in shock?
1early onset - Increased blood pressure secondary to increased HR and vasoconstriction.
Baroreceptors and chemoreceptors are sensitive to pressure changes result in signals being sent to the brain to increase the firing from the vasomotor center and the cardio-regulatory center. Chemoreceptors result in the release of the catecholamines resulting in vasoconstriction whilst baroreceptors are responsible for increasing firing of the SA node leading to increased HR.
The two increase the blood pressure.
2.Late -Onset : Activation of the -RAAS system which results :
Release of aldosterone: Increases sodium retention
ADH -Increases water retention
Increases thirst
Causes vasoconstriction
This results in increase in Blood pressure
What ate the causes of Obstructive Shock?
Pulmonary:
1.PAH
2. Pulmonary Embolism
3. Air Embolism
Mechanical :
1. Tamponade
2.Pneumothorax
3. Pericarditis
4. Compartment Syndrome
What are the causes of distributive shock?
Septic:
Bacterial
Fungal
Viral
Parasitic
Myco-bacterium
Non-septic :
1. Inflammatory
2. Anaphylaxis
3. Neurogenic
4.Transfusion Reaction
What are the causes cardiogenic shock?
Cardiomyopathic:
1.MI
2.Myocarditis
3.Severe Valvular Disease
4. peripartum cardiomyopathy
5.Drugs
Arrythimic:
Heart Block, Tachy, Brady
What is the causes of hypovolemic shock?
Hemorrhagic
1.GI bleed
2.PPH
3.Abruption
4.Ectopic Pregnancy
5. Intra/Post OP
6.Trauma
7.AVM
Non-hemorrhagic
1.GI losses
2.Burns
3.Heat stroke
4.Renal losses
What is the key factor in Cardiogenic shock? And how does SVR,CO and Preload change and why?
Key Factor : Cardiac output (Decreases) as a result of pump failure .
SVR-increases as a compensatory mechanism
Preload : does not change as the volume is still the same.
What is the key factor in Hypovolemic shock? And how does SVR,CO and Preload change and why?
Key Factor: Preload decreases
SVR-increases as a compensatory mechanism
CO : decreases because of decrease in stroke volume
