CardioVascular Response To Shock ** Flashcards
Hypovolemic Shock can arise from what 3 things?
Haemorrhage
Sever burns
Loss of fluids (Cholera)
Low resistance shock can arise from what 2 things?
anaphylaxis
Septic Shock
Cardiogenic Shock occurs when?
Heart cannot maintain CO = MI
Haemorrhagic Shock
Decreased blood/O2 perfusion of vital organs
results from Loss of Blood Volume
What kick starts a Haemorrhagic Shock
Hypovolemic Shock
IF blood loss is <15%?
No change
If blood loss is 20-30%?
BP severely lowered
If blood loss if 30-50%
Irreversible / refractory Severe Shock
.>50% Blood loss
Organ Failure
What are the 2 Main Immediate Compensation mechanisms for Blood Loss?
Baroreceptors
Peripheral Chemoreceptors
Both Increase SNS
What is the purpose of increasing SNS during Blood Loss
Heart Rate Increases
Increased Myocardial Contractility (SV)
Venoconstriction of splanchnic/cutaenous circulation to increase VR
What is the 6 Intermediate Compensation mechanisms in place for Blood Loss
RAAS
Atrial Stretch Receptor
Absorption of Interstitial Fluid
Gluconeogenesis
Ventilation Increases
Blood Coagulation Time increases
How does RAAS recover BP?
AG2 causes Vasoconstriction
Increase of Thirst
Increase of Na/H20 reabsorption
How does Atrial Stretch Receptor affect Vasoconstriction
Blood loss = reduction in atrial stretch receptor activity
ADH / Adrenaline stimulated
Both are vasoconstrictors
How does Absoprtion of Interstitual Fluid affect Blood volume?
Vasoconstriction from other mechanisms
=Decrease in Capillary Hydrostatic Pressure (CHP)
Fluid moves from Interestitum to Vasculature
Increasing Blood volume (VR)
Why does the liver produce more glucose during blood loss?
What does it lead to in terms of Haem?
Increases Plasma OsM
Water drawn out of cells into vasculature
Leads to Haemodilution / Decrease in Haemocrit
Why does the ventilation increase in Blood loss?
Compensate for lack of PO2
Why does the Blood coagulation time decrease in Blood loss?
Increase in platelets / Fibrinogen
Any cuts can be quickly sealed to not further lose more blood
Name 3 Long term mechanisms for Blood Loss
Reduced Urine Output
Albumin Synthesis
Erythropoesis (RBC creation)
Whats the term given when the body reduces Glomerular Filtration rate from SNS
Oliguria
How can Body fluid levels be restored?
Drinking
Why is Albumin Sythesised with Blood loss?
Affects water potential meaning water will stay in bloodstream and not in cells
whats the type of shock called when Blood loss >30%
Progressive Shock
what can progressive shock lead to?
Depressed Cardiac Function
Renal Failure
DIC
Hepatic Failure