Shock (MEDCRAM aka "high yield") Flashcards
3 Major Types of Shock
- Hypovolemic
- Cardiogenic
- Septic
Describe Hypovolemic Shock
(i.e., what happens after volume drops)
Most blood is stored in venous system
(Can lose up to 40% of blood volume before BP decreases)
- Drop in BP = Compensatory increase in HR and EF
- SVR (resistance) increases; increased pressure = better blood delivery w/o adequate volume
- Cardiac Output DROPS (not enough filling)
- PCWP (LA pressure) and JVP (RA pressure) drop due to loss of volume
- Skin temperature drops due to shunting of blood to vital organs
Increased HR/EF and SVR
+
Cool skin temperature
Hypovolemic Shock
Decreased EF
+
Increased RA and LA Pressure (measured via JVP and PCWP, respectively)
+
Cool skin temperature
Cardiogenic Shock
Describe Cardiogenic Shock
Decreased CO despite adequate volume (tissue hypoperfusion)
Usually from acute MI (HR can be too fast or too slow depending on type of heart problem)
- Decreased CO/EF leads to compensatory SVR increase
- RA and LA pressures increase as heart fails to pump correctly
- BP and skin temperature drop
Increased CO and HR
+
Decreased RA/LA Pressure
+
Increased Skin Temperature
Septic Shock
Describe Septic Shock
MOST COMMON
- Cytokines lead to dysregulation of vasocontriction (i.e., SVR decreased and blood is inappropriately shunted to non-vital organs)
- Vital organs extract more oxygen than they otherwise would need to (SvO2 drops below 70%–70 is normal)
- HR and CO increase to compensate
- EF and LA/RA pressure drop as a consequence of decreased BP
- Skin is getting more blood = increase in temperature
How does our body compensate during septic shock?
RAS system (aldosterone)
+
ADH
Eventually, BP will drop despite compensation (i.e., become decompensated)
What happens when oxygen cannot reach tissues?
Cannot be used as final electron acceptor to make ATP
Without ATP, cells die
Tx of Cardiogenic Shock
Diagnosis: EKG, Echo, CXR
ABC Support then fix cause
Digoxin when EF < 40%
Dobutamine (pure β stimulation)
What do you have to be mindful of when giving dobutamine?
Drop in BP (β receptors in the periphery cause vasodilation)
Tx of Septic Shock
EGDT (Early Goald Directed Therapy)
All Tx must occur within 6 hours
- Abx within 1 hour
-
Central Line (want CVP between 8 and 12)
* Correct with normal Saline* -
Vasopressors through central line (want MAP > 65)
* DA or NE* - If SvO2 remains below 70% check Hgb
* Hgb < 10 = blood transfusion*
* Hgb > 10 = correct CO with dobutamine*
Labs show lactic acidosis
Person already suspected of shock
Septic Shock
PCWP
Pulmonary Capillary Wedge Pressure
