Shock Patho

Question 1

Shock

Answer 1

• Many mechanisms each with their own treatment
• All hypo-perfusion to tissues => anaerobic metab
• Hemodynamic Instability: SBP < 90, MAP < 65
• Signs of poor tissue perfusion/anaerobic metabolism: elevated lactate > 4

Question 2

Shock leads to

Answer 2

• Impaired Cellular metabolism: burn ATP more than remake, increased Na+ in cell pulls water from extracellular, decreased circulatory volumes
• Impaired glucose utilization: increased cortisol, GH, and catecholamines, skeletal/cardiac muscle wasting, hyperglycemia/insulin resistance

Question 3

BP/CO/CVP

Answer 3

• BP = CO * SVR
• CO = SV * HR (L/min)
• CVP: pressure of bleed returning to heart (preload) through venous system

Question 4

MAP

Answer 4

1/3SBP + 2/3DBP

• Average of SP and DP in arterial system
• Surrogate marker of tissue perfusion

Question 5

SVR

Answer 5

• 80*(MAP-CVP)/CO

- Total resistance of circulatory system (heart must overcome)

Question 6

Cardiogenic

Answer 6

• “Problems with pump”
• Decompensated HF, MI, PAH, massive PE, dysrhythmias, etc.
• Compensatory INCREASE in SVR further reduces CO
• Treatment: make it pump! (already failing heart has poor outcome)

Question 7

Cardiogenic Treatment

Answer 7

• Inotrope
• Vasopressor
• Cautious diuresis
• Correct underlying cause

Question 8

Hypovolemic Shock

Answer 8

• “Hole in the bucket”

- Hemorrhage (whole blood), burn (plasma), emesis, diarrhea, DM (interstitial fluid)

Question 9

Hypovolemic Shock Treatment

Answer 9

• Plug the whole and fill the bucket
• Hemorrhage => whole blood (PRBC + Platelets + fresh frozen plasma)
• Other volume loss: crystalloid or colloid
• Vasopressors to temposize

Question 10

Neurogenic Shock

Answer 10

• “Profound vasodilation and lack of compensatory tachycardia”
• Too much parasympathetic => bradycardia
• Too little sympathetic of vascular muscle => decreased SVR
• Usually spinal cord injury (high T-spine or C-spine)

Question 11

Neurogenic Shock Treatment

Answer 11

• Fluids
• Vasopressors (increase vascular tone)
• Inotropes (bradycardia)
• Stabilize spine if injured

Question 12

Anaphylactic Shock

Answer 12

• Distributive shock
• Allergic: immune response (IgE mediated)
• Vasodilation (decreased SVR) and vascular permeability (tissue edema/hypovolemia)
• Extra-vascular smooth muscle constriction (bronchoconstriction and laryngospasm)

Question 13

Anaphylactic Shock Treatment

Answer 13

• Remove antigen/anti-vemon
• Glucocorticoids/antihistamine => blunt inflammatory response
• Fluid resuscitation => correct hypovolemia
• EPI => vasoconstriction and vasodilation

Question 14

Septic Shock

Answer 14

• Distributive Shock
• Bacteremia => endo/ecotoxin, lipopolysaccharides gram negative, peptidoglycan, lipoteichoic acid gram positive
• Extremely complex host response designed to eliminate invasive organism: dysregulation and overactive immune response lead to host morbidity/mortality
• *Once positive feedback loops are established, extremely difficult to restore homeostatic function**

Question 15

Septic Shock Treatment

Answer 15

• Remove/suppress infection
• Drain abscess, remove infected heart valve, debridement/amputation
• Antimicrobials
• Supportive care: fluid resuscitation, vasopressors, renal replacement therapy, mechanical ventilation

Question 16

MODS

Answer 16

• Multi-organ dysfunction syndrome
• Results from sustained shock
• Triggers: severe trauma, major surgery, burns, shock, pancreatitis, AKI, ARDS

Question 17

Cardiogenic Diagnostic Criteria

Answer 17

• Sustained hypotension (SBP < 90)

- Reduced Cl (<2.2) in presence of elevated PCWP (>18)

Question 18

Cardiogenic Shock + STEMI Patient Treatments

Answer 18

• Revascularization PCI or CABG if due to pump failure
• Fibrinolytic therapy for those unstable for PCI/CABG
• Intra-aortic balloon pump for unstable after pharmacologic therapy
• Alternative LV assist devices for circulatory support in refractory cardiogenic shock

Question 19

Progression of Sepsis

Answer 19

SIRS => Sepsis (infection)=> Severe Sepsis REDUNDANT (w/ organ dysfunction/tissue hypoperfusion)=> Septic Shock (hypotension or elevated lactate persisting after fluids)

Question 20

SIRS Criteria

Answer 20

-Multifactorial: ischemia, infection, pancreatitis, trauma, burns

Criteria

• Temp >38.3 or <36
• HR >90
• RR > 20 or mechanical ventilation
• WBC >12000 or <4000 OR > 10% immature forms

Question 21

qSOFA

Answer 21

• Quicker way to identify sepsis

- Must have 2 of the following: RR >=22, altered mentation, SBP =<100

Question 22

Sepsis

Answer 22

• Life threatening organ dysfunction caused by deregulate host response
• SOFA >=2
• Scored by respiration, platelets, bilirubin, MAP/pressors, Coma scale, creatinine/urine output
• In-hospital mortality >10%

Question 23

Hour-1 Bundle

Answer 23

• Sepsis Patient Care
• Measure lactate and repeat if elevated (>2)
• Blood cultures and broad spectrum antibiotics
• Fluids for hypotension or lactate >4
• Vasopressors for MAP >= 65

Question 24

Septic Shock

Answer 24

• Subset of sepsis
• Circulatory, cellular, and metabolic abnormalities are associated with greater risk of mortality
• Vasopressor needed to maintain MAP of 65 and serum lactate >2 in absence of hypovolemia (already fluid corrected)
• 40% in-hospital mortality risk