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Flashcards in Shock Deck (59):
1

What is shock?

Inadequate tissue perfusion marked by decreased delivery of required metabolic substrates and inadequate removal of cellular waste products

2

Untreated shock leads to...

Organ dysfunction, organ failure, and death

3

6 types of shock?

Hypovolemic

Cardiogenic

Septic

Neurogenic

Traumatic

Obstructive

4

What are the four different categories of shock based on hemodynamic findings?

Hypovolemic (hemorrhagic, GI/UT volume loss, third spacing)

Cardiogenic (myocardial pump failure)

Distributive (sepsis, anaphylaxis, spinal cord injury, corticosteroid insufficiency)

Obstructive (cardiac tamponade, tension pneumothorax, PE)

5

Hypovolemic shock

HR:

MAP:

CVP:

PAOP:

SVR:

HR: high

MAP: low

CVP: low

PAOP: low

SVR: high

6

Cardiogenic Shock (Left ventricular failure)

HR:

MAP:

CVP:

PAOP:

SVR:

HR: Increased

MAP: Variable

CVP: normal

PAOP: High

SVR: High

7

Cardiogenic shock (right ventricular failure)

HR:

MAP:

CVP:

PAOP:

SVR:

HR: High

MAP: variable

CVP: High

PAOP: Normal

SVR: High

8

Cardiogenic Shock (Biventricular failure)

HR:

MAP:

CVP:

PAOP:

SVR:

HR: High

MAP: Variable

CVP: High

PAOP: High

SVR: High

9

Distributive Shock (Early vs Late)

HR:

MAP:

CVP:

PAOP:

SVR:

HR: Both High

MAP: Both Low

CVP: low or normal (early); high or normal (late)

PAOP: Low or normal (early); high or normal (late)

SVR: Low for both

10

Obstructive shock

HR:

MAP:

CVP:

PAOP:

SVR:

HR: high

MAP: low

CVP: high

PAOP: high

SVR: high

11

Chance of mortality with shock

Hypovolemic:

Cardiogenic:

Septic:

Hypovolemic: Very variable

Cardiogenic: 60%-90%

Septic: 35% - 40%

12

What are some determinants of shock?

  • Loss of circulating intravascular volume
  • Inadequate capillary and tissue perfusion
  • Disturbed cell metabolism
  • Mismatch of oxygen delivery and oxygen demand

13

What are the four stages of shock?

Initial

Compensatory

Progresive

Refractory

14

What happens during each stage of shock?

Initial:

Compensatory:

Progressive:

Refractory:

Initial: hypo-perfusion, tissue hypoxia, lactic acidosis

Compensatory: cytokine release, hypervent. endogenous catecholamine release

Progressive: failing compensation, capillary leakage and metabolic acidosis, increased blood viscosity, organ dysfunction (MODS)

Refractory: irreversible organ damage, cell death, degradation of ATP

15

What is the systemic response to shock?

  • Progressive vasoconstriction
  • Increased BF to vital organs
  • Increase in CO/CI
  • Increase in respiratory rate and tidal volume
  • Reduced urine production
  • Reduction in gastric and intestinal activity

16

What types of organ dysfunction are associated with shock?

Acute kidney injury

Liver congestion

Gastrointestinal ischemia

ARDS

17

What is cardiogenic shock?

Critical reduction in myocardial pump capacity (loss of > 40%) leading to malperfusion of tissues

18

What differential factors should be excluded in cardiogenic shock?

Hypovolemia

Arterial hypoxia

Vasovagal reaction

19

What percentage of patients with acute MI develop a cardiogenic shock?

5-10%

20

What are some of the clinical signs of cardiogenic shock?

  • Signs of centralized circulation and organ dysfunction
  • Agitation
  • Pale, cool, clammy skin
  • RV dysfunction
  • LV dysfunction (leads to pulmonary edema)

21

Hemodynamic effects of Cardiogenic shock?

 

Systolic BP < 90mmHG or blood pressure drop by 30mmHG for > 30 min

May need inotropic therapy or balloon pump to stabilize BP

Increased LVEP

Reduced cardiac index

22

Myocardial etioligies of Cardiogenic shock

Acute MI

Myocarditis

Cardiomyopathy

RV pump failure

Myocardial depressoin

23

Mechanical etiologies of cardiogenic shock

Acute mitral insufficiency

Aortic insufficiency

Rupture of ventricular septum

Rupture of free ventricular wall

Obstruction

24

Ischemic Cardiogenic shock progression

Decreased perfusion → Cardiac injury → Decreased stroke volume → Increased catecholamines → increased Heart rate → decreased perfusion... etc

25

In Cardiogenic shock, the duration of diastole ______ due to  _______ ________

decreases; compensatory tachycardia

26

In cardiogenic shock, what causes metabolic derangement?

Lactic acidosis due to systemic tissue malperfusion → cardiac dysfunction

27

What are some compensatory mechanisms for cardiogenic shock? What is the trigger?

Trigger: critical decrease in SV

Activation of sympathetic nervous system

Result in increased HR, increase SVR, increased catecholamine release (RAA system), aldosterone, and baroreceptor mediated ADH release

28

Overall results of compensatory mechanisms in cardiogenic shock

Increased preload and afterload - leads to worsening of myocardial function

29

Diagnostic tests for cardiogenic shock

EKG

Chest x-ray

arterial blood gas (VBG)

CBC, cardiac enzymes

Serial lactate levels

30

What are cardiac biomarkers with STEMI?

Cardiac troponin (higher with reperfusion)

CKMB (higher with no reperfusion)

31

What are the goals for management of cardiogenic shock?

Optimize ventricular filling

Improve coronary perfusion pressure with: vasopressors, inotropics, IABP

If acute MI is the cause: coronary angiography and immediate revascularization

32

Vasoactive drugs

Inconstrictors (inotropic action + peripheral alpha 1 adrenergic induced vasoconstriction):

Inodilators (inotropic action + peripheral beta 2 adrenergic induced vasodilation):

  • Inoconstrictors
    • Norepinephrine
    • Epinephrine
    • Dopamine
  • Inodilators
    • Dobutamine
    • Dopexamine
    • Isoproterenol
    • Milrinone

33

What is SIRS and what type of shock is it associated with?

Systemic inflammatory response syndrome - septic shock

34

What is MODS

multi-organ dysfunction syndrome - also associated with septic shock

35

SIRS diagnosis has what criteria? How many does it have to meet for diagnosis?

Tachypnea (>20 breath per minute or PACO2 < 32mmHg)

WBC < 4000cells or > 12000 cells

Heart rate > 90bpm

Temperature: fever> 100.4º or hypothermia < 96.8º

 

Must meet at least 2 of the criteria

36

What manifestations of inadequate organ perfusion are found in Sepsis?

Alteration in mental state

Hypoxemia

Elevated plasma lactate level

Olliguria (low urine output)

37

What are the characteristics of septic shock?

Persistent arterial hypotension Despite adequate fluid resuscitation in severe sepsis

Tissue hypoperfusion

Culture positive bacteremia in 30-50% of cases

38

What are Primary and Secondary MODS?

  • Primary
    • Direct result of insult, organ dysfunction occurs early in the course
  • Secondary
    • Consequence of a host response
    • Inflammatory host response to toxins and other components of microorganisms

39

What are some causes of septic and vasodilatory shock?

  • Systemic response to infection
  • Pancreatitis
  • Burns
  • Anaphylaxis
  • Hemorrhagic shock
  • Acute adrenal insufficiency

40

What are the recommendations for sepsis?

Initial resuscitation

Screening of at risk patients

Antimicrobial therapy

Source control

Infection prevention

41

Septic shock treatment (within 3 hours)

  1. Measure lactate level
  2. Obtain blood cultures prior to administration of antibiotics
  3. Administer broad spectrum antibiotics
  4. Administer crystalloid for hypotension or lactate

42

Septic shock treatment (to be complete within 6 hours)

  1. Apply vasopressors (for hypotension)
  2. In the event of persistent hypotension despite resuscitation
    1. measure CVP
    2. Measure central venous oxygen saturation
  3. Remeasure lactate if initial lactate was elevated

43

How is initial resuscitation performed in septic shock patients?

Crystalloids

Hydroxyethyl starches (increased incidence of renal failure)

Albumin suggested in severe sepsis and septic shock when patients require substantial amounts of crystalloids

44

What is the first choice vasopressor for septic shock? whats is the second choice? Which is only in very select patients?

Norepinephrine = first choice

Epinephrine = second choice

Dopamine only in very select patients

45

When would you use inotropic support in septic shock?

In case of myocardial dysfunction (dobutamine)

46

What is hypovolemic shock?

Traumatic or hemmorhagic shock caused by burns or dehydration

47

Describe the progression of traumatic shock

Soft tissue or bony injury lead to activation of inflammatory cells and release of inflammatory mediators  → Combined inflammatory response and effects of hemorrhage create a more complex and amplified deviation from hemostasis

48

Hemorrhagic shock occurs with a loss of _____ supply and delivery

oxygen

49

Oxygen delivery is calculated from ___ x ______ x 10

CO x arterial oxygen content x 10

50

How many classes of hemorrhage exist? What is their order from least blood lost to most?

  • Class I (< 750 ml - <15%)
  • Class II (750 - 1500 ml - 15-30%)
  • Class III (1500-2000ml - 30-40%)
  • Class IV (>2000ml -  >40%)

51

What therapy is used for hemorrhagic shock?

  • Volume therapy
    • Cristalloid solutions
    • Colloid solutions
    • PRBC
    • FFP
    • SDPs
    • Small volume resuscitation

52

What is obstructive shock?

Form of cardiogenic shock that results from mechanical impediment to circulation

Depressed cardiac output rather than primary cardiac failure

53

What are etiologies associated with obstructive shock?

Pulmonary embolism or tension pneumothorax

54

What is Neurogenic shock?

Profound vasodilation of arterial and venous blood vessels caused by injury of the brain stem, the spinal cord or traumatic brain injury

55

What is anaphylactic shock?

Distributive disturbance of the blood volume

or

physical, chemical or osmotic induced

- hypersensitivity reaction

56

What is IgE-dependent anaphylactic shock

What is IgE independent anaphylactic shock

IgE dependent = type-I-allergic anaphylactic

IgE independent  = anaphylactoid

57

Anaphylactic shock classification

 

Class 0 - locally limited cutaneous reaction

Class 1 - disseminated cutaneous reaction

Class 2 - Hemodynamic dyregulation

Class 3 - Shock, bronchospasm

Class 4 - Respiratory and circulatory arrest

58

Therapy for anaphylactic shock?

Rapid infusion of cristalloid (or colloid) solutions

Epinephrine (for bronchodilation, positive inotrope, anti inflamm)

Norepinephrine (refractory hypotension)

Vasopressin

59

Hemodynamic Responses to different types of shock?

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