Exam #2: Hemodynamics V

Question 1

What is the definition of shock?

Answer 1

Inadequate perfusion i.e. inability of the circulatory system to adequately supply tissues with nutrients and remove toxic waste

Question 2

Outline the sequela of shock.

Answer 2

Reduced cardiac output or reduced effective circulating volume leads to:

1) Hypotension
2) Impaired tissue perfusion
3) Hypoxia

Question 3

List the different classifications of shock. What is the mnemonic to remember the etiological classifications of shock?

Answer 3

SSHHOCCKE

S= septic 
S= spinal/neurogenic 
H= hypovolemic 
H= hemorrhagic 
O= Obstructive 
C= Cardiogenic 
C= Cellular toxins 
K= AnaphylaKtic 
E= Endocrine/ adrenal crisis

Question 4

Draw the mechanisms of shock.

Answer 4

N/A

Question 5

What is the common endpoint of shock?

Answer 5

Cellular injury

Question 6

What are the five unifying features of shock?

Answer 6

1) Intracellular Ca++ overload
2) Intracellular H+ ion
3) Cellular & intersitial edema
4) Catabolic metabolism
5) Inflammation

Question 7

What is the manifestation of irreversible shock?

Answer 7

Multisystem organ failure, esp. kidney, liver, brain

Question 8

What are Rosen’s Emperic criteria for the diagnosis of shock?

Answer 8

1) Ill appearance or decreased LOC
2) HR greater than 100
3) RR greater than 22 & decreased PCO2 less than 32 (Normal 35-45) i.e. respiratory alkalosis
4) Lactic acid above 4 or base deficit anuria)
6) Hypotension greater than 20 min. duration

Question 9

What is base deficit?

Answer 9

Amount of base required to neutralize the pH (normal is -2)

Question 10

What are the three stages of shock?

Answer 10

1) Nonprogressive stage
2) Progressive stage
3) Irreversible stage

Question 11

What is the nonprogressive stage of shock?

Answer 11

Blood pressure & cardiac output are maintained via:

1) Baroreceptor reflex
2) Catecholamine release
3) Activation of RAA
4) ADH release
5) General sympathetic stimulation

Question 12

What is the progressive stage of shock?

Answer 12

1) Widespread tissue hypoxia in the microcirculation
2) Lactic acidosis
3) Confusion and decreased urinary output

Question 13

What is the irreversible stage of shock?

Answer 13

1) Widespread cell injury

2) Subsequent decrease in urine output and severe fluid/electrolye disorders occur

Question 14

What is the mortality of shock dependent on?

Answer 14

Physiologic health?
Etiology of shock
Duration of shock

Question 15

What are the morphologic features of shock in the brain?

Answer 15

Ischemic encephalopathy

Question 16

What are the morphologic features of shock in the heart?

Answer 16

Coagulation necrosis

Subendocardial

Question 17

What are the morphologic features of shock in the kidneys?

Answer 17

Acute tubular necrosis

Question 18

What are the morphologic features of shock in the lungs?

Answer 18

Diffuse alveolar damage

Question 19

What are the morphologic features of shock in the adrenal gland?

Answer 19

Cortical cell lipid depletion

Question 20

What are the morphologic features of shock in the GI tract?

Answer 20

Mucosal hemorrhage & necrosis

Question 21

What are the morphologic features of shock in the liver?

Answer 21

Fatty change, central hemorrhagic necrosis

Question 22

What is the definition of cardiogenic shock?

Answer 22

Poor myocardial contractility

Question 23

Outline the sequala of cardiogenic shock.

Answer 23

N/A

Question 24

What are the diagnostic criteria for cardiogenic shock?

Answer 24

1) Hypotension
2) 30 mmHg below baseline
3) Cardiac index is lowered i.e. not enough CO to meet body need
4) Pulmonary Capillary Wedge Pressure >15mmHg*****
5) Rosen’s (4/6)

*****Swann cath.

Question 25

How is cardiogenic shock treated?

Answer 25

1) ABCs 2) Id cause 3) Fluid bolus 4) Ionotropic/ vasopressor support 5) Manage infarct Don't be shy on fluids if RV infarct

Question 26

What are the four different classes of hypovolemic shock classified?

Answer 26

I-IV

Question 27

What is Class I hypovolemic shock?

Answer 27

<100 BP & PP normal LOC= anxious

Question 28

What is Class II hypovolemic shock?

Answer 28

``` 750- 1500 mL lost HR 100-120 PP decreased BP normal LOC= anxious ```

Question 29

What is Class III hypovolemic shock?

Answer 29

``` 1500 - 2,000 mL lost HR 120- 140 PP decreased BP decreased LOC= confused ```

Question 30

What is Class IV hypovolemic shock?

Answer 30

``` >2,000 mL lost HR > 140 PP decreased BP decreased LOC= lethargic ```

Question 31

How is hypovolemic shock managed?

Answer 31

1) Crystalloid bolus 2) Blood transfusion 3) Identify and treat cause

Question 32

What are colloids? What are the advantages & disadvantages?

Answer 32

Colloid solutions refer to solutions that are hypertonic due to the addition of some solute to the fluid Advantages: - Less fluid required - More volume in the vascular space - Shift fluid into vascular space from tissue Disadvantages - Expensive - Allergic reactions can be mounted to solute - Coagulopathies

Question 33

Outline the pathophysiology of septic shock.

Answer 33

N/A

Question 34

Outline the effects of cytokine induction.

Answer 34

N/A

Question 35

What is the temproal progression of the cytokines?

Answer 35

LPS TNF IL-1

Question 36

What are the criteria for the diagnosis of SIRS?

Answer 36

Temp > 38C or < 36C HR >90 RR >20 or PaCOP2 12 or 10% bands

Question 37

What is the definition of sepsis?

Answer 37

SIRS + documented infection

Question 38

What is severe sepsis?

Answer 38

Sepsis + MODS (multi-organ dysfunction)

Question 39

What is septic shock?

Answer 39

Sepsis + Hypotension refractory to volume resuscitation

Question 40

What is one of the most crucial factors in treating septic shock?

Answer 40

Early and appropriate initiation of antibiotics antibiotics

Question 41

What are some of the newer approaches to treating septic shock?

Answer 41

Vasoactive mediators Coagulation Cascade Inflammatory Mediators

Question 42

What is the difference between spinal shock and neurogenic shock?

Answer 42

Spinal= loss of cord function following injury, including motor, sensory, and sympathetic function Neurogenic= loss of sympathetic tone due to spinal cord injury

Question 43

Neurogenic shock is usually seen in lesions at or above what level?

Answer 43

T6 & higher= vasodilation | T4 & higher= bradycardia

Question 44

Outline the pathophysiology of neurogenic shock.

Answer 44

Hypotension - Loss of tone= vasodilation Bradycardia - Unopposed vagal tone on the heart

Question 45

Outline the pathophysiology of anaphylactic shock.

Answer 45

IgE mediated systemic vasodilation and increased vascular permeability--> shock