Shock

Question 1

The definition of shock

Answer 1

inadequate tissue perfusion

supply<VO2)

Question 2

What is the eventual result of shock (2)

Answer 2

anaerobic metabolism->acidosis

decreased cardiac output & acidosis->HYPOtension

Question 3

Delivery of oxygen is a direct function of what?

Answer 3

cardiac output (CO) and the arterial oxygen content (CaO2)
DO2=COxCaO2

Question 4

Which 3 things are direct determinants of blood pressure?

Answer 4

Cardiac output
preload
peripheral vascular resistance

Question 5

Ohm’s law

Answer 5

BP=flow(Q)x Resistance (R)

Question 6

Clinical features of shock

Answer 6

Tachycardia
Tachypnea
+/- hypotension
Signs of poor end-perfusion (altered mental status, oliguria, lactic acidosis, cool, mottled extremities, thread pulses)

Question 7

signs of poor end perfusion (4)

Answer 7

• altered mental status
• oliguria
• lactic acidosis
• cool, mottled extremities, thread pulses

Question 8

How can you increase supply? (DO2)

Answer 8

maximize CO 
-preload
-afterload
-increase contractility -appropriate HR
Maximize CaO2 [arterial oxygen content] 
-Hct
-supplemental O2

Question 9

Causes of cardiogenic shock (3)

Answer 9

decreased function
arrhythmia
obstruction

Question 10

Causes of hypovolemic shock (6)

Answer 10

Hemorrhage (GI bleed, trauma, ruptured aneurysm, post-operative)
Over-diuresis
Diarrhea
Dehydration
Diabetic ketoacidosis
Burns

Question 11

Causes of septic shock (4)

Answer 11

• positive blood cultures of any organism in 40-70%
• widespread endothelial injury
• decreased peripheral vascular resistance cause hypotension
• other findings: tachycardia, fever, leukocytosis, abnormal clotting parameters, acidosis, renal dysfunction

Question 12

Other causes of shock

Answer 12

anaphylactic
neurologic-spinal cord injury
pulmonary embolus
Addisonian crisis
myxedema

Question 13

Which form of shock has a LOW A-VO2 difference?

Answer 13

Septic shock

Question 14

Hypovolemic shock definition

Answer 14

reduction in intravascular volume/preload leading to DECREASED CO & insufficient O2 delivery to cells (mitochondria)
-loss of circulating blood volume (plasma)

Question 15

Normal blood volume (adult, kid)

Answer 15

70Kg adult=5.5 liters (approx. 15 units)

10kg toddler=900ml

Question 16

possible etiologies of non-hemorrhagic hypovolemic shock (5)

Answer 16

Excessive GI losses (vomiting, diarrhea)
Dehydration
Evaporative (burns)
Third-Space Losses
Neurologic/Renal-diabetes insipidus/melitus

Question 17

possible etiologies of hemorrhagic hypovolemic shock (4)

Answer 17

1. Internal bleeding (GI tract, soft tissues, retroperitoneum-can be hard to detect)
2. external bleeding (trauma)
3. operative
4. iatrogenic (open c-line, aline)

Question 18

What word should not be used in shock?

Answer 18

STABLE is for horses, if patients are bleeding, they are NEVER stable

Question 19

What is the body’s response to hypovolemic shock?

Answer 19

Compensated shock->baroreceptor mediated vasoconstriction
-increased Epi, vasopressin, angiotensin
results in:
-tachycardia
-tachypnea
-NARROWED PULSE PRESSURE (under 15-20 is very concerning
-slightly lowered urine output

Question 20

compensated hemorrhagic shock:
how much blood loss
what happens to BP?

Answer 20

0-20% blood loss

BP is maintained via ↑ vascular tone & ↑blood flow to vital organs

↑ contractility maintains SV +slight↑ in HR maintains near normal CO

vasoconstriction maintains near normal BP

Question 21

5 compensations in non-progressive (compensated) shock

Answer 21

1. baroreceptor reflexes
2. renin release
3. ADH release
4. Epi & Norepi Release
5. Compensatory Mechanisms effective

Question 22

In hypovolemic shock, the body will make whatever adjustments it can to maintain ______________.

Who wins? who loses?

Answer 22

Adequate Cardiac Output
more important organs remain normal, less critical organs are stressed by ischemia

WINNERS: brain, heart, kidneys, liver
LOSERS: skin, GI tract, skeletal muscle

Question 23

Progressive (un-compensated) shock

Answer 23

• intravascular volume deficient exceeds heart capacity to maintain CO->INADEQUATE PRELOAD->HR ↑
• sympathetic & neurohormonal response no longer able to maintain enough vasoconstriction to maintain systemic perfusion pressure (P=CO*PVR)
• ACIDOSIS, CHANGE IN MENTAL STATUS, POOR URINE OUTPUT EVIDENT

Question 24

What is evident in progressive (Un-compensated) shock (3)

Answer 24

acidosis
change in mental status
poor urine output

Question 25

problem with cuff pressures in obesity

Answer 25

cuff pressures may falsely over-estimate pressure, difficulty with palpable pulses, difficult airway

Question 26

Relative Hypovolemic Shock (3)

Answer 26

- Tension Pneumothorax - Spinal Shock - Early Septic Shock

Question 27

Cardiogenic shock: simple def

Answer 27

pump failure possibly due to CAD, myocardial loss or arrhythmia

Question 28

progression of Cardiogenic shock

Answer 28

acute hypotension->low CO-> inadequate LV outflow-> poor end organ perfusion! (same signs/sxs you see in other shock, just a different cause)

Question 29

Causes of Cardiogenic Shock (9)

Answer 29

1. Acute exacerbation of cardiomyopathy 2. Acute MI 3. Acute myocarditis 4. Acute Ventricular Septal or Left Ventricular Rupture 5. Acute Aortic Insufficiency-Aortic Dissection 6. Cardiac Tamponade 2* pericardial effusion 7. Arryhythmia 8. Meds: Anti-HTN, AV blockin meds 9. Acute Mitral Regurg (papillary m. rupture, ruptured chordae)

Question 30

Clinical manifestations of cardiogenic shock (9)

Answer 30

``` hypotension BP<90/60 or 80/60 tachypnea tachycardia pallor, mottled skin restlessness confusion, altered mental status weak pulses cold, clammy extremities oliguria ```

Question 31

Tx of cardiogenic shock

Answer 31

``` tx underlying cause inotropes &/or vasopressors fluids if appropriate intraaortic balloon counterpulsation revascularize if acute MI: -fibrinolyrics (tPA, streptokinase) -angioplasty -CABG ```

Question 32

Septic shock: definition/description

Answer 32

exaggerated endogenous inflammatory response to invasive infection leading to: -circulatory collapse -multiple organ failure -death mortality over 35% (sepsis w/hypotension)

Question 33

Cardiac output in fluid resuscitated septic shock is

Answer 33

increased | initially they are hypovolemic, but once you put fluid in them, they are in a high output state

Question 34

Systemic Inflammatory Response Syndrome (SIRS) definition

Answer 34

response to a variety of severe clinical insults, manifested by 2 OR MORE of the following: 1. temp>38*C or90bpm 3. RR>20 or PaCO212,000/mm3, 10% immature (band) forms "left shift"

Question 35

Infection Definition

Answer 35

inflammatory response to microorganisms or invasion of normally sterile tissues

Question 36

Sepsis definition

Answer 36

systemic response to infection-i.e. confirmed or suspected infection PLUS > or = 2 SIRS criteria

Question 37

Severe Sepsis Def

Answer 37

-sepsis a/w organ dysfxn, hypoperfusion or hypotension hypoperfusion abnormalities may include but are not limited to: lactic acidosis, oliguria, acute alteration in mental status

Question 38

Septic Shock: ACCP/SCCM def

Answer 38

sepsis-induced hypotension DESPITE ADEQUATE FLUID RESUSCITATION along w/ perfusion abn (incl. lactic acidosis, oliguria, or acute alteration of mental status) patients receiving inotropic or vasopressor agents may not be hypotensive at the time perfusion abnormalities are measured

Question 39

G+ vs. G- sepsis presentation

Answer 39

G+ may have less hypotension than with G- sepsis

Question 40

What is ARDS

Answer 40

adult respiratory distress syndrome -inflammatory response where you get leaky capillaries in lungs, lungs become stiff (can occur in sepsis/septic shock, blood transfusion), hard to ventilate, very poor oxygenization

Question 41

MSOF- multisystem organ failure

Answer 41

Hepatic: transaminitis,↑bilirubin Renal: ATN, uremia, oliguria progressing to anuria Pulmonary: ARDS, infections Cardiac: myocardial depression, arrhythmias Neuro: altered mental status, confusion, delirium, coma Others: immune, hematopoietic, coagulation

Question 42

Warm (hyperdynamic) shock clinical manifestation

Answer 42

hypotensive, tachycardia, tachypnea - BOUNDING PULSE - WARM, WELL PERFUSED EXTREMITIES - SKIN FLUSHED, MOIST

Question 43

Cold (hypodynamic) shock

Answer 43

hypotensive, tachycardia, tachypnea - NARROW, THREADY PULSE - COLD, POORLY PERFUSED EXTREMITIES - SKIN PALE, DRY

Question 44

Septic Shock hemodynamics

Answer 44

CVP doesn't accurately estimate ventricular filling in the critically ill - when PWP (pulmonary wedge pressure) is appropriately elevated to 12-15 mmHg w/fluid resuscitation, 90% of pts w/septic shock exhibit hyperdynamic circulatory state - hyperdynamic state persist to death

Question 45

hypodynamic septic shock=

Answer 45

inadequately fluid resuscitated septic shock (until PWP shows filling pressures btwn 12-15mm Hg) [if you adequately resuscitate (6-8L saline), they have a better chance]

Question 46

Metabolic derangement in sepsis

Answer 46

↑ lactate, ↑ MVO3 - micro-anatomic shunts (non-nutritive capillaries) - functional shunts (impaired micro-circulatory vasomotor contro) - citric acid (Kreb's) cycle defect w/anaerobic glycolysis - aerobic glycolysis w/lactate production

Question 47

Tx of septic shock

Answer 47

* Fluid Resuscitation (CVP 8‐12, PCWP 12‐15) * IV Antibioticsbroad spread until source identified * Decrease metabolic demands * Support blood pressure,vasoconstrictors after fluids * VentilatorySupport‐ventilator, sedation * Cardiac Support‐inotropes in some cases, monitor  cardiac output and maximize it * Nutritional Support * Watch out for DIC

Question 48

Classes of hypovolemic shock: blood loss, systolic BP, pulse pressure, pulse, mental status

Answer 48

Class I: 40% blood loss (>2000cc), dec to absent SBP, dec. PP, very tachycardic, lethargic