Shock

Question 1

Inadequate organ perfusion and delivery of nutrients necessary for normal tissue and cell function. May be irreversible at first but becomes life-threatening if not treated quickly

Answer 1

Shock

Question 2

Causes of hypovolemic shock

Answer 2

Hemorrhage [hemorrhagic = most common cause]
Dehydration
Burns

[ex: GI bleeding, pelvic bleeding, hemorrhagic pancreatitis, AVM; non-hemmorrhagic causes are vomiting, diarrhea, burns, heat stroke; DKA leads to renal losses, hypoaldosteronism, adrenal insufficiency, third space loss, systemic inflammation]

Question 3

Physiologic parameters used to define preload and afterload while discussing shock

Answer 3

Preload = PCWP

Afterload = SVR

Question 4

4 types of shock

Answer 4

Hypovolemic
Cardiogenic
Obstructive
Distributive

Question 5

Types of shock characterized by cold and clammy skin vs. warm and dry skin

Answer 5

Cold, clammy skin = hypovolemic, cardiogenic, or obstructive shock

Warm, dry skin = distributive shock

Question 6

Describe changes in PCWP (preload), CO, and SVR (afterload) in pt with hypovolemic shock

Answer 6

PCWP markedly decreased

CO decreased

SVR increased

Question 7

General tx for hypovolemic shock

Answer 7

IV fluids

Question 8

General causes of cardiogenic shock

Answer 8

Acute MI
HF
Valvular dysfunction
Arrhythmia

Question 9

Describe changes in PCWP (preload), CO, and SVR (afterload) in pt with cardiogenic shock

Answer 9

PCWP increased

CO markedly decreased

SVR increased

[same as obstructive shock]

Question 10

General tx for cardiogenic shock

Answer 10

Inotropes

Diuresis

Question 11

General causes of obstructive shock

Answer 11

Cardiac tamponade

Pulmonary embolism

[other examples include SVC syndrome, constrictive pericarditis, severe HTN]

Question 12

Describe changes in PCWP (preload), CO, and SVR (afterload) in pt with obstructive shock

Answer 12

PCWP increased

CO markedly decreased

SVR increased

[same as cardiogenic shock]

Question 13

General tx for obstructive shock

Answer 13

Relieve obstruction

Question 14

General causes of distributive shock

Answer 14

Sepsis
Anaphylaxis
CNS injury

Question 15

Describe changes in PCWP (preload), CO, and SVR (afterload) in pt with distributive shock

Answer 15

PCWP decreased

CO increased [unless CNS injury, then may be decreased]

SVR markedly decreased

Question 16

Tx for distributive shock

Answer 16

IV fluids first, then at pressors as needed (epinephrine first choice)

Question 17

______ levels are a reflection of tissue hypoxia

Answer 17

Lactate

[higher lactate = higher mortality]

Question 18

Most common cause of noncardiogenic shock

Answer 18

Distributive shock

Question 19

Describe changes in PCWP (preload), CO, and SVR (afterload) in pt with anaphylactic shock

Answer 19

PCWP normal at first, decreases later

CO may be decreased or increased

SVR decreased

Question 20

Classifications of cardiogenic shock

Answer 20

Cardiomyopathic — MI, severe RVMI, stunned myocardium, severe septic shock (depressed EF), myocarditis, cardiomyopathy

Arrhythmogenic — afib, re-entrant tachycardia, vtach, vfib

Mechanical — severe AI or MR; acute valvular rupture, critical AS, VSD, ruptured ventricle wall aneurysm, atrial myxoma

Question 21

Clinical signs of cardiogenic shock

Answer 21

Decreased BP
Decreased UO
Mental status changes
Cool, mottled extremities
Distended neck veins
Pulmonary edema

Question 22

Most common cause of cardiogenic shock

Answer 22

LV failure d/t AMI

Question 23

Average time to develop cardiogenic shock after a STEMI

Answer 23

7-10 hours

Question 24

Cardiogenic shock due to LAD often associated with ____ wall STEMI

Cardiogenic shock associated with inferior wall STEMI often associated with _____ complications

Answer 24

Anterior; mechanical

Question 25

Mechanical support treatment that can be given in severe cardiogenic shock

Answer 25

IABD — decreased afterload deflates during systole; inflates during diastole — coronary perfusion use for mechanical complication (M, VSD)

LVAD — bridge for transplant; tandem heart/impella

ECMO — when O2 is severely impaired

Question 26

First choice pressor agent in cardiogenic shock d/t STEMI

Answer 26

Norepi — alpha1, B1, B2 agonist (pressor and inotropic)

[second option is dopamine - B1 agonist, or phenylephrine - peripheral alpha agonist]

Question 27

Inotropes used to tx cardiogenic shock

Answer 27

Dobutamine - B1 agonist; peripehral alpha1 and B2 agonist; can vasodilate; used with NE

Milrinone — PDE inhibitor; prevents degradation of cAMP to increase HR, increase SV, increase CO

Question 28

Classifications of obstructive shock

Answer 28

Pulmonary vascular = hemodynamically significant, PE, severe pulmonary HTN, severe or acute obstruction of pulmonary or tricuspid valve

Mechanical = tension pneumothorax (trauma, ventilator induced, iatrogenic), pericardial tamponade, constrictive pericarditis, restrictive cardiomyopathy

Question 29

Presentation of tension pneumothorax

Answer 29

SOB, unilateral pleuritic CP and decreased breath sounds, neck vein distention

Tracheal deviation AWAY from affected side

Question 30

Virchow triad of hemodynamically significant PE

Answer 30

Endothelial injury
Stress
Hypercoagulability

Question 31

Most common EKG finding in PE

Answer 31

Tachycardia

Question 32

Imaging strategy for visualization of thrombi in pulmonary arteries; preferred over ventilation/perfusion lung (V/Q)

Answer 32

CT pulmonary angiography (CTPA)