Exam 2: Ch 20 Shock Flashcards Preview

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Flashcards in Exam 2: Ch 20 Shock Deck (28):
1

circulatory shock

hypo-perfusion of organs

too little O2 for cell functions

2

cellular response to circulatory shock

anaerobic metabolism -- not enough ATP

Na/K pump fails

cells swell and die

3

compensations for circulatory shock

similar to HF -- SNS, RAA

counter-productive over time

4

hypovolemic shock definition and compensations

not enough blood volume in system (15-20% lost)

SNS stimulation increases HR, vasoconstriction, inotrophy, venoconstriction (mobilize blood)

RAA stimulation increases ADH/Aldo to restore circulating volume

5

hypovolemic shock symptoms and treatment

thirst, acidosis, mentation

high HR, systemic vascular resistance, afterload

low BP, venous return, PP, SV, CO, EDV, CVP, PCWP, urine output

give volume

6

causes of hypovolemic shock

hemorrhage

plasma loss from burns

extracellular loss (GI)

7

physiology of hypovolemic shock

15% volume loss well tolerated

after 15%, SNS vasoconstriction maintains BP even though CO is low

PP is narrowed and SVR is high

45% blood loss takes CO and BP to 0

8

cardiogenic shock definition and causes

inadequate pumping of the heart

MI, LV aneurysm, valve dysfunction, ischemia

9

physiology and symptoms of cardiogenic shock

low BP, SV, CO, EF contractility, but high afterload

cyanosis, hypoxia, oliguria, high CVP and PCWP (pulmonary capillary wedge pressure)

10

treatment of cardiogenic shock

up inotropics

nitroprusside (arterial/venous dilator) to dec. after/preload

NTG venous dilator to decrease preload

IABP: intra aortic balloon pump

11

IABP

intra aortic balloon pump used to treat cardiogenic shock

deflates during systole to decrease afterload

inflates during diastole to increase CA blood floow

12

obstructive shock

circulation blocked by an obstuction (pulmonary emboli, tamponade, pneumothorax)

generally Rt HF with high CVP and distended neck veins

13

treatment of obstructive shock

pulmonary emboli may respond to thrombolytics

tamponade requires drainage

pneumothorax requires chest tube

14

distributive shock

blood volume adequate but vessels are dilated

low vessel tone (afterload) --> capacity of vascular space expands and blood can't fill it

low venous return and low CO

LOW SVR

15

types of distributive shock

neurogenic

anaphylactic

septic

16

nerogenic shock

brain or cord damage causes low SNS output and vasodilation

causes: injury, general or spinal anesthesia, hypoxia

17

anaphylactic shock

reaction causes histamine release and vasodilation

treatment: remove allergen and give epi

18

septic shock

bacterial toxins recruit WBC and release cytokines

cytokines disrupt endothelium and causes vasodilation and capillaries leak protein/fluid

result is severe hypovolemia, arterial and venous dilation

19

treatment of septic shock

antibiotics

give volume (fluid, vasopressors)

insulin returns normal blood sugar to dec. mortality

recombinant protein C is anti-inflammatory and an anticoagulant

20

5 complications of shock

acute lung injury/respiratory distress syndrome (ALI/ARDS)

acute renal failure

GI complications

Disseminated intravascular coagulation (DIC)

multiple organ dysfunction syndrome

21

acute lung injury/respiratory distress syndrome (ALI/ARDS)

shock from trauma/sepsis

hypoxemia, hypercapnea, V/Q mismatch

pulmonary capillaries leak fluid so impaired gas exchange

22

cause of ALI/ARDS and Rx

cause: unknown, maybe endothelial damage

Rx: support respiration with mechanical ventilation, avoid O2 toxicity

23

acute renal failure

shock from trauma/sepsis

renal tubules are vulnerable to ischemia and become nectoric

ATN is the most frequent lesion... may be reversible

24

GI complications

shock decreases mucosal perfusion which leads to ulcers and bleeding

Rx: NG suction, proton-pump inhibitors

25

disseminated intravascular coagulation (DIC)

coagulation pathways become activated throughout circulation

seen in 1/3 to 1/2 of septic shock patients

clots lead to organ failure

platelet and clotting factor depletion leads to hemorrhage

26

treatment of DIC

give platelets and anticoagulants

27

multiple organ dysfunction syndrome

strikes kidney, liver, brain, heart, lungs simultaneously

very high mortality rate

28

can shock be progressive?

yes