Shock

Question 1

SHOCK

Answer 1

inadequate CO

failure of the circulatory system to supply the peripheral tissues with adequate BF

Question 2

late sign of failure of compensatory mechanisms

Answer 2

hypotension (abnormally low blood pressure)

Question 3

Types of Shock

Answer 3

Distributive
Obstructive
Cardiogenic
Hypovolemic

Question 4

Distributive shock

Answer 4

-abnormal distribution of blood flow

sepsis, or anaphylaxis from the release of inflammatory mediators

Question 5

Obstructive shock

Answer 5

-physical obstruction of the great vessels or the heart itself

(pulmonary embolism, cardiac tamponade, tension pneumothorax)

Question 6

Cardiogenic shock

Answer 6

-suddenly! the heart can’t pump enough blood to meet the body’s needs

(acute myocardial infarction, heart disease, cardiac arrhythmias)

Question 7

Hypovolemic shock

Answer 7

-decreased blood volume

loss of blood (hemorrahge
loss of plasma (burn)
ECF (GI losses)

Question 8

Distributive shock causes

Answer 8

• loss of vascular tone
• enlargement of vascular compartment
• displacement of vascular volume away from central circulation
• more blood in periphery, less in central circulation
• loss of SNS vasomotor drive (neurogenic shock)
• vasodilators in blood (anaphylactic shock)
• presence of inflammatory mediators (septic shock)

Question 9

3 types of distributive shocks

Answer 9

neurogenic - loss of SNS vasomotor drive

anaphylactic - vasodilators in blood

septic - presence of inflammatory mediators

Question 10

Neurogenic shock

Answer 10

DISTRIBUTIVE SHOCK

-loss of neural influence on vasculature => lose vasomotor tone
(decrease SVR) and MABP falls

rare and transitory

Question 11

Anaphylactic shock

Answer 11

DISTRIBUTIVE SHOCK

• immune mediated reaction
• vasodilators (histamine)
• decrease SVR, MABP falls

Question 12

histamine

Answer 12

anaphylactic shock - distributive shock

decrease SVR, MABP falls

dilates arterioles and venules
increases permeability of capillaries and venules

Question 13

Causes of neurogenic shock

Answer 13

DISTRIBUTIVE SHOCK

• brain injury
• drugs (general anesthesia)
• insulin reaction (lack of glucose)
• hypoxia
• spinal cord injury

Question 14

Causes of anaphylactic shock

Answer 14

DISTRIBUTIVE SHOCK

-allergic reaction: drugs, foods, stings, latex

Question 15

How to alleviate anaphylactic shock?

Answer 15

DISTRIBUTIVE SHOCK

epinephrine - open airways (vasoconstriction to increase SVR)

cold - to delay absorption and spread

Question 16

What is the most common form of shock among patients in the ICU?

Answer 16

septic shock

Question 17

Septic shock definition

Answer 17

sepsis (organ injury or damage in response to infection) leads to dangerously low blood pressure and abnormalities in cellular metabolism

Question 18

What form of shock is hemorrhage and how?

Answer 18

hypovolemic shock

-loss of BV

Question 19

Baroreceptors respond to ___

Answer 19

stretch

high MABP, high BR => inc. psns to compensate

low MABP, low BR => increase sns to compenaste

Question 20

if low arterial baroreceptor firing, what to do to compensate?

Answer 20

increase sns

increase adh

Question 21

In response to hemorraghe, what does the SNS effect?

Answer 21

arterioles increase SVR
veins: decrease compliance, inc VR
heart 
liver
hypothalamus, posterior pituitary for ADH

Question 22

In response to hemorrhage, what does the sns do to the veins?

Answer 22

alpha 1 receptor

decreases compliance
increases venous return
inc. ventricular filling
inc. sv toward normal

Question 23

In response to hemorrhage, what does the sns do to the aterioles?

Answer 23

increase svr,

inc. water reabsorption
inc. lactic acid production

Question 24

CO and MABP is maintained if less than ____ %of BV is lost.

Answer 24

10%

Question 25

MABP is maintained, but CO decreases if ______% of BV is lost.

Answer 25

10-25%

Question 26

___ is a good metabolic index of severity of shock

Answer 26

lactate

Question 27

What is the effect on kidneys when in shock?

Answer 27

vasoconstriction, decrease filtration, less urine formation => less water lost

reabsorption of water by ADH

Question 28

What does aldosterone do?

Answer 28

stimulates Na+ reabsorption and K secretion

(ENaC and NaK ATPase in the renal tubules (principal cells DT and CD) => water follows sodium

Question 29

What does ADH or AVP do?

Answer 29

potent vasoconstrictor
inc. SVR
V1 receptor

potent effect on reabsorption of water from the collecting ducts