Phys-shock

Question 1

___ is the most common type of shock, and it is typically associated with ___ and leads to ___

Answer 1

1. Hypovolemic
2. Hemorrhage or severe dehydration
3. Decreased effective circulating volume (hypovolemia)

Question 2

___ shock is associated with PE that reduces pulmonary a. flow resulting in reduced ____. This in turn results in a reduction in ___ and ___

Answer 2

1. Obstructive
2. LV filling
3. CO
4. Low BP

Question 3

___ shock occurs as a result of heart failure. ___ shock is a result of generalized autonomic failure leading to ___ and ___.

Answer 3

1. Cardiogenic
2. Neurogenic
3. Reduced CO
4. Peripheral vasodilation

Question 4

___ shock is associated with his inappropriate peripheral vasodilation (too much) such that CO cannot increase sufficiently to overcome the massive decrease in peripheral vascular resistance.
Causes?

Answer 4

Distributive

• sepsis secondary to infection or GI dysfunction
• anaphylaxis
• neurogenic shock

Question 5

Features of early hypovolemic shock

6

Answer 5

ATTOCA

1. Altered mental status
2. Tachypnea
3. Tachycardia, weak pulse, orthostatic hypotension
4. Oliguria
5. Cool, clammy, poor refill time, sweating
6. Anemia

Question 6

Features of late hypovolemic shock

9

Answer 6

TOCCCALMA

1. Tachypnea and resp. failure
2. Obtunded CNS (dull reflexes)
3. Cool, clammy, cyanotic, poor refill time
4. Cardiac failure, arrhythmias, hypotension
5. Coagulopathy
6. Anuria
7. Liver failure
8. Mucosal bleeding
9. Acidosis, hypocalcemia, hypomagnesemia

Question 7

Initial treatment of shock

Answer 7

1. Supplemental O2
2. Lay the pt down
3. Warm the pt
4. Determine cause and address it
5. Restore and stabilize the effective circulating blood volume

Question 8

Response to low ECBV

Answer 8

~10% = no change in arterial pressure or CO
~20% = CO drops, no change in arterial pressure 
>20% = both drop

Question 9

Systems that work together to make compensation possible for decreases in ECBV

Answer 9

1. Baroreceptors
2. Chemoreceptors
3. Cerebral ischemia
4. Reabsorption of tissue fluid
5. Vasoconstrictors
6. Renal conservation of Na and H2O
7. CNS ischemic response

Question 10

A decrease in ECBV will elicit a baroreflex that will do what?

Answer 10

1. Increase sympathetic output to the heart (increases rate and SV to increase CO) and peripheral circulation (for arteries: shunts blood away from non essential organs. For veins: enhances venous return to restore CO and arterial pressure)
2. Decrease parasympathetic activity to the heart (increases rate)

Question 11

What “non-essential” organs suffer when the baroreflex increases sympathetic output and arteries shunt blood to the heart?

Answer 11

1. Skeletal muscle
2. Skin
3. Kidneys
4. GI tract

Question 12

When MAP falls below the baroreceptor threshold (which is ___), what happens?

Answer 12

60 mmHg

• the low perfusion pressure and low flow leads to hypoxemia and acidosis
• this stimulates the chemoreceptors in the carotid bodies to increase ventilation to increase PO2 and “blow off” CO2 to minimize the acidosis (by decreasing PCO2)
• stimulating respiration also aids venous return and enhances lymphatic flow

Question 13

When the MAP falls below ___, perfusion of the brain will be impaired resulting in ___. The response that follows is solely targeted at ___

Answer 13

1. 40 mmHg
2. Cerebral ischemia and hypoxia
3. increasing brain blood flow

Question 14

How does the cerebral ischemic response work?

Answer 14

1. Sympathetic and adrenal discharge causing vasoconstriction and increased myocardial contractility (+ inotropic effect)
2. Parasympathetic flow to the heart decreased rate and VO2

Question 15

Peripheral vasoconstriction decreases capillary hydrostatic pressure relative to plasma oncotic pressure which shifts the balance of starling forces, favoring ___

Answer 15

Reabsorption from the interstitial space into the vascular space (-Jv)

Question 16

If there is an increase in osmotic pressure within the extracellular space what happens?

Answer 16

Water leaves the intracellular space to increase extracellular volume
-net effect can be hemodilution

Question 17

Circulating endogenous vasoconstrictors

Answer 17

1. NE - neural release, some from adrenal medulla
2. Epinephrine - from adrenal medulla
3. Angiotensin II - symp. reminds release from kidney leads to formation of angiotensin I
4. Vasopressin/ADH - from posterior pituitary in response to changes in plasma osmolality

Question 18

___ controls the reabsorption of water from the distal nephron. Sensitivity for ___ is increased in low volume states due to ___

Answer 18

1. ADH/Vasopressin
2. ADH release
3. Increased levels of angiotensin II

Question 19

___ activates the renin-angiotensin-aldosterone system (RAAS)

Answer 19

Low volume

Question 20

Low renal perfusion pressure elicits ___

Answer 20

Increases in solute and water reabsorption

Question 21

Functions of angiotensin II

Answer 21

1. Vasoconstriction

2. Increases reabsorption of NaCl and H2O in the proximal tubule of the kidney

Question 22

__ stimulates the release of aldosterone from the adrenal cortex, which ___

Answer 22

1. Angiotensin II

2. Increases NaCl and H2O reabsorption in the collecting ducts of the nephron

Question 23

Functions of vasopressin/ADH

Answer 23

1. Vasoconstriction

2. Increases reabsorption of H2O from the cortical and medullary collecting ducts in the nephron (antidiuretic)

Question 24

When does decompensation occur?

Answer 24

If the pt is not stabilized in time, the compensatory mechanisms begin to fail and then decompensation begins

Question 25

What happens in decompensation?

Answer 25

1. Cardiac failure
2. Vascular failure
3. Metabolic acidosis
4. CNS depression
5. Inappropriate clotting
6. Depression of mononuclear phagocytic system

Question 26

Decompensation:

Cardiac failure

Answer 26

1. Starts as cardiac depression
2. Low arterial pressure leads to low coronary perfusion and not enough O2 to the myocardium
3. Cardiac function is impaired
4. CO falls which further compromises peripheral perfusion

Question 27

Decompensation:

Vascular failure

Answer 27

1. Peripheral vasoconstriction begins to fail
2. relative vasodilation causes peripheral resistance to fall
3. Due to desensitization of alpha 1 receptors resulting in a sympathetic escape

Question 28

Decompensation:

Metabolic acidosis

Answer 28

1. As CO falls, O2 perfusion drops
2. Lactic acid production increases
3. pH decrease consumes bicarbonate resulting in metabolic acidosis
4. Acidosis further depressed cardiac function (- inotropic effect) and causes peripheral vasodilation)

Question 29

What is metabolic acidosis ?

Answer 29

Low HCO3

Question 30

Decompensation:

CNS depression

Answer 30

1. Falling arterial pressure leaders to decreased cerebral blood flow and cerebral hypoxia
2. Sympathetic outflow increases in response (CNS ischemic response)
3. Eventually results in failure of symp. output which then causes pressure to collapse

Question 31

Decompensation:

Clotting

Answer 31

Hypocoagulauon and fibrinolysis

*during the early stages of shock there is hypercoagulation (which can be treated with heparin)

Question 32

Decompensation:

Mononuclear phagocytic system

Answer 32

Endotoxins in the gut flora increase and cause widespread vasodilation, which exacerbates the shock

Question 33

Treatment for shock:

Answer 33

ORDER

1. Oxygen asap
2. Restore circulating volume using crystalloids, colloids, or blood products
3. Drug therapy (inotropic agents: e.g. dopamine, dobutamine)
4. Evaluate response
5. Remedy underlying cause

Question 34

What things must you monitor during shock?

Answer 34

Vitals
Mental status
Urine output
Capillary refill
Electrolyte status
Saturation

Question 35

What systems are affected in late hypovolemic shock but not early?

Answer 35

Hepatic
GI
Metabolic