Shock Overview & Stages of Shock

Question 1

What is shock?

A condition that results from some type of cause that leads to decreased tissue perfusion, which causes cell hypoxia

If the cell hypoxia is severe enough, it’ll cause organ dysfunction (MODS) & eventually lead to death

Answer 1

Cause of shock depends on what type of shock is presenting

Question 2

___ shock

Occurs d/t an allergic reaction

Answer 2

Anaphylactic

Question 3

___ shock

Occurs d/t a severe infection

Answer 3

Septic

Question 4

___ shock

Occurs d/t a weak heart

Answer 4

Cardiogenic

Question 5

___ shock

Occurs d/t severe fluid loss

Answer 5

Hypovolemic

Question 6

___ shock

Occurs d/t severe damage to the neuro system (e.g., spinal injury)

Answer 6

Neurogenic

Question 7

Distributive shock includes which 3 types of shock?

Answer 7

septic
anaphylactic
neurogenic

Question 8

Stages of Shock

• Initial
• Compensatory
• Progressive
• Refractory

Question 9

Initial Stage

✰ CO is low enough to cause the cells to experience ___

Cells switch from aerobic to anaerobic metabolism; the latter will create lactic acid, which’ll accumulate in the blood & lead to lactic acidosis

Answer 9

hypoxia

Question 10

• Decreased tissue perfusion → LOW CO (HR x SV)

Answer 10

• Normally, body can deal w/lactic acid via the liver, but liver is not functioning @ an optimal lvl b/c of the low amt of O2 its cells are receiving

Question 11

• In better circumstances when tissue perfusion is adequate, liver takes lactic acid & converts it to pyruvic acid & then to glucose via gluconeogenesis

! Therefore, lactic acid will start to accumulate in the blood (esp as pt adv to other stages of shock)

Answer 11

• Accumulation of lactic acid causes the blood’s pH lvl to drop (acidosis) & further damages cells

Question 12

Normal serum lactate lvl < ____ mmol/L

Answer 12

1

Question 13

Abnormal indicating lactic acidosis > ____ mmol/L

Answer 13

4

Question 14

Compensatory Stage

✰ Body systems are coming to the rescue; will try to compensate by using hormonal, neural, & biochemical processes in the body

• Will try to fight results of anaerobic metabolism; also, will try to increase CO & BP via stimulation of the SNS & RAS, which’ll increase tissue perfusion

Answer 14

• If the cause of shock is corrected during this stage, it’s REVERSIBLE & pt can make a full recovery; if not, next stage
• Body will succeed @ 1st w/increasing CO & BP via rescue team
• Will result in an increase in tissue perfusion, BUT body is limited on how long it can maintain rescue effort

Question 15

How does the body provide compensation?

• As BP drops, body will sense this (! brain & heart)

1 of the structures to sense this drop in BP is the ____, spec the receptors in the carotid sinus & aortic arch

Will stimulate the SNS to release catecholamines: ___ & ___

Answer 15

baroreceptors

epinephrine; norepinephrine

Question 16

• Catecholamines will cause vasoconstriction
• This’ll result in an increase in BP & HR; when this occurs, there’s an increased perfusion to the vital organs
• Less blood will go to the non-vital organs (GI, renal, skin, lungs) while more will go to the vital organs (heart & brain)

Answer 16

• B/c there was a drop in BP (arterial pressure) there will be a decrease in capillary hydrostatic pressure (the force of pressure the blood creates around the capillary wall)
• If the BP & CO are low, the force of pressure the blood creates around the capillary wall is definitely low

Question 17

• This’ll signal the body to try to increase venous blood flow return by shifting fluid from the interstitial compartment to the intravascular compartment

Answer 17

How are other systems affected & how do they play a role in the compensatory stage?

Question 18

Kidneys

• B/c blood flow is dec to the kidneys they activate the renin-angiotensin system

Answer 18

• Renin stimulates angiotensinogen which creates angiotensin I
• Angiotensin I turns into angiotensin II (a very mighty vasoconstrictor)
• This substance will cause vasoconstriction in both arterial & venous system

Question 19

• Constriction in venous system will lead to more blood return to the heart, & constriction in arterial system will incr BP
• Together, all will lead to an incr in tissue perfusion & the cells will receive more O2

Question 20

Presence of angiotensin II will also trigger the release of ____

Answer 20

aldosterone

Question 21

Aldosterone

• Makes the kidneys keep sodium & water → incr blood volume
• Also, b/c kidneys are incr sodium, it’ll create urine to contain a high amt of sodium, which leads to high osmolality

Answer 21

• High osmolality signals to posterior pituitary gland that body is trying to keep water for some reason, so it releases ADH
• ADH → prevents water from leaving the kidneys; further incr blood volume
• By incr blood volume, CO will be incr along w/tissue perfusion

Question 22

GI

• Perfusion is dec so this system slows down
• Pt is @ risk for paralysis of intestines in a cond called paralytic ileus

Answer 22

Skin

• Perfusion is dec so blood flow is low, which leads the skin to be cold & clammy

! Is not the case during this stage in septic shock → pt’s skin will be hot & flushed d/t vasodilation presenting

Question 23

Lungs

• Perfusion is dec so parts of the lung may not be perfused

! Ventilation & perfusion mismatch & O2 lvls become low in blood

Answer 23

• Will lead pt to hyperventilate

Question 24

Progressive Stage

✰ Rescue effort from prev stage has failed, & body can’t compensate anymore; pt is progressing to MODS

• Is no more compensation in this stage; CO is low, tissue perfusion is low, & cells are NOT receiving O2, which leads to cell hypoxic injury

Answer 24

• Cells will start to swell & CAPILLARY PERMEABILITY is incr

Question 25

Brain

• Cells to the brain aren’t being perfused; MAP is <60 mmHg
• This means cerebral perfusion pressure (CPP) is inadequate to maintain perfusion to brain’s cells

Answer 25

• Will start to see major mental status changes
• Pt will be very slow in their speech, restless, anxious, agitated, & not respond to stimulation

Question 26

Lungs

• ARDS will develop
• This occurs d/t incr capillary permeability in the alveoli sacs (where gas exchange occurs); sacs will collapse d/t fluid surrounding them & lung will lose elasticity

! Will need intubation & mech vent to breathe

Answer 26

• Fluid in the lungs (crackles), incr RR, dec O2 lvl, & resp failure

Question 27

Heart

• Heart cells start to die incl those that play a role in the electrical conduction system of the heart & that help heart contract/pump

! Cardiac dysrhythmias occur along w/death to myocardial tissue

Answer 27

GI

• Gut cells start to die; e.g., cells that protect the lining from its own acid quit working

! Ulcers can develop which can turn into massive GI bleeding (bad b/c clotting abilities are affected d/t liver hypoxia)

Question 28

Liver

• Dec liver perfusion causes cells to die
• Will be a build-up of toxic waste products (e.g., bilirubin, ammonia)

! Risk for infection & bleeding

Question 29

?

Occurs when small clots form in the vessels, further compromising blood flow to organs

Depletes body’s platelets & clotting stores & leads to massive, uncontrollable bleeding

Answer 29

DIC (disseminated intravascular coagulation)

Question 30

____ Stage

• Unmanageable; cannot be reversed; all organs shut down and fail; death inevitable

Answer 30

Refractory