Hypovolemic Shock

Question 1

• Occurs when there is LOW fluid volume in the intravascular system
• Intravascular system is the space that contains the volume of blood in a person’s circulatory system
• Therefore, if there’s a dec in the vol of blood in a person’s circulatory system, heart has hardly anything to pump at all!

Answer 1

If amt of blood heart pumps to organs & tissues ↓, CO ↓, leading to ↓ tissue perfusion which will alter function of cells, limiting their access to O2 & s/s shock will occur

Question 2

A person needs to lose about ___% or MORE of their intravascular volume for hypovolemic shock to occur

• Avg human blood vol is 5L

Answer 2

15

Question 3

What can lead to a loss of fluid vol in the intravascular system?

Answer 3

Any cond that leads to fluid leaving the body externally or there is shifting of fluid within the body that leaves the intravascular space

Question 4

?

Is an INSIDE fluid shift from the intravascular system (tends to be more concealed)

Answer 4

Relative hypovolemic shock

Question 5

! Fluids or blood collecting or leaking inside the body from internal bleeding

! 3rd spacing of fluid (severe burns d/t incr capillary permeability)

! Fx of long bones

Answer 5

! Damage to organs like the pancreas (e.g., Cullen & Grey Turner signs)

! Massive vasodilation from septic shock

Question 6

?

Is an OUTSIDE fluid shift from the intravascular system that leaves the body (tends to be more noticeable)

Answer 6

Absolute hypovolemic shock

Question 7

! Massive bleeding from injury or surgery

Answer 7

! Excessive fluid loss from oral (vomiting), GI (diarrhea), GU (urine), skin (sweating)… many times this is c/b a dz process (diabetes or endocrine disorders) or illnesses

Question 8

Pathophysiology: What is happening in hypovolemic shock?

• Is major depletion of volume in the intravascular system (relative or absolute cause) → this dec the amt of venous return to the heart (amt of blood draining back to heart) → this dec preload (amt ventricles stretch once they’re filled w/blood); won’t be stretching much b/c there isn’t much fluid to fill them

Answer 8

→ this dec SV (amt of blood pumped by the LV w/each beat) → this dec CO (amt of blood heart pumps/min), 4-8L/min; CO = HR x SV

Question 9

• Body will attempt to compensate by activating the ____, which will trigger the body’s built-in survival system
• Now, based on % of fluid volume that’s lost will determine the s/s the pt may present w/ & what stage the pt is likely in

Answer 9

sympathetic nervous system (SNS)

Question 10

• Hypovolemic shock can be divided into 4 stages or classes that are based on the % of fluid volume loss

Answer 10

Remember the #’s

15%
15-30%
30-40%
40%

&

what’s happening to BP, HR, u/o, mental status, & the skin

Question 11

Class I: < ___% volume loss… up to 750 mL in an adult

• Body can maintain CO w/this vol loss; pt mainly asymptomatic w/this class
• HR WNL (<100 bpm)
• BP, RR WNL
• Skin pink, warm, & cap refill normal (<2 sec)
• Normal u/o (>30 mL/hr)
• Mental status normal; may be a little anxious

Answer 11

15

Question 12

Class II: ___-___% volume loss… 750-1500 mL in an adult

• CO starting to fall d/t vol loss
• Major body system compensation via SNS, RAS, & shunting of blood to vital organs
• HR incr (>100 bpm)
• BP dec but WNL (for now d/t vasoconstriction)
• RR incr (mild) d/t low O2 lvl in body
• u/o start to lwr (20-30 mL/hr); blood flow shunted & body will start to keep water from aldosterone & ADH being released d/t angiotensin II
• Skin cool, clammy, incr cap refill >2 sec, blood flow diverted to vital organs
• Diminished peripheral pulses
• Mental status: mild anxiety

Answer 12

15-30

Question 13

Class III: ___-___% volume loss… 1500-2000 mL in an adult

• Body cannot compensate & CO falls such that tissue perfusion is altered, which causes the cells that make up organs to malfunction [heart, liver, lungs, kidneys, brain, etc.]
• Sig tachy (>120 bpm)
• RR incr… prog to resp fail
• Hypotension
• Oliguria (<30 mL/hr)… renal failure… HIGH bun/creat
• Poor peripheral pulses
• Skin very cool, mottled, cap refill >2 sec
• Mental status: very anxious & confused… acidosis, low O2, low perfusion to brain

Answer 13

30-40

Question 14

Class IV: >___% volume loss… >2000 mL in an adult

• Death is very near needing dynamic treatment; body is shutting down & fluid loss is severe
• Sig tachy (>140 bpm)
• Resp fail
• Severe hypotension
• Anuria (no urine production)
• Mental status: lifeless, coma

Answer 14

40

Question 15

s/s Hypovolemic Shock

• Depends on the % of volume loss, but

tachycardia, hypotension, cool/clammy skin, weak peripheral pulses, anxiety, decreased u/o

central venous pressure & PAWP/PCWP: low

Answer 15

Nursing Interventions for Hypovolemic Shock

Treatment goals -
✔️ fluid resuscitation - correct underlying cause that’s leading to the fluid loss
e.g., hemorrhaging → surgery

Question 16

→ Monitor oxygenation & perfusion

→ Monitor BP, HR/rhythm, tissue perfusion to organs, mental status, u/o (will need catheter insertion to closely monitor u/o; needs to be >30mL/hr)

→ If bleeding, hold firm, direct pressure

Answer 16

→ If showing s/s, place in modified Trendelenburg position (feet @ 45° & head flat) [inc venous return to heart & CO]

→ Obtain IV access (@ least 2 IV sites that’re large)
- needed for rapid fluid delivery & other rx’s
* many pts w/severe hypovolemic shock (esp ones who are not responding to fluid treatment) will have a central line & hemodynamic monitoring to monitor CO & fluid replacement

Question 17

→ Labs
Hgb/Hct (blood lvl)
Lactate lvl (status of cell’s metabolism)
Blood gases (? acidosis)
Electrolytes, bun, creat

Answer 17

→ Severe hypovolemic shock: CVP (low) & PAWP/PCWP (low)

Question 18

Fluids for Hypovolemic Shock

___ and ___ solutions are 2 types of volume expanders used in hypovolemic shock: varies depending on the pt’s status & vol loss

Answer 18

crystalloids; colloids

Question 19

Crystalloids

Normal saline or Lactated Ringer’s

• Isotonic fluids that will add more fluid to the intravascular system → inc preload, SV, & CO
• Most commonly started out on a crystalloid solution

Answer 19

! Watch for fluid vol overload
> If in fluid overload, hemodynamic monitoring may show elevated CVP or PAWP/PCWP

> Auscultate for fluid in lungs (crackles)

> Edema, JVD

Question 20

Remember the 3:1 rule for crystalloid solutions:

For every 1 mL of approx blood loss, 3 mL of crystalloid solution is given

Answer 20

Crystalloid solutions are able to diffuse through capillary wall, so there’s less fluid that remains in the intravascular space compared to colloid solutions

Question 21

Colloids

Albumin, Hetastarch

• Made up of large molecules (e.g., proteins) that can’t diffuse through the capillary wall so more fluid stays in the intravascular space for longer

! More expensive
! Pt can have an anaphylactic rxn
! Monitor for fluid overload

Answer 21

If giving large amt of fluids, need to WARM them

Why? If not warmed, can lead to hypothermia, & this will alter clotting enzymes, keep pt warm, but not to point of sweating

Question 22

Blood & Blood Products: PRBCs, Platelets, or FFP

! Monitor for transfusion rxn w/these products !

Question 23

?

Used for when the pt needs clotting factors

Answer 23

Fresh Frozen Plasma (FFP)

Question 24

?

Helps replace fluid & provides the pt w/Hgb, which will carry O2 to deprived cells (crystalloids & colloids CAN’T do this)

These types of fluid may be used when the pt is not responding to crystalloid fluid challenge, experiencing severe bleeding/severe hypovolemic shock, etc.

Answer 24

Packed Red Blood Cells (PRBCs)

Question 25

?

Used for uncontrolled bleeding to help w/thrombocytopenia

Answer 25

Platelets