Fluids

Question 1

Normal Osmolality of a huma

Answer 1

280 - 290 MOSM

Question 2

Normal Saline: osmaolarity and E-lyte concentrations

Answer 2

OSM: 308 mOsmL
Na+: 154 meq
Cl: 154 meq

Question 3

Ringers lactate: osmaolarity and E-lyte concentrations

Answer 3

OSM: 274 mOsmL
Na+: 130
K+: 4
Cl: 109
Lactate: 28

Question 4

Plasmalyte : osmaolarity and E-lyte concentrations

Answer 4

OSM: 295 mOsmL
Na+: 140
K+: 5
Cl: 98
Acetate: 27

Question 5

D5: osmaolarity and E-lyte concentrations

Answer 5

OSM: 252 mOsmL
Glucose: 5%

Question 6

Albumin 5%: osmaolarity and E-lyte concentrations

Answer 6

OSM: 330 mOsmL
Na+: 145 +/-15
K+: <2.5
Cl: 100

Question 7

Hetastarch 6%: osmaolarity and E-lyte concentrations

Answer 7

OSM: 310 mOsmL
Na+: 154
Cl: 154

Question 8

What are the two fluids closest to physiological fluid balances?

Answer 8

Plasmalyte and LR

Question 9

Drawbacks of fluid recessitating with crystalloids

Answer 9

• Tissue edema (lungs, soft tissues, gut)
• Hypercoagulable (clotting factors are diluted)

Question 10

Drawback of fluid resusitating with NS

Answer 10

• Dilutes HCT
• Dilutes albumin
• Increases K and Cl
• hyperchloremic metabolic acidosis
• increased risk of AKI and RRT in critical care pts

Question 11

Lactated ringers is a good choice except in what pathology? why?

Answer 11

Good unless pt has liver failure. Lactate is added as a buffer, but lactate relies on hepatic metabolism
- liver failure causes elevated lactate already - this can build up even more

Question 12

Effects of colloids

Answer 12

• Increased CO because of increased plasma volume expansion
• Causes hemodilution (decreases plasma viscosity, and inhibits RBC aggregation)
• Uncertain immune, coag, and renal effects

Question 13

Hydroxyethyl starch effects

Answer 13

• Derived from potato or maiz
• Renal dysfunction
• Can cause coagulopathy
  
  • VWF, Factor VIII, and clot strength become compromised

Question 14

What are Dextrans primarily used for?

Answer 14

Microvascular surgery
- inhibits factor VIII, VWF, and platelet aggregation
- coats RBC - may interfere with cross matching

Question 15

Signs of low intravascular volume during anesthesia

Answer 15

• tachycardia
• decreased pulse pressure
• hypotension
• decreased cap. refill
• decreased UOP
• low CVP

Question 16

Signs of high intravascular volume during anesthesia

Answer 16

• Excess fluid in lungs, bowel, muscle
• decreased gut motility
• reduced tissue oxygenation
• coag changes (could be hypo or hyper)

Question 17

Classic fluid administration equation for NPO maintanence

Answer 17

4,2,1 rule:
- 1st 10kg = 4mL/Kg/hr
- 2nd 10kg = 2mL/kg/hr
- each 1kg additional = 1mL/kg/hr

Question 18

How do you replace the fluid deficit?

Answer 18

1/2 the total fluid in the 1st hour of surgery
1/4 in the 2nd hour
1/4 in the 3rd hour

Question 19

How much blood can a lap sponge, raytech, and 4x4s hold?

Answer 19

• Lap sponge: 100mL
• Raytech: 20mL
• 4x4: 10mL

Question 20

Parkland burn formula

Answer 20

4mL/kg/%BSA
- 1/2 total volume in 8 hours
- other 1/2 the next 16 hours

Question 21

We are moving away from the 4,2,1 equation and doing what instead?

Answer 21

Goal directed therapy:
- keep CO at a level that delivers the apropriate amounts of O2 to the tissues

Question 22

Limitations on SVV mechanics for goal directed fluid therapy

Answer 22

LIMITS
- Low HR/RR (must have normal HR)
- Irregular heart beats (must have normal rhythm)
- Mechanical ventilation (with low Vt) (must have normal vent pattern)
- Increased abd pressure (muct have normal IAP)
- Thorax open (chest must be closed)
- Spontaneous breathing

Question 23

Types of monitoring for fluid status

Answer 23

• SPV: looks at max systolic apex minus the minimum systolic pressure over the cycle of a mechanical breath (high peak - low peak)
• PP: subtracting high and low
• SVV: area under the curve (variation of SV in 30sec)
  
  • 10-15% difference = normal sono treating with fluid
  • use inotropes or vasoconstriction
  • > 15% fluid bolus of 250cc