Equations

Question 1

Free water deficit

Answer 1

Free water deficit = (current Na/normal Na – 1) x 0.6 x BW

Question 2

Sodium deficit

Answer 2

Sodium Deficit = (target Na – patient Na) x 0.6 x BW

Question 3

Sodium Bicarb Dose

Answer 3

0.3 x BW x base excess (give 50-80% of dose)

Question 4

Anion Gap

Answer 4

(Na + K) – (HCO3 + Cl)

Question 5

Acid-base: Free water effects

Answer 5

Dog: 0.25 (Na – 145)
Cat: 0.22 (Na – 155)

Question 6

Acid base: chloride effects

Answer 6

Dogs: 110- [Cl x (145/Na)]
Cats: 120- [Cl x (155/Na)]

Question 7

Acid base: TP

Answer 7

Dogs: 3 x (6.5 - TP)
Cats: 3 x (7 - TP)

Question 8

Acid base: Albumin

Answer 8

3.7 x (3.1 - Alb)

Question 9

Acid-base: PO4

Answer 9

0.58 x (4.3 - PO4)

Question 10

Plasma Volume

Answer 10

Plasma volume = (1 – HCT) x BW x blood volume

Question 11

Pseudohyponatremia correction (3 formulas)

Answer 11

Corrected Na = measured Na + 0.016 x (BG – 100)

For every 100 mg/dL glucose  Na decreases by 1.6 mEq/L

Corrected Na = measured Na + 1.6 [(BG-100)/100]

Question 12

Free water clearance (Diabetes insipidus)

Answer 12

CFW = Vu x (1 – (Nau + Ku / Nap)

Question 13

Cerebral perfusion pressure

Answer 13

CPP = MAP – ICP

Question 14

Sensitivity

Answer 14

true positive / (true positive + false negative)

Question 15

Specificity

Answer 15

true negative / (true negative + false positive)

Question 16

Parkland Formula

Answer 16

4 mL x TBSA (%) x BW
(IVF for burn tx - give 1/2 within first 8 hrs; give rest over next 16 hours)

Question 17

Whole Blood administration (3)

Answer 17

2 x PCV rise desired (%) x BW

2 mL WB/kg raises PCV by 1%

~20 mL/kg

Question 18

pRBC administration

Answer 18

= 1.5 x PCV rise desired (%) x BW

= [(desired PCV – actual PCV)/donor unit PCV] x blood volume x BW

Question 19

Pulse Pressure Variation

Answer 19

Pulse pressure variation = 100 X (PPmax- PPmin)/{(PPmax+PPmin)/2}

Question 20

Fractional shortening

Answer 20

(LVIDd – LVIDs)/LVIDd

Question 21

Ejection Fraction

Answer 21

(EDV-ESV) (Х) 100/EDV

Question 22

Fick Equation

Answer 22

(VO2) = CO [CaO2 – CvO2]

Question 23

Pulmonary vascular resistance

Answer 23

= [(Mean PAP – PAOP)/CI]

Question 24

Cardiac index (CI)

Answer 24

CO/BSA

Question 25

Plasma Osmolality

Answer 25

2(Na + K) + (gluc/18) + (BUN/2.8)

Question 26

Albumin deficit

Answer 26

10 x (desired albumin-pt albumin) x weight (kg) x 0.3