Formulas

Question 1

SVR

Answer 1

{( MAP - CVP ) / CO } x 80

Question 2

Alveolar Gas Equation

Answer 2

PAO2 = [( Patm - PH2O ) x FiO2 ] - ( PACO2 / R )

Question 3

Adult oxygen consumption

Answer 3

3-4 mL/kg/min

Question 4

FRC (healthy adult)

Answer 4

30 mL/kg

Question 5

Oxygen Delivery (DO2)

Answer 5

CO x CaO2

CaO2 = arterial oxygen content

Question 6

Arterial Oxygen Content (CaO2)

Answer 6

( SaO2 x Hb x 1.34 ) + ( 0.003 x PaO2 )

Question 7

Maximum allowable blood loss

Answer 7

[ EBV x ( starting Hct - target Hct )] / ( starting Hct )

where adult male EBV = 65-60 mL/kg

Question 8

Coronary Perfusion Pressure (CPP)

Answer 8

AoDP - LVEDP

Question 9

Anatomical Dead Space

Answer 9

2 mL/kg

Question 10

Poiseuille’s Law (resistance to flow)

Answer 10

R = ( 8 nl ) ÷ ( π r^4 )

R = resistance
n = viscosity
l = length
r = radius 
* assuming laminar flow

Question 11

Estimated Blood Volume

Answer 11

Adult Female: 60-65 mL/kg
Adult Male: 65-70 mL/kg
Child 1-12 y: 70-75 mL/kg
Infant 3-12 m: 70-80 mL/kg
Newborn: 80-90 mL/kg
Premature infant: 90-105 mL/kg

Question 12

LaPlace Law

Answer 12

P = 2T / R

the pressure (P) necessary to keep a sphere (alveolus) open is proportional to the surface tension (T) and inversely proportional to the radius (R) of the sphere

Applies to premature lungs (surfactant deficiency) and cardiac work

Question 13

Cole Formula

Pediatric ETT size

Answer 13

internal diameter of uncuffed ETT = (Age / 4) + 4

Question 14

Cardiac Output

Answer 14

CO = SV x HR