Equations

Question 1

Flow, Pressure, Resistance

Answer 1

Q = delta P/ R R = delta P/ Q Q = cardiac output R = PVR, SVR

Question 2

Resistance

Answer 2

R = 8nl/ pie r^4

n = viscosity

l= length

r = radius

Increase resistance:

• increased viscosity
• increased length
• decreased radius

Question 3

ETT Size

Answer 3

Age/4 + 4

0.5 size lower for cETT (Age/4 +3.5)

Age+16/4

NICU

<1000g 2.5, blade 0

1000-2000g 3.0, blade 0

2-3kg 3.5, blade 0

>3kg 3.5-4, blade 1

Question 4

ETT Depth

Answer 4

3xsize

Age+10

Question 5

CO

Answer 5

CO = HR x SV

Preload

Afterload

Contractility

Question 6

Ohm’s Law Applied

V = I x R

V = voltage

I = current

R = resistance

Answer 6

delta P = Q x R

deltaP/R = Q

delatP/Q = R

Q = flow, cardiac output

R = resistance, SVR or PVR