Equations for CRT

Estimated 1ml per lb of ideal body weight for V_D

Heart rate X stroke volume

• Mean: 90
• Monitors perfusion
• Normal:120/80

CPP=MAP-ICP

Normal: 70-90

Pack years= # of packs/day x # of years smoked

4 packs a day x 10 years equals 40 pack years

Size= weight in kg divided by 10

Oral: 21-25 cm mark at lip

Nasal: 26-29 cm mark

8.0/2 =4x3 =12 french

(FiO2 x 7) - (PaCO2 + 10)

• 50%= 300 torr
• 100% O2= 600 torr

A-aDO2 = PAO2 - PaO2

CaO2 = (Hb x 1.34 x SaO2) + (PaO2 x .003)

Normal: 17-20%

Good PaO2, good Hb, Good SaO2 then answer is gonna be in high teens

Bad PaO2, Bad Hb, Bad SaO2 then answer is gonna be in low teens

Bad arteriol

CVO2 = (Hb x 1.34 x SVO2) + (PVO2 x .003)

Normal: 14%

C(a-v)O2 = CaO2-CvO2

Normal:4-5%

Calculate the percent shunt when the A-aDO2 is 300 torr and the C(a-v)O2 is 3.6 vol %!

For every 100 on the A-a gradient, add another 5% shunt to normal

Answer is 20%

Total flow=(flow meter setting x factor)

What is the total flow when a venti mask is set at 5 L/min and the dilution control is set at 28%?

• Air/O2 entrainment ratio is 10:1 for 28%
• Total flow factor is 11

5 x 11 = 55 L/min

(Peak pressure- Plateau pressure)/ flow L/sec