30 terms

# respiratory math

###### PLAY
LUNG COMPLIANCE
Plat-Peep / Vt
Currant Rate * Currant PaCo2 / Desired PaCo2
DESIRED VE
Currant PaCo2 * VE / Desired PaCo2
DESIRED VENT RATE
Desired Vent Rate * Currant Vent Rate / VE
ALVEOLAR MINUTE VENTILATION
(Vt- VD) RR
MINUTE VENTILATION
Vt * RR / 1000
VENT TUBING CALCULATION
Volume / Pressure
PF RATIO
PaO2 / Fio2
ALVEOLAR AIR EQUATION
Fio2(Bp-47) - (Paco2 * CF)
Bp= 760
CF= 1.25 for and
PAo2-Pa02
V/Q SHUNT
IDEAL BODY WEIGHT
MALE: 50kg for first 60" then add 2.3kg/inch over
BABE: 45kg for first 60" then add 2.3 kg/imch over
TO CHANGE PH IMMEDIATLY, WHAT LEVEL DP YOU CHANGE PaCO2
Desired PH-Currant PH then divide answer by .008
VENT SETTING FOR VE
Middle of Vt * Vent Rate
CYCLE TIME
Divide Cylce time into 60 to get Rate
E CYLINDER
E Cylinder= 2200psi
Psi * .28 / Liters / Minute
Remember there is the safety of 500psi to subtract from the 2200
PaCo2-PeCo2 / PaCo2
ARTERIAL OXYGEN CONTENT
(Sao2 Hb 1.34) + (Po2 * 0.003ml)
RAW
PIP-Plat/ Flow Rate, Then take Flow rate and divide into 60.
VT CORRECTION FOR UNCOMPENSATED VENT
VT - ( TF * [pip - peep]
TF= 3
WEIGHT TO KG
wt / 2.2 8 12
8 and 12 are NBRC Guidelines
KG TO POUNDS
multiply by 2.2
POUNDS TO KG
Divide by 2.2
FiO2
Air L/minute
O2L/minute
RA= .21 medical air= .21
(step one) Multiply .21 by Air L/m then add O2 L/m to that. (step 2) Add the original Air and O2 together. Take that anwer and divide it in to the Multiplied answer that was first done (step one)
LIQUID O2
(cylinder full - cylinder empty)* 860L/KG
LIQUID WEIGHT OF O2
344 is the constant
Multiply the constant by the weight then divide by the liter flow. Take that answer and divide by 60 to get liters/hours
GAS
Done in minutes
Liquid
done in hours
INSPIRATORY TIME
60 seconds in one minute = the constant
1. Rate divided by 60
2. Add I:E Ratio together (1:3= 1+3=4)
3. Divide the answers together to get inspiratory time
EXPIRATORY TIME
Take E time from the I:E Ratio and multiply it by the inspiratory time