4 - Normal Lung Values and Formulas

normal range for PEP

< 160 cmH₂O

normal range for VC

65-75 mL/kg IBW

normal range for V_T

5-8 mL/kg IBW

normal range for RR/f

8-20 b/min

normal range for C_stat

60-100 mL/cmH₂O

normal range for V_E

5-10 L/min

normal range for P_A-aO₂

3-30 mmHg

normal range for P_aO₂/P_AO₂

≥ 75%

normal range for P_aO₂/F_iO₂

≥ 475

normal range for Q_S/Q_T

< 5%

normal range for RVR

< 100

P_AO₂ formula

\left\lbrack F_{i}O_2\left(P_{B}-PH_2O\right)\right\rbrack-\left(\frac{P_{a}CO_2}{0.8}\right)

IBW formula for males

106+6\left(in.-60\right)

(Answer in lb. For kg, ÷ 2.2)

IBW formula for females

105+5\left(in.-60\right)

(Answer in lb. For kg, ÷ 2.2)

i-time formula

\frac{V_{T}}{\cdot V}

desired F_iO₂ formula

\frac{F_{i}O_2\left(current\right)\cdot P_{a}O_2\left(desired\right)}{P_{a}O_2\left(current\right)}

desired V_T formula

\frac{V_{T}\left(current\right)\cdot P_{a}CO_2\left(current\right)}{P_{a}CO_2\left(desired\right)}

desired RR/f formula

\frac{RR\left(current\right)\cdot P_{a}CO_2\left(current\right)}{P_{a}CO_2\left(desired\right)}

maximum O₂ transport formula

C.O.\cdot C_{a}O_2

arterial O₂ content (C_aO₂) formula

\left(S_{a}O_2\cdot1.34\cdot Hb\right)+\left(P_{a}O_2\cdot0.003\right)

rate-volume ratio (RVR) formula

\frac{RR}{V_{T}\left(L\right)}