Equations Flashcards
sensitivity
TP/(TP+FN)
specificity
TN/(TN+FP)
PPV
TP/(TP+FP)
NPV
TN/(FN+TN)
odds ratio (case control)
(a/c)/(b/d) = ad/bc
relative risk
(a/(a+b))/(c/(c+d))
attributable risk
a/(a+b) - c/(c+d)
NNT
1/absolute risk reduction
NNH
1/attributable risk
hardy-weinberg equilibrium
p^2+2pq+q^2 = 1
p + q = 1
volume of distribution
amount of drug in body/plasma drug concentration
half-life
(0.693xvolume of distribution)/clearance
clearance
rate of elimination of drug/plasma drug concentration
= Vd x Ke (elimination constant)
loading dose
(Cp x Vd)/F
maintenance dose
(Cp x CL x tau)/F
CO
CO = SV x HR CO = rate of O2 consumption/(arterial O2 content - venous O2 content)
MAP
MAP = CO x TPR MAP = 2/3DBP + 1/3SBP
EF
EF = SV/EDV = (EDV-ESV)/EDV
Resistance
R = deltaP/Q
Renal clearance
Cx = UxV/Px
GFR
GFR = Uinulin x V/Pinulin = Cinulin
Effective renal plasma flow
ERPF = Upah x V/Ppah = Cpah
Renal blood flow
RBF = RPF/(1 - Hct)
Filtration fraction
FF = GFR/RPF
HH equation
pH = 6.1 + log [HCO3-]/0.03Pco2
Winters formula
Pco2 =1.5 [HCO3-] + 8 +/- 2
physiologic dead space
VD = TV x (Paco2 - Peco2)/Paco2
pulmonary vasc resistance
PVR = (pulm arterial pressure - left atrial pressure)/CO
alveolar gas equation
PAO2 = PIO2 - PaCO2/R
