Equation Review Flashcards
(32 cards)
volume of distribution
Vd = amount of drug in body/plasma drug concentration
half-life
t1/2 = 0.7*Vd/CL
drug clearance
CL = rate of elimination of drug/plasma drug concentration = Vd*Ke(elimination constant)
loading dose
LD = Cp*Vd/F
maintenance dose
D = CpCLt/F
sensitivity
sensitivity = TP/(TP+FN)
specificity
specificity = TN/(TN+FP)
positive predictive value
PPV = TP/(TP+FP)
negative predictive value
NPV = TN/(FN+TN)
odds ratio
OR = a/c / b/d = ad/bc
relative risk
RR=a/(a+b) / c/(c+d)
attributable risk
AR = a/(a+b) - c/(c+d)
relative risk reduction
RRR = 1-RR
absolute risk reduction
ARR = c/(c+d) - a/(a+b)
number needed to treat
NNT = 1/ARR
number needed to harm
NNH = 1/AR
cardiac output
CO = rate of O2 consumption/(arterial O2 - venous O2)
CO = SV * HR
mean arterial pressure
MAP = CO * TPR
MAP = 2/3 diastolic + 1/3 systolic
ejection fraction
EF = SV/EDV = (EDV-ESV)/EDV
resistance
resistance = driving pressure/flow = viscositylength/pir^4
stroke volume
SV = EDV - ESV
capillary fluid exchange
Jv = net fluid flow = Kf[(Pc-Pi)-(pic-pii)]
renal clearance
Cx = Ux*V/Px
glomerular filtration rate
GFR = Uinulin*V/Pinulin = Cinulin
GFR = Kf[(Pgc-Pbs) - (pigc-pibs)]
