In Japan, Shinzato’s fomula for calculating Kt/V, an indicator of efficiency of dialysis, is recommended by JSDT. Since integral equation is used to solve Shinzato’s method, you couldn’t solve algebraically. In K/DOQQI, it is usual to solve Kt/V with Daugirdas’ method. Shinzato has described that Daugirdas’ Kt/V is similar to Shinzato’s Kt/V.
![\displaystyle \mathrm{Kt/V} = - LN( R - 0.08 \times t ) + \left[ 4 - \left( 3.5 \times R \right) \right] \times\frac{\mathrm{UF}}{\mathrm{W}}\\ = - LN \left( \frac{\mathrm{postBUN}}{\mathrm{preBUN}} - 0.008 \times t \right) + \left[ 4 - \left( 3.5 \times \frac{\mathrm{postBUN}}{\mathrm{preBUN}} \right) \right] \times \frac{\mathrm{preWeight} - \mathrm{postWeight}}{\mathrm{postWeight}} \cdots(1)](https://s0.wp.com/latex.php?latex=%5Cdisplaystyle+%5Cmathrm%7BKt%2FV%7D+%3D+-+LN%28+R+-+0.08+%5Ctimes+t+%29+%2B+%5Cleft%5B+4+-+%5Cleft%28+3.5+%5Ctimes+R+%5Cright%29+%5Cright%5D+%5Ctimes%5Cfrac%7B%5Cmathrm%7BUF%7D%7D%7B%5Cmathrm%7BW%7D%7D%5C%5C++%3D+-+LN+%5Cleft%28+%5Cfrac%7B%5Cmathrm%7BpostBUN%7D%7D%7B%5Cmathrm%7BpreBUN%7D%7D+-+0.008+%5Ctimes+t+%5Cright%29+%2B+%5Cleft%5B+4+-+%5Cleft%28+3.5+%5Ctimes+%5Cfrac%7B%5Cmathrm%7BpostBUN%7D%7D%7B%5Cmathrm%7BpreBUN%7D%7D+%5Cright%29+%5Cright%5D+%5Ctimes+%5Cfrac%7B%5Cmathrm%7BpreWeight%7D+-+%5Cmathrm%7BpostWeight%7D%7D%7B%5Cmathrm%7BpostWeight%7D%7D+%5Ccdots%281%29&bg=T&fg=000000&s=0 "\displaystyle \mathrm{Kt/V} = - LN( R - 0.08 \times t ) + \left[ 4 - \left( 3.5 \times R \right) \right] \times\frac{\mathrm{UF}}{\mathrm{W}}\\ = - LN \left( \frac{\mathrm{postBUN}}{\mathrm{preBUN}} - 0.008 \times t \right) + \left[ 4 - \left( 3.5 \times \frac{\mathrm{postBUN}}{\mathrm{preBUN}} \right) \right] \times \frac{\mathrm{preWeight} - \mathrm{postWeight}}{\mathrm{postWeight}} \cdots(1)")
![\displaystyle \mathrm{Ce} = \mathrm{Cs} Exp\left( - \frac{\mathrm{Kt}}{\mathrm{V}} \right) + \frac{\mathrm{G}}{\mathrm{K}}\left[ 1 - Exp\left( - \frac{\mathrm{Kt}}{\mathrm{V}} \right) \right] \cdots(3)](https://s0.wp.com/latex.php?latex=%5Cdisplaystyle+%5Cmathrm%7BCe%7D+%3D+%5Cmathrm%7BCs%7D+Exp%5Cleft%28+-+%5Cfrac%7B%5Cmathrm%7BKt%7D%7D%7B%5Cmathrm%7BV%7D%7D+%5Cright%29+%2B+%5Cfrac%7B%5Cmathrm%7BG%7D%7D%7B%5Cmathrm%7BK%7D%7D%5Cleft%5B+1+-+Exp%5Cleft%28+-+%5Cfrac%7B%5Cmathrm%7BKt%7D%7D%7B%5Cmathrm%7BV%7D%7D+%5Cright%29+%5Cright%5D+%5Ccdots%283%29&bg=T&fg=000000&s=0 "\displaystyle \mathrm{Ce} = \mathrm{Cs} Exp\left( - \frac{\mathrm{Kt}}{\mathrm{V}} \right) + \frac{\mathrm{G}}{\mathrm{K}}\left[ 1 - Exp\left( - \frac{\mathrm{Kt}}{\mathrm{V}} \right) \right] \cdots(3)")
Execute the procedure as following;
CREATE FUNCTION Function_KtV ( @preBUN DEC(4, 1) , @postBUN DEC(4, 1) , @preWeight DEC(4, 1) , @postWeight DEC(4, 1) , @DialysisDuration int ) RETURNS DEC(3,2) AS BEGIN DECLARE @KtV DEC(3, 2) SELECT @KtV = - LOG(@postBUN / @preBUN - 0.008 * @DialysisDuration / 60) + (4 - (3.5 * @postBUN / @preBUN)) * ((@preWeight - @postWeight) / @postWeight) RETURN @KtV END GO
References: JSDT 29 (12): 1511-1516, 1996
Second Generation Logarithmic Estimates of Single-Pool Variable Volume
