Patient selection: advanced renal disease with GFR < 20 mL per min
Parameters:
(1) creatinine clearance in mL per minute per 1.73 square meter BSA
(2) urea clearance in mL per minute per 1.73 square meter BSA
average of the creatinine and urea clearances =
= ((creatinine clearance) + (urea clearance)) / 2
average of the creatinine and urea clearances =
= (1.034 * (inulin clearance in mL per min per 1.73 square meter BSA)) + 0.24
If this is rearranged:
inulin clearance in Ml per min per 1.73 square meter BSA =
= ((average of creatinine and urea clearances) - 0.24) / 1.034 =
= (0.967 * (average of the creatinine and urea clearances)) - 0.232
Note that Levey et al estimated the GFR from an average of the creatinine and urea clearances in the previous section).
