Case A: Cr
. Effect of changing glomerular filtration rate (GFR) on calculated plasma creatinine is shown. (a) Plasma creatinine. Open circles represent measured plasma creatinine concentrations, and solid grey lines represent modeled plasma creatinine concentrations according to respective GFR decreases of 65%, 70%, 75%, and 85%. The dotted black line represents the best-fit modeled plasma creatinine that results from step changes in GFR shown at the bottom of panel (a) (right axis). The solid black line represents the best fit taking into account a loss of creatinine production, assumed to be the same as the median loss modeled for the Crdecrease group (Figure 4b), in addition to changes in GFR. This suggests that the measured creatinine values can be explained by an immediate 90% decrease in GFR followed by two step increases of approximately 15% in GFR with an initial decrease in creatinine production of 25%. (b) Measured fluid input (shaded area), measured urine output (solid line), and calculated plasma volume (dashed line). The rate of fluid input initially exceeded urine output, resulting in increases in total body water and in plasma volume. Plasma volume returned to normal toward the end of this period. Crincrease, group of patients with a plasma creatinine increase of more than 20% at 24 hours after cardiac arrest.