Serum Creatinine Modeling

Renal Function Change Simulation

Enter demographics, an initial SCr (mg/dL), and a CrCl change factor (0.25–4× the initial Cockcroft-Gault CrCl). The change in renal functon is assumed to have occurred before or up to the time of the initial measurement. SCr is then projected from 0 to 120 hours using: 

SCr(t) = SCr0·exp(-k·t) + 0.1 · Ratein · (1 - exp(-k·t)) / CL

where  Vd = 0.6 · LBW   (L)
       k   = CL / Vd   (1/hr)
       CL  = (initial CrCl × factor) × 60 / 1000   (L/hr)
       Ratein (adult) = (28 - 0.2·age) · LBW / 24   (mg/hr;  ×0.85 for female)

The age, sex, weight, and height entered below are also used by the Inputs card to compute LBW, BSA, and Cockcroft-Gault CrCl.

Range: 0.5–10 mg/dL
Range: 0.25–4 (e.g., 0.5 = halved CrCl, 2.0 = doubled CrCl)

Enter up to five (SCr, time) pairs and visualize the calculated creatinine clearance (CrCl, mL/min) across time under each of the four Renal Function Models used by this application. The first measurement is fixed at t = 0 hr. SCr range: 0.5–10 mg/dL. Demographics are taken from the Renal Function Change Simulation card above.

Inputs — Serum Creatinine Measurements

SCr range: 0.5–10 mg/dL. Time is in hours relative to t = 0. Pair #1 is required at t = 0 hr. Pairs #2–#5 are optional; at least one additional pair is recommended to compare the unstable algorithms.

Fixed at 0 (anchor point)
References
  1. Chow MS, Schweizer R. Estimation of renal creatinine clearance in patients with unstable serum creatinine concentrations: comparison of multiple methods. Drug Intell Clin Pharm. 1985;19(5):385–390. doi:10.1177/106002808501900513