VGH CKRT Sodium Kinetics Tool (Nass) v1.0

Assumptions: CVVHDF (Na sieving ≈ 1). Dialysate is treated as post-dilution equivalent. Net fluid balance = 0. Time-course: Na(t) = Nass + (Na₀ − Nass)·e^−kt, where k = K/Vd and K = Qe·Qp/(Qp + Qpre + Qpbp).

① Patient profile

Initial serum Na₀ (mmol/L)

Sex

Age (yr)

Height (cm)

Body weight (kg)

② Blood flow

Qb (mL/min) Hct (%)

③ PBP

PBP fluid preset

[Na]pbp (mmol/L) — manual override Qpbp (mL/hr)

④ Replacement

Replacement preset

[Na]rep (mmol/L)

Qrep (mL/hr)

Pre-dilution (%)

⑤ Dialysate

Dialysate preset

[Na]d (mmol/L) Qd (mL/hr)

⑥ IV infusion (post-circuit)

IV fluid preset (post-circuit)

[Na]iv (mmol/L) — manual override Qiv (mL/hr)

Results

Time slider (0–48 hrs)

t = 0.0 hr ｜ Na(t) = — mmol/L