Table 4.

Effects of intravenous solutions and urine output on the effective replacement fluid sodium concentration

SolutionRF0.45%Solution ASolution BUO4-Hour Resultsa
Flow rate, L/h2.0Single doseSingle doseSingle dose−0.1
Time, h4.04.04.0
[Na], mM130.077.0154.040.050.0
Volume, L8.−0.408.05
Cation, mmol1040.07.715.410.0−20.01053.1
Eff-NaRF, mMb130.0129.3130.3127.3134.2130.8
  • The replacement fluid is infused simultaneously with three separate solutions as shown, with ongoing urine output. To simplify calculations, the RF-potassium concentration is assumed equal to plasma potassium concentration and not described. RF, replacement fluid with [Na] 130 mM; UO, urine output; [Na], sodium concentration; Eff-NaRF, effective [Na] of RF and one of the solutions listed and/or UO.

  • a Aggregate effect of solutions and urine output on Eff-NaRF.

  • b Isolated effect of each solution or urine output on Eff-NaRF.