Acid-base balance disturbances in plasma exchange depend on the replacement fluid used.
BACKGROUND
Metabolic alkalosis occurs as a direct result of plasma exchange (PE) because of metabolism of citrate. However, we observed a decrease of serum pH and bicarbonate after PE when albumin was used as replacement fluid.


METHODS
The acid-base balance in 2730 PEs using different replacement fluids (albumin, fresh-frozen plasma [FFP], or both) was measured, and absolute changes (Δ) in acid-base balance were compared. The frequency of adverse effects (AEs) before and after using prophylactic administration of sodium bicarbonate was compared.


RESULTS
A decrease of serum pH and bicarbonate was observed after PEs when albumin was used as replacement fluid (Δ pH = -0.06 ± 0.04; Δ bicarbonate = -4.03 ± 2.29 mmol/L; Δ base excess = -2.54 ± 3.82 mmol/L). An increase of serum pH and bicarbonate was observed after PEs when FFP was used as replacement fluid (Δ pH = +0.04 ± 0.05; Δ bicarbonate = +3.6 ± 3.68 mmol/L; Δ base excess = +1.62 ± 4.51 mmol/L). The prophylactic administration of sodium bicarbonate corrected partially the decrease of serum pH and bicarbonate after finishing PEs when albumin was used as replacement fluid (Δ pH = -0.04 ± 0.04; Δ bicarbonate = -3.1 ± 2.47 mmol/L; Δ base excess = -3.35 ± 3.06 mmol/L). The frequency of AEs after using prophylactic administration of sodium bicarbonate was lower in comparison with the frequency of AEs before using prophylactic administration of sodium bicarbonate (2.0% vs. 4.8%; p < 0.001).


CONCLUSIONS
A decrease of serum pH and bicarbonate appeared in patients after PEs when albumin was used as replacement fluid; it was corrected partially with prophylactic administration of sodium bicarbonate, and it was associated with fewer AEs.
Apheresis Unit, Department of Hemotherapy and Hemostasis, CDB, IDIBAPS, Hospital Clínic, University de Barcelona, Barcelona, Spain.
Joan
J
Cid
Apheresis Unit, Department of Hemotherapy and Hemostasis, CDB, IDIBAPS, Hospital Clínic, University de Barcelona, Barcelona, Spain.
Gloria
G
Carbassé
Apheresis Unit, Department of Hemotherapy and Hemostasis, CDB, IDIBAPS, Hospital Clínic, University de Barcelona, Barcelona, Spain.
Montse
M
Gamir
Apheresis Unit, Department of Hemotherapy and Hemostasis, CDB, IDIBAPS, Hospital Clínic, University de Barcelona, Barcelona, Spain.
María
M
Jiménez
Apheresis Unit, Department of Hemotherapy and Hemostasis, CDB, IDIBAPS, Hospital Clínic, University de Barcelona, Barcelona, Spain.
Eduardo
E
Arellano-Rodrigo
Apheresis Unit, Department of Hemotherapy and Hemostasis, CDB, IDIBAPS, Hospital Clínic, University de Barcelona, Barcelona, Spain.
Miguel
M
Lozano
D000136:Acid-Base Equilibrium; D001639:Bicarbonates / Q000097:blood; D019343:Citric Acid / Q000009:adverse effects; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D010951:Plasma Exchange / Q000009:adverse effects*; D012189:Retrospective Studies
D001639:Bicarbonates; D019343:Citric Acid