Canis ISSN: 2398-2942
Fluid therapy: for acid-base imbalance
Contributor(s): Ken Bovee, John Dodam, Elisa Mazzaferro, Claire Waters
- Generally, it is most important to correct the underlying cause that led to acid-base imbalance Acid base imbalance.
- Normal kidneys will correct mild to moderate acid-base imbalance as long as adequate circulating blood volume is restored.
- pH >7.1’ infusion of crystalloid solution, such as Hartmann's solution, will dilute the acidosis and improve renal perfusion.
- pH <7.1’ bicarbonate infusion may be given. Total MEq NaHCO3 = 0.3 x bodyweight (kg) x base deficit. Give half of this amount slowly, then re-evaluate.
For composition of solutions see the parenteral fluids comparison table Parenteral fluids comparison table.
- If metabolic acidosis is strongly suspected from the clinical history and signs but blood-gas analysis is unavailable, then 1-2 MEq/kg bicarbonate Sodium bicarbonate - may be given slowly.
Bicarbonate administration can be dangerous if unnecessary or too rapid. Side-effects include paradoxical cerebrospinal fluid (CSF) analysis, hypokalemia, overshoot alkalosis and reduced O2 supply to tissues.It is easier to correct acidosis than alkalosis.
- Metabolic acidosis may be corrected rapidly by ECF expansion with 0.9% NaCl.
- Administration of chloride - encourages renal excretion of bicarbonate ion.
- Concurrent hypokalemia is common and should be corrected by supplementing fluids with KCl.