Carbon dioxide removal using low bicarbonate dialysis in rodents

Extracorporeal carbon dioxide removal may be used to manage hypercapnia, but compared to dialysis, it's not widely available. A recent in vitro study showed that dialysis with low bicarbonate dialysates removes CO₂.

To show that bicarbonate dialysis removes CO₂ in an animal model to validate in-vitro findings and quantify the effect on arterial pH.

Male Sprague-Dawley hypercapnic rats were dialyzed with either a conventional dialysate (Prismasol^TM) or a bicarbonate-free dialysate (Bicarb0). The effect of dialysis on standard blood gases and electrolytes was measured.

Partial pressure of CO₂ and bicarbonate concentration in blood decreased significantly after exposure to Bicarb0 compared to Prismasol^TM (filter outflow values 12.8 vs 81.1 mmHg; p < 0.01 for CO₂ and 3.5 vs 22.0 mmol/L; p < 0.01 for bicarbonate). Total CO₂ content of blood was reduced by 459 mL/L during dialysis with Bicarb0 (filter inflow 546 ± 91 vs filter outflow 87 ± 52 mL/L; p < 0.01), but was not significantly reduced with Prismasol^TM.

Bicarbonate dialysis removes CO₂ at rates comparable to existing low-flow ECCO₂R.