Features of an alternative hemodialysis method using a hemoconcentrator during cardiopulmonary bypass surgeries

This study clarified the features of a hemoconcentrator-based, alternative hemodialysis (ALTHD) method that improves the speed of serum potassium (K(+)) concentration adjustments, compared with dilutional ultrafiltration (DUF), during cardiopulmonary bypasses.

Standardized bovine blood was recirculated (300 ml/min) through an in vitro hemoconcentrator circuit; hematocrit, K(+) and glucose levels were measured at 5-20 min after DUF or ALTHD. We evaluated DUF at dialysis speeds of 50-250 ml/min and ALTHD at speeds of 50-1000 ml/min.

ALTHD rapidly corrected K(+) and glucose concentrations at speeds up to 800 ml/min. ALTHD took 8.9 min to reach a K(+) level of 4.5 mmol/L, faster than DUF (12.8 min). The ALTHD efficiency curves plateaued at 600 ml/min.

ALTHD allowed faster adjustment of electrolyte levels, with peak efficiency at 600 ml/min. ALTHD has possible clinical application if available for potential use during all cardiopulmonary bypass surgeries involving extracorporeal circulation.