Low bicarbonate replacement fluid normalizes metabolic alkalosis during continuous veno-venous hemofiltration with regional citrate anticoagulation.

Abstract

BACKGROUND:

Metabolic alkalosis is a frequently occurring problem during continuous veno-venous hemofiltration (CVVH) with regional citrate anticoagulation (RCA). This study aimed to evaluate the effectiveness of switching from high to low bicarbonate (HCO3-) replacement fluid in alkalotic critically ill patients with acute kidney injury treated by CVVH and RCA.

METHODS:

A retrospective-comparative study design was applied. Patients who underwent CVVH with RCA in the ICU between 09/2016 and 11/2017 were evaluated. Data were available from the clinical routine. A switch of the replacement fluid Phoxilium® (30 mmol/l HCO3-) to Biphozyl® (22 mmol/l HCO3-) was performed as blood HCO3- concentration persisted ≥ 26 mmol/l despite adjustments of citrate dose and blood flow. Data were collected from 72 h before the switch of the replacement solutions until 72 h afterwards.

RESULTS:

Of 153 patients treated with CVVH during that period, 45 patients were switched from Phoxilium® to Biphozyl®. Forty-two patients (42 circuits) were available for statistical analysis. After switching the replacement fluid from Phoxilium® to Biphozyl® the serum HCO3- concentration decreased significantly from 27.7 mmol/l (IQR 26.9-28.9) to 25.8 mmol/l (IQR 24.6-27.7) within 24 h (p < 0.001). Base excess (BE) decreased significantly from 4.0 mmol/l (IQR 3.1-5.1) to 1.8 mmol/l (IQR 0.2-3.4) within 24 h (p < 0.001). HCO3- and BE concentration remained stable from 24 h till the end of observation at 72 h after the replacement fluid change (p = 0.225). pH and PaCO2 did not change significantly after the switch of the replacement fluid until 72 h.

CONCLUSIONS:

This retrospective analysis suggests that for patients developing refractory metabolic alkalosis during CVVH with RCA the use of Biphozyl® reduces external HCO3- load and sustainably corrects intracorporeal HCO3- and BE concentrations. Future studies have to prove whether correcting metabolic alkalosis during CVVH with RCA in critically ill patients is of relevance in terms of clinical outcome.

• Authors: Paul Köglberger, Sebastian J Klein, Georg Franz Lehner, Romuald Bellmann, Andreas Peer, Daniel Schwärzler, Michael Joannidis
• Journal: Annals of intensive care (Ann Intensive Care) Vol. 11 Issue 1 Pg. 62 (Apr 23 2021) ISSN: 2110-5820 [Print] Germany
• PMID: 33891213 (Publication Type: Journal Article)