Phoxilium® as a Phosphate-Sparing Solution for Continuous Renal Replacement Therapy in Paracetamol-Induced Acute Liver Failure.

Background: Hypophosphatemia is common in Acute Liver Failure (ALF) and may worsen during continuous renal replacement therapy (CRRT) with phosphate-free fluids. We aimed to evaluate the safety and efficacy of Phoxilium®, a phosphate-containing CRRT fluid.

Methods: We conducted a retrospective single-centre cohort study of paracetamol-induced ALF patients treated with CRRT between as our ICU transitioned from Accusol® to Phoxilium®. We obtained data on demographics, biochemistry, and outcomes. We compared biochemical variables every 6 hours up to 48 hours post-CRRT initiation and then every 12 hours until 168 hours. The primary outcome was the occurrence of severe hypophosphatemia (< 0.32 mmol/L).

Results: In 38 ALF patients (Phoxilium®=14 and Accusol®=24). Phoxilium® was associated with elimination of severe hypophosphatemia (0% vs. 38%; p=0.014), a reduction in its median burden (proportion of phosphate readings < 0.81 mmol/L: 13% [IQR; 2-33%] vs. 44% [29-51%]; p=0.001), and significantly lower phosphate supplementation requirements (median, 45 mmol [20-70 mmol] vs. 100 mmol [60-210 mmol]; p=0.008). Phoxilium® patients experienced a small but significant decrease in median arterial pH and standard base excess, which remained within normal limits, but lower than with Accusol® (p = 0.018 and p = 0.046, respectively). No significant differences were observed in clinical outcomes.

Conclusions: In paracetamol-induced ALF patients, Phoxilium® was associated with reduced incidence of severe hypophosphatemia, hypophosphatemia burden, and need of phosphate supplementation. Larger studies are needed to further assess its impact on ALF patient outcomes.