Comparison of the efficacy and safety of two regional citrate anticoagulation protocols using acid citrate dextrose A or Prismocitrate 10/2, in patients with acute renal failure undergoing continuous venovenous haemodiafiltration

Introduction

Continuous renal replacement therapy (CRRT) is the treatment of choice for acute renal failure in critically ill patients. Our study compared the efficacy and safety of regional citrate anticoagulation (RCA) with acid citrate dextrose A (ACD-A) against Prismocitrate 10/2 (Gambro). Use of Prismocitrate 10/2 eliminates the need for a separate infusion pump for ACD-A as it doubles as replacement fluid and anticoagulant. This removes a source of error in the calculation of fluid balance. The combination of tri-sodium citrate and citric acid in Prismocitrate 10/2 avoids the metabolic alkalosis associated with ACD-A [1, 2].

Methods

This was a prospective sequential cohort study. All patients admitted to the surgical ICU who required CRRT for ARF were recruited. Group A, using ACD-A, was recruited from October 2007 to September 2008 (n = 23). Group B, using Prismocitrate 10/2, was recruited from October 2008 to September 2009 (n = 20). We evaluated the incidence of metabolic alkalosis and other biochemical changes, azotemia control, filter lifespan and complications.

Results

The incidence of metabolic alkalosis in Group B from treatment day 2 onwards was significantly lower than Group A. The Group A median pH was 7.42 (6.81 to 7.62) compared with Group B pH 7.35 (7.2 to 7.49), P = 0.001. The control of electrolytes and azotemia was not significantly different. The mean filter duration was 58.8 hours (95% CI 38.0 to 79.6) for Group A and 61.8 hours (95% CI 45.8 to 77.8) for Group B (P = 0.678). Longitudinal analysis revealed a statistically significant result for reduced metabolic alkalosis for Group B. (standard bicarbonate P < 0.001, base excess P < 0.001). Repeat treatment sessions also showed a statistically significant reduction of metabolic alkalosis using Prismocitrate 10/2 rather than ACD-A (P = 0.029).

Conclusions

RCA with Prismocitrate 10/2 reduces the incidence of metabolic alkalosis associated with ACD-A. This regime is safe, feasible and improved patient safety, with no increase in complication rates. Our unit has now converted to Prismocitrate 10/2 for RCA.