[Use of isolated epoprostenol or associated to heparin for the maintenance of the patency of the continuous renal replacement technical circuits]

Efficacy of Prostacyclin Anticoagulation in Critically Ill Patients Requiring Extracorporeal Support: A Systematic Review and Meta-Analysis

Extracorporeal support modalities are highly prothrombotic. Anticoagulation is frequently used for patients receiving Continuous Renal Replacement Therapy (CRRT), Molecular Adsorbent Recirculating System (MARS), and Extracorporeal Membrane Oxygenation (ECMO). The objective of this systematic review and meta-analysis is to determine if prostacyclin-based anticoagulation strategies are effective compared to other anticoagulation strategies, in critically ill children and adults who needs extracorporeal support, such as continuous renal replacement therapy. We conducted a systematic review and meta-analysis using multiple electronic databases and included studies from inception to June 1, 2022. Circuit lifespan, proportion of bleeding, thrombotic, and hypotensive events, and mortality were evaluated. Out of 2,078 studies that were screened, 17 studies (1,333 patients) were included. The mean circuit lifespan was 29.7 hours in the patients in the prostacyclin-based anticoagulation series and 27.3 hours in the patients in the heparin- or citrate-based anticoagulation series, with a mean difference of 2.5 hours (95%CI -12.0;16.9, p=0.74, I2=0.99, n=4,003 circuits). Bleeding occurred in 9.5% of the patients in the prostacyclin-based anticoagulation series and in 17.1% of the patients in the control series, which was a statistically significant decrease (LogOR -1.14 (95%CI -1.91;-0.37), p<0.001, I2=0.19, n=470). Thrombotic events occurred in 3.6% of the patients in the prostacyclin-based anticoagulation series and in 2.2% of the patients in the control series, which was not statistically different (LogOR 0.97 (95%CI -1.09;3.04), p=0.35, I2=0.0, n=115). Hypotensive events occurred in 13.4% of the patients in the prostacyclin-based anticoagulation series and in 11.0% of the patients in the control series, which was not statistically different (LogOR -0.56 (95%CI -1.87;0.74), p=0.40, I2=0.35, n=299). The mortality rate was 26.3% in the prostacyclin-based anticoagulation series, and 32.7% in the control series, which was not statistically different (LogOR -0.40 (95%CI -0.87;0.08), p=0.10, I2=0.00, n=390). The overall risk of bias was low to moderate. In this systematic review and meta-analysis of 17 studies, prostacyclin-based anticoagulation was associated with fewer bleeding events, but with similar circuit lifespans, thrombotic events, hypotensive events, and mortality rates. The potential benefits of prostacyclin-based anticoagulation should be explored in large randomized controlled trials.

Prostacyclin as an Anticoagulant for Continuous Renal Replacement Therapy in Children

Effective delivery of continuous renal replacement therapy (CRRT) depends on the longevity of the filter and circuit used in the CRRT machine. Safe and effective anticoagulation is crucial for maintaining the patency of these circuits. In children, heparin and citrate are the commonly used anticoagulants but they are limited by serious side effects and thus calls for meticulous monitoring. In conditions where neither of these can be used, prostacyclin can be an effective alternative. Prostacyclin is a platelet inhibitor that can be safely used as an efficient anticoagulant in CRRT. When combined with heparin, it induces a heparin-sparing effect, which can reduce the dosage and side effects of heparin. Furthermore, there is no need for performing time-consuming monitoring tests. Although prostacyclin seems to be an attractive option, there is scanty evidence about its use as an anticoagulant in CRRT in children. We review the evidence and practicalities, and propose a guideline for the use of prostacyclin as an anticoagulant in children requiring CRRT.

Dialysis Efficiency of AN69, a Semisynthetic Membrane Not Well Suited for Diffusion

AN69 membrane is not suited for diffusion, with an suggested limit at 25 mL/min dialysate flow rate. When prescribing continuous hemodialysis this threshold must be surpassed to achieve. We designed a study aimed to check if a higher dose of dialysis could be delivered efficiently with this membrane. Ten ICU patients under continuous hemodiafiltration with 1.4 m² AN69 membrane were included and once a day we set the monitor to exclusively 50 mL/min dialysate flow rate and 250 mL/min blood flow rate and after 15 minutes measured dialysate saturation for urea, creatinine, and β₂-microglobulin. We detected that urea saturation of dialysate was nearly complete (1.1 ± 0.09) for at least 40 hours, while creatinine saturation showed a large dispersion (0.86 ± 0.22) and did not detect any relation for these variables with time, blood flow, or anticoagulation regime. Saturation of β₂-microglobulin was low (0.34 ± 0.1) and decreased discretely with time (r² = 0.15, P < 0.05) and significantly with TMP increases (r² = 0.31, P < 0.01). In our experience AN69 membrane shows a better diffusive capability than previously acknowledged, covering efficiently the range of standard dosage for continuous therapies. Creatinine is not a good marker of the membrane diffusive capability.