Objective: To study the safety and effect of simplified regional citrate anticoagulation (RCA) in continuous veno-venous hemofiltration (CVVH).
Methods: Fourteen patients were treated with CVVH using simplified RAC. Simplified anticoagulation protocol included the addition of 4% sodium citrate into the replacement fluid. The citrate replacement fluid was infused in a speed of 2,000 ml/h or 3,000 ml/h, and at the same time 10% calcium gluconate and 25% magnesium sulfate were infused post filter or with venous pump into peripheral veins. Serum electrolytes, arterial blood gas analysis, coagulation at the beginning and 4, 8, 12 hours after the treatment were monitored. Patient's general condition was observed carefully. After treatment, blood volume in the hollow fiber filter was measured.
Results: Fourteen patients underwent altogether 34 times of this procedure for a total of 544 hours. Each treatment lasted 4-36 hours, with a mean of (16.0+/-7.5) hours. The filter was not changed for 30 procedures. After treatment, the blood volume in the filter was higher than 80% of the original volume. The life span of the filter was (14.79+/-5.98) hours on the average. Twelve hours after infusing citrate, there was a marked shortening of prothrombin time [PT, (12.2+/-1.2) s vs. (14.0+/-3.3) s], while plasma total calcium was increased markedly [(2.46+/-0.30) mmol/L vs. (2.07+/-0.36) mmol/L, both P<0.05]. There was no significant difference in activated partial thromboplastin time (APTT), thrombin time (TT), the concentration of Ca(2+) and Mg(2+), pH and base excess (BE). In one patient with hypoxemia the treatment was stopped due to the appearance of serious complications. No hypernatremia or metabolic alkalosis was found during the RCA in all the patients. No significant bleeding events attributed to RCA occurred.
Conclusion: The simplified anticoagulation protocol by adding sodium citrate replacement fluid can be applied safely in replacement fluid>2,000 ml/h of CVVH without complications of hypernatremia and metabolic alkalosis caused by sodium citrate anticoagulation.