Plasma exchange parameter selection and safety observation of children with severe ricinism.

The aim of this study was to investigate the selection of plasma exchange (PE) parameters and the safety of children with severe ricinism. The PE parameters and heparin dosage in 7 children with severe ricinism were recorded, and changes in the patients' vital signs and coagulation function were monitored before and after PE. All patients successfully completed PE. The speed of blood flow was 50-80 mL/min, speed of exchange flow was 600-800 mL/h, and isolating rate of blood plasma was 12.5-19.05%. Transmembrane pressure was stable at approximately 100 mmHg, and venous pressure was stable at approximately 95 mmHg. The first dose of heparin was 0.39 ± 0.04 mg/kg, and the maintaining heparin dose was 0.40 ± 0.05 to 0.22 ± 0.03 mg·kg(-1)·h(-1). During the PE process, mean arterial pressure, heart rate, respiratory rate, and pulse oxygen saturation were steady. After PE, the activated partial thromboplastin time and thrombin time prolonged to 2-3 times greater than that before PE. However, no bleeding tendency was seen. For children with severe ricinism, the choice of PE to eliminate the toxin from blood, tissues, and organs was safe and effective.