Removal of toxic substances by a selective membrane plasma separator

Efficacy of direct hemoperfusion for the removal of phenobarbital through blood concentration analysis

Aim

Phenobarbital overdose can cause coma and even death. The consciousness disturbance is often prolonged due to its long half-life. In this study, we investigated the efficacy of direct hemoperfusion (DHP) for the removal of phenobarbital by measuring the blood levels of phenobarbital.

Methods

Study subjects included five patients with phenobarbital poisoning who were transferred to our hospital. Direct hemoperfusion was carried out in three of the five patients (six times in total), and the elimination rate was calculated by measuring the blood levels before and after DHP. Furthermore, the disappearance rate of phenobarbital without DHP was calculated in all five patients (seven times in total) for comparison with the elimination rate.

Results

The elimination rate of phenobarbital with DHP was significantly higher than the disappearance rate without DHP．.

Conclusion

This study suggests that early introduction of DHP should be considered as a treatment option for phenobarbital poisoning.

Recent advances in heparinization of polymeric membranes for enhanced continuous blood purification

Continuous blood purification technology such as hemodiafiltration has been used worldwide for saving patients suffering from severe diseases or organ function failure, especially in the intensive care unit and emergency setting. The filters as core devices are commonly made of polymer materials as hollow fiber membranes. However, the membrane is often inductively blocked by blood clot formation due to its interactions with blood components. Heparin is the anticoagulant often used in clinical practice for anti-coagulation. Recently, heparin is also employed to modify the hollow fiber membranes either chemically or physically to improve the filtration performance. This review summarizes recent advances in methodology for surface heparinization of such hollow fiber membranes, and their filtration performance improvement. The review also provides expert opinions for further research in this rapidly expanding field.

Selective Plasma Exchange for Critically Ill Patients Accompanied With Thrombocytopenia

Selective plasma exchange is a blood purification therapy in which simple plasma exchange is performed using a selective membrane plasma separator (pore size of 0.03 µm). Seven critically ill patients accompanied with thrombocytopenia were treated with selective plasma exchange using fresh frozen plasma. The total bilirubin levels and prothrombin time international normalized ratios decreased significantly after treatment. The total protein, albumin, and fibrinogen levels increased significantly after treatment. Selective plasma exchange may be a useful blood purification therapy for removing causal substances and retaining coagulation factors in patients accompanied with thrombocytopenia.

Developments in extracorporeal therapy for the poisoned patient

The modern use of extracorporeal therapies to treat poisoning and drug overdoses dates back to the early 20th century and has evolved along with their use as treatment for acute kidney injury or as maintenance therapy in advanced kidney disease. As our understanding of drug pharmacokinetics and membrane materials has increased, the technologies of extracorporeal therapy and their applications have become more sophisticated. Despite that, there is little robust evidence to guide clinicians on the optimal use of extracorporeal therapy in treating poisoning beyond case reports and series. New efforts are underway to remedy that: the Extracorporeal Treatments in Poisoning Workgroup (EXTRIP) is an international effort on the part of nephrologists, pharmacists and toxicologists to review the available data and formulate evidence-based guidelines on how to use extracorporeal techniques to treat poisoning and improve patient outcomes. Meanwhile, new techniques and membranes are under development. This review will summarize those key scientific and technologic developments, the efforts to optimize their use and new directions in research.