Continuous arteriovenous hemoperfusion in meprobamate poisoning

Early hemoperfusion may improve survival of severely paraquat-poisoned patients

BACKGROUND

Thousands of paraquat (PQ)-poisoned patients continue to die, particularly in developing countries. Although animal studies indicate that hemoperfusion (HP) within 2-4 h after intoxication effectively reduces mortality, the effect of early HP in humans remains unknown.

METHODS

We analyzed the records of all PQ-poisoned patients admitted to 2 hospitals between 2000 and 2009. Patients were grouped according to early or late HP and high-dose (oral cyclophosphamide [CP] and intravenous dexamethasone [DX]) or repeated pulse (intravenous methylprednisolone [MP] and CP, followed by DX and repeated MP and/or CP) PQ therapy. Early HP was defined as HP <4 h, and late HP, as HP ≥ 4 h after PQ ingestion. We evaluated the associations between HP <4 h, <5 h, <6 h, and <7 h after PQ ingestion and the outcomes. Demographic, clinical, laboratory, and mortality data were analyzed.

RESULTS

The study included 207 severely PQ-poisoned patients. Forward stepwise multivariate Cox hazard regression analysis showed that early HP <4 h (hazard ratio [HR] = 0.38, 95% confidence interval (CI) 0.16-0.86; P = 0.020) or HP <5 h (HR = 0.60, 95% CI: 0.39-0.92; P = 0.019) significantly decreased the mortality risk. Further analysis showed that early HP reduced the mortality risk only in patients treated with repeated pulse therapy (n = 136), but not high-dose therapy (n = 71). Forward stepwise multivariate Cox hazard regression analysis showed that HP <4.0 h (HR = 0.19, 95% CI: 0.05-0.79; P = 0.022) or <5.0 h (HR = 0.49, 95% CI: 0.24-0.98; P = 0.043) after PQ ingestion significantly decreased the mortality risk in repeated pulse therapy patients, after adjustment for relevant variables.

CONCLUSION

The results showed that early HP after PQ exposure might be effective in reducing mortality in severely poisoned patients, particularly in those treated with repeated pulse therapy.

Activated charcoal microcapsules and their applications

Activated charcoal, long known to the ancients as a substance of therapeutic value in a variety of maladies, has recently been "rediscovered" to be of great value in medical applications. Activated charcoal hemoperfusion is effective in blood purification for removal of various circulating toxic materials and waste metabolites, directly. However, particulate release and platelet adhesion prevent its continued clinical use. Polymeric coatings or microencapsulation of charcoal within polymers have improved their blood compatibility. Chitosan encapsulated activated charcoal (ACCB) beads have been extensively investigated in our group for the removal of various toxins such as urea, creatinine, uric acid, bilirubin, etc. This article highlights various methods of microencapsulation procedures of activated charcoal and the importance of this novel material for a variety of biomedical applications. Further, this review provides an insight to the future perspectives for using them in clinical practice.