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 224 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.