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.