Veiled Paraquat Poisoning: A Focus on Clinical Characteristics

PURPOSE: Most paraquat poisonings are easily diagnosed by history taking on physical examination, however, some are failed to be diagnosed initially if the poisoning was veiled. The purpose of this study was to explore the clinical characteristics of veiled paraquat poisoning. METHODS: We retrospectively reviewed the medical records of patients whose discharge diagnosis was paraquat poisoning in one university teaching hospital between 1 Jan, 2001 and 31 Dec, 2010. Veiled paraquat poisoning was determined when there was a positive urine paraquat kit in patients who did not mention paraquat poisoning in an initial physical examination or had unknown cause of pulmonary fibrosis, acute renal failure, or multi-organ failure. RESULTS: Of the 117 patients with paraquat poisoning during the study period, 6 patients (5.1%) had veiled paraquat poisoning. The clinical characteristics were 1) proteinuria - 6 (100%), 2) increased creatinine - 4 (66.7%), 3) green skin stains - 2 (33.3%), 4) mucosal ulcer - 3 (50%). Blood chemistry results were variable. CONCLUSION: We should suspect veiled paraquat poisoning for patients who have proteinuria, increased creatinine, green skin stain, mucosal ulcer and vomiting, or if they have rapidly progressing acute renal failure or multi-organ failure with unknown cause, even if patients didn't mention about paraquat poisoning upon the initial physical examination. In cases with the above clinical conditions, a thorough repeated physical examination including history taking and use of urine paraquat kits should be performed.

Prediction of Mortality in Patients with Acute Paraquat Intoxication Using Simplified Acute Physiology Score II / 대한구급학회지

BACKGROUND: The prognosis of paraquat intoxication patients is poor and this makes the prediction of mortality important in administering aggressive treatment and admission. This article investigates the usefulness of simplified acute physiology score II (SAPS II), as a predictor of the mortality in paraquat intoxication. METHODS: We retrospectively reviewed 65 patients who were admitted in one hospital between January in 2005 and December in 2010. We calculated their SAPS II, serum paraquat level, and severity index of paraquat poisoning (SIPP) at the time of intensive care unit (ICU) admission. We investigated the relationship between each systems and the mortality. RESULTS: Overall mortality was 73.8%: 48 out of 65 patients died. Non-survived group (n = 48) had a higher SAPS II score (30.44 +/- 15.99) than survived group (n = 17 [15.7 +/- 6.26], p < 0.001). Serum paraquat level and SIPP were significantly higher in non-survived group than in survived group (p < 0.05, in all comparisons). By using the area under receiver operating characteristic curves (AUC), the SAPS II system yielded equal discriminative power (AUC = 0.82) with serum paraquat level (AUC = 0.896) and SIPP (AUC = 0.865). Hosmer-Lemeshow goodness-of-fit test C indicated SAPS II score validated well in paraquat intoxication group (p = 0.33). CONCLUSIONS: Serum paraquat level is the best way for prediction of mortality in patients with acute paraquat intoxication. If checking serum paraquat level is impossible or delayed, SAPS II score can be an alternative tool for evaluating the prognosis in paraquat intoxication.