The development of discolored urine may have many possible causes. Here we present the case of a 76-year-old woman who was admitted after ingesting the inorganic herbicides, mefenacet and imazosulfuron. Her urine color changed to green almost immediately. Since the patient had no specific medication or medical history we considered that the most likely cause of the change in urine color was the ingestion of the herbicides. Spectrophotometric analysis of the urine was conducted and a peak was observed in the green area of the wavelength spectrum. These findings show that mefenacet and imazosulfuron should be considered in the differential diagnosis of green discolored urine.
Acetanilides/*poisoning/urine ; Aged ; Benzothiazoles/*poisoning/urine ; Color ; Eating ; Female ; Herbicides/*poisoning/urine ; Humans ; Poisoning/diagnosis/urine ; Pyridines/*poisoning/urine ; Pyrimidines/*poisoning/urine ; Urinalysis

OBJECTIVE: To establish a new method for the analysis of paraquat in blood and urine by sodium borohydride/nickel chloride chemical reduction-gas chromatography/thermionic specific detector. METHODS: An initial procedure of precipitation was performed by adding hydrochloric solution with sodium chloride and a mixture of chloroform and ethanol. Then the analyte contained in supernatant was reduced by a reduction system of sodium borohydride and nickel chloride and extracted by acetic ether. Ethyl paraquat (EPQ) was used as internal standard. GC/TSD was used to identify and quantify the analyte. RESULTS: The limits of detection (S/N=3) in blood and urine were 0.002 and 0.004 microg/mL, respectively. The linear ranges were 0.050-30.0 microg/mL. Correlation coefficients in blood and urine were 0.999 and 0.998, respectively. The recoveries exceeded 80% both in blood and urine. CONCLUSION This method is applicable for quantification of paraquat in biological fluids.
Borohydrides/chemistry* ; Chromatography, Gas/methods* ; Forensic Toxicology ; Herbicides/urine* ; Humans ; Nickel/chemistry* ; Oxidation-Reduction ; Paraquat/urine* ; Sensitivity and Specificity

To identify a prognostic marker that is less sensitive to variations in the elapsed time since paraquat ingestion, we assessed the time between paraquat ingestion and a negative dithionite urine test as a prognostic parameter in patients with acute paraquat intoxication. Forty-one patients with acute paraquat intoxication were enrolled in this study and analyzed to verify significant determinants of mortality and organ dysfunction. The amount of paraquat ingested, paraquat plasma levels, and the time to a negative urine dithionite test were significant independent risk factors predicting mortality. The amount of paraquat ingestion, and the time to a negative urine dithionite test were independent risk factors predicting organ dysfunction. With a cut-off value of 34.5 hr for the time to negative conversion of the urine dithionite test, the sensitivity and specificity for mortality were 71.4% and 75.0%, respectively. The incidence of acute kidney injury and respiratory failure above 34.5 hr were 100% and 85.0%, respectively. In conclusion, the time to a negative urine dithionite test is the reliable marker for predicting mortality and/or essential organ failure in patients with acute paraquat intoxication, who survive 72 hr.
Acute Kidney Injury/etiology/mortality ; Adult ; Aged ; Dithionite/*urine ; Female ; Herbicides/blood/*toxicity ; Humans ; Liver Diseases/etiology/mortality ; Male ; Middle Aged ; Paraquat/blood/*toxicity ; Respiratory Insufficiency/etiology/mortality ; Risk Factors ; Time Factors

Paraquat (PQ) has known negative human health effects, but continues to be commonly used worldwide as a herbicide. Our clinical data shows that the main prognostic factor is the time required to achieve a negative urine dithionite test. Patient survival is a 100% when the area affected by ground glass opacity is <20% of the total lung volume on high-resolution computed tomography imaging 7 days post-PQ ingestion. The incidence of acute kidney injury is approximately 50%. The average serum creatinine level reaches its peak around 5 days post-ingestion, and usually normalizes within 3 weeks. We obtain two connecting lines from the highest PQ level for the survivors and the lowest PQ level among the non-survivors at a given time. Patients with a PQ level between these two lines are considered treatable. The following treatment modalities are recommended to preserve kidney function: 1) extracorporeal elimination, 2) intravenous antioxidant administration, 3) diuresis with a fluid, and 4) cytotoxic drugs. In conclusion, this review provides a general overview on the diagnostic procedure and treatment modality of acute PQ intoxication, while focusing on our clinical experience.
Acute Kidney Injury/*diagnosis/pathology/therapy ; Antioxidants/therapeutic use ; Creatinine/blood ; Hemoperfusion ; Herbicides/*poisoning ; Humans ; Iron Chelating Agents/therapeutic use ; Lung Diseases/*diagnosis/pathology/therapy ; Paraquat/blood/*poisoning/urine ; Tomography, X-Ray Computed