Paraquat Ingestion Research Articles

APACHE score, Severity Index of Paraquat Poisoning, and serum lactic acid concentration in the prognosis of paraquat poisoning of Chinese Patients.

Many prognostic indictors have been studied to evaluate the prognosis of paraquat poisoning. However, the optimal indicator remains unclear. To determine the value of the Acute Physiology and Chronic Health Evaluation II (APACHE II) score, the Severity Index of Paraquat Poisoning (SIPP), and serum lactate levels in the prognosis of paraquat poisoning, we performed a prospective study that enrolled 143 paraquat patients. Data were collected from patients (161) at West China Hospital in Chengdu, China, including details about the patients' general conditions, laboratory examinations, and treatment. Receiver operating characteristic curves for predicting inpatient mortality based on APACHE II score, SIPP, and lactate levels were generated. To analyze the best cutoff values for lactate levels, APACHE II scores, and SIPP in predicting the prognosis of paraquat poisoning, the initial parameters on admission and 7-day survival curves of patients with lactate levels greater than or equal to 2.95 mmol/L, APACHE II score greater than or equal to 15.22, and SIPP greater than or equal to 5.50 h · mg/L at the time of arrival at West China Hospital were compared using the 1-way analysis of variance and the log-rank test. The APACHE II score (5.45 [3.67] vs 11.29 [4.31]), SIPP (2.78 [1.89] vs 7.63 [2.46] h · mg/L), and lactate level (2.78 [1.89] vs 7.63 [2.46] mmol/L) were significantly lower in survivors (77) after oral ingestion of paraquat, compared with nonsurvivors (66). The APACHE II score, SIPP, and lactate level had different areas under the curve (0.847, 0.789, and 0.916, respectively) and accuracy (0.64, 0.84, and 0.89, respectively). Respiratory rate, serum creatinine level, Paco2, and mortality rate at 7 days after admission in patients with lactate levels greater than or equal to 2.95 mmol/L were markedly different compared with those of other patients (P < 0.05). The predictive value of lactic acid was superior to that of APACHE II score and SIPP for acute oral paraquat poisoning.

Effects of rapamycin against paraquat-induced pulmonary fibrosis in mice.

Ingestion of paraquat (PQ), a widely used herbicide, can cause severe toxicity in humans, leading to a poor survival rate and prognosis. One of the main causes of death by PQ is PQ-induced pulmonary fibrosis, for which there are no effective therapies. The aim of this study was to evaluate the effects of rapamycin (RAPA) on inhibiting PQ-induced pulmonary fibrosis in mice and to explore its possible mechanisms. Male C57BL/6J mice were exposed to either saline (control group) or PQ (10 mg/kg body weight, intraperitoneally; test group). The test group was divided into four subgroups: a PQ group (PQ-exposed, non-treated), a PQ+RAPA group (PQ-exposed, treated with RAPA at 1 mg/kg intragastrically), a PQ+MP group (PQ-exposed, treated with methylprednisolone (MP) at 30 mg/kg intraperitoneally), and a PQ+MP+RAPA group (PQ-exposed, treated with MP at 30 mg/kg intraperitoneally and with RAPA at 1 mg/kg intragastrically). The survival rate and body weight of all the mice were recorded every day. Three mice in each group were sacrificed at 14 d and the rest at 28 d after intoxication. Lung tissues were excised and stained with hematoxylin-eosin (H&E) and Masson's trichrome stain for histopathological analysis. The hydroxyproline (HYP) content in lung tissues was detected using an enzyme-linked immunosorbent assay (ELISA) kit. The expression of transforming growth factor-β1 (TGF-β1) and α-smooth muscle actin (α-SMA) in lung tissues was detected by immunohistochemical staining and Western blotting. A mice model of PQ-induced pulmonary fibrosis was established. Histological examination of lung tissues showed that RAPA treatment moderated the pathological changes of pulmonary fibrosis, including alveolar collapse and interstitial collagen deposition. HYP content in lung tissues increased soon after PQ intoxication but had decreased significantly by the 28th day after RAPA treatment. Immunohistochemical staining and Western blotting showed that RAPA treatment significantly down-regulated the enhanced levels of TGF-β1 and α-SMA in lung tissues caused by PQ exposure. However, RAPA treatment alone could not significantly ameliorate the lower survival rate and weight loss of treated mice. MP treatment enhanced the survival rate, but had no significant effects on attenuating PQ-induced pulmonary fibrosis or reducing the expression of TGF-β1 and α-SMA. This study demonstrates that RAPA treatment effectively suppresses PQ-induced alveolar collapse and collagen deposition in lung tissues through reducing the expression of TGF-β1 and α-SMA. Thus, RAPA has potential value in the treatment of PQ-induced pulmonary fibrosis.

Paraquat Poisoning: Analysis of an Uncommon Cause of Fatal Poisoning from Manipal, South India.

Background:Morbidity and mortality related to acute poisoning is a serious health concern worldwide. Paraquat is known to be responsible for a number of acute poisonings in south India.Aim:The study aims at presenting the various aspects of paraquat poisoning that include patient profile, clinical presentation, end-organ complications, and observations at autopsy.Materials and Methods:The present registry-based retrospective research was conducted in a tertiary care teaching hospital in south India. All the confirmed cases of paraquat poisoning were included in the present study. The postmortem and hospital records of these patients were retrieved and relevant information was collected and analyzed.Results:Paraquat poisonings constituted 14.4% of the total poisoning fatalities during the study period. Equal number of males and females were observed in the present study. The victims were aged between 17 and 65 years (mean ± SD = 30.2 ± 13.1 years). Manner of death was suicidal in 92.9% cases. Common presenting symptoms after ingestion of paraquat included vomiting, followed by difficulty in breathing. In the present series, overall survival post paraquat consumption ranged between 10 h and 25 days. Half of the victims died within 2 days of consumption of poison. The underlying cause of death included acute renal failure (ARF), adult respiratory distress syndrome (ARDS), multiorgan failure (MOF), acute liver failure, etc., In all the cases, brain was congested and edematous, and visceral organs showed marked congestion at autopsy. Lungs were congested with marked edema in 10 cases.Conclusion:It is recommended that the availability of this highly toxic substance be restricted so as to prevent its misuse as a method of suicide.

Outcome of Paraquat Self-poisoning a Case series

Introduction –Paraquat is available as 20% solution for agricultural purposes and deliberate ingestion can be lethal despite newer modalities of management.Methods - We present a case series from a tertiary care hospital, consisting of six patients admitted from January 2012 to December 2013 with history of paraquat ingestion. All of them weretreated with supportive and specific care in the form of charcoal hemoperfusion (HP) and immunosuppression with cyclophosphamide and steroids and outcome was evaluated.Results - All patients developed respiratory, renal and hepatic dysfunction. Three patients died within one week of paraquat ingestion, two patients at the end of second week and one patient lost follow-up after discharge. Autopsy showed ARDS in three of them.Conclusion -Paraquat is highly toxic. Ingestion of concentrated form most likely results in non responsiveness to available modalities of treatment.

Common Pesticides Used in Suicide Attempts Following the 2012 Paraquat Ban in Korea.

To determine the change in pesticides used during suicide attempts after the 2012 paraquat (PQ) ban, we evaluated the annual number of suicide attempts by pesticide ingestion between 2011 and 2014. We extracted demographic, clinical outcome, and pesticide class data from the medical records of 1,331 patients that attempted suicide by pesticide ingestion. Pesticides were sorted into 5 groups: herbicides, insecticides, fungicides, other pesticides, and combined pesticides. Each group was subdivided into various classes based on publications by the respective Resistance Action Committees. The chi-square test for trends was used to compare the annual incidence of categorical variables. The total number of suicide attempts decreased each year, from 399 in 2011 to 245 in 2014. Simultaneously, PQ ingestion decreased from 253 patients in 2011 to 60 in 2014. The proportion of PQ to pesticides also decreased from 63.4% in 2011 to 24.5% in 2014. Furthermore, the rate of decrease in the proportion of PQ to all herbicide categories increased by calendar year. In conclusion, there is a significant trend in increased annual number of suicides and proportion of suicides using glyphosates and glufosinates versus total herbicides. However, the number of suicide attempts using glyphosate and glufosinate is lower than that using PQ. The ratio of persons completing suicide to those attempting suicide after pesticide ingestion has decreased every year after the PQ ban.

Early haemoperfusion with continuous venovenous haemofiltration improves survival of acute paraquat-poisoned patients.

To determine whether haemoperfusion (HP) with continuous venovenous haemofiltration (CVVH) improves the survival of patients with acute paraquat poisoning, compared with those treated using HP alone. Medical records of patients with acute paraquat poisoning were analysed. Patients were randomised to undergo HP or HP + CVVH within 24 h of paraquat ingestion. Mortality rate, survival duration and cause of death were recorded. There were no significant differences in mortality rate between the HP group (n = 458) and the HP + CVVH group (n = 226) (57.4% and 58.4%, respectively). The mean survival duration was significantly longer in the HP + CVVH group than the HP group (8.6 ± 3.1 and 5.1 ± 2.3 days, respectively). Early circulatory collapse was a major cause of death in the HP group. The major cause of death in the HP + CVVH group was late respiratory failure. Combined therapy with HP and CVVH can prevent early death and prolong survival duration following acute paraquat poisoning, providing the opportunity for further treatment.

Influence of the length of time elapsed from ingestion of paraquat to hemoperfusion on prognosis in patients with acute paraquat poisoning

Objective To explore the influence of the length of time elapsed from ingestion of paraquat to hemoperfusion on prognosis in patients with acute paraquat poisoning.Methods The investigation was carried out with retrospective analysis.A total of 303 patients with acute paraquat poisoning were admitted to the Emergency Intensive Care Unit (EICU) of the First Affiliated Hospital of China Medical University from January 2009 to December 2012.According to the length of time between ingestion and hemoperfusion,patients were divided into three groups,Group A:the time interval between ingestion and hemoperfusion ＜ 4 h ; Group B:4h ≤ the time interval between ingestion and hemoperfusion ＜ 8 h; Group C:8 h≤the time interval between ingestion and hemoperfusion ＜ 12 h.Compared the extent of target organ injury,28-d mortality and the survival time of non-survivors among three groups for determining the influence of the length of time elapsed from ingestion to hemoperfusion on the prognosis of patients.Results Totally 303 patients with average age of 34.8 ± 10.8 years old (ranging from 15 to 72 years),and 117 male and 186 female.The median estimated amount of 20％ paraquat ingested was 50 mL (ranging from 10 to 270 mL,IQR:45 mL).The hemoperfusion was employed (3.6 ±1.2) times (ranging from 2 to 5 times) for every paitient within 24 h after ingestion.The overall mortality rate was 68.6％ (208/304)during a 28 days follow-up period,and only 95 of 303 patients survived.The median length of time between paraquat ingestion and hemoperfusion at the emergency department was 6.6 h (ranging from 1.4 to 11.5 h,IQR:3.5 h).However,it was 7.2 h (ranging from 3.1 to 11.5 h,IQR:2.4 h) in non-survivors and 4.9 h (ranging from 1.4 to 7.6 h,IQR:1.5 h) in survivors.The difference was statistically significant (U =2.014,P =0.043).The difference in 28-day mortality among three groups was statistically significant (x2 =9.27,P =0.009),and the difference in average survival time of non-survivors among three groups was statistically significant (F =3.31,P =0.038).The length of time between ingestion and hemoperfusion and the survival time of non-survivors was a negative correlation (r2 =0.421,P =0.045).The difference in ALTmax,SCrmax,AMYmax and PaO2 min,as the severity indicators of acute liver injury,acute kidney injury,acute pancreas injury and acute lung injury among the three groups were statistically significant (all P ＜ 0.05).Conclusions Employment of hemoperfusion within 4 h after ingestion can attenuate the degree of target organ injury,reducing 28 day mortality of patients with acute paraquat poisoning. Key words: Hemoperfusion; Paraquat; Poisoning; Prognosis

Prediction of outcome following paraquat poisoning by arterial lactate concentration-time data.

The present study retrospectively analyzed 170 patients diagnosed with paraquat (PQ) poisoning with the aim of clarifying whether the arterial lactate-time (arterial lactate concentration × time between ingestion and arterial lactate measurement) was a good predictor of mortality in patients with acute PQ poisoning. The results indicated that there was a positive correlation between the arterial lactate-time and PQ concentration-time (ρ=0.485). In addition, the arterial lactate-time data exhibited a similar discriminative power to the plasma PQ concentration-time data (z=0.712; P=0.864). For the receiver operating characteristic curve analysis, the lactate-time data had an area of 0.782 with a cut-off value of 11.95 mmol/l.h (sensitivity, 64.52%; specificity, 84.42%). To calculate the predicted probability of survival for any specified time and initial arterial lactate concentration, the following formula was derived based on the logistic regression coefficients: Logit(p) = 3.066 − 0.139 × (time lag following PQ ingestion) − 0.177 × (initial arterial lactate concentration); where the probability of survivors = 1/1 + e−logit(p). Therefore, the arterial lactate-time data exhibited a good predictive power for evaluating the prognosis of patients with acute PQ poisoning.

Fluorescence detecting of paraquat using host-guest chemistry with cucurbit[8]uril

Paraquat (PQ) is one of the most widely used herbicides in the world, which has a good occupational safety record when used properly. While, it presents high mortality index after intentional exposure. Accidental deaths and suicides from PQ ingestion are relatively common in developing countries with an estimated 300,000 deaths occurring in the Asia–Pacific region alone each year, and there are no specific antidotes. Good predictors of outcome and prognosis may be plasma and urine testing within the first 24 h of intoxication. A fluorescence enhancement of approximately 30 times was seen following addition of PQ to a solution of the supramolecular compound 2MB@CB[8], which comprised two methylene blue (MB) molecules within one cucurbit[8]uril (CB[8]) host molecule. The fluorescence intensity was linearly proportional to the amount of PQ added over the concentration range 2.4 × 10−10 M–2.5 × 10−4 M. The reaction also occurred in living cells and within live mice.

Paraquat intoxication induced sick sinus syndrome

Abstract Introduction: Paraquat (1,1’-dimethyl-4, 4’-dipyridylium) intoxication is a major medical problem in developing countries. The ingestion of paraquat is fatal in humans and its mortality rate is as high as 50%. Paraquat intoxication has a systemic effect on the lung, kidney, gastrointestinal tract, central nervous system, and even on the heart. Case report: A female patient visited our emergency room after suicidal ingestion of paraquat herbicide. The patient received a conventional treatment, including gastric lavage with large amounts of normal saline and charcoal, steroids and antioxidant therapy. Hemoperfusion was consecutively done twice within 12 hours. During the conventional treatment, her heart rate abruptly dropped to below 50 beats per minute and she complained of associated symptoms like dizziness and weakness. At that time her systolic blood pressure was below 80 mmHg. A sinus bradycardia was shown on her electrocardiogram (ECG) and the 24 hours ambulatory ECG monitoring showed a severe sinus bradycardia, sometimes junctional escape rhythms, and non-conducted atrial premature complexes. We administered dopamine as an inotropic agent for two days. After the prompt treatment, her heart rhythm returned back to normal sinus rhythm and the blood pressure was stabilized. Discussion: The heart is one of the most severely affected organs in paraquat intoxication. After paraquat intoxication, cardiac complications like arrhythmia or myocardial necrosis aggravate the general condition of the patients. Consequently, the early detection of multi-organ dysfunctions and the prompt initiation of proper management for specific organ injuries are very important for the prognosis of a patient intoxicated with paraquat, especially in case of cardiac involvement such as arrhythmia, myocardial necrosis or others.

Predictors of Acute Respiratory Distress Syndrome in Patients with Paraquat Intoxication

IntroductionParaquat poisoning is characterized by acute lung injury, pulmonary fibrosis, respiratory failure, and multi-organ failure, resulting in a high rate of mortality and morbidity. The objectives of this study were to identify predictors of acute respiratory distress syndrome (ARDS) in cases of paraquat poisoning and determine the association between these parameters.Materials and MethodsIn total, 187 patients were referred for management of intentional paraquat ingestion between 2000 and 2010. Demographic, clinical, and laboratory data were recorded. Sequential organ failure assessment (SOFA) and Acute Kidney Injury Network (AKIN) scores were collected, and predictors of ARDS were analyzed.ResultsThe overall mortality rate for the entire population was 54% (101/187). Furthermore, the mortality rate was higher in the ARDS patients than in the non-ARDS patients (80% vs. 43.80%, P<0.001). Additionally, the ARDS patients not only had higher AKIN48-h scores (P<0.009), SOFA48-h scores (P<0.001), and time to ARDS/nadir PaO2 (P=0.008) but also suffered from lower nadir PaO2 (P<0.001), nadir AaDO2 (P<0.001), and nadir eGFR (P=0.001) compared to those in the non-ARDS patients. Moreover, pneumomediastinum episodes were more frequent in the ARDS patients than in the non-ARDS patients (P<0.001). A multivariate Cox regression model revealed that blood paraquat concentrations (P<0.001), SOFA48-h scores (P=0.001), and steroid and cyclophosphamide pulse therapies (P=0.024) were significant predictors of ARDS. The cumulative survival rates differed significantly (P<0.001) between patients with SOFA48-h scores <3 and SOFA48-h scores ≥3, with a sensitivity of 95.8%, specificity of 58.4%, and overall correctness of 67.6%. Finally, the area under the receiver operating characteristic (AUROC) analysis showed that SOFA48-h scores (P<0.001) had a better discriminatory power than blood paraquat concentrations (P=0.01) for predicting ARDS. ConclusionsThe analytical results indicate that SOFA48-h scores, blood paraquat concentrations, and steroid and cyclophosphamide pulse therapies are significantly associated with ARDS complications after paraquat intoxication.

Fast determination of paraquat in plasma and urine samples by solid-phase microextraction and gas chromatography–mass spectrometry

A simple, sensitive and reliable gas chromatographic-mass spectrometric method (GC-MS) for quantifying paraquat concentration in biological samples has been developed, using ethyl paraquat as an internal standard. The method involved the procedures of sodium borohydride-nickel chloride (NaBH4-NiCl2) reduction and solid-phase microextraction (SPME) of the perhydrogenated products. GC-MS was used to identify and quantify the analytes in selected ion monitoring (SIM) mode. Under the optimal conditions, recoveries in plasma and urine samples were 94.00-99.85% and 95.00-100.34%, respectively. Excellent sample clean-up was observed and good linearities (r=0.9982 for plasma sample and 0.9987 for urine sample) were obtained in the range of 0.1-50μg/mL. The limits of detection (S/N=3) were 0.01μg/mL in plasma and urine samples. The intra-day precision was less than 8.43%, 4.19% (n=3), and inter-day precision was less than 10.90%, 10.49% (n=5) for plasma and urine samples, respectively. This method was successfully applied to the analysis of the biological samples collected from a victim who died as a result of ingestion of paraquat.

Arterial lactate as a predictor of mortality in emergency department patients with acute paraquat poisoning

Objective To study the prognostic value of initial arterial lactate level and to explore the relationship between early arterial lactate and the outcome of patients with acute paraquat poisoning by analyzing the clinical data of 235 cases.Methods A total of 235 patients with acute paraquat poisoning were admitted to the Emergency Intensive Care Unit (EICU) from January 2009 to June 2012.Demographics,clinical and laboratory findings were compared between the survivors and non-survivors.Receiver operating characteristic (ROC) curves were used to identify the optimal cut-off points for initial arterial lactate level.Results Totally 235 patients with average age of (33.6 ± 11.5) years old (ranging from 18 to 74),89 male and 146 female.The median estimated amount of 20％ paraquat ingested was 55 mL,(ranging from 10 to 280,IQR:27 mL,77 mL),the median length of time between paraquat ingestion and the arrival at the emergency department was 4.5 h (ranging from 0.5 to 10.5,IQR:2.3 h,6.8 h).The overall mortality rate was 74.0％ (174/235) during a 28 days follow-up period,only 61 of 235 patients survived.The initial arterial lactate level was higher in non-survivors than that in survivors (2.79 ± 0.76) mmol/L vs.(1.62 ± 0.48) mmol/L,P =0.028).Correlation analyses showed that the initial arterial lactate level was associated with increased risk of 28-day mortality (r =0.26,P =0.004),and as the initial lactate increased,the survival time of non-survivors shortened (F =3.246,P =0.037).Using the ROC curve analysis,the initial arterial lactate level had an area of 0.799 (95％ CI:0.745-0.866) and the cut-off point of concentration was 2.57 mmol/L for prediction of prognosis in patients with acute paraquat poisoning (sensitivity 85.2％,specificity 79.6％,the best Youden index was 0.648).The initial arterial lactate level was higher in patients died from circulatory failure rather than from respiratory failure (5.22 ± 1.46) mmol/L vs.(1.87 ± 0.62) mmol/L,P =0.042.And the survival time of patients died from circulatory failure was shorter than that from respiratory failure (4.1 ± 1.3) d vs.(11.6 ± 3.2)d,P =0.023.With the ROC curve analysis,the initial arterial lactate level had an area of 0.882 (95％ CI:0.805-0.941) and the cut-off point of concentration was 3.65 mmol/L for prediction of prognosis of patients died from circulatory failure (sensitivity 87.6％,specificity 82.5％,the best Youden index was 0.701).Conclusions The initial arterial lactate level may be one of early indicators of prognosis in patients with acute paraquat poisoning and it had high potential in predicting the outcome of patients died from circulatory failure. Key words: Lactate; Paraquat; Poisoning; Prognosis

Tissue concentration of paraquat on day 32 after intoxication and failed bridge to transplantation by extracorporeal membrane oxygenation therapy

BackgroundParaquat is a highly toxic herbicide, which not only leads to acute organ damage, but also to pulmonary fibrosis. There are only anecdotal reports of rescue lung transplantation, as paraquat is stored and only slowly released from different tissues. Bridging the time to complete depletion of paraquat from the body could render this exceptional therapy strategy possible, but not much is known on the time interval after which transplantation can safely be performed.Case presentationWe report on a case of accidental paraquat poisoning in a 23 years old Caucasian man, who developed respiratory failure due to pulmonary fibrosis. The patient was listed for high urgency lung transplantion, and extracorporeal membrane oxygenation was implemented to bridge the time to transplantation. The patient died 32 days after paraquat ingestion, before a suitable donor organ was found. In postmortem tissue specimen, no paraquat was detectable anymore.ConclusionThis case report indicates that complete elimination of paraquat after oral ingestion of a lethal dose is achievable. The determined time frame for this complete elimination might be relevant for patients, in which lung transplantation is considered.

Toll-like receptor 4 is involved in myocardial damage following paraquat poisoning in mice

The ingestion of the herbicide paraquat (PQ) can cause multiple organ injury including cardiac lesions. However, the underlying mechanism of myocardial damage is not known. Toll-like receptor 4 (TRL4) is a pattern-recognition receptor in the innate immune response to microbial pathogens. TLR4 is involved in heart dysfunction such as septic shock or myocardial ischemia. We investigated whether TLR4 would be linked to the pathogenesis of heart disease due to PQ exposure. Wild type mice (WT) and TLR4-deficient mice were injected intraperitoneally with 75mg/kg of PQ to induce myocardial damage and tested for echocardiographic assessment, histopathology, pro-inflammatory cytokine and TLR4 expression. WT mice after PQ exposure displayed deteriorate cardiac function, pathological damages, increased TLR4 mRNA and protein levels as well as myocardial TNF-α and IL-1β levels. Compared with WT mice, TLR4-deficient mice were significantly resistant to the PQ-induced injury. We concluded that the TLR4 was required as a mediator and played an important role in myocardial damage due to PQ.

Clinical Characteristics of Paraquat Poisoning in 22 Chinese Children

To retrospectively analyze the clinical characteristics and experience of Chinese children with paraquat poisoning. Twenty-two children with paraquat poisoning who presented to the hospital from October 2007 through September 2012 were enrolled into this study. The clinical indices of these cases were collected and analyzed. All the children were poisoned due to oral ingestion of paraquat. Different degrees of damage were found in multiple systems in their bodies. All of them were administered pulse therapy using methylprednisolone (20 mg/kg/d × 3d) and Gamma globulin (total 2 g/kg divided into 3 d to 5 d) in the early stage. Prednisone was then given orally for 4 wk to 8 wk. The total mortality rate of the patients was 63.6 % (14 of 22 patients died). Statistical differences (P < 0.05) were found between the surviving and dead patients, with regard to age, plasma paraquat levels, the highest levels of alanine aminotransferase, aspartate aminotransferase, γ-glutamyl transferase, total bilirubin, direct bilirubin, indirect bilirubin, blood urea nitrogen, creatinine and pH value, the lowest levels of PaO2, PaCO2 and SaO2. Plasma paraquat level was positively related to pH value, but was negatively related to PaO2, PaCO2 and SaO2 levels. None of the patients died from hepatic and renal complications. Pulmonary fibrosis was the most severe complication and the primary cause of death. Paraquat poisoning is difficult to cure. In this study, pulmonary fibrosis was the primary cause of death. Treatment by administering large doses of glucocorticoids and Gamma globulin proved to be effective in the early stage. However, the treatment may not reverse the development of pulmonary fibrosis. The long-term prognosis of paraquat poisoning was not optimistic. The plasma paraquat level could be a significant factor in predicting the prognosis.

A simple and rapid chemiluminescence assay for on-site analysis of paraquat using a portable luminometer

Paraquat (N,N′-dimethyl-4,4′-bipyridinium dichloride) is one of the most widely used herbicides owing to its high efficacy and low environmental persistence. However, because paraquat has significant acute toxicity, fatalities are often caused by accidental or voluntary ingestion of paraquat. In consideration of the strong toxicity and fast-acting property of paraquat, on-site analysis at accident scenes should be effective in facilitating immediate medical treatment. In this study, a simple and rapid chemiluminescence assay using a portable luminometer was developed for on-site analysis of paraquat. The proposed assay is based on luminol chemiluminescence detection of superoxide anion radical resulting from the redox reaction between paraquat and dithiothreitol. Intense chemiluminescence was observed after mixing of paraquat and dithiothreitol in the presence of luminol. Because the chemiluminescence intensity was proportional to the concentration of paraquat, a quantitative measurement of paraquat was possible. The calibration curve for standard paraquat solution was linear from 0.025 to 2.5 μM with the correlation coefficient of 0.992; the detection limit (blank + 3SD) was 22 nM. The proposed assay was applied to determine paraquat in beverage samples after a cation exchange clean-up procedure. Given that the portable luminometer used in this study is small and lightweight, the proposed assay should be useful for on-site analysis of paraquat.

Comments on ‘Spectrum of toxic hepatitis following intentional paraquat ingestion’

Comments on ‘Spectrum of toxic hepatitis following intentional paraquat ingestion’

Paraquat poisoning: A case report and review of literature

Paraquat (1, r-dimethyl-4,4’-bipyridium dichloride), a brown syrupy liquid is an effective herbicide that has low chronic toxicity because of its rapid deactivation on contact with soil. A high dose of paraquat or severe poisoning has a poor prognosis. At present there is no specific antidote to paraquat poisoning, hence the need to focus on prevention and in case of exposure or ingestion, aggressive decontamination to prevent further absorption. Although uncommon, paraquat ingestion can lead to severe and often fatal toxicity. However, despite its widespread availability, reports of this herbicide poisoning in India are uncommon.

Ratio of Angiopoietin-2 to Angiopoietin-1 predicts mortality in acute lung injury induced by paraquat

BackgroundTo determine whether initial reactive oxygen species (ROS)-induced endothelial cell injury is involved in early death after paraquat intoxication and concentrations of angiopoietin-1 (Ang-1), angiopoietin-2 (Ang-2), and von Willebrand factor (VWF) reflecting endothelial cell injury, we investigated the initial endothelial cell injury marker involved in the pathogenesis of death within 5 days after paraquat ingestion.Material/MethodsSixty patients with paraquat poisoning were prospectively enrolled. Plasma samples were collected at admission. Plasma concentrations of Ang-1, Ang-2, and VWF were measured by enzyme-linked immunosorbent assay. The patients were classified into 3 categories: survivors, early death (died within 5 days after ingestion), and late death (died more than 5 days after ingestion).ResultsThe baseline concentration of Ang-2 and the Ang-2: Ang-1 ratio were significantly higher in patients who died (Ang-2 [pg/mL], 1012.75±468.02 vs. 1986.07±1675.37 [p=0.002]; Ang-2: Ang-1, 0.90±0.49 vs. 2.16±2.28 [p=0.002]). The Ang-2: Ang-1 ratio was significantly higher in the early death group (2.41±2.54) than in the survivors (0.90±0.49) and the late death group (1.33±0.64). The Ang-2: Ang-1 ratio was significantly associated with early death (OR, 2.602; 95% CI, 1.106–6.117; p=0.028) after adjusting for plasma levels of paraquat, age, PCO2, and creatinine. VWF did not predict mortality.ConclusionsEndothelial cell damage could be involved in the pathogenesis of early death following paraquat ingestion.