Serum total antioxidant statuses of survivors and nonsurvivors after acute paraquat poisoning

Prediction of mortality and morbidity following paraquat poisoning based on trend of liver and kidney injury

Background

Paraquat is a non-selective herbicide that causes severe tissue damage in various organs including the liver and kidney. The aim of this study was to determine the trend of the liver and kidney injury in patients with paraquat poisoning.

Methods

This retrospective cross-sectional study was performed at the Khorshid Hospital referral poisoning emergency center. The medical records of all patients with acute paraquat poisoning admitted from March 2017 to October 2020 were reviewed. Demographic factors, liver and kidney function tests and outcomes were recorded. Patients were divided into two groups based on the outcome of mortality (death or survived). The two groups were compared in terms of changes in creatinine and liver enzymes during hospitalization.

Results

A significant difference in mean creatinine levels between the two groups was observed from the third day after admission. The peak median Cr was 3.5 mg/dl for deceased patients in day 6 and 1.47 mg/dl for survived patients on 4th day. Minor elevations of ALT and AST were present in those who died. Logistic regression analysis shows patients who had level of creatinine higher than normal from the 2nd to 6th day post overdose, the risk of mortality was 4.83 to 7.44 times more than patients with normal creatinine level. The mean (SD) area under the curve for outcome prediction was reported to be excellent for creatinine on the 8th day post overdose (85.7 ± 13.2). Creatinine was higher than 2 on the 8th day post ingestion and had a sensitivity 100% and specificity 85.7% for mortality prediction (P value, 0.05).

Conclusions

The risk of mortality secondary to paraquat ingestion was highly associated with a rise in creatinine. Minor elevations of ALT and AST were also present in those who died. The creatinine concentration on different days post overdose can be helpful in predicting the severity of poisoning especially when the serum paraquat levels are not available.

ADME/T-based strategies for paraquat detoxification: Transporters and enzymes

Paraquat (PQ) is a toxic, organic herbicide for which there is no specific antidote. Although banned in some countries, it is still used as an irreplaceable weed killer in others. The lack of understanding of the precise mechanism of its toxicity has hindered the development of treatments for PQ exposure. While toxicity is thought to be related to PQ-induced oxidative stress, antioxidants are limited in their ability to ameliorate the untoward biological responses to this agent. Summarized in this review are data on the absorption, distribution, metabolism, excretion, and toxicity (ADME/T) of PQ, focusing on the essential roles of individual transporters and enzymes in these processes. Based on these findings, strategies are proposed to design and test specific and effective antidotes for the clinical management of PQ poisoning.

Hyperamylasemia as an early predictor of mortality in patients with acute paraquat poisoning

Objective

This study aimed to evaluate the relationship between elevated serum amylase levels and the prognosis of paraquat poisoning.

Methods

Patients were categorized into the elevated and non-elevated serum amylase groups according to serum amylase levels. Demographics, mortality, risk factors of elevated serum amylase levels, and injury to the pancreas were analyzed.

Results

A total of 457 patients were enrolled in this study and the overall mortality rate was 51.9%. Patients in the elevated group had worse indices than those in the non-elevated group. Kaplan–Meier survival analysis showed that the mortality rate in the elevated group was significantly higher than that in the non-elevated group (hazard ratio: 10.65, 95% confidence interval [CI]: 7.55–15.02). Multivariate Cox proportional hazards analysis showed that elevated serum amylase levels were related to mortality (hazard ratio: 2.066, 95% CI: 1.239–3.444). The receiver operating characteristic curve showed that the area under the curve was 0.724 (95% CI: 0.666–0.783) for serum amylase levels with 70.4% sensitivity and 74.0% specificity.

Conclusion

Elevated serum amylase levels are observed in PQ poisoning. This elevation might be one of the most accurate early prognostic factors for predicting severity and mortality.

Radiomics Nomogram Analyses for Differentiating Pneumonia and Acute Paraquat Lung Injury

Paraquat poisoning has become a serious public health problem in some Asian countries because of misuse or suicide. We sought to develop and validate a radiomics nomogram incorporating radiomics signature and laboratory bio-markers, for differentiating bacterial pneumonia and acute paraquat lung injury. 180 patients with pneumonia and acute paraquat who underwent CT examinations between December 2014 and October 2017 were retrospectively evaluated for testing and validation. Clinical information including demographic data, clinical symptoms and laboratory test were also recorded. A prediction model was built by using backward logistic regression and presented on a nomogram. The radiomics-based features yielded areas under the receiver operating characteristic curve of 0.870 (95% CI 0.757–0.894), sensitivity of 0.857, specificity of 0.804, positive predictive value of 83.3%, negative predictive value of 0.818 in the primary cohort, while in the validation cohort the model showed similar results (0.865 (95% CI 0.686–0.907), 0.833, 0.792, 81.5%, respectively). The individualized nomogram included radiomics signature, body temperature, nausea and vomiting, and aspartate transaminase. We have developed a radiomics nomogram that combination of the radiomics features and clinical risk factors to differentiate paraquat lung injury and pneumonia for patients with an unclear medical history of exposure to paraquat poisoning, providing appropriate therapy decision support.

Point-of-care testing in the early diagnosis of acute pesticide intoxication: The example of paraquat

Acute pesticide intoxication is a common method of suicide globally. This article reviews current diagnostic methods and makes suggestions for future development. In the case of paraquat intoxication, it is characterized by multi-organ failure, causing substantial mortality and morbidity. Early diagnosis may save the life of a paraquat intoxication patient. Conventional paraquat intoxication diagnostic methods, such as symptom review and urine sodium dithionite assay, are time-consuming and impractical in resource-scarce areas where most intoxication cases occur. Several experimental and clinical studies have shown the potential of portable Surface Enhanced Raman Scattering (SERS), paper-based devices, and machine learning for paraquat intoxication diagnosis. Portable SERS and new SERS substrates maintain the sensitivity of SERS while being less costly and more convenient than conventional SERS. Paper-based devices provide the advantages of price and portability. Machine learning algorithms can be implemented as a mobile phone application and facilitate diagnosis in resource-limited areas. Although these methods have not yet met all features of an ideal diagnostic method, the combination and development of these methods offer much promise.

Hyperamylasemia as an Early Predictor of Mortality in Patients with Acute Paraquat Poisoning

Background

Paraquat (PQ) is a non-selective and fast-acting contact herbicide which has been widely used in developing countries. Hyperamylasemia was reported in patients with PQ poisoning. This study investigated the predictive value and clinical characteristics of hyperamylasemia in patients with PQ poisoning.

Material/Methods

This study included 87 patients with acute PQ poisoning admitted from July 2012 to May 2015. Data were collected from medical records. Receiver operating characteristic (ROC) analysis was conducted to analyze the discriminatory potential of serum amylase with respect to 90-day mortality.

Results

Of 87 patients, 29 patients had elevated serum amylase. We found that serum amylase was significantly higher among patients with AKI than those with non-AKI (p<0.001), and was an independent predictor of mortality (hazard ratio [HR]=3.644; 95% [CI], 1.684–7.881; p=0.001). The area under the ROC curve for the serum amylase (area under curve [AUC]=0.796; 95% [CI], 0.690–0.903) had a better discriminatory potential than plasma PQ concentration (0.698;0.570–0.825) or urinary PQ concentration (0.647;0.514–0.781) in predicting 90-day mortality.

Conclusions

Hyperamylasemia is a valuable early predictor of 90-day mortality in PQ poisoning.

Abnormal pancreatic enzymes and their prognostic role after acute paraquat poisoning

Ingestion of paraquat causes multi-organ failure. Prognosis is best estimated through measurement of blood paraquat concentrations but this facility is not available in most hospitals. We studied the prognostic significance of abnormal pancreatic enzymes for survival. Patients with acute paraquat poisoning were recruited. An extensive series of blood tests including serum amylase were serially checked. Patients were sorted according to their serum amylase activity (normal [<220 U/L], mildly elevated [220 to 660 U/L], elevated [>660 U/L]), and survival compared between groups. 177 patients were enrolled to the study, of whom 67 died and 110 survived. 122 (70.62%), 27 (15.25%) and 25 (14.13%) patients were in the normal, mildly elevated and elevated amylase activity groups, respectively. The case fatality in the elevated group was 100% compared to 17% in the normal group (P < 0.001). We found four independent factors for paraquat death prediction: amylase, PaCO₂, leukocyte number, and neutrophil percentage. Models using pancreatic enzyme activity showed good prediction power. We have found that abnormal pancreatic enzymes are useful prognostic marker of death after acute paraquat poisoning. Including serum amylase activity into a prognostic model provides a good prognostication.

The significance of serum uric acid level in humans with acute paraquat poisoning

Hyperuricemia is a strong and independent predictor of all-cause mortality in cardiovascular disease and has been found to play a role in diseases exacerbated by oxidative stress and inflammation. This study aimed to evaluate whether serum uric acid (UA) level is an indicator of outcome in patients with acute paraquat poisoning. A total of 205 subjects who had attempted suicide by oral ingestion of paraquat were admitted to the emergency room between January 2009 and June 2014. Initial serum UA level and other laboratory parameters were measured. A total of 66 patients died during the 30 days after admission, corresponding to a 32.2% cumulative incidence of mortality. UA levels were higher in non-survivors than survivors (P < 0.001) and 30-day mortality increased with increasing baseline serum UA level (P < 0.001). In a prediction analysis for 30-day mortality, the serum UA level had a cut-off concentration of 284 µmol/L in female patients and 352 µmol/L in male patients. Multivariate Cox proportional hazards regression analyses showed that white blood cell counts and UA were independent prognostic factors. In conclusion, we showed that serum UA may be an independent predictor of 30-day mortality in patients with paraquat poisoning.

Successful treatment of patients with paraquat intoxication: three case reports and review of the literature

OBJECTIVE

To report on three patients with paraquat (PQ) intoxication surviving after combined therapy with hemoperfusion (HP), cyclophosphamide (CTX), and glucocorticoid.

METHODS

Three patients suffered acute renal failure in a few days after ingesting a lethal amount of PQ. Chest computed tomography (CT) scans revealed obvious pulmonary inflammation, pleural effusion, and fibrous lesions several days after ingestion. HP was performed immediately, followed by large doses of glucocorticoid (methylprednisolone, 500 g/d) and CTX (approximately 4 g).

RESULTS

After 50 d of treatments, all three patients were discharged in healthy condition, with chest CT showing small fibrous lesions, exudation, and both lungs clear of auscultation.

CONCLUSIONS

The protective effect of the lungs may have been due to timely treatment at adequate doses.

Association of the superoxide dismutase (V16A) and catalase (C262T) genetic polymorphisms with the clinical outcome of patients with acute paraquat intoxication

BACKGROUND/AIMS

Many patients with acute paraquat (PQ) intoxication die even at low PQ concentrations, whereas others with similar concentrations recover. Therefore, it is possible that individual differences in antioxidant capacity are responsible for the variable clinical outcome in patients with acute PQ intoxication.

METHODS

We investigated whether there was a relationship between the genetic polymorphisms of SOD (V16A), catalase (C262T), and GPX1 (C593T) in 62 patients with acute PQ intoxication and the clinical outcomes of these patients.

RESULTS

The frequency of the Mn-SOD V/V, V/A, and A/A genotypes were 56.3, 43.5, and 0% in survivors and 86.9, 13.1, and 0% in non-survivors (p > 0.05). The GPX1 C/C, C/T, and T/T genotypes were present in 100, 0, and 0% of all subjects. The catalase C/C, C/T, and T/T genotypes were present in 100, 0, and 0% of survivors, and in 82.6, 17.4, and 0% of non-survivors. Neither erythrocyte SOD activity nor catalase activity were significantly different between survivors and non-survivors.

CONCLUSIONS

No association was found between clinical outcome of acute PQ intoxication and the genetic polymorphism of GPX1 (C593T) or the genetic polymorphisms or enzyme activity of superoxide dismutase (V16A) or catalase (C262T).