Hypokalemia and hypothermia are associated with 30-day mortality in patients with acute paraquat poisoning

The significance of APACHE II as a predictor of mortality in paraquat poisoning: A systematic review and meta-analysis

The Acute Physiology and Chronic Health Evaluation II (APACHE II) scoring system is utilised as a prognostic method in paraquat poisoning; however, current evidence shows ambiguity. Although some studies have shown APACHE II to be a superior tool, others have reported it inferior to other prognostic markers, such as lactate, severity index of paraquat poisoning and urine paraquat concentration. Hence, to address this ambiguity, we conducted a systematic review and meta-analysis to analyse prognostic accuracy of APACHE II score in predicting mortality in paraquat poisoning. We included twenty studies with 2524 paraquat poisoned patients in the systematic review, after a comprehensive literature search in databases PubMed, Embase, Web of Science, Scopus and Cochrane Library, from which 16 studies were included in the meta-analysis. The survivors of paraquat poisoning were found to have significantly lower APACHE II scores (Mean Difference (MD): -5.76; 95% CI: -7.93 to -3.60 p < 0.0001; n = 16 studies) compared to non-survivors. The pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR) and diagnostic odds ratio (DOR) for APACHE II score <9 was found to be 74%, 68%, 2.58, 0.38 and 7.10, respectively (n = 5 studies). The area under the curve (AUC) of the bivariate summary receiver operating characteristic (SROC) curve was found to be 0.80. The pooled sensitivity, specificity, PLR, NLR and DOR for APACHE II score ≥9 was found to be 73%, 86%, 4.69, 0.33 and 16.42, respectively (n = 9 studies). The AUC of the SROC curve was found to be 0.89. Pairwise AUC comparison of APACHE II with other prognostic markers showed serum presepsin to have a significantly better discriminatory ability than APACHE II. Through the findings of this study, we conclude that APACHE II was found to be a good indicator of death in paraquat poisoning patients. However, higher APACHE II scores (≥9) depicted greater specificity in predicting mortality in paraquat poisoning. Thus, APACHE II can be used as a practical tool in the hand of physicians to prognose patients with paraquat poisoning to aid clinical decisions.

Pathophysiological Changes in Rhesus Monkeys with Paraquat-Induced Pulmonary Fibrosis

Purpose

Pulmonary fibrosis is a life-threatening lung disorder. A comprehensive understanding of the pathophysiological changes in the development of pulmonary fibrosis will lead to new insights into its treatment.

Methods

We used a paraquat (PQ)-induced rhesus monkey model of pulmonary fibrosis to comprehensively investigate the process of pulmonary fibrosis development. Rhesus monkeys were orally administered PQ at concentrations of 25 mg/kg, 40 mg/kg, and 80 mg/kg. The dose was given once. Behavior and clinical data, such as PQ concentration, arterial oxygen saturation, biochemical evaluation, lung histopathology, and medical imaging, were continuously observed.

Results

Paraquat-exposed monkeys developed pulmonary fibrosis following an expected time course, especially at 25 mg/kg. CT images showed ground-glass lesions in the lung after 4 weeks, and pulmonary fibrosis persisted until the end of follow-up. Using pathological examination, the lung sustained collagen deposition and slight inflammatory cell infiltration. All rhesus monkeys had obvious inflammatory infiltration within 1 week according to the immunohistochemical results and the number of leukocytes in the blood. The CT results showed that pulmonary fibrosis had not formed, indicating that drugs with powerful anti-inflammatory ability are potential candidates for early pulmonary fibrosis treatment.

Conclusion

Our study describes the dynamic process of paraquat-induced pulmonary fibrosis in rhesus monkeys and provided a pathophysiological basis for the treatment of pulmonary fibrosis.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00408-022-00572-9.

The acute paraquat poisoning mortality (APPM) score to predict the risk of death in paraquat-poisoned patients

CONTEXT

Mortality prediction in paraquat poisoning is a major issue since most prediction rules are inapplicable if the exact ingestion time cannot be determined and/or the serum paraquat concentration is not readily available, as in most countries. Therefore, we aimed to develop and validate a new prediction rule not requiring these two parameters.

METHODS

We designed a 10-year observational cohort study including all consecutive paraquat-poisoned patients managed in two Taiwanese hospitals. We built one cohort to define and one cohort to validate this prediction rule. Parameters independently related to mortality determined using a multivariate analysis were used to formulate the Acute Paraquat Poisoning Mortality (APPM) score.

RESULTS

Overall, 321 paraquat-poisoned patients were included, 156 in the derivation and 165 in the validation cohort. Mortality rates in the derivation and validation cohorts were 73% and 81%, respectively (p = 0.20). The three parameters chosen of 28-day mortality at presentation were urine paraquat level >10 ppm (using a colorimetric sodium dithionite-based test; odds ratio (OR), 12.70; 95% confidence interval (CI), 2.64-61.24), white blood cells >13.0 G/L (OR, 5.50; CI, 1.41-21.48) and blood glucose >140 mg/dL [7.8 mmol/L] (OR, 7.45; CI, 1.70-32.86). In the derivation cohort, the area under the ROC curve (AUC-ROC) of the APPM score did not significantly differ from AUC-ROCs of serum paraquat (0.95, p = 0.25) and the Severity Index of Paraquat Poisoning (0.95, p = 0.33). AUC-ROCs of the APPM score in the derivation and validation cohorts were 0.91 and 0.94, respectively.

CONCLUSION

We built and validated a reliable score to predict 28-day mortality in paraquat-poisoned patients at presentation, independently from the ingestion time and serum paraquat measurement.

A novel flowchart to predict mortality and analyse effectiveness of routinely used pharmacological regimens in paraquat poisoning

Paraquat is responsible for an extremely high case-fatality rate poisoning. Mortality prediction remains a major issue since evidence to support benefits of routinely used treatments is lacking. We aimed to develop an easy-to-use prediction flowchart not requiring the ingestion time, for which accuracy is frequently questionable, and to evaluate the effectiveness of routinely used pharmacological therapies on mortality. We designed a two-centre cohort study including consecutive paraquat-poisoned adults with confirmed diagnosis based on serum/urine paraquat measurement. We built a flowchart using a multivariate analysis of death predictors and analysed the outcome according to the administered therapies. Overall, 256 patients were enrolled. Mortality rate was 75%. Independent death predictors on admission were serum creatinine (odds ratio [OR], 5.07; 95% confidence interval [CI], 1.97-13.05) and serum paraquat concentration (OR, 2.26; CI, 1.66-3.09). The area-under-the flowchart curve was 0.91. Overall sensitivity and specificity were 81.5% and 94.8%, respectively. More survivors than non-survivors of severe poisoning received methylprednisolone (P = 0.04). While not significantly differing in severity, methylprednisolone-treated patients had better survival (P = 0.04). To conclude, we defined an efficient flowchart to predict mortality in paraquat poisoning at presentation, even if ingestion time is undetermined. Methylprednisolone seems effective to improve the outcome, especially in the most severe cases.

Identify the Characteristics of Metabolic Syndrome and Non-obese Phenotype: Data Visualization and a Machine Learning Approach

Introduction: A third of the world's population is classified as having Metabolic Syndrome (MetS). Traditional diagnostic criteria for MetS are based on three or more of five components. However, the outcomes of patients with different combinations of specific metabolic components are undefined. It is challenging to be discovered and introduce treatment in advance for intervention, since the related research is still insufficient.

Methods: This retrospective cohort study attempted to establish a method of visualizing metabolic components by using unsupervised machine learning and treemap technology to discover the relations between predicting factors and different metabolic components. Several supervised machine-learning models were used to explore significant predictors of MetS and to construct a powerful prediction model for preventive medicine.

Results: The random forest had the best performance with accuracy and c-statistic of 0.947 and 0.921, respectively, and found that body mass index, glycated hemoglobin, and controlled attenuation parameter (CAP) score were the optimal primary predictors of MetS. In treemap, high triglyceride level plus high fasting blood glucose or large waist circumference group had higher CAP scores (>260) than other groups. Moreover, 32.2% of patients with high CAP scores during 3 years of follow-up had metabolic diseases are observed. This reveals that the CAP score may be used for detecting MetS, especially for the non-obese MetS phenotype.

Conclusions: Machine learning and data visualization can illustrate the complicated relationships between metabolic components and potential risk factors for MetS.

Hypokalemia is a biochemical signal of poor prognosis for acute paraquat poisoning within 4 hours

Anecdotal reports have suggested that hypokalemia is an independent predictor of mortality in patients with acute paraquat poisoning. However, the clinical significance of hypokalemia has not been systematically investigated in the early stage of paraquat poisoning. This study aimed to evaluate whether initial hypokalemia is a good predictor of mortality in patients with acute paraquat poisoning within 4 h. We retrospectively analyzed patients who were admitted to the emergency department after paraquat poisoning between September 2012 and January 2015. Demographic, clinical, and laboratory data were recorded, and the prognostic significance of hypokalemia was analyzed. A total of 120 patients were included. The 60-day mortality was 71.7 %. Serum potassium concentrations were significantly lower in non-survivors (3.1 ± 0.5 mmol/L) than in survivors (3.8 ± 0.3 mmol/L, P < 0.001). Independent predictors of death were amount of paraquat ingested (hazard ratio 1.005; 95 % confidence interval 1.002-1.007), serum potassium (0.498, 0.277-0.897), bicarbonate (0.934, 0.876-0.995), and white blood cell count (1.032, 1.001-1.065). For receiver operating characteristic curve analysis, serum potassium had an area under the curve of 0.852 (95 % confidence interval 0.784-0.920, P < 0.001), and the best cutoff value was 3.5 mmol/L (sensitivity, 88.2 %; specificity, 75.6 % in predicting survivors). Kaplan-Meier analysis showed that decreased serum potassium concentrations were associated with an increase in 60-day mortality (P < 0.001). Hypokalemia may be a reliable predictor in evaluating prognosis in paraquat poisoning within 4 h. The mechanism is not clear, and further studies verifying the precise mechanism of hypokalemia are required.

The value of APACHE II in predicting mortality after paraquat poisoning in Chinese and Korean population: A systematic review and meta-analysis

BACKGROUND

The Acute Physiology and Chronic Health Evaluation II (APACHE II) score is used to determine disease severity and predict outcomes in critically ill patients. However, the prognostic significance of APACHE after acute paraquat (PQ) poisoning remains unclear. The meta-analysis was aimed to study the value of APACHE II in predicting mortality in PQ-exposed Chinese and Korean patients.

METHODS

Databases that included PubMed, Embase, Cochrane Library, and the Chinese National Knowledge Infrastructure were searched through August 2016. Studies using APACHE II to predict mortality in PQ-poisoned patients were selected. The odds ratio and weighted mean difference (WMD) were used to pool binary and continuous data. Additionally, we aggregated sensitivity, specificity, and other measures of accuracy. Statistical analyses were made using the Stata V.13.0 software.

RESULTS

This study included 29 studies, and 25 studies evaluated APACHE II scores on admission. Pooled data showed that survivors had significantly lower total scores than nonsurvivors (WMD = -7.29, and I = 98.2%, both P <.05). The pooled sensitivity of an APACHE II score ≥5 for predicting mortality was 75% and the pooled specificity was 86%. The positive likelihood ratio (PLR) was 5.3 and the negative likelihood ratio (NLR) was 0.29. The pooled sensitivity of an APACHE II score ≥10 for predicting mortality was 88% and the pooled specificity was 84%. The pooled PLR and NLR was 5.5 and 0.15, respectively.

CONCLUSION

This study showed PQ-poisoned nonsurvivors had significantly higher APACHE II score than did survivors. APACHE II scores satisfactorily predicted mortality.

Predictive values of urine paraquat concentration, dose of poison, arterial blood lactate and APACHE II score in the prognosis of patients with acute paraquat poisoning

The present study investigated the predictive values of urine paraquat (PQ) concentration, dose of poison, arterial blood lactate and Acute Physiology and Chronic Health Evaluation (APACHE) II score in the prognosis of patients with acute PQ poisoning. A total of 194 patients with acute PQ poisoning, hospitalized between April 2012 and January 2014 at the First Affiliated Hospital of P.R. China Medical University (Shenyang, China), were selected and divided into survival and mortality groups. Logistic regression analysis, receiver operator characteristic (ROC) curve analysis and Kaplan-Meier curve were applied to evaluate the values of urine paraquat (PQ) concentration, dose of poison, arterial blood lactate and (APACHE) II score for predicting the prognosis of patients with acute PQ poisoning. Initial urine PQ concentration (C0), dose of poison, arterial blood lactate and APACHE II score of patients in the mortality group were significantly higher compared with the survival group (all P<0.05). Logistic regression analysis revealed that C0, dose of poison and arterial blood lactate correlated with mortality risk of acute PQ poisoning (all P<0.05). ROC curve analysis suggested that the areas under the curve (AUC) values of C0, dose of poison, arterial blood lactate and APACHE II score in predicting the mortality of patients within 28 days were 0.921, 0.887, 0.808 and 0.648, respectively. The AUC of C0 for predicting early and delayed mortality were 0.890 and 0.764, respectively. The AUC values of urine paraquat concentration the day after poisoning (Csec) and the rebound rate of urine paraquat concentration in predicting the mortality of patients within 28 days were 0.919 and 0.805, respectively. The 28-day survival rate of patients with C0 ≤32.2 µg/ml (42/71; 59.2%) was significantly higher when compared with patients with C0 >32.2 µg/ml (38/123; 30.9%). These results suggest that the initial urine PQ concentration may be the optimal index for predicting the prognosis of patients with acute PQ poisoning. Additionally, dose of poison, arterial blood lactate, Csec and rebound rate also have referential significance.

External validation of the prognostic index in acute paraquat poisoning

OBJECTIVE

Some studies have evaluated the prognostic indicators associated with acute paraquat (PQ) poisoning. In this study, we externally validated the Yamaguchi index, which showed a good prognostic relevance in predicting the outcome of PQ poisoning.

METHODS

A retrospective analysis of 297 patients was performed. The Yamaguchi index was calculated using the following equation: Eq1 = (K(+) × HCO3(-))/(Creatinine × 0.088)(mEq/L) against time from PQ ingestion (T). The patients were divided into three groups: group A: Eq1 > 1500 - 399 × log T, group B: 930 - 399 × log T < Eq1 ≤ 1500 - 399 × log T, and group C: Eq1 ≤ 930 - 399 × log T).

RESULTS

The overall mortality rate was 65.3% (194 of 297). The mortality rates of the three groups stratified by the Yamaguchi index were 7.1% (2 of 28), 22.4% (15 of 67), and 87.6% (177 of 202). The area under the receiver-operating characteristic curve for predicting mortality from the external validation of the Yamaguchi index was 0.842 (95% confidence interval: 0.795-0.882).

CONCLUSION

The Yamaguchi index is a reliable prognostic factor and could be helpful in predicting mortality due to PQ poisoning.

Predictors of acute respiratory distress syndrome in patients with paraquat intoxication

Introduction

Paraquat 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 Methods

In 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.

Results

The 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 AKIN_48-h scores (P<0.009), SOFA_48-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), SOFA_48-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 SOFA_48-h scores <3 and SOFA_48-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 SOFA_48-h scores (P<0.001) had a better discriminatory power than blood paraquat concentrations (P=0.01) for predicting ARDS.

Conclusions

The analytical results indicate that SOFA_48-h scores, blood paraquat concentrations, and steroid and cyclophosphamide pulse therapies are significantly associated with ARDS complications after paraquat intoxication.

Sequential organ failure assessment score can predict mortality in patients with paraquat intoxication

Introduction

Paraquat poisoning is characterized by multi-organ failure and pulmonary fibrosis with respiratory failure, resulting in high mortality and morbidity. The objective of this study was to identify predictors of mortality in cases of paraquat poisoning. Furthermore, we sought to determine the association between these parameters.

Methods

A total of 187 patients were referred for management of intentional paraquat ingestion between January 2000 and December 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 mortality were analyzed.

Results

Overall hospital mortality for the entire population was 54% (101/187). Using a multivariate logistic regression model, it was found that age, time to hospitalization, blood paraquat level, estimated glomerular filtration rate at admission (eGFR _{first day}), and the SOFA_48-h score, but not the AKIN_48-h score, were significant predictors of mortality. For predicting the in-hospital mortality, SOFA_48-h scores displayed a good area under the receiver operating characteristic curve (AUROC) (0.795±0.033, P<0.001). The cumulative survival rate differed significantly between patients with SOFA_48-h scores <3 and those ≥3 (P<0.001). A modified SOFA (mSOFA) score was further developed by using the blood paraquat level, and this new score also demonstrated a better AUROC (0.848±0.029, P<0.001) than the original SOFA score. Finally, the cumulative survival rate also differed significantly between patients with mSOFA scores <4 and ≥4 (P<0.001).

Conclusion

The analytical data demonstrate that SOFA and mSOFA scores, which are based on the extent of organ function or rate of organ failure, help to predict mortality after intentional paraquat poisoning.

Triage vital signs predict in-hospital mortality among emergency department patients with acute poisoning: a case control study

BACKGROUND

To document the relationship between triage vital signs and in-hospital mortality among emergency department (ED) patients with acute poisoning.

METHODS

Poisoning patients who admitted to our emergency department during the study period were enrolled. Patient's demographic data were collected and odds ratios (OR) of triage vital signs to in-hospital mortality were assessed. Receiver operating characteristic curve was used to determine the proper cut-off value of vital signs that predict in-hospital mortality. Logistic regression analysis was performed to test the association of in-hospital mortality and vital signs after adjusting for different variables.

RESULTS

997 acute poisoning patients were enrolled, with 70 fatal cases (6.7%). A J-shaped relationship was found between triage vital signs and in-hospital mortality. ED triage vital signs exceed cut-off values independently predict in-hospital mortality after adjusting for variables were as follow: body temperature <36 or >37°C, p < 0.01, OR = 2.8; systolic blood pressure <100 or >150 mmHg, p < 0.01, OR: 2.5; heart rate <35 or >120 bpm, p < 0.01, OR: 3.1; respiratory rate <16 or >20 per minute, p = 0.38, OR: 1.4.

CONCLUSIONS

Triage vital signs could predict in-hospital mortality among ED patients with acute poisoning. A J-curve relationship was found between triage vital signs and in-hospital mortality. ED physicians should take note of the extreme initial vital signs in these patients.

Factors associated with the decline in suicide by pesticide poisoning in Taiwan: a time trend analysis, 1987-2010

OBJECTIVE

Pesticide self-poisoning accounts for one-third of suicides worldwide, but few studies have investigated the national epidemiology of pesticide suicide in countries where it is a commonly used method. We investigated trends in pesticide suicide, and factors associated with such trends, in Taiwan, a rapidly developing East Asian country.

METHODS

We conducted an ecological study using graphical approaches and Spearman's correlation coefficients to examine trends in pesticide suicide (1987-2010) in Taiwan in relation to pesticide sales, bans on selected pesticides, the proportion of the workforce involved in agriculture and unemployment. We compared pesticide products banned by the Taiwanese government with products that remained on the market and pesticides that accounted for the most poisoning deaths in Taiwan.

RESULTS

Age-standardised rates of pesticide suicide showed a 67% reduction from 7.7 per 100,000 (42% of all suicides) in 1987 to 2.5 per 100,000 (12% of all suicides) in 2010, in contrast to a 69% increase in suicide rates by other methods. Pesticide poisoning was the most commonly used method of suicide in 1987 but had become the third most common method by 2010. The reduction was paralleled by a 66% fall in the workforce involved in agriculture but there was no strong evidence for its association with trends in pesticide sales, bans on selected pesticide products or unemployment. The bans mostly post-dated the decline in pesticide suicides; furthermore, they did not include products (e.g. paraquat) that accounted for most deaths and were mainly restricted to selected high-strength formulated products whilst their equivalent low-strength products were not banned.

CONCLUSIONS

Access to pesticides, indicated by the size of agricultural workforce, appears to influence trends in pesticide suicide in Taiwan. Targeted bans on pesticides should focus on those products that account for most deaths.