QTc prolongation as a useful prognostic factor in 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.

Alveolar-arterial partial pressure difference as an early predictor for patients with acute paraquat poisoning

Objective

Paraquat (PQ) is associated with high mortality rates in acute poisoning. This study aimed to determine the importance of the alveolar–arterial partial pressure difference (A-aDo₂) in the expected consequences of acute PQ poisoning.

Methods

Patients who were hospitalized for PQ poisoning in 2018 were enrolled in this retrospective study. A-aDo₂ data were collected. Multivariate analysis was performed using binary logistic regression to determine whether A-aDo₂ is an independent risk factor for mortality from PQ.

Results

A total of 352 cases were analyzed. The mean PQ dose was 36.84 ± 50.30 mL (0.3–500 mL). There were 185 survivors and 167 non-survivors. The mean A-aDo₂ was not significantly correlated between survivors and non-survivors on day 1. However, there were significant differences in A-aDo₂ between survivors and non-survivors on days 3, 7, 14, and 21. Increased A-aDo₂ values were correlated with an increased mortality rate. The mean A-aDo₂ on day 14 showed the most significant difference between survivors and non-survivors.

Conclusion

Our study suggests that A-aDo₂ plays an important role as a reference index, which could be a useful predictor in assessing acute PQ poisoning, especially on the 14th day after onset of poisoning.

Hemodynamic and electromechanical effects of paraquat in rat heart

Paraquat (PQ) is a highly lethal herbicide. Ingestion of large quantities of PQ usually results in cardiovascular collapse and eventual mortality. Recent pieces of evidence indicate possible involvement of oxidative stress- and inflammation-related factors in PQ-induced cardiac toxicity. However, little information exists on the relationship between hemodynamic and cardiac electromechanical effects involved in acute PQ poisoning. The present study investigated the effects of acute PQ exposure on hemodynamics and electrocardiogram (ECG) in vivo, left ventricular (LV) pressure in isolated hearts, as well as contractile and intracellular Ca2+ properties and ionic currents in ventricular myocytes in a rat model. In anesthetized rats, intravenous PQ administration (100 or 180 mg/kg) induced dose-dependent decreases in heart rate, blood pressure, and cardiac contractility (LV +dP/dtmax). Furthermore, PQ administration prolonged the PR, QRS, QT, and rate-corrected QT (QTc) intervals. In Langendorff-perfused isolated hearts, PQ (33 or 60 μM) decreased LV pressure and contractility (LV +dP/dtmax). PQ (10-60 μM) reduced the amplitudes of Ca2+ transients and fractional cell shortening in a concentration-dependent manner in isolated ventricular myocytes. Moreover, whole-cell patch-clamp experiments demonstrated that PQ decreased the current amplitude and availability of the transient outward K+ channel (Ito) and altered its gating kinetics. These results suggest that PQ-induced cardiotoxicity results mainly from diminished Ca2+ transients and inhibited K+ channels in cardiomyocytes, which lead to LV contractile force suppression and QTc interval prolongation. These findings should provide novel cues to understand PQ-induced cardiac suppression and electrical disturbances and may aid in the development of new treatment modalities.

Platelet-lymphocyte ratio is not a prognostic predictor for acute paraquat-intoxicated patients: A retrospective analysis

This study aimed to investigate the prognostic predictive value of the platelet-lymphocyte ratio (PLR) in patients with acute paraquat (PQ) intoxication.A total of 107 patients with acute PQ intoxication via oral ingestion were admitted in Cangzhou Central Hospital from May 2012 to September 2018. Valuable detection indices were screened out by using Cox proportional hazard regression and receiver operating characteristic (ROC) curve analyses, and their diagnostic efficiency was evaluated by using Kaplan-Meier curve.The 90-day mortality was 58.9% (63/107). The Kaplan-Meier curve showed that PLR was not associated with 90-day survival (log-rank test; P = .661). In Cox proportional hazard regression analyses, PLR was not an independent risk factor. Meanwhile, the ROC curves showed that PLR had an AUC value of 0.569 (95% confidence interval: 0.459-0.679, P = .227) in predicting 90-day survival.PLR is not a prognostic predictor for patients with acute PQ intoxication.

Cardiovascular Effects and Fatality May Differ According to the Formulation of Glyphosate Salt Herbicide

This study aimed to compare adverse cardiovascular events and fatalities and to identify the risk factors for fatalities associated with the glyphosate salt herbicide formulation. Additionally, we examined whether glyphosate ammonium salt herbicides increased serum ammonia levels. One hundred forty-seven patients were divided into an ammonium group (glyphosate ammonium salt herbicide) and an isopropylamine (IPA) group (glyphosate IPA salt herbicide) according to the type of glyphosate salt formulation ingested. Although no differences in the variables were observed between the groups, the IPA group had more fatalities, a higher incidence of QTc prolongation and a higher tendency for PR prolongation than the ammonium group. Additionally, the IPA group required a longer duration of vasopressor administration. PR prolongation and age were independently associated with fatalities in glyphosate IPA salt poisoning cases in the multivariate regression. Serum ammonia levels were higher at presentation and decreased continuously during the first 48 h after presentation in the ammonium group. This study is the first to suggest potentially different toxicities, especially cardiovascular effects, of glyphosate herbicide poisoning in humans based on the glyphosate salt herbicide formulation and to determine the association between PR prolongation and fatality in glyphosate IPA salt herbicide poisoning cases.

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.

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.