Leukocyte count: A reliable marker for the severity of organophosphate intoxication?

The relationship of serum amylase levels in acute organophosphorus poisoning with its clinical severity and outcome: a cross-sectional study

There are limited literatures studying the pancreatic involvement in organophosphate (OP) poisoning using biochemical means. This study focused on assessing the type of OP poisoning and determining the association of serum amylase levels with the patient's presentation and outcome.

Materials and methods

A cross-sectional study was carried out in the Maharajgunj Medical Campus, Tribhuwan University Teaching Hospital, Kathmandu, Nepal, after ethical approval [Ref: IRB/308 (6-11-E)]. We collected data from 172 participants with OP poisoning over the period of 2 years using nonprobability purposive sampling method. All patients with age group 16-75 years having a history of OP poisoning within the previous 24 h with clinical features and physical evidence of poisoning were included in the study. Those participants with indications of exposure to an entirely different poisons, poisoning with multiple poisons, OP poisoning along with alcohol, chronic alcoholics, comorbid conditions, taking drugs that could affect serum amylase levels (azathioprine, thiazides, furosemide, etc.), and/or treated in other hospitals after poisoning were excluded from the study. Appropriate statistical calculations were made using the statistical package for social sciences (SPSS), version 21. The P-value of less than 0.05 was considered statistically significant.

Results

Metacid (53.5%, 92) was the most common OP poison. There were significantly higher mean values of serum amylase levels either within 12 h of exposure (468.60 vs. 135.4 IU/ml, P<0.001) or after 12 h of exposure (152.0 vs. 58.9 IU/ml, P<0.001) in dead participants than alive ones. The participants with initial and after 12 h of exposure-serum amylase level 100 or more IU/ml had more than two-fold and 18-fold higher odds of severe/life-threatening severity (odds ratio=2.40, 95% CI: 1.28-4.52, P=0.007 and odds ratio=18.67, 95% CI: 8.02-43.47, P<0.001) respectively than those with less than 100 IU/ml.

Conclusions

The clinical severity of OP poisoning is directly related to serum amylase levels. Importantly, higher mean values of serum amylase levels were depicted in those participants with OP poisoning culminating to death. Thus, serum amylase level could be one of the easy measurable prognostic marker of OP poisonings.

Biochemical responses as early and reliable biomarkers of organophosphate and carbamate pesticides intoxication: A systematic literature review

Inhibition of cholinesterase (ChE) activity has been long considered as the main diagnostic method of organophosphate (OP) and carbamate pesticides poisoning; however, it has been shown that ChE activity may also be altered due to exposure to other non-organophosphorus toxicants and variety of different medical conditions. Hence, to avoid misdiagnosis, we aimed to systematically review available documents to look for additional biomarkers of OP and carbamate poisoning. The electronic databases in addition to Google scholar were searched for eligible articles on March 2022 using "organophosphate," "carbamate," and "biomarker" including all their similar terms. After collecting the relevant documents, the data were extracted and described qualitatively. In total, data of 66 articles from 51 human and 15 animal studies were extracted. Findings demonstrated that enzymes such as β-glucuronidase, neuropathy target esterase, amylase, and lipase, in addition to hematological indicators such as CBC, CRP, lactate dehydrogenase, and CPK have high sensitivity and accuracy in the diagnosis of OP poisoning. Findings suggest that using various markers for diagnosis of OP intoxication is helpful for appropriate management, and early identifying the patients at risk of death. The suggested biomarkers also help to avoid misdiagnosis of OP poisoning with other similar conditions.

Prediction of acute organophosphate poisoning severity using machine learning techniques

Poisoning with organophosphate compounds is a significant public health risk, especially in developing countries. Considering the importance of early and accurate prediction of organophosphate poisoning prognosis, the aim of this study was to develop a machine learning-based prediction model to predict the severity of organophosphate poisoning. The data of patients with organophosphate poisoning were retrospectively extracted and split into training and test sets in a ratio of 70:30. The feature selection was done by least absolute shrinkage and selection operator method. Selected features were fed into five machine learning techniques, including Histogram Boosting Gradient, eXtreme Gradient Boosting, K-Nearest Neighborhood, Support Vector Machine (SVM) (kernel = linear), and Random Forest. The Scikit-learn library in Python programming language was used to implement the models. Finally, the performance of developed models was measured using ten-fold cross-validation methods and some evaluation criteria with 95 % confidence intervals. A total of 1237 patients were used to train and test the machine learning models. According to the criteria determining severe organophosphate poisoning, 732 patients were assigned to group 1 (patients with mild to moderate poisoning) and 505 patients were assigned to group 2 (patients with severe poisoning). With an AUC value of 0.907 (95 % CI 0.89-0.92), the model developed using XGBoost outperformed other models. Feature importance evaluation found that venous blood gas-pH, white blood cells, and plasma cholinesterase activity were the top three variables that contribute the most to the prediction performance of the prognosis in patients with organophosphate poisoning. XGBoost model yield an accuracy of 90.1 % (95 % CI 0.891-0.918), specificity of 91.4 % (95 % CI 0.90-0.92), a sensitivity of 89.5 % (95 % CI 0.87-0.91), F-measure of 91.2 % (95 % CI 0.90-0.921), and Kappa statistic of 91.2 % (95 % CI 0.90-0.92). The machine learning-based prediction models can accurately predict the severity of organophosphate poisoning. Based on feature selection techniques, the most important predictors of organophosphate poisoning were VBG-pH, white blood cell count, plasma cholinesterase activity, VBG-BE, and age. The best algorithm with the highest predictive performance was the XGBoost classifier.

Initial clinical and laboratory parameters triaging non-pharmaceutical acute pediatric poisoned patients for potential adverse outcomes: a three-year retrospective study

Identifying high-risk pediatric patients with non-pharmaceutical poisoning is crucial to avoid prospective complications and decrease the evident hospital economic burden. Although the preventive strategies have been well studied, determining the early predictors for poor outcomes remains limited. Therefore, this study focused on the initial clinical and laboratory parameters as a triage of non-pharmaceutical poisoned children for potential adverse outcomes taking the causative substance effects into account. This retrospective cohort study included pediatric patients admitted to Tanta University Poison Control Center from January 2018 to December 2020. Sociodemographic, toxicological, clinical, and laboratory data were retrieved from the patient's files. Adverse outcomes were categorized into mortality, complications, and intensive care unit (ICU) admission. Out of enrolled 1,234 pediatric patients, preschool children constituted the highest percentage of the patients investigated (45.06%), with a female predominance (53.2%). The main non-pharmaceutical agents included pesticides (62.6%), corrosives (19%), and hydrocarbons (8.8%), mainly associated with adverse consequences. The significant determinants for adverse outcomes were pulse, respiratory rate, serum bicarbonate (HCO3), Glasgow Coma Scale, O2 saturation, Poisoning Severity Score (PSS), white blood cells (WBCs), and random blood sugar. The cutoffs of serum HCO3 < 17.55 mmol/l, WBCs >8,650 cells/microliter, and PSS > 2 points were the best discriminators for mortality, complications, and ICU admission, respectively. Thus, monitoring these predictors is essential to prioritize and triage pediatric patients who require high-quality care and follow-up, particularly in aluminum phosphide, sulfuric acid, and benzene intoxications.

Impact of Serum Amylase Level in the Outcome of Acute Organophosphorus Poisoning: 2-Year Cross-Sectional Study at Rural Teaching Hospital

Introduction  Prompt recognition and aggressive management of acute intoxication due to organophosphorus poisoning are essential to minimize the morbidity and mortality. The present study was undertaken to know the prognosis and outcome of organophosphorus poisoning patients with the estimation of low-cost enzymes like the serum amylase level in a population with financial constraints.

Methods  In this cross-sectional study, we had enrolled 100 cases that had a history of exposure to organophosphorus compounds, and the serum amylase level was measured in all the patients. We assessed the outcome of all the patients in the form of discharge, need of ventilators, intensive care unit stay, and death.

Results  The mean serum amylase level in discharge patients was 335.40 ± 192.45, and in the patients who died it was 843.37 ± 22.60. It was significant to predict the outcome ( t -value 7.07, p -value 0.0001, statistically significant).

Conclusion  Serum amylase level shows significant correlation with clinical outcomes in organophosphorus poisoning.

Prognostic nomogram for the severity of acute organophosphate insecticide self-poisoning: a retrospective observational cohort study

OBJECTIVE

To develop a convenient nomogram for the bedside evaluation of patients with acute organophosphorus poisoning (AOPP).

DESIGN

This was a retrospective study.

SETTING

Two independent hospitals in northern China, the First Hospital of Jilin University and the Lequn Hospital of the First Hospital of Jilin University.

PARTICIPANTS

A total of 1657 consecutive patients admitted for the deliberate oral intake of AOPP within 24 hours from exposure and aged >18 years were enrolled between 1 January 2013 and 31 December 2018. The exclusion criteria were: normal range of plasma cholinesterase, exposure to any other type of poisonous drug(s), severe chronic comorbidities including symptomatic heart failure (New York Heart Association III or IV) or any other kidney, liver and pulmonary diseases. Eight hundred and thirty-four patients were included.

PRIMARY OUTCOME MEASURE

The existence of severely poisoned cases, defined as patients with any of the following complications: cardiac arrest, respiratory failure requiring ventilator support, hypotension or in-hospital death.

RESULTS

440 patients from one hospital were included in the study to develop a nomogram of severe AOPP, whereas 394 patients from the other hospital were used for the validation. Associated risk factors were identified by multivariate logistic regression. The nomogram was validated by the area under the receiver operating characteristic curve (AUC). A nomogram was developed with age, white cells, albumin, cholinesterase, blood pH and lactic acid levels. The AUC was 0.875 (95% CI 0.837 to 0.913) and 0.855 (95% CI 0.81 to 0.9) in the derivation and validation cohorts, respectively. The calibration plot for the probability of severe AOPP showed an optimal agreement between the prediction by nomogram and actual observation in both derivation and validation cohorts.

CONCLUSION

A convenient severity evaluation nomogram for patients with AOPP was developed, which could be used by physicians in making clinical decisions and predicting patients' prognosis.

Clinical profile and outcome of acute organophosphate poisoning in children of Upper Egypt: a cross-sectional study

Background

Organophosphates are one of the most common agents of poisoning in developing countries including Egypt. Due to lack of data about characteristics of organophosphates poisoning in our localities, we aimed to evaluate its clinical pattern and factors affecting outcome.

Methods

It was a cross-sectional study conducted in South valley University hospital between January 2019 and December 2019. It included all children ≤16 years of age presented with organophosphates poisoning. Diagnosis was performed from the history taken from the patient’s relatives and presenting symptoms. Demographic data, mode and route of poisoning, time from exposure to presentation, clinical symptomatology, grading and routine investigations were evaluated in addition to treatment taken and outcome.

Results

During the study period, 108 children; mean age was 7.95 ± 4.11 years (range 1. 5-16 years) presented with organophosphorous poisoning. Sixty five (60%) cases were females and 43 (40%) were males. Unintentional acts (87%) were detected more than suicidal (13%) and inhalation route (63.8%) more than ingestion (36. 2%). Miosis was the most frequent clinical sign (100%) followed by respiratory distress (77.7%). Regarding time of presentation to emergency department, 43 (40%) cases were presented within 6 h while others presented more than 6 h post-exposure. Mechanical ventilation (MV) was needed for 14 (13%) cases and 6 (5.5%) cases died due to respiratory failure. Duration of hospital stay, mean time interval from toxic exposure to hospital presentation, leucocytosis, need for MV and cumulative dose of pralidoxime were significantly higher in non survivors than survivors while Pao2 (partial arterial oxygen) and GCS (Glasgow coma scale) were significantly lower.

Conclusion

This study concluded that time consumed till presentation to hospital, low GCS, need for MV, leucocytosis, decreased PaO2 and increased cumulative dose of pralidoxime were independent risk factors of mortality.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-021-02563-w.

Sub-chronic dermal exposure to aircraft engine oils impacts the reproductive organ weights and alters hematological profiles of Sprague Dawley rats

There is little data available for the toxicity of used aircraft engine oils relative to their unused (new) versions. This study was conducted to determine if grade 3 (G3) and 4 (G4) aircraft engine oils in their new states (G3-N and G4-N) and their used versions (G3-U and G4-U) have the potential to induce toxicity via dermal application. Male and female Sprague Dawley rats were dermally exposed to water (control), new and used versions of G3 and G4 oils to determine the oil sub-chronic toxicity potentials. A volume of 300 μL of undiluted oil was applied to the pad of the Hill Top Chamber System©. Then the chamber was attached to a fur-free test site located at the back of the rat for 6 h/day for 5 consecutive days/week for 21 days (15 total exposures). Recovery rats also received similar treatments and were kept for 14 days post-exposure to screen for reversibility, persistence, or delayed occurrence of toxic effects. Both G3 and G4 oils had a significant impact on the weight of male and female reproductive organs: testes weights for recovery rats exposed to G3-N significantly decreased (12%) relative to controls; G3-N and G3-U decreased uterus weights by 23% and 29%, respectively; G4-N decreased uterus weights by 32% but were resolved at the end of the recovery period; G4-N increased the weight of the adrenals and spleen for females by 34% and 27%, respectively, during the recovery period. G3 and G4 induced more changes in female blood indices than in those for males. Of all versions of oils, G4-N induced the most changes in profiles of female blood. G4-N significantly decreased the white blood cells, lymphocytes, neutrophils, eosinophils and increased the mean platelet volumes. Interestingly, males were not affected by exposure to G4-N oil. While G3-N decreased the white blood cells and lymphocytes for females it slightly increased those for males. In summary, G3 and G4 oils impacted the weights for male and reproductive organs. This study highlights the health risks that aircraft maintenance workers may be exposed to if precautions are not taken to minimize exposure to these oils.

•

Grade 3 and grade 4 aircraft engine oils contain organophosphate compounds.

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Dermal exposure to these oils impacted organ weights of female and male rats.

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Unused versions of these oils had more effects on blood indices than used versions.

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Females may be more susceptible to exposure to these oils than males.

Development of a practical prediction scoring system for severe acute organophosphate poisoning

Acute organophosphorus poisoning (AOPP) is a serious public health issue, especially in the rural areas. This study was designed to establish a scoring system to assess the risk of cases with severe AOPP. A retrospective cohort study was conducted at two independent hospitals. The derivation cohort included 444 patients with AOPP and the validation cohort included 274 patients. A risk score for patients with severe AOPP was developed. The rates of severe AOPP cases were 20.7% and 20.1% in the derivation and validation cohorts, respectively. A scoring system for severe AOPP risk was developed that included: (1) age >50 years, (2) white blood cell count of >15 × 10⁹ /L, (3) plasma cholinesterase of <360 U/L, (4) plasma albumin of <35 g/L, (5) blood pH <7.3, and (6) lactic acid >3.0 mmol/L. The predicted score in severe cases of AOPP had good accuracy in both the derivation (area under the receiver operating characteristic curve [AUC] 0.88, 95% confidence interval [CI], 0.85-0.92) and validation cohorts (AUC 0.83, 95% CI, 0.77-0.90). A practical bedside prediction scoring system was developed for patients with severe AOPP. The routine use of this scoring system could rapidly assist in identifying patients at higher risk who require more intensive care or transfer to a larger better-equipped hospital.

Serum ubiquitin C-terminal hydrolase L1 predicts cognitive impairment in patients with acute organophosphorus pesticide poisoning

BACKGROUND

To assess the usefulness of serum C-terminal hydrolase L1 (UCH-L1) level as a biomarker for predicting cognitive impairment in patients with acute organophosphorus pesticide poisoning (AOPP).

METHODS

Two hundred and seven adult patients with AOPP were included in this study. Serum UCH-L1 levels were assessed on admission (Day 1 postpoisoning) and on Days 3 and 7 postpoisoning. The associations between serum UCH-L1 levels, other clinical predictors, and cognitive function evaluated on Day 30 postpoisoning were investigated.

RESULTS

On multivariate analysis, serum UCH-L1 levels on admission (odds ratio [OR] 1.889, 95% confidence interval [CI] 1.609-3.082, P = 0.002) and 24-hour APACHE II score (OR 1.736, 95% CI 1.264-3.272, P = 0.012) were independent predictors of cognitive impairment on Day 30 postpoisoning. Based on the receiver operating characteristic curve, serum UCH-L1 levels >5.9 ng/mL on admission predicted cognitive impairment on Day 30 postpoisoning with 86.1% sensitivity and 72.5% specificity (area under the curve, 0.869; 95% CI 0.815-0.923). On admission [8.51 (6.53-10.22) ng/mL vs 4.25 (2.57-6.31) ng/mL, P < 0.001] and Day 3 [9.31 (7.92-10.98) ng/mL vs 3.32 (2.25-5.13) ng/mL, P < 0.001] and Day 7 [4.96 (3.28-7.26) ng/mL vs 2.27 (1.55-3.24) ng/mL, P < 0.001] postpoisoning, serum UCH-L1 concentration was significantly higher in patients that developed cognitive impairment compared to those that did not.

CONCLUSION

This study demonstrates that serum UCH-L1 level has potential as a novel biomarker for predicting cognitive impairment 30 days after AOPP.