Outcomes of elderly patients with organophosphate intoxication

Organophosphate toxicity patterns: A new approach for assessing organophosphate neurotoxicity

Organophosphorus compounds or organophosphates (OPs) are widely used as flame retardants, plasticizers, lubricants and pesticides. This contributes to their ubiquitous presence in the environment and to the risk of human exposure. The persistence of OPs and their bioaccumulative characteristics raise serious concerns regarding environmental and human health impacts. To address the need for safer OPs, this study uses a New Approach Method (NAM) to analyze the neurotoxicity pattern of 42 OPs. The NAM consists of a 4-step process that combines computational modeling with in vitro and in vivo experimental studies. Using spherical harmonic-based cluster analysis, the OPs were grouped into four main clusters. Experimental data and quantitative structure-activity relationships (QSARs) analysis were used in conjunction to provide information on the neurotoxicity profile of each group. Results showed that one of the identified clusters had a favorable safety profile, which may help identify safer OPs for industrial applications. In addition, the 3D-computational analysis of each cluster was used to identify meta-molecules with specific 3D features. Toxicity was found to correspond to the level of phosphate surface accessibility. Substances with conformations that minimize phosphate surface accessibility caused less neurotoxic effect. This multi-assay NAM could be used as a guide for the classification of OP toxicity, helping to minimize the health and environmental impacts of OPs, and providing rapid support to the chemical regulators, whilst reducing reliance on animal testing.

Human Poisoning with Chlorpyrifos and Cypermethrin Pesticide Mixture: Assessment of Clinical Outcome of Cases Admitted in a Tertiary Care Hospital in Taiwan

Background and Purpose

There is an overall paucity of data regarding the human toxicity of chlorpyrifos and cypermethrin pesticide mixture. Both organophosphate and pyrethroid insecticides are metabolized by carboxylesterases. Thus, its pesticide combination, organophosphates may boost the toxicity of pyrethroids via inhibited its detoxification by carboxylesterases. This study examined the clinical course, laboratory tests, and outcomes of patients with chlorpyrifos, cypermethrin or their pesticide mixture poisoning, and to determine what association, if any, might exist between these findings.

Patients and Methods

Between 2000 and 2021, 121 patients poisoned with chlorpyrifos, cypermethrin, or their pesticide mixture were treated at Chang Gung Memorial Hospital. Patients were categorized as chlorpyrifos (n=82), cypermethrin (n=27) or chlorpyrifos and cypermethrin (n=12) groups. Demographic, clinical, laboratory and mortality data were collected for analysis.

Results

The patients experienced a broad range of clinical symptoms, including aspiration pneumonia (44.6%), salivation (42.5%), acute respiratory failure (41.3%), acute kidney injury (13.9%), seizures (7.5%), hypotension (2.6%), etc. Leukocytosis (12,700±6600 /uL) and elevated serum C-reactive protein level (36.8±50.4 mg/L) were common. The acute respiratory failure rate was 41.3%, comprising 48.8% in chlorpyrifos, 11.1% in cypermethrin as well as 58.3% in chlorpyrifos and cypermethrin poisoning. Patients with chlorpyrifos and cypermethrin pesticide mixture poisoning suffered higher rates of acute respiratory failure (P=0.001) and salivation (P=0.001), but lower Glasgow Coma Scale score (P=0.011) and serum cholinesterase level (P<0.001) than other groups. A total of 17 (14.0%) patients expired. The mortality rate was 14.0%, including 17.1% in chlorpyrifos, 3.7% in cypermethrin as well as 16.7% in chlorpyrifos and cypermethrin poisoning. No significant differences in mortality rate were noted (P=0.214).

Conclusion

Chlorpyrifos pesticide accounted for the major toxicity of the pesticide mixture. While the data show a higher rate of respiratory failure in the chlorpyrifos and cypermethrin pesticide mixture group than others, other measures of toxicity such as mortality and length of stay were not increased.

Individual Risk Assessment for Population Living on the Territories Long-Term Polluted by Organochlorine Pesticides

The long-term storage of unutilized pesticides raised new problems of long-term environmental contamination. The study presents the results of surveying 151 individuals in 7 villages living close to pesticide-contaminated localities. All individuals have been surveyed concerning their consumption habits and lifestyle characteristics. An assessment of the general exposure risks of the local population was carried out using the analysis of pollutants in food products and the average levels of their consumption in the region. The cohort risk evaluation revealed that the greatest risk was associated with the regular consumption of cucumbers, pears, bell peppers, meat, and milk. The new model to estimate individual risks of long-term pesticide pollution was proposed as a calculation of the combined action of 9 risk factors, including individual genotypes, age, lifestyle, and personal pesticide consumption rates. The analysis of the predictive ability of this model showed that the final score for individual health risks corresponded to the development of chronic diseases. A high level of chromosomal aberrations was evidenced for individual genetic risk manifestations. The combined influence of all risk factors revealed contributions of 24.7% for health status and 14.2% for genetic status, while other impacts go to all unaccounted factors.

Human Poisoning with Methomyl and Cypermethrin Pesticide Mixture

There is limited literature analyzing the outcome of human poisoning with methomyl and cypermethrin pesticide mixture. Between 2002 and 2018, a total of 63 patients intoxicated with methomyl, cypermethrin, or their pesticide mixture were treated at Chang Gung Memorial Hospital. The patients were categorized into three groups based on the type of pesticide, as methomyl (n = 10), cypermethrin (n = 31), or methomyl and cypermethrin (n = 22). Demographic, clinical, laboratory, and mortality data were obtained for analysis. The patients were aged 54.9 ± 18.9 years. Following ingestion, the patients experienced a wide range of clinical symptoms, including aspiration pneumonia (50.8%), acute respiratory failure (41.3%), acute kidney injury (33.3%), multiple organ failure (19.0%), emesis (19.0%), acute hepatitis (12.7%), diarrhea (7.9%), seizures (4.8%), lacrimation (4.8%), etc. After analysis, it was found that patients with methomyl and cypermethrin poisoning suffered higher incidences of acute respiratory failure (p < 0.001), aspiration pneumonia (p = 0.004), acute kidney injury (p = 0.011), and multiple organ failure (p < 0.001) than the other groups. Laboratory analyses revealed that patients with methomyl and cypermethrin poisoning had a higher creatinine level (p = 0.011), white blood cell count (p < 0.001), and neutrophil count (p = 0.019) than the other groups. A total of seven (11.1%) patients died. The average duration of hospitalization was 9.8 ± 10.0 days. In a multivariate logistic regression model, it was revealed that methomyl pesticide (p = 0.045) or methomyl and cypermethrin pesticide mixture (p = 0.013) were significant risk factors for acute respiratory failure. Nevertheless, no mortality risk factor could be identified. Therefore, the analytical results suggest that methomyl pesticide is the major contributor to the toxicity of methomyl and cypermethrin pesticide mixture poisoning. More research is needed.

Organophosphorus Poisoning: Acute Respiratory Distress Syndrome (ARDS) and Cardiac Failure as Cause of Death in Hospitalized Patients

Industrial production of food for animals and humans needs increasing amounts of pesticides, especially of organophosphates, which are now easily available worldwide. More than 3 million cases of acute severe poisoning are estimated to occur worldwide every year, and even more cases remain unreported, while 200,000–350,000 incidentally or intentionally poisoned people die every year. Diagnostic and therapeutic procedures in organophosphate poisoning have, however, remained unchanged. In addition to several neurologic symptoms (miosis, fasciculations), hypersecretion of salivary, bronchial, and sweat glands, vomiting, diarrhea, and loss of urine rapidly induce dehydration, hypovolemia, loss of conscience and respiratory distress. Within hours, signs of acidosis due to systemic hypoxia can be observed at first laboratory investigation after hospitalization. While determination of serum-cholinesterase does not have any diagnostic value, it has been established that hypoalbuminemia alone or accompanied by an increase in creatinine, lactate, or C-reactive protein serum levels has negative prognostic value. Increased serum levels of C-reactive protein are a sign of systemic ischemia. Protective mechanical ventilation should be avoided, if possible. In fact, acute respiratory distress syndrome characterized by congestion and increased weight of the lung, accompanied by heart failure, may become the cause of death. As the excess of acetylcholine at the neuronal level can persist for weeks until enough newly, locally synthesized acetylcholinesterase becomes available (the value of oximes in reducing this time is still under debate), after atropine administration, intravenous albumin and fluid infusion should be the first therapeutic interventions to reestablish normal blood volume and normal tissue oxygenation, avoiding death by cardiac arrest.

Direct Thermal Growth of Gold Nanopearls on 3D Interweaved Hydrophobic Fibers as Ultrasensitive Portable SERS Substrates for Clinical Applications

Surface-enhanced Raman spectroscopy (SERS)-based biosensors have attracted much attention for their label-free detection, ultrahigh sensitivity, and unique molecular fingerprinting. In this study, a wafer-scale, ultrasensitive, highly uniform, paper-based, portable SERS detection platform featuring abundant and dense gold nanopearls with narrow gap distances, are prepared and deposited directly onto ultralow-surface-energy fluorosilane-modified cellulose fibers through simple thermal evaporation by delicately manipulating the atom diffusion behavior. The as-designed paper-based SERS substrate exhibits an extremely high Raman enhancement factor (3.9 × 10¹¹ ), detectability at sub-femtomolar concentrations (single-molecule level) and great signal reproductivity (relative standard deviation: 3.97%), even when operated with a portable 785-nm Raman spectrometer. This system is used for fingerprinting identification of 12 diverse analytes, including clinical medicines (cefazolin, chloramphenicol, levetiracetam, nicotine), pesticides (thiram, paraquat, carbaryl, chlorpyrifos), environmental carcinogens (benzo[a]pyrene, benzo[g,h,i]perylene), and illegal drugs (methamphetamine, mephedrone). The lowest detection concentrations reach the sub-ppb level, highlighted by a low of 16.2 ppq for nicotine. This system appears suitable for clinical applications in, for example, i) therapeutic drug monitoring for individualized medication adjustment and ii) ultra-early diagnosis for pesticide intoxication. Accordingly, such scalable, portable and ultrasensitive fibrous SERS substrates open up new opportunities for practical on-site detection in biofluid analysis, point-of-care diagnostics and precision medicine.

Clinical characteristics and early prediction of mortality risk in patients with acute organophosphate poisoning-induced shock

Objective

To further get insights of clinical characteristics of acute organophosphate poisoning-induced shock, investigate the relationship between shock and prognosis, and screen risk indicators for prognosis.

Methods

A total of 73 patients with acute organophosphate poisoning admitted to our hospital between January 2014 and December 2021 were enrolled in this retrospective study. Patients were divided into the shock group and the non-shock group. The pH value of blood, arterial blood carbon dioxide partial pressure (PaCO₂), arterial partial pressure of oxygen (PaO₂), base excess (BE), lactic acid (Lac), serum albumin (ALB), total bilirubin (TBIL), alanine aminotransferase (ALT), serum creatinine (Cr), serum potassium (K), serum calcium (Ca), serum sodium (Na), blood chloride (Cl), serum troponin I (cTNI), brain natriuretic peptide (BNP), white blood cell count (WBC), hemoglobin (HGB), platelet count (PLT), and other clinical indicators of patients were recorded. Incidence of shock, time of shock onset, and outcomes of patients were also recorded. Cox proportional hazards regression models were performed for analysis.

Results

The incidence of organophosphate poisoning-induced shock was 30.1% (22/73), and 72.7% of shock patients developed shock blood pressure within 6 h. The levels of blood lactate, ALT, Cr, cTNI, BNP, and Cl in the shock group were significantly higher than those in the non-shock group, while the level of Ca and pH value was significantly lower than that in the non-shock group (all p < 0.05). Moreover, compared with patients without shock (2.0%), the mortality rate was significantly increased in patients with shock (36.4%), which was supported by the results from adjusted Cox proportional hazards regression model. We found that shock and elevated serum creatinine were associated with increased risk of death in patients with organophosphate poisoning (shock: HR, 10.9; 95% CI 1.2-96.3; elevated serum creatinine: HR, 1.0, 95% CI 1.0-1.0).

Conclusion

This study indicated the association between elevated serum creatinine and increased mortality rates in patients with organophosphate poisoning, highlighting the importance of the comprehensive management of shock, especially the control of renal function, in these poisoning patients.

The Relative Risk of Toxico-Clinical Parameters with respect to Poisoning Severity and Outcomes in Patients with Acute Poisoning

Background

Complications or death risk factors is necessary for better monitoring and treatment. The aim of this study was to define the relative risk of toxico-clinical parameters with regard to poisoning severity and outcomes in patients with acute poisoning.

Materials and Methods

This cross-sectional study entailed of patients with acute poisoning admitted to the poisoning emergency center of khorshid hospital, Isfahan, Iran from December 2018 until March 2019. Patients (n = 300) were categorized into four groups (minor, moderate, severe, and fatal poisoning) based on severity. Multivariate logistic regression analysis was employed to calculate the odds ratio (OR) as the estimate of the relative risk of the different variables for the poisoning severity and outcomes prediction.

Results

In the minor group, opioids/opiates, alcohols, and benzodiazepines (14.7%) were the most prevalent poisoning, multidrug (23.3%) was in the moderate and severe groups and finally, pesticides poisoning (23%) was most common in the fatal group. The predictive factors for poisoning severity were pre-hospital antidote administration [OR, (95%CI); P value) [7.08 (1.77-28.34); 0.006]; loss of consciousness [4.38 (1.84-10.42), 0.001]; abnormal ECG [4.56 (1.65-12.56); 0.003]; and time interval of poisoning to admission in the hospital [1.15 (1.02-1.28); 0.01). Patients without complications was observed in 49.7% of subjects. Patients with the loss of consciousness [66.06 (2.41-180.07); 0.01); underlying disease [3.65 (1.09-12.24); 0.03]; abnormal respiration [1.14 (1.02-1.27); 0.02); have had a greater risk of complications and death.

Conclusion

Important factors for poisoning severity and/or outcome were loss of consciousness, pre-hospital antidote administration, abnormal ECG or respiration, underlying disease, and delay to presentation to hospital.

Assessing the suitability of self-healing rubber glove for safe handling of pesticides

Rubber gloves used for protection against chemicals or hazards are generally prone to tearing or leaking after repeated use, exposing the worker to potentially hazardous agents. Self-healing technology promises increased product durability and shelf life appears to be a feasible solution to address these issues. Herein, we aimed to fabricate a novel epoxidized natural rubber-based self-healable glove (SH glove) and investigate its suitability for handling pesticides safely. In this study, breakthrough time analysis and surface morphological observation were performed to determine the SH glove's ability to withstand dangerous chemicals. The chemical resistance performance of the fabricated SH glove was compared against four different types of commercial gloves at different temperatures. Using malathion as a model pesticide, the results showed that the SH glove presented chemical resistance ability comparable to those gloves made with nitrile and NR latex at room temperature and 37 °C. The self-healing test revealed that the SH glove could be self-healed and retained its chemical resistance ability close to its pre-cut value. Our findings suggested that the developed SH glove with proven chemical resistance capability could be a new suitable safety glove for effectively handling pesticides and reducing glove waste generation.