Relationship between blood alcohol concentration on admission and outcome in dimethoate organophosphorus self-poisoning

The role of alcohol use in pesticide suicide and self-harm: a scoping review

PURPOSE

Suicide and self-harm by pesticide self-poisoning is common in low- and middle-income countries (LMICs). Alcohol is an important risk factor for self-harm; however, little is known about its role in pesticide self-poisoning. This scoping review explores the role that alcohol plays in pesticide self-harm and suicide.

METHODS

The review followed the Joanna Briggs Institute scoping review guidance. Searches were undertaken in 14 databases, Google Scholar, and relevant websites. Articles were included if they focussed on pesticide self-harm and/or suicide and involvement of alcohol.

RESULTS

Following screening of 1281 articles, 52 were included. Almost half were case reports (n = 24) and 16 focussed on Sri Lanka. Just over half described the acute impact of alcohol (n = 286), followed by acute and chronic alcohol use (n = 9), chronic use, (n = 4,) and only two articles addressed harm to others. One systematic review/meta-analysis showed increased risk of intubation and death in patients with co-ingested alcohol and pesticides. Most individuals who consumed alcohol before self-harming with pesticides were men, but alcohol use among this group also led to pesticide self-harm among family members. Individual interventions were recognised as reducing or moderating alcohol use, but no study discussed population-level alcohol interventions as a strategy for pesticide suicide and self-harm prevention.

CONCLUSION

Research on alcohol's role in pesticide self-harm and suicide is limited. Future studies are needed to: further assess the toxicological effects of combined alcohol and pesticide ingestion, explore harm to others from alcohol including pesticide self-harm, and to integrate efforts to prevent harmful alcohol use and self-harm.

A lethal cocktail - shining a light on the relationship between alcohol use and pesticide self-poisoning

INTRODUCTION

Alcohol and pesticides are toxic substances that each cause acute and chronic harm to humans. Alcohol plays an important and complex role in pesticide self-poisoning, involving toxicological, public health, and social aspects important for research, prevention, and interventions.

ALCOHOL USE DISORDER AND SOCIAL HARMS

While the evidence on alcohol co-ingestion in the context of pesticide self-poisoning is limited, it appears that alcohol use increases complications. Even fewer studies address alcohol use disorder and dependence among pesticide self-poisoning patients. The harmful use of alcohol also impacts social life, families, and communities in several ways, including pesticide self-poisoning among individuals around the alcohol user. This, however, is vastly understudied.

OUTSIDE INFLUENCES

Agrochemicals and alcohol are produced by industries with financial interests, and the outcome of individual acts of pesticide self-poisoning depends on the lethality of the pesticide purchased and ingested. The promotion of acutely toxic pesticides by companies must be acknowledged within this issue.

CONCLUSION

The relationship between alcohol and pesticide self-poisoning is increasingly clear, but more studies are needed to guide management. We cannot ignore that pesticide self-poisoning and harmful use of alcohol occur within the context of wider, often structural, stressors and are influenced by commercial entities.

Alcohol use, self-harm and suicide: a scoping review of its portrayal in the Sri Lankan literature

Background

Suicide is a global public health problem. Compared to other middle-income countries, much literature has been generated on the topic of self-harm and suicide in Sri Lanka. Harmful use of alcohol is a well-known risk factor to self-harm and suicide, however the connection needed further exploration.

Aim

The aim was to investigate alcohol's role in self-harm and suicide in Sri Lanka to inform policy and prevention programs and future research priorities.

Methods

We performed a scoping review exploring how the association between alcohol use, self-harm and suicide in Sri Lanka is presented in scientific literature from August 1, 2008 to December 31, 2022. Thematic analysis was used to explore emerging themes.

Results

Altogether 116 peer-reviewed articles were included. Three themes emerged: (i) gendered, inter-relational explanations of alcohol's role in self-harm, (ii) hospital management of patients who co-ingested alcohol and pesticides, and (iii) proposed research and interventions targeting alcohol, self-harm and suicide. The articles' recommendations for policy, prevention and research priorities included: Family- and community-based alcohol, self-harm and suicide reduction interventions; viewing self-harm as a window of opportunity for health personnel to intervene in families affected by harmful alcohol consumption; and introduction of and increased access to treatment of alcohol use disorder at the individual level.

Conclusion

Suggestions for alcohol, self-harm, and suicide prevention interventions were primarily targeted at the community, though this might also reflect the limited treatment, mental health, and alcohol support available in the country. Future research should explore and test context-appropriate interventions integrating alcohol and self-harm prevention and treatment.

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.

Conceptualising the commercial determinants of suicide: broadening the lens on suicide and self-harm prevention

Suicide is preventable, yet, in many settings, robust suicide prevention strategies have not been implemented. Although a commercial determinants of health lens is increasingly being applied to industries important to the field of suicide prevention, the interplay between the vested interests of commercial actors and suicide has received little attention. There is a need to shift attention to the causes of the causes, directing more focus to the ways that commercial determinants influence suicide and shape suicide prevention strategies. Such a shift in perspective, with an evidence base and precedents to draw upon, has transformative potential for research and policy agendas dedicated to understanding and addressing upstream modifiable determinants of suicide and self-harm. We propose a framework intended to help guide efforts to conceptualise, research, and address the commercial determinants of suicide and their inequitable distribution. We hope these ideas and lines of inquiry help to catalyse connections between disciplines and open further debate and discussion as to how to take such an agenda forward.

Relationship Between Alcohol Co-Ingestion and Clinical Outcome in Pesticide Self-Poisoning: A Systematic Review and Meta-Analysis

AIM

Alcohol is a commonly co-ingested compound during self-poisoning with pesticides. Clinical experiences suggest alcohol co-ingestion (or withdrawal) makes patient management more difficult after self-poisoning and may contribute to poor clinical outcomes. We aimed to systematically review the world literature to explore the relationship between alcohol co-ingestion and outcome in pesticide self-poisoning.

METHODS

We searched 13 electronic databases and Google scholar, conducted citation searching and a review of reference lists to find studies which investigated the relationship of alcohol with clinical outcome of pesticide self-poisoning in different countries. Thirteen studies, including 11 case series/reports and two cohort studies were considered for inclusion.

RESULTS

Meta-analysis showed that alcohol co-ingestion in pesticide self-poisoning was associated with increased risk of death [odds ratio (OR) 4.9, 95% confidence interval (CI) 2.9-8.2 P<0.0001] and that alcohol co-ingested group required intubation eight times more often than non-co-ingested group in organophosphorus insecticide self-poisoning (OR 8.0, 95% CI 4.9-13.0 P<0.0001). Cases who co-ingested alcohol were older than non-alcohol group in two studies. One cohort study demonstrated that alcohol co-ingestion was associated with larger pesticide ingestions but did not itself affect the outcome.

CONCLUSIONS

This systematic review indicates that alcohol co-ingestion may worsen clinical outcome in pesticide self-poisoning.

Lung injury caused by aspiration of organophosphorus insecticide and gastric contents in pigs

INTRODUCTION

Patients who require mechanical ventilation after self-poisoning with ingested organophosphorus (OP) insecticides often die. Aspiration of stomach contents may contribute to lung injury and lethality. This study was designed to assess the severity of direct and indirect pulmonary injury created by pulmonary instillation of mixtures of OP insecticide, solvent (Solv) and porcine gastric juice (GJ) compared to controls.

METHODS

Terminally anaesthetised minipigs (groups n = 5) were exposed to sham bronchoscopy or given mixtures (0.5 mL/kg) of: saline, GJ, OP insecticide and GJ (OP + GJ), or Solv and GJ (Solv + GJ), placed into the right lung, and monitored for 48 h. Lung injury was assessed through analysis of bronchoalveolar lavage fluid (BALF), computed tomography and histopathology.

RESULTS

OP + GJ created a direct lung injury consisting of neutrophil infiltration, oedema and haemorrhage, as well as indirect injury to the other lung. OP + GJ directly-injured lung parenchyma had increased concentrations of BALF protein, albumin, IL-6, IL-8 and C-reactive protein (CRP) at 24 h (p < 0.05), and BALF protein, albumin and CRP at 48 h (p < 0.05), when compared with controls. Aspiration of GJ produced similar direct effects to OP + GJ but less indirect lung injury. Lung injury was less severe after Solv + GJ, for combined lung histopathology scores (vs. OP + GJ, p < 0.05) and for the proportion of directly-injured lung that was poorly/non-aerated at 48 h.

CONCLUSION

Pulmonary instillation of OP + GJ created more lung damage than controls or Solv + GJ. In patients with severe OP insecticide poisoning and reduced consciousness, early airway protection is likely to reduce pulmonary damage.

CON: Oximes should be used routinely in organophosphorus insecticide poisoning

Organophosphorus (OP) insecticide poisoning causes respiratory failure due to acetylcholinesterase (AChE) inhibition. The AChE reactivating antidote pralidoxime was developed in the 1950s and soon noted to benefit patients occupationally poisoned with the highly potent OP insecticide parathion. Routine use of pralidoxime and other oximes such as obidoxime then became widely recommended. However, nearly all severe cases of OP poisoning now result from self-poisoning with large volumes of less potent (WHO hazard class Ib and II) insecticides and co-formulated solvents. Unfortunately, oxime clinical trials have never shown benefit from their use for these patients, and some have shown that pralidoxime may be associated with harm, including increased mortality. Oximes should not be used routinely for the care of OP insecticide poisoned patients until translational and clinical studies have identified a safe and effective oxime regimen and identified the patients who benefit.

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.

Acute phenthoate self-poisoning: a prospective case series

BACKGROUND

The clinical characteristics following self-poisoning with organophosphorus (OP) insecticides differs according to the insecticide ingested. Phenthoate is a dimethoxy WHO Hazard Class II OP pesticide with limited literature on its clinical characteristics and outcome. We aimed to better understand its clinical characteristics by studying patients with phenthoate self-poisoning in Sri Lanka.

METHODS

We conducted a prospective cohort study of patients presenting with phenthoate self-poisoning to eight hospitals in Sri Lanka between 2002 and 2018. Clinical outcomes were recorded for each patient. Blood samples for measuring plasma phenthoate concentration, cholinesterase activity, and response to oximes were available for a very small number of patients recruited to a clinical trial.

RESULTS

Two hundred and ninety-two patients who ingested agricultural phenthoate formulations were included in the study. Median time to admission was 3.9 (IQR 2.4 - 6.8) h. Forty-two (14.4%) patients were intubated, mostly (30/37, 81%) within 24 h of ingestion (median time to intubation 7.2 [IQR 2.6-20.9] h). Median duration of intubation was 74.8 (IQR 26.8-232.5) h; the longest duration in a survivor was 592 h. Nineteen died (case fatality 6.5%, 95% CI 4.0-10.0); median time to death was 37 (IQR 16 - 101.7) h. Median plasma phenthoate concentration in patients with samples (n = 81) was 135 (IQR 62.7-356.5) ng/mL (0.42 µmol/mL [0.2 to 1.1 µmol/mL]). Five of six patients receiving pralidoxime chloride 2 g showed an initial increase in AChE and BuChE activity that was not sustained despite an infusion of pralidoxime.

CONCLUSION

Phenthoate self-poisoning has a 6.5% case fatality rate. Most patients who experience respiratory failure undergo early intubation; most deaths occurred among those patients who were intubated less than 24 h after ingestion. There was a non-sustained increase in cholinesterase activity with pralidoxime, but further studies are required to analyse the extent to which oximes are clinically effective in phenthoate self-poisoning.

Organophosphorus compounds and oximes: a critical review

Organophosphorus (OP) pesticides and nerve agents still pose a threat to the population. Treatment of OP poisoning is an ongoing challenge and burden for medical services. Standard drug treatment consists of atropine and an oxime as reactivator of OP-inhibited acetylcholinesterase and is virtually unchanged since more than six decades. Established oximes, i.e. pralidoxime, obidoxime, TMB-4, HI-6 and MMB-4, are of insufficient effectiveness in some poisonings and often cover only a limited spectrum of the different nerve agents and pesticides. Moreover, the value of oximes in human OP pesticide poisoning is still disputed. Long-lasting research efforts resulted in the preparation of countless experimental oximes, and more recently non-oxime reactivators, intended to replace or supplement the established and licensed oximes. The progress of this development is slow and none of the novel compounds appears to be suitable for transfer into advanced development or into clinical use. This situation calls for a critical analysis of the value of oximes as mainstay of treatment as well as the potential and limitations of established and novel reactivators. Requirements for a straightforward identification of superior reactivators and their development to licensed drugs need to be addressed as well as options for interim solutions as a chance to improve the therapy of OP poisoning in a foreseeable time frame.

Factors associated with outcomes in organophosphate and carbamate poisoning: a retrospective study

Organophosphate and carbamate (OPC) poisoning is a major global health hazard requiring immediate medical intervention. Atropine (ATR) is an essential antidote in organophosphate and carbamate poisoning, with the inclusion of cholinesterase reactivators and other anticholinergics, namely pralidoxime (PAM) and glycopyrrolate (GPR). This study aimed to compare the efficacy of various treatment regimens and identify the factors affecting mortality. The data of patients presented at the emergency unit with the consumption of OPC compounds between the years 2013 and 2017 were retrospectively reviewed. The study population was then categorized into four treatment patterns (1) ATR alone, (2) ATR and PAM, (3) ATR and GPR, (4) ATR, PAM and GPR. The outcome of the patients was assessed in terms of survival, intubation, ICU days, and days of ventilation and hospitalization. Univariate and multivariate analyses were performed to investigate the risk factors associated with mortality and odds ratio (OR). A total of 441 patients were included in the study, of which 69.16% were males, and 375 patients survived. Consumption of poison with a suicidal intention was reported in 98.19% of the patients, and the treatment with ATR and PAM (42.86%) was observed to have lower days of ventilation in comparison to the treatment with ATR and GPR (p = 0.003). Patients requiring intubation were also lowest in the group treated with ATR and PAM (27.51%). The age group of > 50 years (OR 4.275 [CI 2.179-8.387]), male gender (OR 2.608 [CI 1.258-5.406]), and the treatment pattern with ATR, PAM and GPR (OR 2.233 [CI 1.002-4.040]) were independently associated with mortality. In summary, male gender, elderly population, and treatment patterns followed adversely affected the outcome in patients with OPC poisoning.

Differences between organophosphates in respiratory failure and lethality with poisoning post the 2011 bans in Sri Lanka

Introduction: Self-poisoning with organophosphorus pesticides (OPs) has high morbidity and mortality. The most toxic OP formulations have been progressively banned in Sri Lanka over the past three decades. However, respiratory failure (RF) requiring ventilation remains a major contributor to fatalities. Therefore, this study was conducted to examine the frequency of RF and death after poisoning with the currently available OPs to determine if further bans might be warranted to reduce the burden of OP poisoning in Sri Lanka.Methods: Five hundred and forty patients with confirmed OP self-poisoning were prospectively observed throughout their hospital stay following admission to Peradeniya hospital in the Central Province of Sri Lanka. Clinical data including the time and duration of intubation were documented prospectively in structured datasheets.Results: One hundred and forty-nine patients required ventilation (27%), and 34 (23%) of those died. Males with alcohol co-ingestion were more likely to develop RF. Compared to other OPs, profenofos (Odds Ratio [OR] = 2.5, 95% CI: 1.5-3.9), and quinalphos (OR = 4.5, 95% CI: 1.6-12.6) were more likely to, and chlorpyrifos (OR = 0.2, 95% CI: 0.1-0.4) less likely to lead to RF than other OPs. Profenofos was also associated with higher mortality (OR = 2.3, 95% CI: 1.1-4.6) than other OPs. The median time to intubation was longer for profenofos, but the duration of intubation was similar for all OP formulations.Conclusion: RF and deaths following OP ingestion continue to be a major problem in Sri Lanka, with profenofos being the major current agent of concern. Strategies to replace profenofos and quinalphos use with less toxic insecticides should be explored. Doctors should be alert to the high probability of delayed and prolonged RF after profenofos poisoning.

Novel Clinical Toxicology and Pharmacology of Organophosphorus Insecticide Self-Poisoning

Organophosphorus insecticide self-poisoning is a major global health problem, killing over 100,000 people annually. It is a complex multi-organ condition, involving the inhibition of cholinesterases, and perhaps other enzymes, and the effects of large doses of ingested solvents. Variability between organophosphorus insecticides—in lipophilicity, speed of activation, speed and potency of acetylcholinesterase inhibition, and in the chemical groups attached to the phosphorus—results in variable speed of poisoning onset, severity, clinical toxidrome, and case fatality. Current treatment is modestly effective, aiming only to reactivate acetylcholinesterase and counter the effects of excess acetylcholine at muscarinic receptors. Rapid titration of atropine during resuscitation is lifesaving and can be performed in the absence of oxygen. The role of oximes in therapy remains unclear. Novel antidotes have been tested in small trials, but the great variability in poisoning makes interpretation of such trials difficult. More effort is required to test treatments in adequately powered studies.

Relationship between alcohol co-ingestion and outcome in profenofos self-poisoning - A prospective case series

INTRODUCTION

The importance of alcohol co-ingestion for outcome in organophosphorus (OP) insecticide self-poisoning has only been studied for the relatively hydrophilic dimethyl insecticide, dimethoate. We aimed to assess the effect of alcohol in acute poisoning with the lipophilic S-alkyl OP insecticide, profenofos.

METHODOLOGY

Demographic and clinical data, including an alcohol history, were prospectively collected from all cases of acute poisoning with agricultural profenofos EC50 presenting to two Sri Lankan hospitals over seven years.

RESULTS

Of 1859 patients with acute OP insecticide self-poisoning, 243 (13.1%) reported ingestion of profenofos (male 182/243, 74.9%). Alcohol co-ingestion was reported by 64/243 (26.3%). All patients reporting alcohol co-ingestion were male (64/64 [100%] vs 118/179 [65.9%] not reporting alcohol ingestion, p<0.001). More patients reporting alcohol co-ingestion died (10/64 [15.6%] vs 10/179 [5.6%]; p = 0.013) and required intubation (13/64 [20.3%] vs 16/179 [8.9%], p = 0.016) compared to those who did not co-ingest alcohol. Using multi-logistic regression, controlling for the estimated dose ingested, age (OR 11.1 [2.5 to 48.9] for age > 35 years vs ≤35 years) and alcohol co-ingestion (OR 3.1 [1.2 to 7.9]) were independently associated with increased risk of death. Increased risk of intubation was independently associated with age (OR 3.2 [1.6 to 6.6] for age > 35 years vs ≤35 years) and alcohol co-ingestion (OR 3.2 [1.6 to 6.4]).

CONCLUSION

A history of alcohol co-ingestion, as well as older age, is independently associated with worse outcome in patients' self-poisoned with profenofos.

Substance use and suicidal ideation and behaviour in low- and middle-income countries: a systematic review

Background

Understanding relationships between substance use and suicidal ideation and behaviour (SIB) has important public health implications for suicide prevention in low- and middle-income countries (LMICs), where 75% of suicides occur. This systematic review explored the associations between substance use and SIB in LMICs.

Methods

We searched five databases using a combination of keywords for substance use, SIB and LMICs to identify English-written quantitative studies published between January 2006 and February 2016. Data were extracted to provide an overview of what is known about the topic, highlight gaps in the literature, and explore the implications of current knowledge for suicide prevention. Studies included in the review were assessed for methodological quality using the Scottish Intercollegiate Guidelines Network checklist.

Results

Analysis of included studies (N = 108) demonstrated a consistent positive association between substance use and SIB across all substances (i.e. alcohol, tobacco, cannabis, illicit drugs, non-medical use of prescription drugs), all substance use dimensions (i.e. intoxication, use, and pathological use) and all SIB dimensions (i.e. suicidal ideation, non-fatal suicidal behaviour, and suicide). Most of the available research evidence comes from upper-middle-income countries, only 22% comes from lower-middle-income and low-income countries. Most studies focused on alcohol and tobacco, while neglecting substances such as cannabis, opioids, sedatives, stimulants, misuse of prescription medication, inhalants, and hallucinogens. Most of the studies employed a cross-sectional design, were conducted within a risk-factor paradigm, and provided little information about the potential interaction between variables.

Conclusions

Public health suicide prevention policy and research in LMICs should take account of the fact that: substance use is a potentially modifiable risk factor; assessment and management of substance use is integral to the care of at-risk patients; reducing consumption and hazardous use of substances in LMICs is important for suicide prevention; and research needs to be expanded to include more theory driven research that focuses on all substance use dimensions and SIB dimensions, while employing more sophisticated statistical methods.

Electronic supplementary material

The online version of this article (10.1186/s12889-018-5425-6) contains supplementary material, which is available to authorized users.

The association of alcohol consumption with patient survival after organophosphate poisoning: a multicenter retrospective study

Organophosphate (OP) intoxication remains a serious worldwide health concern, and many patients with acute OP intoxication have also consumed alcohol. Therefore, we evaluated the association of blood alcohol concentration (BAC) with mortality among patients with OP intoxication. We retrospectively reviewed records from 135 patients who were admitted to an emergency department (ED) for OP intoxication between January 2000 and December 2012. Factors that were associated with patient survival were identified via receiver operating characteristic curve, multiple logistic regression, and Kaplan-Meier survival analyses. Among 135 patients with acute OP poisoning, 112 patients survived (overall mortality rate: 17 %). The non-survivors also exhibited a significantly higher BAC, compared to the survivors [non-survivors: 192 mg/dL, interquartile range (IQR) 97-263 mg/dL vs. survivors: 80 mg/dL, IQR 0-166.75 mg/dL; p < 0.001]. A BAC cut-off value of 173 mg/dL provided an area under the curve of 0.744 [95 % confidence interval (CI) 0.661-0.815], a sensitivity of 65.2 %, and a specificity of 81.2 %. A BAC of >173 mg/dL was associated with a significantly increased risk of 6-month mortality in the multiple logistic regression model (odds ratio 4.92, 95 % CI 1.45-16.67, p = 0.001). The Cox proportional hazard model revealed that a BAC of >173 mg/dL provided a hazard ratio of 3.07 (95 % CI 1.19-7.96, p = 0.021). A BAC of >173 mg/dL is a risk factor for mortality among patients with OP intoxication.

High lethality and minimal variation after acute self-poisoning with carbamate insecticides in Sri Lanka - implications for global suicide prevention

Background: Highly hazardous organophosphorus (OP) insecticides are responsible for most pesticide poisoning deaths. As they are removed from agricultural practice, they are often replaced by carbamate insecticides of perceived lower toxicity. However, relatively little is known about poisoning with these insecticides.

Methods: We prospectively studied 1288 patients self-poisoned with carbamate insecticides admitted to six Sri Lankan hospitals. Clinical outcomes were recorded for each patient and plasma carbamate concentration measured in a sample to confirm the carbamate ingested.

Findings: Patients had ingested 3% carbofuran powder (719), carbosulfan EC25 liquid (25% w/v, 389), or fenobucarb EC50 liquid (50% w/v, 127) formulations, carbamate insecticides of WHO Toxicity Classes Ib, II, and II, respectively. Intubation and ventilation was required for 183 (14.2%) patients while 71 (5.5%) died. Compared with carbofuran, poisoning with carbosulfan or fenobucarb was associated with significantly higher risk of death [carbofuran 2.2%; carbosulfan 11.1%, OR 5.5 (95% CI 3.0–9.8); fenobucarb 6.3%, OR 3.0 (1.2–7.1)] and intubation [carbofuran 6.1%; carbosulfan 27.0%, OR 5.7 (3.9–8.3); fenobucarb 18.9%, OR 3.6 (2.1–6.1)]. The clinical presentation and cause of death did not differ markedly between carbamates. Median time to death was similar: carbofuran 42.3 h (IQR 5.5–67.3), carbosulfan 21.3 h (11.5–71.3), and fenobucarb 25.3 h (17.3–72.1) (p = 0.99); no patients showed delayed onset of toxicity akin to the intermediate syndrome seen after OP insecticide poisoning. For survivors, median duration of intubation was 67.8 h (IQR 27.5–118.8) with no difference in duration between carbamates. Reduced GCS at presentation was associated with worse outcome although some patients with carbosulfan died after presentation with normal GCS.

Conclusions: We did not find carbamate insecticide self-poisoning to vary markedly according to the carbamate ingested although the case fatality varied according to the concentration and formulation of the insecticide. Carbamate poisoning did not appear to be much less toxic than poisoning with some liquid OP insecticide formulations, e.g., chlorpyrifos EC40, that we have previously noted in these same hospitals (Lancet 2005, 366:1452–1459; QJM 2006, 99:513–522). Replacement of WHO Class II Toxicity OP insecticides in agriculture with high-strength liquid carbamate formulations may not substantially reduce case fatality after pesticide poisoning and, therefore, global suicide rates.

Profile of adult acute cholinesterase inhibitors substances poisoning - a 30 years analysis

Objectives

The objective of this study was to assess the pattern and outcome of acute cholinesterase inhibitors substances (CIS) poisoning cases, in a cohort from a regional tertiary care hospital.

Methods

cases admitted in the Toxicology Clinic of “Sf. Spiridon” Emergency Clinic Hospital Iasi, Romania between 1983 and 2013 were studied.

Results

a total number of 606 patients were included. The reason for exposures was intentional in 70% of cases and the commonest route of poisoning was oral in 92.2%. The highest percent of cases was females (56.4), the age group 20–29 (25.4%) and the majority (66.7%) coming from rural areas, 28.2% being agricultural workers. 36.6% of cases were severe clinical forms. Overall mortality rates were 3.8%, more than half of the death patients (65.2%) had concomitant alcohol intake. It was a significant statistical association between decrease level of serum cholinesterase on admittance and severe forms (p 0.000) and between survival and deaths groups (p 0.000). The pattern of poisoning described by our retrospective study suggests that CIS poisoning are mainly preventable. The main effective goals for prevention are restriction in free accessibility to toxic pesticides, together with sustained efforts in education concerning the life-threatening danger of pesticide poisoning.

Applied clinical pharmacology and public health in rural Asia--preventing deaths from organophosphorus pesticide and yellow oleander poisoning

Self-poisoning with pesticides or plants is a major clinical problem in rural Asia, killing several hundred thousand people every year. Over the last 17 years, our clinical toxicology and pharmacology group has carried out clinical studies in the North Central Province of Sri Lanka to improve treatment and reduce deaths. Studies have looked at the effectiveness of anti-digoxin Fab in cardiac glycoside plant poisoning, multiple dose activated charcoal in all poisoning, and pralidoxime in moderate toxicity organophosphorus insecticide poisoning. More recently, using a Haddon matrix as a guide, we have started conducting public health and animal studies to find strategies that may work outside of the hospital. Based on the 2009 GSK Research in Clinical Pharmacology prize lecture, this review shows the evolution of the group's research from a clinical pharmacology approach to one that studies possible interventions at multiple levels, including the patient, the community and government legislation.

Cardiovascular autonomic modulation by nitric oxide synthases accounts for the augmented enalapril-evoked hypotension in ethanol-fed female rats

In this study, we investigated the role of nitric oxide synthase (NOS) isoforms in the enhanced enalapril-evoked hypotension in ethanol-fed female rats by examining the effect of the selective inhibitors of eNOS [N(5)-(1-iminoethyl)-l-ornithine; l-NIO], nNOS (N(ω)-propyl-l-arginine; NPLA), or iNOS (1400W) inhibition on the cardiovascular effects of enalapril in ethanol- (5% w/v) fed rats and in their pair-fed controls. In liquid diet-fed control rats, enalapril- (10 mg/kg) evoked hypotension was abolished by l-NIO (20 mg/kg), but not by NPLA (1 mg/kg) or 1400W (5 mg/kg), suggesting a preferential role for eNOS in this response. Enalapril had no effect on spectral indices of hemodynamic variability or +dP/dtmax (myocardial contractility). However, in ethanol-fed rats, the greater enalapril-evoked hypotension was associated with reductions in (i) +dP/dtmax, (ii) low-frequency/high-frequency ratio of interbeat intervals (IBILF/HF), suggesting cardiac parasympathetic dominance, and (iii) low-frequency spectral band of systolic blood pressure (BP), a marker of vasomotor sympathetic tone. While NPLA or 1400W attenuated the enalapril-evoked hemodynamic and autonomic responses in ethanol-fed rats, l-NIO virtually abolished the hypotensive response and was more efficacious in rectifying autonomic responses to enalapril. Together, these findings implicate NOS isoforms, particularly eNOS, in the altered cardiovascular autonomic control that leads to the augmented enalapril-evoked hypotension in ethanol-fed female rats.

Differential modulation by vascular nitric oxide synthases of the ethanol-evoked hypotension and autonomic dysfunction in female rats

We recently reported that chronic exposure to ethanol lowers blood pressure (BP) via altering cardiac contractility and autonomic control in female rats. In this investigation we conducted pharmacological and molecular studies to elucidate the role of constitutive and inducible nitric oxide synthase (NOS) in these hemodynamic effects of ethanol. Changes caused by selective inhibition of eNOS [N(5)-(1-iminoethyl)-l-ornithine; l-NIO], nNOS (N(ω)-propyl-l-arginine; NPLA), or iNOS (1400W) in BP, heart rate (HR), myocardial contractility index (dP/dt(max)), and power spectral indices of hemodynamic variability were evaluated in telemetered female rats receiving ethanol (5%, w/v) or control liquid diet for 8 weeks. Ethanol increased plasma nitrite/nitrate (NOx) and enhanced the phosphorylation of eNOS and nNOS, but not iNOS, in the tail artery. Ethanol also reduced BP, +dP/dt(max), low-frequency bands of interbeat intervals (IBI(LF), 0.25-0.75 Hz) and IBI(LF/HF) ratio while high-frequency bands (IBI(HF), 0.75-3 Hz) were increased, suggesting parasympathetic overactivity. l-NIO (20 mg/kg i.p.) caused greater increases in BP in control than in ethanol-fed rats but elicited similar reductions in IBI(LF/HF) and +dP/dt(max) both groups. NPLA (1 mg/kg i.p.) caused minimal effects in control rats but exacerbated the reductions in BP, +dP/dt(max), and IBI(LF/HF) in ethanol-fed rats. No hemodynamic modifications were caused by 1400W (5 mg/kg i.p.) in either rat group. Together, these findings suggest that nNOS acts tonically to offset the detrimental cardiovascular actions of ethanol in female rats, and the enhanced vascular NO bioavailability may explain the blunted l-NIO evoked pressor response in ethanol-fed rats.

Exacerbation of myocardial dysfunction and autonomic imbalance contributes to the estrogen-dependent chronic hypotensive effect of ethanol in female rats

Our previous studies showed that the hypotensive effect of chronic ethanol in female rats is reduced by ovariectomy (OVX) rats and was restored after estrogen replacement (OVXE(2)). Further, in randomly cycling rats, chronic ethanol increased cardiac parasympathetic dominance and subsequently reduced myocardial contractility and blood pressure (BP). In this study, we tested the hypothesis that alterations in myocardial contractility and sympathovagal control account for the E(2) exacerbation of the hemodynamic effects of ethanol. BP, myocardial contractility (+dP/dt(max)), and spectral cardiovascular autonomic profiles were evaluated in radiotelemetered OVX, and OVXE(2) rats receiving liquid diet with or without ethanol (5%, w/v) for 13 weeks. In OVX rats, ethanol caused modest hypotension along with significant increases in +dP/dt(max) during weeks 2-5. The high-frequency (IBI(HF), 0.75-3 Hz) and low-frequency (IBI(LF), 0.25-0.75 Hz) bands of interbeat intervals were briefly increased and decreased, respectively, by ethanol. Compared with its effects in OVX rats, chronic treatment of OVXE(2) rats with ethanol elicited significantly greater and more sustained reductions in systolic (SBP) and diastolic (DBP) blood pressures and +dP/dt(max). Altered sympathovagal balance and parasympathetic overactivity were more evident in ethanol-treated OVXE(2) rats as suggested by the sustained: (i) increases in high-frequency bands of interbeat intervals (IBI(HF), 0.75-3 Hz), and (ii) decreases in low-frequency IBI bands (IBI(LF), 0.25-0.75 Hz), IBI(LF/HF) ratio and +dP/dt(max). The plasma ethanol concentration was not affected by changes in the hormonal milieu. These findings suggest that estrogen exacerbates the ethanol-evoked reductions in myocardial contractility and BP and the associated parasympathetic overactivity in female rats.