The hazards of gastric lavage for intentional self-poisoning in a resource poor location

Prehospital Gastric Lavage for the Treatment of Critically Ill Overdose or Poisonings: A Case Report

A 72 year-old female with past medical history that included anxiety, depression, hypertension, and hyperlipidemia was found unconscious in her bed at home by family members, surrounded by pill bottles and numerous loose baclofen tablets. Emergency medical service (EMS) was activated and responded quickly, finding an unresponsive patient with snoring respirations, clenched jaw, and foamy, bilious emesis. Vital signs included bradycardia and hypoxia. Initial attempts at basic airway management were followed by movement to a waiting ambulance, and the arrival of an EMS physician and advanced paramedic. Despite use of sodium bicarbonate and multiple doses of a vasopressor, the patient developed widening QRS complex on electrocardiogram and refractory hypotension. After rapid sequence intubation, aspiration and low-volume gastric lavage was performed with a 34 F Edlich tube, resulting in removal of visible pill fragments. Subsequently, the patient's hypotension resolved, and she was transferred to the care of the emergency department in stable condition. Gastric lavage remains clinically indicated for rare cases of recent, potentially lethal ingestions of poisons without effective antidotes, and is a standard component of emergency medicine residency training. The proliferation of EMS fellowship trained physicians suggests that this procedure should be considered an option in highly select cases, and EMS physician vehicles may consider carrying Edlich lavage tubes or similar prepackaged kits.

Patterns and determinants of potentially harmful first aid practices in children with acute poisoning

OBJECTIVE

To assess the patterns and determinants of harmful first aid practices in children with acute poisoning, and identify factors influencing caregivers' pre-hospital management.

RESULTS

This study included 384 children under 12 years, with 29.4% receiving harmful first aid measures. The most common poisoning agents were household chemicals (31.5%), followed by medicines (29.2%). First aid was provided to 29.4% of children, with water and coconut milk being the most common remedies. Harmful first aid was more likely in household chemical poisoning (p = 0.046). Univariate analysis revealed associations between harmful practices and factors such as low maternal education (p = 0.002), remote healthcare access (p = 0.0001), and cultural beliefs (p = 0.003). Multivariate analysis identified remote healthcare access (p = 0.001), low socio-economic status (p = 0.001), low maternal education (p = 0.03), and cultural beliefs (p = 0.05) as significant determinants. Qualitative findings revealed knowledge gaps, financial constraints, and cultural beliefs influencing first aid decisions, highlighting the need for targeted interventions.

Gut decontamination in the poisoned patient

Poisoning management includes gastrointestinal decontamination strategies to decrease the burden of poison entering the body and change the expected severe toxicity expected to a less toxic, more favourable outcome. Common modalities are orogastric lavage, oral-activated charcoal and whole-bowel irrigation. Endoscopic retrieval and laparotomy are rare options reserved for severe ingestions and body packers. Although supporting data are generally of low quality, gastrointestinal decontamination is likely to improve patient outcome in many situations. Unfortunately, technical limitations and contraindications can explain their infrequent use. Orogastric lavage can be useful for early lethal ingestions, albeit with significant complications such as aspiration and perforation. Activated charcoal cannot adsorb every substance. Usual dosing is 1 g/kg per dose. Whole-bowel irrigation is reserved for charged molecules or substances not adsorbed to activated charcoal but requires intact gut motility. Indications depend on several factors inherent to the ingestion (dose, time, poison) and patient's characteristics. During recent decades, studies of newer pharmaceuticals or modified-release formulations showed that significant amounts of poison, especially pharmacobezoars, persist in the gut hours postingestion, thus are amenable to gastrointestinal decontamination. Improved understanding of gut motility in volunteer studies and overdose showed clinically significant reduction in drug exposure with activated charcoal. The 1-h dogma for gastrointestinal decontamination, especially activated charcoal, is now obsolete. Clinicians must perform a risk assessment for each ingestion to determine the expected benefit at the time of decision-making, choosing the modality to achieve reduction in the toxicity burden while planning for complications or contraindications.

A Case of Acute Human Self-Poisoning With Bispyribac Sodium Presenting as Lactic Acidosis

This case report describes a 65-year-old male who presented to the emergency department with significant lactic acidosis after self-poisoning by ingesting bispyribac sodium, a commonly known herbicide. This case highlights the rarity of poisoning with freely available herbicides in the literature, which may be elusive in clinical history and life-threatening in presentation. The patient had attempted to commit suicide with ingestion of an unidentified herbicide and was brought to the emergency department post two hours after the incident. He complained of abdominal pain. The hemodynamics of the patient were within normal limits. However, his initial lactate levels were elevated along with a high anion gap metabolic acidosis. The patient was provided symptomatic care and close monitoring. The ingested substance was later found to be bispyribac sodium. The patient symptomatically improved over time, with lactate levels attaining normal ranges, and was discharged after observation of 24 hours. Human ingestion of bispyribac sodium is mostly asymptomatic and non-fatal. The management in this case mainly consisted of symptomatic care. The initial presentation of herbicide poisoning in an emergency department setting as lactic acidosis and the subsequent evaluation to rule out other possible causes of lactic acidosis in the patient was challenging for the treating physician. The possibility of herbicide-mediated cellular damage and subsequent lactic acidosis is thought to be the reason for this rare presentation.

Epidemiology, risk factors, and strategies to prevent and manage poisonings due to pharmaceuticals in children in low income and low-middle income countries: A systematic review

Background

There are significant disparities in the burden of disease due to poisoning between children in low- and high-income countries (HICs). However, there is limited data on the impact of increasing pharmaceutical access in low income countries (LICs) and low-middle income countries (LMICs) on the epidemiology of and risk factors associated with poisoning in children in these settings. Furthermore, while strategies in HICs have effectively reduced the burden of disease due to poisonings in children, there is limited information regarding the efficacy of these interventions in LICs/LMICs.

Methods

We conducted a systematic review in eight databases for literature published between January 2000 to April 2022 to evaluate the epidemiology and risk factors associated with poisonings due to pharmaceuticals and effective strategies to prevent and manage them in children in LICs/LMICs. From 16 061 retrieved articles, 41 were included in the final analysis.

Results

Pharmaceuticals were a common cause of poisoning in children in LICs/LMICs, occurring in between 12.4% and 72.36% of cases. Major risk factors were unsafe medication storage and inadequate caregiver knowledge. Delayed access to care and younger age were associated with increased mortality. Prevention strategies that included education demonstrated improvements in knowledge; however, their impact on incidence and mortality was unclear. Management strategies detailed individual patient care interventions, most commonly gastric lavage and activated charcoal. Meanwhile, delayed presentation, limited provider knowledge, and inadequate laboratory resources to support therapeutic monitoring hindered optimal management.

Conclusions

The combination of educational interventions for prevention, along with regulatory processes to maximise medication storage and formulation safety, could be effective in reducing the burden of poisoning in LICs/LMICs. The development of national or regional protocols for the management of common medication poisonings, augmented by the development of poison control centers and expansion of laboratory access in facilities may help reduce the morbidity and mortality associated with pharmaceutical poisonings in children in LICs/LMICs. Further evidence regarding contextual factors, risk and benefit profiles, the pattern of poisoning, and the impact of preventive and treatment interventions specific to LICs/LMICs is needed to better refine recommendations in these settings.

Registration

PROSPERO: CRD42022315686.

Quantification of Organophosphorus Insecticide Removed by Gastric Lavage in Acutely Poisoned Patients: An Observational Study

Introduction

The effectiveness of gastric lavage in organophosphorus (OP) poisoning has not been established. We assessed the ability of gastric lavage to remove OP insecticides as a preliminary stage in assessing effectiveness.

Patients and methods

Organophosphorus poisoning patients presenting within 6 hours were included, irrespective of prior gastric lavage. A nasogastric tube was placed and gastric contents aspirated, followed by at least three cycles of gastric lavage with 200 mL of water. Samples from the initial aspirate and the first three lavage cycles were sent for identification and quantification of the OP compounds. Patients were monitored for complications of gastric lavage.

Results

Around 42 patients underwent gastric lavage. Eight (19.0%) patients were excluded from the study because of a lack of analytical standards for ingested compounds. Insecticides were detectable in the lavage samples of 24 of 34 (70.6%) patients. Lipophilic OP compounds were detected in 23 of 24 patients, while no hydrophilic OP compounds could be detected in six patients with reported ingestion of hydrophilic compounds. For chlorpyrifos poisoning (n = 10), only 0.65 mg (SD 1.2) of the estimated ingested amount (n = 5) of 8,600 mg (SD 3,200) was recovered by gastric lavage. The mean proportion of the compound removed by initial gastric aspirate was 79.4% and subsequent three cycles removed 11.5, 6.6, and 2.7%.

Conclusion

Lipophilic OP insecticides could be quantified in the stomach contents of OP poisoning patients with the first aspiration or lavage being most effective. The amount removed was very low; hence, routine use of gastric lavage for OP poisoning patients arriving within 6 hours is unlikely to be beneficial.

How to cite this article

Mathansingh AJ, Jose A, Fleming JJ, Abhilash KPP, Chandiraseharan VK, Lenin A, et al. Quantification of Organophosphorus Insecticide Removed by Gastric Lavage in Acutely Poisoned Patients: An Observational Study. Indian J Crit Care Med 2023;27(6):397-402.

Pesticide exposure and poisoning in Brazil: Outcome severity, clinical manifestations and management of cases reported to a poison control center

This work aimed to identify variables associated with increased risk of outcome severity as well as to describe clinical manifestations/symptoms and management of pesticide-related cases reported to a poison center in Brazil. An increased risk of more severe outcomes was observed when exposures occurred in rural areas, involved suicide attempts and moderately to extremely hazardous pesticides. Clinical manifestations with higher frequencies included vomiting, nausea, sialorrhea, headache, miosis and sweating. From the treatment initially applied to the patient, 51.91% encompassed gastric lavage, but this procedure was only recommended in 20.01% of cases by the CIATox. Identifying risk factors associated with poor outcome, describing clinical manifestations, and contrasting initial treatment measures adopted against those recommended by the Poison Center can help determine diagnosis, prognosis and ensure appropriate clinical interventions are used in cases of pesticide 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.

Management of pharmaceutical and recreational drug poisoning

BACKGROUND

Poisoning is one of the leading causes of admission to the emergency department and intensive care unit. A large number of epidemiological changes have occurred over the last years such as the exponential growth of new synthetic psychoactive substances. Major progress has also been made in analytical screening and assays, enabling the clinicians to rapidly obtain a definite diagnosis.

METHODS

A committee composed of 30 experts from five scientific societies, the Société de Réanimation de Langue Française (SRLF), the Société Française de Médecine d'Urgence (SFMU), the Société de Toxicologie Clinique (STC), the Société Française de Toxicologie Analytique (SFTA) and the Groupe Francophone de Réanimation et d'Urgences Pédiatriques (GFRUP) evaluated eight fields: (1) severity assessment and initial triage; (2) diagnostic approach and role of toxicological analyses; (3) supportive care; (4) decontamination; (5) elimination enhancement; (6) place of antidotes; (7) specificities related to recreational drug poisoning; and (8) characteristics of cardiotoxicant poisoning. Population, Intervention, Comparison, and Outcome (PICO) questions were reviewed and updated as needed, and evidence profiles were generated. Analysis of the literature and formulation of recommendations were then conducted according to the GRADE® methodology.

RESULTS

The SRLF-SFMU guideline panel provided 41 statements concerning the management of pharmaceutical and recreational drug poisoning. Ethanol and chemical poisoning were excluded from the scope of these recommendations. After two rounds of discussion and various amendments, a strong consensus was reached for all recommendations. Six of these recommendations had a high level of evidence (GRADE 1±) and six had a low level of evidence (GRADE 2±). Twenty-nine recommendations were in the form of expert opinion recommendations due to the low evidences in the literature.

CONCLUSIONS

The experts reached a substantial consensus for several strong recommendations for optimal management of pharmaceutical and recreational drug poisoning, mainly regarding the conditions and effectiveness of naloxone and N-acetylcystein as antidotes to treat opioid and acetaminophen poisoning, respectively.

Fundaments of Toxicology-Approach to the Poisoned Patient

Management of the poisoned patient begins with supportive care, assessment of organ function and dysfunction, and consideration of known or suspected poisons. The possibility of multiple ingestions should be considered with intentional exposures or suicide attempts. Enteric decontamination involves treatment to prevent the absorption of toxins from the gastrointestinal system and includes the use of activated charcoal. Poisoned patients may benefit from the use if antidotes are available, or enhanced elimination as with salicylate ion trapping during urinary alkalinization. The use of intravenous lipid therapy is of clinical benefit in poisoning from bupivacaine, amitriptyline, and bupropion. Hemodialysis is the most inexpensive, widely available, and most commonly used method of extracorporeal drug removal in the treatment of poisoning. Chelators with different chemical properties can bind toxic metals, providing an essential mechanism for detoxification, and may be used in combination with extracorporeal therapies such as DFO with HD for aluminum or iron, and DMSA or DMPS with HD to treat arsenic or mercury intoxication. The use of displacers with hemodialysis can be considered to augment clearance of protein-bound toxins.

Evaluation of gastric lavage efficiency and utility using a rapid quantitative method in a swine paraquat poisoning model

BACKGROUND

Gastric lavage (GL) is one of the most critical early therapies for acute paraquat (PQ) poisoning; however, details of the treatment protocol remain to be established.

METHODS

A rapid quantitative method involving sodium dithionite testing was developed. It was validated for the determination of the PQ concentrations in gastric juice and eluate samples from a swine acute PQ poisoning model with early or delay GL, or without. The vital signs, laboratory testing, and PQ plasma concentrations were collected for therapeutic effect evaluation.

RESULTS

The reaction conditions of the test were optimized for two types of samples. Early GL at one hour (H1) could improve the signs and symptoms after acute PQ poisoning at 24 hours (H24). In contrast, GL at 6 hours (H6) could only partially relieve the vital signs. The H1 GL group effectively reduced the peak of the plasma PQ concentration. In addition, the PQ concentrations in the plasma and the gastric juice were significantly decreased in both the GL groups as compared to the untreated group at H24. Moreover, there was no significant difference in the washing efficiencies calculated from the total eluates between the two GL groups. However, the washing efficiency of the first 10 L eluate is superior to that of the additional 10 L eluate.

CONCLUSION

GL only at early stage may it benefit PQ poisoning in an animal model. The currently used 20 L GL volume may need to be reduced in view of the low washing efficiency in the later 10 L eluate. The rapid quantitative method can be used for gastric juice sample and has a certain value for clinical GL practices.

Epidemiological and clinical profiles of acute poisoning in patients admitted to the intensive care unit in eastern Iran (2010 to 2017)

BACKGROUND

Acute poisoning is a common chief complaint leading to emergency department visits and hospital admissions in developing countries such as Iran. Data describing the epidemiology of different poisonings, characteristics of the clinical presentations, and the predictors of outcome are lacking. Such data can help develop more efficient preventative and management strategies to decrease morbidity and mortality related to these poisonings. This manuscript describes the epidemiology of acute poisoning among patients admitted to the intensive care unit (ICU) in Birjand, Iran.

METHODS

This retrospective, cross-sectional study was conducted to characterize acute poisonings managed in the ICU during a 7-year period from March 2010 to March 2017 in a single center in Birjand, Iran. Patient characteristics, suspected exposure, the route of exposure, and outcome data were collected from hospital medical records.

RESULTS

During the study period, 267 (64% male and 36% female) patients met inclusion criteria. Pharmaceutical medication (36.6%), opioids (26.2%) followed by pesticides (13.9%) were the most common exposures 38.2% of these cases were identified as suicide attempts. There were different frequencies in terms of xenobiotic exposure in relation to gender (p = 0.04) and the survival (p = 0.001). There was a significant difference between various xenobiotics identified as the cause of poisoning (p = 0.001). Mortality rate in our study was 19.5%. The incidence of outcomes was significantly higher in patients poisoned with opioids, pesticides, benzodiazepines, and tricyclic antidepressants (p < 0.05). The median length of hospital stay was higher in pesticide-poisoned patients (p = 0.04).

CONCLUSION

Opioids and pesticides were the most common exposures. The mortality rate of the poisoned patients in the ICU was proportionately high. The mortality rate due to opioid poisoning is a major concern and the most significant cause death due to poisoning in the region. Further monitoring and characterization of acute poisoning in Birjand, Iran is needed. These data can help develop educational and preventative programs to reduce these exposures and improve management of exposures in the prehospital and hospital settings.

Characteristics of Pesticide Poisoning in Rural and Urban Settings in Uganda

Pesticide poisoning is a significant burden on health care systems in many low-income countries. This study evaluates cases of registered pesticide poisonings treated in selected rural (N = 101) and urban (N = 212) health facilities in Uganda from January 2010 to August 2016. In the urban setting, pesticides were the most prevalent single poison responsible for intoxications (N = 212 [28.8%]). Self-harm constituted a significantly higher proportion of the total number of poisonings in urban (63.3%) compared with rural areas (25.6%) where unintentional poisonings prevailed. Men were older than women and represented a majority of around 60% of the cases in both the urban and rural settings. Unintentional cases were almost the only ones seen below the age of 10, whereas self-harm dominated among adolescents and young persons from 10 to 29 years of age. Organophosphorus insecticides accounted for 73.0% of the poisonings. Urban hospitals provided a more intensive treatment and had registered fever complications than rural health care settings. To minimize self-harm with pesticides, a restriction of pesticide availability as shown to be effective in other low-income countries is recommended. Training of health care workers in proper diagnosis and treatment of poisonings and improved equipment in the health care settings should be strengthened.

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.

Time-dependent haemoperfusion after acute paraquat poisoning

Early haemoperfusion (HP) therapy has been found to be very effective in acute paraquat (PQ) poisoning, but the effective rescue window is still uncertain. Demographic data and the type of therapies administered of 621 patients were included as confounding factors in this retrospective study. After receiver operating characteristic curve analysis and intra-group/subgroup analysis, the initiation of glucocorticoid therapy within 3 hrs of exposure with a second treatment given <21 hrs after exposure, HP initiated within 4 hrs of exposure with a second treatment given <20 hrs after exposure, the appearance of pulmonary lesions ≤8 days after exposure and six other variables were used in a multiple analysis. The strength of positivity of the PQ urine test on admission, HP initiated within 4 hrs of exposure with a second treatment given <20 hrs after exposure, the appearance of pulmonary lesions ≤8 days after exposure, and stage III AKI on admission were independent factors of survival probability. HP therapy for acute PQ poisoning was the main therapeutic intervention investigated in this study. Outcomes were time dependent, and the crucial factor was the initiation of therapy within 4 hrs of PQ poisoning followed by a second treatment within 20 hrs.

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.

Respiratory complications of organophosphorus nerve agent and insecticide poisoning. Implications for respiratory and critical care

Organophosphorus (OP) compound poisoning is a major global public health problem. Acute OP insecticide self-poisoning kills over 200,000 people every year, the majority from self-harm in rural Asia. Highly toxic OP nerve agents (e.g., sarin) are a significant current terrorist threat, as shown by attacks in Damascus during 2013. These anticholinesterase compounds are classically considered to cause an acute cholinergic syndrome with decreased consciousness, respiratory failure, and, in the case of insecticides, a delayed intermediate syndrome that requires prolonged ventilation. Acute respiratory failure, by central and peripheral mechanisms, is the primary cause of death in most cases. However, preclinical and clinical research over the last two decades has indicated a more complex picture of respiratory complications after OP insecticide poisoning, including onset of delayed neuromuscular junction dysfunction during the cholinergic syndrome, aspiration causing pneumonia and acute respiratory distress syndrome, and the involvement of solvents in OP toxicity. The treatment of OP poisoning has not changed over the last 50 years. However, a better understanding of the multiple respiratory complications of OP poisoning offers additional therapeutic opportunities.

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.

Effects of a provincial ban of two toxic organophosphorus insecticides on pesticide poisoning hospital admissions

Background.

Pesticide self-poisoning causes one third of global suicides. Sri Lanka halved its suicide rate by banning WHO Class I organophosphorus (OP) insecticides and then endosulfan. However, poisoning with Class II toxicity OPs, particularly dimethoate and fenthion, remains a problem. We aimed to determine the effect and feasibility of a ban of the two insecticides in one Sri Lankan district.

Methods.

Sale was banned in June 2003 in most of Polonnaruwa District, but not Anuradhapura District. Admissions with pesticide poisoning to the district general hospitals was prospectively recorded from 2002.

Results.

Hospital admissions for dimethoate and fenthion poisoning fell by 43% after the ban in Polonnaruwa, while increasing by 23% in Anuradhapura. The pesticide case fatality fell from 14.4% to 9.0% in Polonnaruwa (odds ratio [OR] 0.59, 95% confidence interval [CI] 0.41–0.84) and 11.3% to 10.6% in Anuradhapura (OR 0.93, 95%CI 0.70–1.25; p = 0.051). This reduction was not sustained, with case fatality in Polonnaruwa rising to 12.1% in 2006–2007. Further data analysis indicated that the fall in case fatality had actually been due to a coincidental reduction in case fatality for pesticide poisoning overall, in particular for paraquat poisoning.

Conclusions.

We found that the insecticides could be effectively banned from agricultural practice, as shown by the fall in hospital admissions, with few negative consequences. However, the ban had only a minor effect on pesticide poisoning deaths because it was too narrow. A study assessing the agricultural and health effects of a more comprehensive ban of highly toxic pesticides is necessary to determine the balance between increased costs of agriculture and reduced health care costs and fewer deaths.

Gastrointestinal decontamination in the acutely poisoned patient

Objective

To define the role of gastrointestinal (GI) decontamination of the poisoned patient.

Data Sources

A computer-based PubMed/MEDLINE search of the literature on GI decontamination in the poisoned patient with cross referencing of sources.

Study Selection and Data Extraction

Clinical, animal and in vitro studies were reviewed for clinical relevance to GI decontamination of the poisoned patient.

Data Synthesis

The literature suggests that previously, widely used, aggressive approaches including the use of ipecac syrup, gastric lavage, and cathartics are now rarely recommended. Whole bowel irrigation is still often recommended for slow-release drugs, metals, and patients who "pack" or "stuff" foreign bodies filled with drugs of abuse, but with little quality data to support it. Activated charcoal (AC), single or multiple doses, was also a previous mainstay of GI decontamination, but the utility of AC is now recognized to be limited and more time dependent than previously practiced. These recommendations have resulted in several treatment guidelines that are mostly based on retrospective analysis, animal studies or small case series, and rarely based on randomized clinical trials.

Conclusions

The current literature supports limited use of GI decontamination of the poisoned patient.

Profile and outcome of patients with acute toxicity admitted in intensive care unit: Experiences from a major corporate hospital in urban India

BACKGROUND AND AIM

There is scarcity of data from the Indian subcontinent regarding the profile and outcome of patients presenting with acute poisoning admitted to intensive care units (ICU). We undertook this retrospective analysis to assess the course and outcome of such patients admitted in an ICU of a tertiary care private hospital.

METHODS

We analyzed data from 138 patients admitted to ICU with acute poisoning between July 2006 and March 2009. Data regarding type of poisoning, time of presentation, reason for ICU admission, ICU course and outcome were obtained.

RESULTS

Seventy (50.7%) patients were males and majority (47.8%) of admissions were from age group 21 to 30 years. The most common agents were benzodiazepines, 41/138 (29.7%), followed by alcohol, 34/138 (24.63%) and opioids, 10/138 (7.2%). Thirty-two (23%) consumed two or more agents. Commonest mode of toxicity was suicidal (78.3%) and the route of exposure was mainly oral (97.8%). The highest incidence of toxicity was due to drugs (46.3%) followed by household agents (13%). Organ failure was present in 67 patients (48.5%). During their ICU course, dialysis was required in four, inotropic support in 14 and ventilator support in 13 patients. ICU mortality was 3/138 (2.8%). All deaths were due to aluminium phosphide poisoning.

CONCLUSIONS

The present data give an insight into epidemiology of poisoning and represents a trend in urban India. The spectrum differs as we cater to urban middle and upper class. There is an increasing variety and complexity of toxins, with substance abuse attributing to significant number of cases.

Organophosphorus poisoning (acute)

INTRODUCTION

Acetylcholinesterase inhibition by organophosphorus pesticides or organophosphate nerve agents can cause acute parasympathetic system dysfunction, muscle weakness, seizures, coma, and respiratory failure. Prognosis depends on the dose and relative toxicity of the specific compound, as well as pharmacokinetic factors.

METHODS AND OUTCOMES

We conducted a systematic review and aimed to answer the following clinical question: What are the effects of treatments for acute organophosphorus poisoning? We searched: Medline, Embase, The Cochrane Library, and other important databases up to April 2010 (Clinical Evidence reviews are updated periodically; please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).

RESULTS

We found 62 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.

CONCLUSIONS

In this systematic review we present information relating to the effectiveness and safety of the following interventions: activated charcoal (single or multiple doses), alpha(2) adrenergic receptor agonists, atropine, benzodiazepines, butyrylcholinesterase replacement therapy, cathartics, extracorporeal clearance, gastric lavage, glycopyrronium bromide (glycopyrrolate), ipecacuanha (ipecac), magnesium sulphate, milk or other home remedy immediately after ingestion, N-methyl-D-aspartate receptor antagonists, organophosphorus hydrolases, oximes, removing contaminated clothes and washing the poisoned person, and sodium bicarbonate.

Formulation changes and time trends in outcome following paraquat ingestion in Sri Lanka

INTRODUCTION

Deliberate self-harm with pesticides is a significant public health problem in rural Asia. We have previously shown an improved survival of patients with paraquat self-poisoning following the introduction of a new formulation with an increased emetic concentration, an alginate and a purgative in Sri Lanka. Further, formulation changes were introduced in October 2006; this study was designed to assess the impact of these changes on 6-week mortality following paraquat ingestion.

METHODS

Prospective, cohort study of patients admitted with paraquat poisoning to 10 hospitals across Sri Lanka between September 2006 and September 2008.

RESULTS

Overall, there was a significant (p < 0.001) increase in survival in the 533 patients included in this study compared to previous data (44.5 vs. 35.2% before September 2006 and 27.1% before October 2004). Patients ingesting the new INTEON formulation had a higher survival rate than those ingesting standard formulation (40.2 vs. 31.0%), but this effect was not statistically significant in Cox's proportional hazards model (hazard ratio 0.81, 95% CI 0.61?1.08 (unadjusted) and 1.17, 95% CI 0.82?1.68 (fully adjusted), respectively).

CONCLUSIONS

This study has confirmed a continued improvement in survival of patients following self-harm with paraquat in Sri Lanka in recent years; however, in contrast to previous investigations, a beneficial effect associated with the INTEON formulation could not be substantiated. This may be partly due to the large number of patients in whom paraquat concentrations were too low for analytical confirmation of the formulation (n = 105) and who had a very high survival rate (86.7%).

Acute human lethal toxicity of agricultural pesticides: a prospective cohort study

BACKGROUND

agricultural pesticide poisoning is a major public health problem in the developing world, killing at least 250,000-370,000 people each year. Targeted pesticide restrictions in Sri Lanka over the last 20 years have reduced pesticide deaths by 50% without decreasing agricultural output. However, regulatory decisions have thus far not been based on the human toxicity of formulated agricultural pesticides but on the surrogate of rat toxicity using pure unformulated pesticides. We aimed to determine the relative human toxicity of formulated agricultural pesticides to improve the effectiveness of regulatory policy.

METHODS AND FINDINGS

we examined the case fatality of different agricultural pesticides in a prospective cohort of patients presenting with pesticide self-poisoning to two clinical trial centers from April 2002 to November 2008. Identification of the pesticide ingested was based on history or positive identification of the container. A single pesticide was ingested by 9,302 patients. A specific pesticide was identified in 7,461 patients; 1,841 ingested an unknown pesticide. In a subset of 808 patients, the history of ingestion was confirmed by laboratory analysis in 95% of patients. There was a large variation in case fatality between pesticides-from 0% to 42%. This marked variation in lethality was observed for compounds within the same chemical and/or WHO toxicity classification of pesticides and for those used for similar agricultural indications.

CONCLUSION

the human data provided toxicity rankings for some pesticides that contrasted strongly with the WHO toxicity classification based on rat toxicity. Basing regulation on human toxicity will make pesticide poisoning less hazardous, preventing hundreds of thousands of deaths globally without compromising agricultural needs. Ongoing monitoring of patterns of use and clinical toxicity for new pesticides is needed to identify highly toxic pesticides in a timely manner.

Acute human self-poisoning with bispyribac-containing herbicide Nominee: a prospective observational study

INTRODUCTION

Self-poisoning with herbicides is an important reason for hospital admission and death in Asia. Although some herbicides have a well-described toxicity profile in humans, many of the newer compounds rely on extrapolation from animal results as no published literature on clinical outcomes of human self-poisoning has been described. One example of these compounds is bispyribac, a selective herbicide used in rice and wheat cultivation that is marketed in two containers, one containing bispyribac 400 g/L with a solvent and the other the surfactant, polyethylene glycol. We present the first case series of acute human self-poisoning with an herbicide product containing bispyribac.

METHODS

Clinical data for all patients who presented with acute poisoning from a bispyribac-containing herbicide (Nominee) to two general hospitals in Sri Lanka from June 2002 to January 2009 were collected prospectively. Admission and serial blood samples were collected from consenting patients to confirm exposure and to study the toxicokinetics of bispyribac, respectively.

RESULTS

One hundred ten patients with a history of bispyribac ingestion presented after a median time of 4 h post-ingestion. There were three deaths at 15, 6, and 5 h post-ingestion because of asystolic cardiac arrest. All three patients had reduced Glasgow Coma Score (GCS) (3, 12, and 13, respectively) of whom the former two had co-ingested ethanol and developed tonic-clonic seizures. Admission blood sample was obtained from the former two of these patients but bispyribac was detected in only one of these patients. The other patient presented 2.5 h post-ingestion with a GCS of 12 but bispyribac was not detected. Excluding the patient with undetectable bispyribac, a conservative estimate of the case fatality ratio at 1.81% (95% confidence interval 0.32-5.8) can be made. The majority of the remaining patients had self-limiting upper gastrointestinal symptoms and eight patients had an abnormal GCS on presentation to hospital. The overall median hospital stay was 3 days. Bispyribac was not detectable on admission in 21 patients; in the remaining patients, the median plasma concentration was 50.55 microg/mL (interquartile range 1.28-116.5; n=32). The peak concentration was noted around 3 h post-ingestion and plasma bispyribac concentration did not predict the severity of poisoning.

CONCLUSION

The majority of patients developed self-resolving symptoms and were successfully managed in rural general hospitals without transfer to larger tertiary hospitals. Patients who died developed significant poisoning within 6 h and plasma bispyribac concentrations did not appear to predict mortality. The lack of correlation between bispyribac outcomes and the available plasma concentrations may be because of exposure to nonbispyribac components or other undefined factors. Clinical outcomes from acute self-poisoning with bispyribac-containing herbicides appear to be relatively more favorable than other commonly used herbicides.

Comparative evaluation of Glasgow Coma Score and gag reflex in predicting aspiration pneumonitis in acute poisoning

PURPOSE

The purpose of the study was to assess the incidence of aspiration pneumonitis (AP) and its association with gag reflex and Glasgow Coma Score (GCS).

MATERIALS AND METHODS

In a retrospective analysis study after prospective data collection, 155 poisoned patients with GCS less than or equal to 12 were evaluated. An assessment of GCS and the quality of gag reflex was made on arrival and recorded. Intubation status before gastrointestinal decontamination was noted. All patients were subsequently followed for developing of AP.

RESULTS

The incidence of AP was 15.5%, with significant variance among patients with respect to the gag reflex, GCS, and the performance of intubation. A logistic regression model for predicting AP contained the following predictors: GCS (odds ratio [OR], 0.43; 95% confidence interval [CI], 0.30-0.62), intubation (OR, 0.07; 95% CI, 0.01-0.49), organophosphate ingestion (OR, 1.39; 95% CI, 0.96-2.01), and gastric evacuation (OR, 4.29; 95% CI, 0.94-9.51). In patients with reduced gag reflex, variations in GCS were associated with AP (OR, 0.43; 95% CI, 0.20-0.90), whereas in patients with absent gag reflex, age was the most important predictor of AP (OR, 2.67; 95% CI, 0.99-7.22).

CONCLUSIONS

A reduced GCS and a nonintubated trachea are associated with an increased incidence of AP.

Systematic review of controlled clinical trials of gastric lavage in acute organophosphorus pesticide poisoning

BACKGROUND

Organophosphorus pesticide (OP) self-poisoning is a major problem in the developing rural world. There is little clinical trial data to guide therapy, hindering the identification of best therapy. Despite the recognition of adverse effects, gastric lavage is commonly done in Asia. We aimed to identify studies assessing its effectiveness.

METHOD

We systematically searched the literature for controlled clinical studies that assessed the effect of gastric lavage in OP pesticide self-poisoning.

RESULTS

All 56 studies identified were Chinese and reported benefit from the intervention studied, including multiple gastric lavages, use of norepinephrine or pralidoxime in the lavage fluid, concurrent treatment with naloxone or scopolamine, insertion of the gastric tube via a laparotomy incision, and lavage later than 12 h post-ingestion. However, only 23 were RCTs and none presented adequate methodology for their quality to be assessed. The patient population and study treatment protocol were not defined - large variation in case fatality in the control arm of the studies (from 4.5 to 93%) suggests marked variation between studies and likely between study arms. No study compared an intervention against a control group receiving no gastric lavage or provided any data to indicate whether a significant quantity of poison was removed.

CONCLUSION

Despite widespread use of multiple gastric lavages for OP pesticide poisoning across Asia, there is currently no high-quality evidence to support its clinical effectiveness. There is a need for studies to identify in which patients and for what duration gastric lavage is able to remove significant quantities of poison. Following these studies, large clinical trials will be required to address the effectiveness and safety of gastric lavage (either single or multiple) in acute OP pesticide poisoning.

Prediction of outcome after paraquat poisoning by measurement of the plasma paraquat concentration

BACKGROUND

Paraquat is a herbicide with a good occupational safety record, but a high mortality after intentional ingestion that has proved refractory to treatment. For nearly three decades paraquat concentration-time data have been used to predict the outcome following ingestion. However, none of the published methods has been independently or prospectively validated. We aimed to use prospectively collected data to test the published predictive methods and to determine if any is superior.

METHODS

Plasma paraquat concentrations were measured on admission for 451 patients in 10 hospitals in Sri Lanka as part of large prospective cohort study. All deaths in hospital were recorded; patients surviving to hospital discharge were followed up after 3 months to detect delayed deaths. Five prediction methods that are based on paraquat concentration-time data were then evaluated in all eligible patients.

RESULTS

All methods showed comparable performance within their range of application. For example, between 4- and 24-h prediction of prognosis was most variable between Sawada and Proudfoot methods but these differences were relatively small [specificity 0.96 (95% CI: 0.90-0.99) vs. 0.89 (0.82-0.95); sensitivity 0.57 vs. 0.79, positive and negative likelihood ratios 14.8 vs. 7.40 and 0.44 vs. 0.23 and positive predictive values 0.96 vs. 0.92, respectively].

CONCLUSION

All five published methods were better at predicting death than survival. These predictions may also serve as tools to identify patients who need treatment and for some assessment to be made of new treatments that are trialled without a control group.

Critical care toxicology

Emergency physicians are regularly called on to care for critically poisoned patients. This article reviews the general approach and management of the critically poisoned patient. Specific clinical characteristics are identified that may clue the clinician into a specific toxin class as a diagnosis. Appropriate testing in the poisoned patient is reviewed. Complications of poisoning that may bring a rapid demise of the critically ill poisoned patient are highlighted and the management of those complications is discussed.

Adjuncts and Alternatives to Oxime Therapy in Organophosphate Poisoning—is There Evidence of Benefit in Human Poisoning? A Review

Organophosphate poisoning is common in developing countries. The morbidity and mortality with organophosphate poisoning is relatively high despite the use of atropine as specific antidotal therapy and oximes to reactivate acetylcholinesterase. Several adjunct and alternative therapies have been explored in animal and human studies. We reviewed the literature to ascertain if there was evidence of benefit of such therapies. Adjunct and alternative therapies included treatments to reduce poison absorption by topical application of creams, enhance toxin elimination by haemoperfusion or bioremediation and neutralise the poison by scavenging free organophosphate with cholinesterase-rich human plasma. In addition, magnesium, clonidine, diazepam, N-acetyl cysteine and adenosine receptor agonists have also been used to counteract poison effects. Detailed assessment was limited by the paucity of trials on adjunct/alternative therapies. The limited evidence from the review process suggested potential benefit from the use of human plasma infusion, early initiation of haemoperfusion and intravenous magnesium, in addition to standard therapy with atropine and pralidoxime. There appeared to be no additional benefit with alkalinisation or use of glycopyrrolate instead of atropine in human trials. Diazepam administration has been advocated by military authorities if symptoms developed following exposure to organophosphate. Bioremediation, clonidine, N-acetyl cysteine and adenosine receptor agonists have been evaluated only in animal models. The impact of adjunct and alternate therapies on outcomes in human poisoning needs to be further explored before implementation as standard treatment.

Management of acute organophosphorus pesticide poisoning

Organophosphorus pesticide self-poisoning is an important clinical problem in rural regions of the developing world, and kills an estimated 200,000 people every year. Unintentional poisoning kills far fewer people but is a problem in places where highly toxic organophosphorus pesticides are available. Medical management is difficult, with case fatality generally more than 15%. We describe the limited evidence that can guide therapy and the factors that should be considered when designing further clinical studies. 50 years after first use, we still do not know how the core treatments--atropine, oximes, and diazepam--should best be given. Important constraints in the collection of useful data have included the late recognition of great variability in activity and action of the individual pesticides, and the care needed cholinesterase assays for results to be comparable between studies. However, consensus suggests that early resuscitation with atropine, oxygen, respiratory support, and fluids is needed to improve oxygen delivery to tissues. The role of oximes is not completely clear; they might benefit only patients poisoned by specific pesticides or patients with moderate poisoning. Small studies suggest benefit from new treatments such as magnesium sulphate, but much larger trials are needed. Gastric lavage could have a role but should only be undertaken once the patient is stable. Randomised controlled trials are underway in rural Asia to assess the effectiveness of these therapies. However, some organophosphorus pesticides might prove very difficult to treat with current therapies, such that bans on particular pesticides could be the only method to substantially reduce the case fatality after poisoning. Improved medical management of organophosphorus poisoning should result in a reduction in worldwide deaths from suicide.

Multiple-dose activated charcoal in acute self-poisoning: a randomised controlled trial

BACKGROUND

The case-fatality for intentional self-poisoning in the rural developing world is 10-50-fold higher than that in industrialised countries, mostly because of the use of highly toxic pesticides and plants. We therefore aimed to assess whether routine treatment with multiple-dose activated charcoal, to interrupt enterovascular or enterohepatic circulations, offers benefit compared with no charcoal in such an environment.

METHODS

We did an open-label, parallel group, randomised, controlled trial of six 50 g doses of activated charcoal at 4-h intervals versus no charcoal versus one 50 g dose of activated charcoal in three Sri Lankan hospitals. 4632 patients were randomised to receive no charcoal (n=1554), one dose of charcoal (n=1545), or six doses of charcoal (n=1533); outcomes were available for 4629 patients. 2338 (51%) individuals had ingested pesticides, whereas 1647 (36%) had ingested yellow oleander (Thevetia peruviana) seeds. Mortality was the primary outcome measure. Analysis was by intention to treat. The trial is registered with controlled-trials.com as ISRCTN02920054.

FINDINGS

Mortality did not differ between the groups. 97 (6.3%) of 1531 participants in the multiple-dose group died, compared with 105 (6.8%) of 1554 in the no charcoal group (adjusted odds ratio 0.96, 95% CI 0.70-1.33). No differences were noted for patients who took particular poisons, were severely ill on admission, or who presented early.

INTERPRETATION

We cannot recommend the routine use of multiple-dose activated charcoal in rural Asia Pacific; although further studies of early charcoal administration might be useful, effective affordable treatments are urgently needed.

Study protocol: a randomised controlled trial of multiple and single dose activated charcoal for acute self-poisoning

BACKGROUND

The case fatality for intentional self-poisoning in rural Asia is 10-30 times higher than in the West, mostly due to the use of highly toxic poisons. Activated charcoal is a widely available intervention that may - if given early - bind to poisons in the stomach and prevent their absorption. Current guidelines recommend giving a single dose of charcoal (SDAC) if patients arrive within an hour of ingestion. Multiple doses (MDAC) may increase poison elimination at a later time by interrupting any enterohepatic or enterovascular circulations. The effectiveness of SDAC or MDAC is unknown. Since most patients present to hospital after one hour, we considered MDAC to have a higher likelihood of clinical benefit and set up a study to compare MDAC with no charcoal. A third arm of SDAC was added to help determine whether any benefit noted from MDAC resulted from the first dose or all doses.

METHODS/DESIGN

We set up a randomised controlled trial assessing the effectiveness of superactivated charcoal in unselected adult self-poisoning patients admitted to the adult medical wards of three Sri Lankan secondary hospitals. Patients were randomised to standard treatment or standard treatment plus either a single 50 g dose of superactivated charcoal dissolved in 300 ml of water or six doses every four hours. All patients with a history of poison ingestion were approached concerning the study and written informed consent taken from each patient, or their relative (for unconscious patients or those <16 yrs), recruited to the study. The exclusion criteria were: age under 14 yrs; prior treatment with activated charcoal during this poisoning episode; pregnancy; ingestion of a corrosive or hydrocarbon; requirement for oral medication; inability of the medical staff to intubate the patient with a Glasgow Coma Score <13; presentation >72 hrs post-ingestion, and previous recruitment. The primary outcome was in-hospital mortality; secondary outcomes included the occurrence of serious complications (need for intubation, time requiring assisted ventilation, fits, cardiac dysrhythmias). Analysis will be on an intention-to-treat basis; the effects of reported time to treatment after poisoning and status on admission will also be assessed.

DISCUSSION

This trial will provide important information on the effectiveness of both single and multiple dose activated charcoal in the forms of poisoning commonly seen in rural Asia. If charcoal is found to be effective, it should be possible to make it widely available across rural Asia in an affordable formulation.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN02920054.

Organophosphorus poisoning (acute)

INTRODUCTION

Acute organophosphorus poisoning occurs after dermal, respiratory, or oral exposure to either low-volatility pesticides (e.g. chlorpyrifos, dimethoate) or high-volatility nerve gases (e.g. sarin, tabun). Most cases occur in resource-poor countries as a result of occupational or deliberate exposure to organophosphorus pesticides.

METHODS AND OBJECTIVES

We conducted a systematic review and aimed to answer the following clinical question: What are the effects of treatments for acute organophosphorus poisoning? We searched: Medline, Embase, The Cochrane Library and other important databases up to August 2006 (Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).

RESULTS

We found 22 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.

CONCLUSIONS

In this systematic review we present information relating to the effectiveness and safety of the following interventions: activated charcoal, alpha2 adrenergic receptor agonists, atropine, benzodiazepines, butyrylcholinesterase replacement therapy, cathartics, extracorporeal clearance, gastric lavage, glycopyrronium bromide, ipecacuanha, magnesium sulphate, milk or other home remedies, N-methyl-D-aspartate receptor antagonists, organophosphorus hydrolases, oximes, sodium bicarbonate, washing the poisoned person and removing contaminated clothing.