Efficacy and Safety of Plasma Exchange Combined with Hemoperfusion in the Treatment of Organophosphorus Poisoning: A Meta-Analysis.

INTRODUCTION: The aim of the study was to systematically evaluate the efficacy and safety of plasma exchange combined with hemoperfusion in the treatment of organophosphorus poisoning. METHODS: PubMed, Embase, the Cochrane Library, China National Knowledge Internet, Wanfang database, and Weipu database were searched for articles about this subject. Literature screening and selection were conducted in strict accordance with the inclusion and exclusion criteria. RESULTS: 14 randomized controlled trials with 1,034 participants were included in this meta-analysis study, including 518 cases in plasma exchange combined with hemoperfusion group (the combination treatment group) and 516 cases in hemoperfusion group (the control group). Compared with the control group, the combination treatment group was associated with a higher effective rate (relative risk [RR] = 1.20, 95% confidence interval [CI] [1.11, 1.30], p < 0.00001) and lower fatality rate (RR = 0.28, 95% CI [0.15, 0.52], p< 0.0001); reduced TNF-α (standardized mean difference [SMD] = -1.95, 95% CI [-2.42, -1.48], p < 0.00001), IL-6 (SMD = -1.94, 95% CI [-3.08, -0.80], p = 0.0009), and C-reactive protein (CRP) (SMD = -1.94, 95% CI [-2.86, -1.03], p < 0.0001); shorten coma time (SMD = -1.99, 95% CI [-2.75, -1.24], p < 0.00001), recovery time of cholinesterase activity (SMD = -1.71, 95% CI [-1.90, -1.53], p < 0.00001), and hospital stay (SMD = -1.29, 95% CI [-1.59, -0.98], p < 0.00001). The incidence of complications in the combination treatment group such as liver and kidney damage (RR = 0.30, 95% CI [0.18, 0.50], p < 0.00001), pulmonary infection (RR = 0.29, 95% CI [0.18, 0.47], p < 0.00001), and intermediate syndrome (RR = 0.32, 95% CI [0.21, 0.49], p < 0.00001) was lower than that in the control group. CONCLUSIONS: The current evidence suggests that the combination of plasma exchange with hemoperfusion therapy can reduce the mortality of patients with organophosphorus poisoning, shorten the recovery time of cholinesterase activity and the time of coma, reduce the average length of hospital stay, and reduce the levels of IL-6, TNF-α, and CRP, but high-quality randomized double-blind controlled trials are still required to confirm the current findings in the future.

Study of Organophosphorus Compound Poisoning in a Tertiary Care Hospital and the Role of Peradeniya Organophosphorus Poisoning Scale as a Prognostic Marker of the Outcome.

Organophosphate compounds (OPC) cause most selfpoisoning deaths in India due to their easy availability and lack of stringent laws. AIM: To evaluate the clinical profile and outcome of the patients presenting with OPC poisoning and to study the prognostic value of Peradeniya Organophosphorus Poisoning Scale (POPS) in predicting the clinical outcomes. MATERIAL: This was a prospective study involving 100 patients of OPC poisoning admitted to Tata Main Hospital from June 2018 to May 2020 based on the inclusion criteria. Demographic profile, clinical features, treatment details, and need for ventilatory support were noted. POPS was applied on admission, and the patients were followed up for the outcome in terms of morbidity and mortality. OBSERVATION: Of the 100 patients, most patients were between 20 and 29 years with male to female ratio being 1.2:1. Vomiting (94%), followed by excessive secretions (84%) were the most common symptoms. Overall mortality was 22%. On grading of severity as per the POP scale, 27% of the patients had mild poisoning, 37% patients had moderate, whereas 36% had severe poisoning. Only 11.11% of the patients with POPS 0-3 required ventilator support, whereas 16.2% of the patients with POPS 4-7, and 100% of patients with POPS 8-11 required ventilator assistance (P < 0.0001). Similarly, the total dose of atropine required (P < 0.0001), length of intensive care unit (ICU) stay, complications, and mortality (P < 0.0001) were significantly associated with higher POPS. CONCLUSION: POPS at admission, correlated well with the need for ventilator support, the total dose of atropine required, length of stay in the ICU, complications, and mortality. It can thus be used for prognostication and risk stratification of patients with OPC poisoning.

Prolonged apnea after ECT in organophosphorus poisoning - the need to redefine norms.

BACKGROUND: Poisoning and deaths by organo-phosphorous (OP) compounds are one of the major causes of death in developing and poor countries, and a common admission in the emergency ward and the ICU. OP compounds act by irreversibly binding to pseudocholinesterase enzyme and hence prolong the apnea in patients being given suxamethonium. We present a unusual case of OP poisoning (OPP) in which prolonged apnea ensued in a patient of severe depression following MECT (modified electroconvulsive therapy) in which suxamethonium was used as muscle relaxant, in whom we were cautious of the side-effect of prior organophosphorus poisoning. Since the cases of OPP are very high worldwide, a thorough knowledge of the interaction of the action of the drug and the receptors on which it acts takes pride of place. This article highlights the nuances in the field of psychiatry and anaesthesia in diagnosis and management of prolonged apnea after ECT. CASE PRESENTATION: A 53/F patient consumed OP 38 days prior to MECT. Since existing literature recommend a delay of 4 weeks and a subminimal dose of suxamethonium to prevent prolonged apnea, both these points were taken into consideration. Despite 38 days post exposure to OP, and a dose of succinylcholine of < 0.3 mg/kg, the patient remained apneic for 3 h. Suxamethionum apnea was managed with elective ventilation. After recovery, patient had no residual effect. Subsequently her pseudocholinesterase levels were done which were found to be very low. CONCLUSION: This case is being presented to emphasize that behaviour of post synaptic receptors cannot be relied upon after OP poisoning and pseudocholinesterase levels needs to be mandatorily checked, irrespective of duration post-exposure. In strong suspects dibucaine number and fluoride number also needs to be estimated.

Efficacy of fresh frozen plasma transfusion in comparison with conventional regimen in organophosphate poisoning treatment: a meta-analysis study.

OBJECTIVE: To evaluating the efficacy of fresh frozen plasma (FFP) in comparison with conventional regimen in the treatment of organophosphate (OP) poisoning. METHODS: PubMed, ScopeMed, Cochrane, Scopus, and Google Scholar databases were searched. The search strategy used the following key words "organophosphate" and "poisoning or toxicity", "(atropine and oxime)", "fresh frozen plasma", "clinical trial", "outcome". The treatment with atropine or/and oxime was considered conventional therapy. The length of hospitalization, the length of ICU admission, need for mechanical ventilation and its duration, clinical recovery point, choline esterase level, mortality rate, and intermediate syndrome (IMS) occurrence were the key outcomes of interest. Databases were searched during the period of 2003-2019. Five studies were included in the analysis. RESULTS: Pooling of data showed that the relative risk (RR) of mortality in OP poisoning for five included trials comparing FFP-treated group with conventional regimen therapy was [0.563 (95% CI (0.252, 1.255)]. The summary of RR for IMS in two studies was [RR: 1.34, 95% CI (0.655, 2.742)]. In addition, there was a non-significant mean difference (MD) in hospital stay [MD: -0.106, 95% CI (-0.434, 0.223)] in three included trials. A significant MD was observed in the length of ICU admission in two trials between FFP-treated group compared to the conventional treatment group [MD: -2.672, 95% CI (-4.189, -1.154)], but after random effects meta-analysis, the changes were not significant [MD: -2.015, 95% CI (-6.308, 2.277)]. The summary of fixed-effect meta-analysis for choline esterase level in three trails was [MD: -0.117, 95% CI (-0.468, 0.234)]. The RR of ventilation requirement for two included trials in the FFP-treated group comparing to the conventional regimen therapy was [0.84, 95% CI (0.691, 1.022)] while for ventilation duration in two studies was [MD: -0.183, 95% CI (-0.567, 0.201)]. CONCLUSION: The addition of FFP to conventional therapy did not improve the outcomes of mortality, IMS, hospital length of stay, cholinesterase levels, need or duration of mechanical ventilation, and only the length of ICU stay could affect in the treated group.

Combination effect of exercise training and eugenol supplementation on the hippocampus apoptosis induced by chlorpyrifos.

The aim of this study was to investigate the combination effect of exercise training and eugenol supplementation on the hippocampus apoptosis induced by CPF. 64 adult male albino rats were randomly selected and devided into eight groups of eight including: control, exercise (EXE), chlorpyrifos (CPF), Control + Oil (Co + Oil), Control + DMSO (Co + DMSO), chlorpyrifos + eugenol (CPF + Sup), chlorpyrifos + exercise (CPF + Exe) and, chlorpyrifos + exercise + eugenol (CPF + Exe + Eu). Four experimental groups received intraperitoneal injection (5 days a week) of 3.0 mg/kg body weight CPF in DMSO for 6 consecutive weeks. The exercise groups performed aerobic 5 days per week over 4 weeks. Eugenol were administered by gavage. Finally, the animals were sacrificed using CO2 gas (a half of the rats were anesthetized with ketamine and xylazine and then perfused) to evaluate hippocampus histology and parameters. The results of this study showed that CPF injection significantly decreased BDNF, AChE and ATP in CA1 area of the hippocampus (p ˂ 0.05). Also, CA1 apoptosis by tunnel assay, it was found that CPF receiving groups with different dosage, showed a significant increase compared to other groups, which was confirmed by increasing cytochrome C and procaspase-3 in CPF groups (p ˂ 0.05). The result of this study show that 4 weeks of exercise training and eugenol supplementation does not improve the destructive effects of CPF in CA1 area of the hippocampus. As a result, it is recommended that future studies longer periods for treatment with exercise and eugenol supplementation.

Organophosphorus nerve agent poisoning: managing the poisoned patient.

Organophosphorus (OP) nerve agent poisoning made the headlines in 2018 with the nerve agent 'Novichok' poisonings in Salisbury, England. This event highlighted a gap in the knowledge of most clinicians in the UK. In response, this special article aims to enlighten and signpost anaesthetists and intensivists towards the general management of OP nerve agent poisoned patients. Drawing on a broad range of sources, we will discuss what OP nerve agents are, how they work, and how to recognise and treat OP nerve agent poisoning. OP nerve agents primarily act by inhibiting the enzyme acetylcholinesterase, causing an acute cholinergic crisis; death usually occurs through respiratory failure. The antimuscarinic agent atropine, oximes (to reactivate acetylcholinesterase), neuroprotective drugs, and critical care remain the mainstays of treatment. The risk to medical staff from OP poisoned patients appears low, especially if there is a thorough decontamination of the poisoned patient and staff wear appropriate personal protective equipment. The events in Salisbury in the past year were shocking, and the staff at Salisbury District General Hospital performed admirably in treating those affected by Novichok nerve agent poisoning. We eagerly anticipate their future clinical publications so that the medical community might learn from their valuable experiences.

Efficacy and outcomes of lipid resuscitation on organophosphate poisoning patients: A systematic review and meta-analysis.

OBJECTIVE: Organophosphate (OP) pesticides are still widely available in developing countries, leading to numerous accidental or suicidal poisonings every year. Lipid emulsion treatments are commonly used in resuscitating OP poisoning patients but few studies regarding their use have been reported. Our meta-analysis aimed to analyze the efficacy and outcomes of lipid resuscitation on OP poisoning patients. METHODS: A systematic search for associated studies was conducted in Pubmed, EMBASE, MEDLINE, the Cochrane Library and the Chinese National Knowledge Infrastructure. Collected data was pooled using Revman v5.3. Outcomes included prognosis (cured vs. mortality rates), hepatic function (serum ALT, AST, Total Bilirubin (TBIL) level), serum acetylcholinesterase (AchE) level and respiratory function (rate of respiratory muscular paralysis). RESULTS: Seven randomized controlled studies consisting of 630 patients meeting inclusion criteria were identified. Lipid emulsion helped to improve the cure rate [OR = 2.54, 95% CI (1.33, 4.86), p = 0.005] and lower the mortality rate [OR = 0.31, 95% CI (0.13, 0.74), p = 0.009]. Serum ALT, AST and TBIL in patients undergoing lipid resuscitation were lower than those in the control groups [ALT, SMD = -1.52, 95% CI (-2.64, 0.40), p = 0.008; AST, SMD = -1.66, 95% CI (-3.15, 0.16), p = 0.03; TBIL, SMD = -1.26, 95% CI (-2.32, 0.20), p = 0.02]. Serum AchE level were increased in patients treated with lipid emulsion [SMD = 2.15, 95% CI (1.60, 2.71), p < 0.00001]. Rate of respiratory muscular paralysis was lower in patients undergoing lipid resuscitation than those in the control groups [OR = 0.19, 95% CI (0.05, 0.71), p = 0.01]. CONCLUSION: Based on our meta-analysis of included RCT reports, lipid resuscitation seems likely to help improve prognosis and liver function of OP poisoning patients. However, larger multi-center RCTs are still recommended.

[Organophosphorus poisoning: Towards enzymatic treatments]. / Intoxication aux organophosphorés : vers des traitements enzymatiques.

Organophosphorus compounds (OP) are toxic molecules developed as insecticides and chemical warfare nerve agents (CWNAs). Most OP are neurotoxic and act as nervous system disruptors by blocking cholinergic transmission. They are therefore responsible for many poisonings worldwide. OP toxicity may result either from acute or chronic exposure, and their poisoning effect were evaluated using several animal models. These latter were also used for evaluating the efficacy of antidotes. Strategies based on enzymes that can trap (stoichiometric bioscavengers) or degrade (catalytic bioscavengers) OP, were particularly studied since they allow effective decontamination, without toxicity or environmental impact. This review summarizes the results obtained in vivo with enzymes through three levels: prophylaxis, treatment and external decontamination. The efficiency of enzymatic treatments in different animal models is presented and the relevance of these models is also discussed for a better extrapolation to humans.

In vivo effects of intravenous lipid emulsion on lung tissue in an experimental model of acute malathion intoxication.

Malathion can be ingested, inhaled, or absorbed through the skin, but acute toxicity is maximized when administered orally. Intravenous lipid emulsion (ILE) treatment is used as a new therapeutic method in cases of systemic toxicity caused by some lipid soluble agents. This study aimed to examine the potential treatment effect of ILE on rat lung tissue in a toxicokinetic model of malathion exposure. Twenty-one adult Wistar albino rats were randomly divided into three equal groups. The groups were organized as group I (control), group II (malathion), and group III (malathion + ILE treatment). Malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) were evaluated in lung tissues. Immunohistochemical and Western blot analyses were performed to determine the bax, bcl-2, and caspase-3 expression levels. Tissue GSH-Px and SOD activities were decreased and MDA levels were increased in the malathion group. ILE administration increased GSH-Px and SOD activity and decreased MDA levels compared to the malathion group. Furthermore, expression of bax, bcl-2, and caspase-3 significantly increased in the malathion group, and ILE infusion reduced these expression levels. The present study revealed that acute oral malathion administration increased oxidative stress and apoptosis in the lung tissue of rats. ILE infusion prevented oxidative stress and decreased the deleterious effects of malathion. Taken together, the findings of our study suggest that lipid emulsion infusion has treatment efficacy on malathion-induced lung toxicity.

Toxicology of organophosphorus compounds in view of an increasing terrorist threat.

The implementation of the Chemical Weapon Convention (CWC), prohibiting the development, production, storage and use of chemical weapons by 192 nations and the ban of highly toxic OP pesticides, especially class I pesticides according to the WHO classification, by many countries constitutes a great success of the international community. However, the increased interest of terrorist groups in toxic chemicals and chemical warfare agents presents new challenges to our societies. Almost seven decades of research on organophosphorus compound (OP) toxicology was mainly focused on a small number of OP nerve agents despite the fact that a huge number of OP analogues, many of these agents having comparable toxicity to classical nerve agents, were synthesized and published. Only limited physicochemical, toxicological and medical information on nerve agent analogues is available in the open literature. This implies potential gaps of our capabilities to detect, to decontaminate and to treat patients if nerve agent analogues are disseminated and may result in inadequate effectiveness of newly developed countermeasures. In summary, our societies may face new, up to now disregarded, threats by toxic OP which calls for increased awareness and appropriate preparedness of military and civilian CBRN defense, a broader approach for new physical and medical countermeasures and an integrated system of effective detection, decontamination, physical protection and treatment.

Acute severe organophosphate poisoning in a child who was successfully treated with therapeutic plasma exchange, high-volume hemodiafiltration, and lipid infusion.

Acute severe organophosphate poisoning is a serious complication seen in developing and agricultural countries. Pralidoxime and high dose atropine are the standard treatments. There is no consensus about acute severe organophosphate poisonings that are unresponsive to pralidoxime, atropine, and supportive therapies. We report a case of acute severe organophosphate poisoning that was unresponsive to standard treatments and successfully treated with high-volume continuous venovenous hemodiafiltration and therapeutic plasma exchange combined with lipid infusion. J. Clin. Apheresis 31:467-469, 2016. © 2015 Wiley Periodicals, Inc.

Tracheoesophageal Fistula following Endotracheal Intubation for Organophosphorus Poisoning.

Tracheoesophageal fistula (TEF) is an abnormal communication between the trachea and esophagus. Iatrogenic TEF can be due to endotracheal intubation, rigid bronchoscopy or tracheostomy. Tracheostomy tube cuff volumes and pressures require constant monitoring to avoid tracheal injury. Acquired TEF which occurs after prolonged intubation, usually develops after 15-200 days of mechanical ventilation. We report a case of a large TEF secondary to endotracheal intubation for organophosphorus poison-induced respiratory failure. Patient presented with dysphagia and recurrent aspiration pneumonia after extubation. She underwent trachea-esophageal fistulectomy and closure with a sternocleidomastoid muscle flap.

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.

Clinical management of organophosphate poisoning in pregnancy.

BACKGROUND: Acute organophosphorus pesticide poisoning during pregnancy may lead to spontaneous abortion. Now, there is no definite strategy focused on maintaining pregnancy. METHOD: This is a retrospective analysis of 2 cases of organophosphorus poisoning during pregnancy. All patients received penehyclidine hydrochloride injection,until the tracheobronchial tree is cleared of the secretions, and most secretions were dried. In addition, magnesium sulfate was used in one woman for the correction of hyperdynamic uterine activity. RESULTS: Two women all survived, one fetus died of spontaneous abortion, and one fetus died of incoordinate uterine action. The 2 women had no significant complications during postpartum period. CONCLUSION: Penehyclidine hydrochloride and magnesium sulfate may be used to treat organophosphorus during pregnancy. However, futher study and new experimental need to be designed.

Coronary artery bypass grafting in a patient with organophosphate poisoning.

A 43-year-old male, with no previous history of mental illness, was diagnosed with coronary heart disease, after which he became acutely depressed and attempted suicide by ingesting an organophosphate pesticide. He was admitted to an intensive care unit and treated with pralidoxime, atropine, and oxygen. His coronary occlusion pattern required early coronary artery bypass grafting (CABG) surgery. His family, apprehensive of a repeat suicidal attempt, requested surgery be performed as soon as possible. He recovered well from the OP poisoning and was mentally fit to express informed consent 2 weeks after admission. Seventeen days after poisoning, he underwent coronary artery bypass grafting and recovered uneventfully. Six years later, he remains in excellent health. We report this case because to the best of our knowledge there is no literature regarding CABG performed soon after organophosphate poisoning.

Early Clinical Outcome of Acute Poisoning Cases Treated in Intensive Care Unit.

INTRODUCTION: A variety of factors have influenced the significant incidence of morbidity and mortality of acute poisoning and the timely recognition and properly management of critically ill poisoned patients is a key component. The aim of this study is to reveal the reasons for ICU admission of acutely poisoned patients, the main factors influencing the course and outcome of patients in relation with clinical approaches applied, available resources and infrastructure of treatment. MATERIALS AND METHODS: This is a retrospective study based on most reachable variables extracted from patients' medical records and ED registers of patients admitted at the medical ICU of "Mother Teresa" University Hospital in Tirana over two (2012-2013) years. Demography, time of exposure, etiology and circumstances of poisonings, assessment and treatment, reasons for ICU admission, course and outcome were duly obtained. RESULTS: The number of ICU treated patients was 118, consisting in 47.4% (56) males and 52.5% (62) females which represented 10.2% of poisoned patients admitted during this two-year-period in ED and 9.2% of other etiology ICU admitted patients. Mean was 42.6 years for males, and 38 years for females. About 55.9% were urban residents and 44% rural ones. The elapsed time from toxic exposure to treatment initiation had varied between 2-6 hours, 44% arrived in the hospital <4 hours. The toxic exposures were intentional in 87.2% of cases, with a male:female ratio was 0.8:1. Agrochemicals such as Aluminum phosphide and organophosphates were involved in 77.1% of cases. Cardiovascular collapse and respiratory failure were the main clinical syndromes encountered. Mechanical ventilation was required in 31.4% of patients. The length of ICU stay was 2.73 (0.96) days and the mortality was 54.2%. CONCLUSION: This study evidenced that highly lethal toxicants used in poisoning acts such as agrochemicals, high rate of suicide, notwithstanding the infrastructure and resources available employed for ICU patients' treatment, all had played a role in the very high rate of mortality in this cluster of patients.

[Today's threat of use of organophosphorus compounds]. / Wspólczesne zagrozenie uzyciem zwiazków fosforoorganicznych.

Organophosphates are stable cholinesterases inhibitors (AChE). Inhibition of AChE activity leads to the accumulation of large amounts of acetylcholine and hyperactivity of the cholinergic system by stimulating acetylcholine receptors - muscarinic and nicotinic. This group included tabun, sarin, soman and VX gases. Exposure to gaseous form causes symptoms within a few seconds of exposure. This depends on the gas concentration in the atmosphere. The most sensitive organ is the eyes and the respiratory system. Severe poisoning are characterized by the immediate loss of consciousness with convulsions. Therapeutic management of acute poisoning organophosphorus compounds boils down to treating symptomatic and supportive vital functions. Monitoring of cardiovascular, respiratory and renal failure in intensive care gives only guarantee the effective treatment of poisoning. Properties toxic organophosphorus compounds also are of interest to terrorist groups.

Therapeutic effectiveness of sustained low-efficiency hemodialysis plus hemoperfusion and continuous hemofiltration plus hemoperfusion for acute severe organophosphate poisoning.

There is no report on the effects of sustained low-efficiency dialysis (SLED) plus hemoperfusion (HP) (SLED + HP) in patients with acute severe organophosphate (OP) poisoning (ASOPP). This study was designed to compare the therapeutic effectiveness between SLED + HP and continuous hemofiltration (CHF) plus HP (CHF + HP) in patients with ASOPP. In order to assess the two treatment methods, 56 patients with ASOPP were divided into CHF + HP group and SLED + HP group. The biochemical indicators, in-hospital duration, hemodynamic parameters, Acute Physiology, and Chronic Health Evaluation (APACHE II) score, and survival and mortality rates were compared. In both groups after treatment, the levels of serum creatine kinase isozyme MB, creatine kinase, creatinine, glutamic-oxalacetic transaminease, and glutamate-pyruvate transaminase, and the APACHE II scores on the first, second, and seventh day decreased (P < 0.05), whereas the levels of serum acetylcholinesterase increased. The two groups showed no statistical differences in in-hospital duration, biochemical indicators, APACHE II score, hemodynamic parameters, survival rate, or the mortality rate (P > 0.05). In conclusion, SLED has similar hemodynamic stability to CHF and the two treatment methods have similar effects on ASOPP patients. More importantly, SLED plus HP is relatively economical and convenient for patients with ASOPP in clinical practice.

Body mass index as a prognostic factor in organophosphate-poisoned patients.

Organophosphate poisoning is a serious clinical entity and considerable morbidity and mortality. Several factors have been identified to predict outcomes of organophosphate poisoning. Organophosphates are lipophilic and therefore predicted to have a large volume of distribution and to rapidly distribute into tissue and fat. Thus, toxic effects of organophosphate would be expected to last longer in obese patients. We investigated the relationship between obesity and clinical course in 112 acute organophosphate-poisoned patients from an initial medical record review of 234 patients. One hundred twenty-two patients were excluded: 6 were children, 14 had an uncertain history of exposure and of uncertain agent, 10 were transferred to another hospital, 67 were discharged from the emergency department because their toxicity was mild, 21 had carbamate poisoning, and 4 did not have height or weight checked. Clinical features, body mass index, Glasgow Coma Scale, laboratory findings, serum cholinesterase activity, electrocardiogram finding, management, and outcomes were examined. The lipid solubility of the implicated organophosphate was characterized by its octanol/water coefficient. Forty of 112 patients were obese. Obese patients who were poisoned by high lipophilicity organophosphate compounds had a need for longer use of mechanical ventilation, intensive care unit care, and total length of admission. Body mass index can provide a guide to physicians in predicting clinical course and management in organophosphate-poisoned patients.

Effect of acetylcholinesterase (AChE) point-of-care testing in OP poisoning on knowledge, attitudes and practices of treating physicians in Sri Lanka.

BACKGROUND: Toxicology and Emergency medicine textbooks recommend measurement of acetylcholinesterase (AChE) in all symptomatic cases of organophosphorus (OP) poisoning but laboratory facilities are limited in rural Asia. The accuracy of point-of-care (POC) acetylcholinesterase testing has been demonstrated but it remains to be shown whether results would be valued by clinicians. This study aims to assess the effect of seeing AChE POC test results on the knowledge, attitudes and practices of doctors who frequently manage OP poisoning. METHODS: We surveyed 23 clinicians, who had different levels of exposure to seeing AChE levels in OP poisoned patients, on a) knowledge of OP poisoning and biomarker interpretation, b) attitudes towards AChE in guiding poison management, oxime therapy and discharge decisions, and c) practices of ordering AChE in poisoning scenarios. RESULTS: An overall high proportion of doctors valued the test (68-89%). However, we paradoxically found that doctors who were more experienced in seeing AChE results valued the test less. Lower proportions valued the test in guidance of acute poisoning management (50%, p = 0.015) and guidance of oxime therapy (25%, p = 0.008), and it was apparent it would not generally be used to facilitate early discharge. The highest proportion of respondents valued it on admission (p < 0.001). A lack of correlation of test results with the clinical picture, and a perception that the test was a waste of money when compared to clinical observation alone were also comments raised by some of the respondents.Greater experience with seeing AChE test results was associated with increased knowledge (p = 0.034). However, a disproportionate lack of knowledge on interpretation of biomarkers and the pharmacology of oxime therapy (12-50%) was noted, when compared with knowledge on the mechanism of OP poisoning and management (78-90%). CONCLUSIONS: Our findings suggest an AChE POC test may not be valued by rural doctors. The practical use of AChE in OP poisoning management is complex, and a poor understanding of how to interpret test results may have affected its perceived utility. Future research should evaluate the impact of providing both AChE and training in interpretation on clinicians' attitudes and practice.