Oximes in acute organophosphorus pesticide poisoning: a systematic review of clinical trials

BACKGROUND: Acute organophosphorus (OP) pesticide poisoning is widespread in the developing world. Standard treatment involves the administration of intravenous atropine and an oxime to counter acetylcholinesterase inhibition at the synapse, but the usefulness of oximes is uncertain. AIM: To assess the evidence on the use of oximes in OP poisoning. DESIGN: Systematic review. METHODS: We searched Medline, Embase, and Cochrane databases (last check 01/02/02) for 'organophosphate' or 'oxime' together with 'poisoning' or 'overdose'. We cross-referenced from other articles, and contacted experts to identify unpublished studies. A Web search engine [www.google.com] was also used, with the keywords 'organophosphate', 'oxime', and 'trial' (last check 01/02/02). RESULTS: We found two randomized controlled trials (RCTs) involving 182 patients treated with pralidoxime. The RCTs found no benefit with pralidoxime, and have been used to argue that pralidoxime should not be used in OP poisoning. DISCUSSION: The RCT authors must be congratulated for attempting important studies in a difficult environment. However, their studies did not take into account recently clarified issues regarding outcome, and their methodology is unclear. A generalized statement that pralidoxime should not be used in OP poisoning is not supported by the published results. Oximes may well be irrelevant in the overwhelming self-poisoning typical of the tropics, but a large RCT comparing the current WHO-recommended pralidoxime regimen (>30 mg/kg bolus followed by >8 mg/kg/h infusion) with placebo is needed for a definitive answer. Such a study should be designed to identify any patient subgroups that might benefit from oximes.     

电动洗胃机洗胃法的改良与评价

胸椎黄韧带骨化症的患病率在脊柱疾患中比较低，但却严重影响患者的生活质量和工作能力。采用全椎板截骨原位再植、椎管扩大成形术，可明显增加椎管矢状径，解除脊髓压迫，完善护理计划，可提高疗效，减少手术并发症，现将护理报道如下。     

Case report: severe mercuric sulphate poisoning treated with 2,3-dimercaptopropane-1-sulphonate and haemodiafiltration

Introduction

Inorganic mercury poisoning is uncommon, but when it occurs it can result in severe, life-threatening features and acute renal failure. Previous reports on the use of extracorporeal procedures such as haemodialysis and haemoperfusion have shown no significant removal of mercury. We report here the successful use of the chelating agent 2,3-dimercaptopropane-1-sulphonate (DMPS), together with continuous veno-venous haemodiafiltration (CVVHDF), in a patient with severe inorganic mercury poisoning.

Case report

A 40-year-old man presented with haematemesis after ingestion of 1 g mercuric sulphate and rapidly deteriorated in the emergency department, requiring intubation and ventilation. His initial blood mercury was 15 580 μg/l. At 4.5 hours after ingestion he was started on DMPS. He rapidly developed acute renal failure and so he was started on CVVHDF for renal support and in an attempt to improve mercury clearance; CVVHDF was continued for 14 days.

Methods

Regular ultradialysate and pre- and post-filtrate blood samples were taken and in addition all ultradialysate generated was collected to determine its mercury content.

Results

The total amount of mercury in the ultrafiltrate was 127 mg (12.7% of the ingested dose). The sieving coefficient ranged from 0.13 at 30-hours to 0.02 at 210-hours after ingestion. He developed no neurological features and was discharged from hospital on day 50. Five months after discharge from hospital he remained asymptomatic, with normal creatinine clearance.

Discussion

We describe a patient with severe inorganic mercury poisoning in whom full recovery occurred with the early use of the chelating agent DMPS and CVVHDF. There was removal of a significant amount of mercury by CVVHDF.

Conclusion

We feel that CVVHDF should be considered in patients with inorganic mercury poisoning, particularly those who develop acute renal failure, together with meticulous supportive care and adequate doses of chelation therapy with DMPS.     

Spontaneous Ignition Due to Intentional Acute Aluminum Phosphide Poisoning

Background: Acute aluminum phosphide (AlP) poisoning is one of the most common cause of acute pesticide poisoning in Iran. Spontaneous ignition is a rare finding in AlP poisoning. Objective: To present two cases of fatal AlP poisoning that involved spontaneous ignition. Case Report: Two patients presented with suicidal ingestion of AlP tablets. In the Emergency Department (ED), they received gastric lavage. During insertion of a nasogastric tube, both patients experienced spontaneous ignition, and flames were witnessed by the medical personnel. Unfortunately, both patients died due to systemic effects of AlP poisoning. Conclusion: Patients who present with acute aluminum phosphide poisoning may experience spontaneous ignition in the ED.     

农药速测卡在有机磷农药中毒患者洗胃应用中的效果评价

目的:探讨农药速测卡在快速评价有机磷中毒患者洗胃效果中的作用。方法:根据农药速测卡提示的操作规程对洗胃不同时段留取的胃液标本进行检测并根据检测结果判断洗胃是否彻底,当检测结果显示阴性时(试纸变为深蓝色)即停止洗胃。结果:用农药速测卡检测AOPP患者142例,3例洗胃前检测结果显示阴性,46例3×104ml时显示阴性,84例5×104ml时显示阴性,9例7×104ml时显示阴性。结论:农药速测卡能为AOPP患者的洗胃效果提供客观的评价依据,但其检测速度、评价效率仍需进一步探讨。     

Repetitive Endoscopy and Continuous Alkaline Gastric Irrigation in a Case of Arsenic Poisoning

Background: The poor prognosis of patients with persistent gastrointestinal radio-opacities after oral arsenic poisoning supports efficient gastrointestinal decontamination as critical for survival. In a case of massive arsenic ingestion, we performed repetitive gastric endoscopy and a continuous alkaline irrigation of the stomach over several days.Case Report: A 41-year-old woman was admitted 4 hours after intentional ingestion of trivalent arsenic powder 5 g. The admission abdominal X-ray confirmed the presence of multiple gastric opacities. Initial treatment was gastric lavage with normal saline, dimercaprol chelation, and supportive therapy. Since gastric opacities persisted on the abdominal X-ray at 34 hours despite repeated gastric lavage, a gastroscopy was performed showing nonremovable agglomerates. In an attempt to achieve further gastric decontamination, we performed a continuous gastric alkaline irrigation. After 3 days of alkaline irrigation, the abdomen was normal on X-ray but the gastroscopy still showed arsenic concretions. Alkaline irrigation was continued for another 3 days until total disappearance of arsenic agglomerates at the gastroscopy. Admission urinary arsenic was 3663 μgmg/L. A total of 46.2-mg of inorganic arsenic, or less than 1% the ingested dose, was extracted from the stomach by this technique. The patient was discharged from the intensive care unit 20 days after admission without sequelae.     

Survival Pattern in Patients with Acute Organophosphate Poisoning Receiving Intensive Care

Background. Approximately 35% of patients acutely poisoned with organophosphates (OP) in developing countries like Sri Lanka require intensive care and mechanical ventilation. However, death rates remain high. Objective. To study the outcomes and predictors of mortality in patients with acute OP poisoning requiring intensive therapy at a regional center in Sri Lanka over a period of 40 months. Methods. Retrospective analysis of all intensive care records of patients with acute OP poisoning admitted to the Intensive Care Unit (ICU) between March 1998 and July 2001. Results. During the study period, 126 subjects were admitted to the ICU with acute OP poisoning. Records of 10 patients were lost and those of 37 were incomplete and hence were excluded. All the remaining 71 patients (59 male) had required endotracheal intubation and mechanical ventilation for a period of four (median) days (range 1–27) in addition to gastric lavage and standard therapy with atropine and oximes and adequate hydration. Of these 71 patients, 36 (28 male) had died. Life table analysis demonstrated a steep decline in the cumulative survival to 67% during the first three days. Systolic blood pressure of < 100 mmHg and FiO₂ of > 40% to maintain a SpO₂ of > 92% within the first 24 h were recognized as poor prognostic indicators among mechanically ventilated patients. Conclusion. Mortality following OP poisoning remains high despite adequate respiratory support, intensive care, and specific therapy with atropine and oximes. One‐third of the subjects needing mechanical ventilation and reaching intensive care units die within the first 72 h of poisoning. Systolic blood pressure of less than 100 mmHg and the necessity of a FiO₂ > 40% to maintain adequate oxygenation are predictors of poor outcome in patients mechanically ventilated in the ICU.     

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.     

Acid-base interpretation can be the predictor of outcome among patients with acute organophosphate poisoning before hospitalization

Objectives

Acute organophosphate (OP) poisoning causing alteration in acid-base equilibrium was reported before. Hence, different acid-base statuses may present in patients with acute poisoning due to OP exposure. This study aims to determine the impact of acid-base interpretation in patients with acute OP poisoning before hospitalization in medical care units and to describe the pattern of mortality with different acid-base statuses.

Design and Patients

Over a 9-year retrospective study, from July 1996 to August 2005, a total of 82 consecutive patients with acute OP poisoning were admitted to the China Medical University Hospital (Taichung, Taiwan) within 24 hours after exposure to OP and were enrolled into this study.

Results

Patients with acute OP poisoning were divided into 4 groups: without acidosis, metabolic acidosis, respiratory acidosis, and mixed acidosis. Overall survival (Kaplan-Meier curves) among groups was statistically significant (P < .0001). The mortality rate of acute OP poisoned patients with metabolic acidosis was 25%, and 75% of those patients died of cardiovascular failure. The mortality rate of acute OP poisoning with respiratory acidosis was 50%, and 50% of those patients died of respiratory failure.

Conclusions

Acid-base interpretation can be effective in quick diagnosis and prediction of the outcome of patients with acute OP poisoning (without acidosis < metabolic acidosis < respiratory acidosis < mixed acidosis) before hospitalization. Major causes of death are different between the respiratory acidosis and metabolic acidosis groups of patients with acute OP poisoning.     

Intensive care management of organophosphate insecticide poisoning

Introduction  

Organophosphate (OP) insecticides inhibit both cholinesterase and pseudo-cholinesterase activities. The inhibition of acetylcholinesterase causes accumulation of acetylcholine at synapses, and overstimulation of neurotransmission occurs as a result of this accumulation. The mortality rate of OP poisoning is high. Early diagnosis and appropriate treatment is often life saving. Treatment of OP poisoning consists of intravenous atropine and oximes. The clinical course of OP poisoning may be quite severe and may need intensive care management. We report our experience with the intensive care management of serious OP insecticide poisonings.     

洗胃术致胃食管损伤四例并文献复习

目的探讨洗胃术致胃食管损伤的临床特点并分析发生原因。方法结合相关文献对4例洗胃术致胃食管损伤的临床资料进行回顾性分析。结果本组均因急性中毒行洗胃术,术中发生急性胃穿孔3例,食管损伤1例。行胃穿孔修补术后痊愈1例;死亡3例,于术中猝死1例,术后1 h死于消化道出血1例,继发腹膜炎行剖腹探查胃穿孔修补术后死于脓毒症1例。结论患者配合插胃管、防止恶心呕吐、轻柔操作和改善洗胃机设计是减少洗胃严重并发症的关键。     

Stramonium Poisoning

Stramonium poisoning, caused by the ingestion or infusion of parts of the plant Datura stramonium, has a wide geographical distribution and a long history. It first appeared in this country in 1676 and since has occurred sporadically. The author reviews three cases of stramonium poisoning in children. Treatment consisted of gastric lavage and administration of small doses of phenobarbital and 5 per cent glucose in saline.     

急性有机磷农药中毒患者洗胃术后心理状况的调查

目的 了解急性有机磷农药中毒患者洗胃术后的心理状态,分析相关因素,寻找有效的护理方法.方法 采用菲精神科住院患者心理状态评定量表（MSSNS）,对84例急性有机磷农药中毒患者洗胃术后患者进行问卷调查,并对结果进行分析.结果 急性有机磷农药中毒患者洗胃术后各因子（焦虑、抑郁、愤怒、孤独）平均得分及总分[（24.21±5.36）,（16.67±3.74）,（12.94±2.65）,（13.73±3.85）,（67.55±11.64）分]均高于非精神科住院患者心理状态的常模[（19.20±5.82）,（13.70±4.20）,（9.19±2.17）,（12.25±3.72）,（54.33±13.36）分],差异均有统计学意义（t分别为6.273,7.893,9.471,3.431,8.151;P＜0.01）.其中小学及以下文化程度的患者在抑郁（25.31±8.47）、孤独（18.37±4.90）两项因子的得分和总分（73.89±11.32）均高于文化程度较高的患者.＜30岁患者焦虑评分高于其他组,＞40岁组患者各项评分及总分得分高于其他组,差异均有统计学意义（P＜0.05）.结论 急性有机磷农药中毒术后患者的各种负性心理状态较常模患者明显,特别是焦虑、孤独感的发生率较高,提示护理人员应加强监测患者的心理反应,采取有效的个体化心理干预,以缓解洗胃术后患者不良的心理状态.     

Behaviour change interventions to improve medication adherence in patients with cardiac disease: Protocol for a mixed methods study including a pilot randomised controlled trial

Background

Suboptimal adherence to medication increases mortality and morbidity; individually tailored supportive interventions can improve patients’ adherence to their medication regimens.

A comparison of three gastric lavage methods using the radionuclide gastric emptying study

To determine the percentage of liquid gastric contents experimentally removable by available orogastric lavage systems, five healthy young volunteers were asked to ingest 1 mCi of liquid technicium-99m diethylenetriaminepentaacetic acid (Tc^99m-DTPA) mixed with 50 ml tap water. Five minutes afterwards, the radionuclide was lavaged using one of three different techniques—a single syringe method, a closed gravity drainage system, and a closed double syringe method—while continuous radioisotope camera images were taken. Control images, with no lavage performed, were also taken. All of the orogastric lavage methods removed a mean of between 80% and 85% of the stomach contents. The double syringe method was the quickest, while the single syringe method was least tolerated. When compared with control, none of the lavage techniques pushed gastric contents into the duodenum. Thus, in terms of amount of liquid gastric contents removed, there was no one method that removed more than the others. Caution should be exercised in assuming that 80–85% of a liquid gastric ingestion can be removed by lavage in the uncontolled clinical setting. The use of any orogastric lavage for ingestion evacuation should be undertaken knowing that it is a morbid procedure and usually not necessary.     

A prospective trial of elective extubation in brain injured patients meeting extubation criteria for ventilatory support: a feasibility study

Introduction

To assess the safety and feasibility of recruiting mechanically ventilated patients with brain injury who are solely intubated for airway protection and randomising them into early or delayed extubation, and to obtain estimates to refine sample-size calculations for a larger study. The design is a single-blinded block randomised controlled trial. A single large academic medical centre is the setting.

Methods

Sixteen neurologically stable but severely brain injured patients with a Glasgow Coma Score (GCS) of 8 or less were randomised to early or delayed extubation until their neurological examination improved. Eligible patients met standard respiratory criteria for extubation and passed a modified Airway Care Score (ACS) to ensure adequate control of respiratory secretions. The primary outcome measured between groups was the functional status of the patient at hospital discharge as measured by a Modified Rankin Score (MRS) and Functional Independence Measure (FIM). Secondary measurements included the number of nosocomial pneumonias and re-intubations, and intensive care unit (ICU) and hospital length of stay. Standard statistical assessments were employed for analysis.

Results

Five female and eleven male patients ranging in age from 30 to 93 years were enrolled. Aetiologies responsible for the neurological injury included six head traumas, three brain tumours, two intracerebral haemorrhages, two subarachnoid haemorrhages and three ischaemic strokes. There were no demographic differences between the groups. There were no unexpected deaths and no significant differences in secondary measures. The difference in means between the MRS and FIM were small (0.25 and 5.62, respectively). These results suggest that between 64 and 110 patients are needed in each treatment arm to detect a treatment effect with 80% power.

Conclusions

Recruitment and randomisation of severely brain injured patients appears to be safe and feasible. A large multicentre trial will be needed to determine if stable, severely brain injured patients who meet respiratory and airway control criteria for extubation need to remain intubated.     

Home visits reduce the number of hazards for childhood home injuries in Karachi, Pakistan: a randomized controlled trial

Background

Although unintentional injuries are major causes of morbidity and mortality in less developed countries, they have received scant attention, and injury prevention policies and programs have just begun to be addressed systemically.

Aims

To reduce hazards associated with home injuries due to falls and ingestions through an injury prevention program administered by home visitors.

Methods

Non-blinded randomized controlled trial design of two interventions where one branch of the study group served as the control for the other in an urban neighborhood in Karachi, Pakistan. The study participants included 340 families with at least one child aged 3 years or less, discharged home from the Emergency Department following a visit for any reason other than an injury. The interventions included: (1) counseling to reduce falls; (2) counseling to reduce poisoning and choking. The primary outcome measure for each intervention was the relative risk of change in the home status from “unsafe” to “safe” after the intervention.

Results

There were 170 families in the fall prevention and 170 families in the ingestion prevention branch of the study. The percentage of homes deemed “safe” in which the families had received fall intervention counseling was 13.5% compared to 3.5% in the control group (relative risk 3.8; 95% CI: 1.5 to 10.0; p = 0.002), whereas the percentage of homes deemed “safe” in which the families had received the ingestions intervention counseling was 18.8% compared to 2.4% in the control group (relative risk 7.8; 95% CI: 2.4 to 25.3; p?Conclusions Our study demonstrates the effectiveness of an educational intervention aimed at improving the home safety practices of families with young children.     

急性重度有机磷农药中毒胃黏膜pH值监测的意义

目的：探讨胃黏膜内pH值（pHi）监测在急性重度有机磷农药中毒（ASOPP）中的应用及临床意义。方法：28例ASOPP患者在洗胃后立即经鼻插入TRIP－NGS导管测定pHi,以后每12小时监测1次;另以12例健康者为对照。结果：在ASOPP未并发急笥呼吸衰竭（ARF）时,患者的pHi就明显降低（P＜0.05）,而此时全身氧供指标－－动脉氧分压（PaO2)无明显改变（P＞0.05）;在ASOPP并发ARF时,患者的pHi比PaO2降低得更明显。结论：pHi监测对早期发现ASOPP患者局部组织缺氧及采取措施预防ARF与多脏器功能衰竭的发生具有重要临床指导意义。     

Food Poisoning Associated with Kudoa Septempunctata

Background

Kudoa septempunctata is a recently identified cause of food poisoning. We report three cases of food poisoning due to ingestion of this parasite.

Case Reports

Among the 358 people exposed during the same catered meal, 94 (including our 3 patients) developed vomiting and diarrhea within 1–9 h after ingestion of raw muscle from contaminated aquacultured olive flounders (Paralichthys olivaceus). These symptoms occurred frequently but were temporary; only 1 patient was hospitalized for dehydration and was discharged 2 days later.

Conclusion

In Japan, cases of food poisoning due to eating olive flounder have increased during recent years. This increase should prompt heightened awareness among clinicians diagnosing food poisoning.     

Patterns of acute poisoning with pesticides in the paediatric age group

Background

Pesticides are identified as one of the dangerous poisons globally in children and are associated with increased short- and long-term morbidity. Pesticide poisoning is the most common method of self-poisoning among adults in rural Sri Lanka, and the clinical management is associated with significant healthcare costs to the country. There is however little data published on acute pesticide poisoning among children in rural Sri Lanka. The current study aimed to comprehensively evaluate clinical profiles, harmful first aid measures, emergency clinical management, complications and outcomes related to acute pesticide poisoning among children in the rural community of Sri Lanka.

Methods

This multicenter study was conducted in the North Central Province of Sri Lanka involving all children with acute pesticide poisoning and who were between 9 months and 12 years of age. Data were collected over 7 years (2007–2014), and children from 36 hospitals were recruited. Data collection was carried out by pretested, multi-structured, interviewer-administered questionnaires to identify clinical profiles of children, harmful first aid measures, emergency clinical management, reasons for delayed management, complications and outcomes of pesticide poisoning events.

Results

Among 1621 children with acute poisoning, 9.5% (155) comprised children with acute pesticide poisoning. Male children outnumbered female children, and the majority of children were less than 5 years. Most common pesticides implicated in poisoning of children were organophosphates and carbamates. Gastrointestinal and neurological symptoms were predominant clinical features. Limited transport and lack of concern regarding urgency among caregivers were leading reasons for delayed management. Most common location for poisoning was cultivation lands. Harmful first aid measures were practiced in 32.4%. 7.1% had intentional pesticide poisoning. The case fatality rate of all pesticide poisonings in the study was 1.9%. 58.1% of patients were transferred between regional hospitals and teaching hospital. Cardiac and respiratory arrests, aspiration pneumonia and convulsions were among the reported complications.

Conclusions

Acute pesticide poisoning in paediatric age group (<12 years) is a relatively uncommon yet significant cause of child health-related morbidity and mortality in rural Sri Lanka. Patterns of poisoning represent the pattern of pesticide use by the rural community. The practice of harmful first aid measures by caregivers and delay in attending the emergency department may negatively impact patient outcomes.