Serum Acetylcholinesterase and Prognosis of Acute Organophosphate Poisoning

Objective: The aim of this study is to investigate the prognostic value of serum acetylcholinesterase levels and their relationship with neurological syndromes (Type 1 syndrome, intermediate syndrome, and delayed polyneuropathy) in acute organophosphate poisoning. Materials and methods: Thirty-two consecutive patients with acute organophosphate poisoning admitted to the Ondokuz Mayis University Emergency Department from June 1999 to January 2001 were evaluated. Patients were assessed according to admission time, symptoms, and results of clinical exams and their serum acetylcholinesterase levels were determined on days 1, 2, 3, 7, and the last day. Results: There was no significant difference between the first-day serum acetylcholinesterase of the patients with severe poisoning (n=22, 68.75%) and of the patients with mild poisoning (n=10, 31.25%; NS). There was no discernible difference between the serum acetylcholinesterase obtained on days 1 and 3 after poisoning from the patients with intermediate syndrome (n=5, 15.6%; means: 0.90±0.65 vs. 0.88±0.53, 19.35 vs. 18.92%; NS, sensitivity=80%; specificity=87.5%). There was a significant difference between the serum acetylcholinesterase obtained on days 1 and 3 from the patients with nonintermediate syndrome (n=24, 75%; means: 1.05±0.24 vs. 1.68±0.29, 22.58 vs. 36.12%; p<0.001). There was no discernible significant difference in serum acetylcholinesterase between the patients with organophosphorus-induced delayed polyneuropathy (n=7, 21.8%) and nonorganophosphorus-induced delayed polyneuropathy. In the patients who died (n=5, 15.6%), serum acetylcholinesterase showed no discernible increase day 1–the last day (means: 0.50±0.25 vs. 0.46±0.26, 10.75 vs. 9.89%; NS). There was a significant difference between the serum acetylcholinesterase levels obtained on days 1 and the last day from the patients who survived (n=27, 84.3%; means: 1.14±0.25 vs. 2.32±0.26, 24.51 vs. 49.89%; p<0.001). Conclusion: In the acute phase of organophosphate poisoning, low serum acetylcholinesterase (>50% of minimum normal value) supports the diagnosis of organophosphate poisoning but it does not show a significant relationship to the severity of poisoning (NS). The serum acetylcholinesterase activity may be a useful parameter in following the acute prognosis of organophosphate poisoning.     

52例有机磷农药急性中毒并发急性肺水肿分析

目的 探讨有机磷农药急性中毒并发急性肺水肿的机理、临床特点、影像学特征及治疗方法。方法 分析1994年1月-1998年12月间,经抢救和治疗的52例有机磷农药急性中毒并发急性肺水肿患的症状、胸部X线摄片、诊断及治疗结果的临床资料。结果 52例患中44例（84.6%),治愈好转出院,死亡8例（15.4%),其中死于肺水肿致呼吸衰竭3例（5.8%)。结论 急性有机磷农药中毒并发急性肺水肿临床特点和X线表现早期表现不明显,易被中毒的其它全身表现所掩盖。在治疗措施上,既要针对肺水肿的临床表现,又要考虑到原发疾病的病因治疗。     

急性有机磷农药中毒中间综合征17例分析

目的：探讨急性有机磷农药中毒中间综合征（IMS）的临床特点及临床处理对策。方法：对17例急性有机磷农药中毒中间综合征患者的临床资料进行分析。结果：IMS出现在中毒后1～5d,经积极救治17例中完全治愈13例,好转1例,死亡3例。结论：中间综合征以对症支持治疗为主。急性期应用阿托品的同时,及早、足量、重复应用肟类复能剂以及适时应用机械通气可有效防治中间综合征。     

Electrophysiological correlates of respiratory failure in acute organophosphate poisoning: Evidence for differential roles of muscarinic and nicotinic stimulation

Background. Respiratory failure in acute organophosphate (OP) poisoning can occur early and also relatively late in the clinical course, and the pathophysiology of respiratory failure at these different phases may have important clinical implications. Objective. To compare the electrophysiological findings in patients with early and late respiratory failure following acute OP poisoning. Methods. A prospective observational case series of consenting symptomatic patients with acute OP poisoning were assessed with daily physical examinations and repetitive nerve stimulation (RNS) studies. RNS was done on right and left median and ulnar nerves at 1, 3, 10, 15, 20, and 30 Hz. Outcomes such as need for ventilation and development of intermediate syndrome (IMS) were noted. Early respiratory failure was defined as occurring within 24 hours of ingestion. Results. Seventy-eight patients were recruited for the clinical and electrophysiological study and of those 59 (75.6%) patients had ingested chlorpyrifos. Seven patients developed respiratory failure within 24 hours of ingestion with overt muscarinic signs. They had no electrophysiological abnormalities at median and ulnar nerves before intubation. Three of them later developed “forme fruste” IMS. Five other patients developed late respiratory failure after 24 hours of ingestion, and all of them showed progressive RNS changes indicating severe IMS prior to intubation. Conclusion. The normal RNS in all patients developing early respiratory failure suggests that it is due to a central nervous system (CNS) and muscarinic effect. This emphasizes the need for early rapid atropinisation as a priority, combating the nicotinic effects being less urgent. This is in contrast with the late respiratory failure, which has been shown to be associated with neuromuscular dysfunction. Further studies are needed to quantify CNS and muscarinic dysfunction to assist in the development of better treatments for the severe and early OP poisoning.     

Acute focal dystrophy of the myocardium with hibernating or stunned myocardium

Opportunities of clinical, laboratory and device diagnosis of acute focal dystrophy (AFD) with hibernating or stunned myocardium are postulated. Myocardial AFD belongs to intermediate coronary syndrome and is a clinico-morpho-functional manifestation of one of the acute coronary syndromes in ischemic heart disease. Differentiation of hibernating with stunned myocardium is made after myocardial revascularization. 230 coronaroventriculographies have been made, of them 72 were urgent with balloon angioplasty and stenting.     

Definition, classification, and pathophysiology of acute coronary ischemic syndromes

The acute coronary syndrome (ACS) is now used to describe a spectrum of clinical presentations that share an underlying pathophysiology, replacing the previous nomenclature of ischemic chest pain. The accurate diagnosis and proper management of patients with these entities require the emergency medicine physician to consider the entire spectrum of ACS, with emphasis placed on early diagnosis and rapid treatment. Each of these syndromes has its own prognosis, pathophysiology, and specific management strategy.     

Diagnosis and risk stratification of acute coronary syndrome in general practice and in the hospital

Acute coronary syndromes usually present as acute chest pain but a manifestation with atypical symptoms or entirely without symptoms makes rapid diagnosis of this potentially lethal syndrome difficult and may lead to delay of the appropriate therapy. The role of the practitioner in this situation is complex since early exclusion of an acute coronary syndrome may be very difficult with the means available in a private practice; on the other hand the early hours which are critical for early therapy may be lost in a private practice. In the early phase of an acute coronary syndrome, diagnoses and risk stratification are based primarily on history, clinical presentation, ECG and biological markers. In the hospital, the time course of these parameters, functional tests for diagnosis and risk stratification as well as determination of left ventricular function and coronary angiography have additional relevance. Recent developments are the availability of highly sensitive and specific biological markers (Troponins), the new classification in acute coronary syndrome with and without ST-elevation and the identification of inflammatory processes in the coronary artery, which have added importantly to our understanding of the acute coronary syndrome. The availability of very early therapy and the possibilities of telemedicine have the potential to influence the pre-hospital diagnostic strategy and management of acute coronary syndromes.     

The Clinical Significance of Hyperamylasemia in Organophosphate Poisoning

Abstract

Objective: Hyperamylasemia with a presumptive diagnosis of acute pancreatitis has been reported following organophosphate poisoning but there are no large-scale studies incorporating more specific diagnostic criteria. Methods; Retrospective review of the medical records of 159 patients with a diagnosis of organophosphate poisoning over 3 years. Serum amylase, pancreatic amylase, salivary amylase, lipase and cholinesterase levels, and the clinical manifestations were analyzed. Results; Serum amylase data was available for 121 of the 159 study patients. Hyperamylasemia (amylase ≥ 360 U/L) was found in 44 patients (36%). Lipase was measured in 28 patients with hyperamylasemia; 9 of 28 had hyperlipasemia (lipase ≥ 380 U/L). The finding of hyperamylasemia was closely related to clinical severity and presence of shock. A presumptive diagnosis of painless acute pancreatitis was diagnosed by hyperlipasemia associated with hyperamylasemia, clinical severity, serum LDH, and leukocyte counts. Two patients with presumptive pancreatitis died. Shock, coma, and hypoalbuminemia were the factors predicting fatality. Conclusions: Hyperamylasemia is frequent in severe organophosphate poisoning. However, hyperamylasemia is not synonymous with acute pancreatitis and pancreatic amylase is not a reliable parameter in the diagnosis of organophosphate-induced pancreatitis due to its low sensitivity and specificity. Lipase assay is indicated in patients with hyperamylasemia for early diagnosis of pancreatitis. Proper image studies and even pathological examination are also needed to confirm the extent of pancreatic injury. With prompt diagnosis and appropriate treatment, a complete recovery can be anticipated unless the patient has otherwise unrelated complications.     

脑钠肽前体及肌钙蛋白I在老年急性有机磷中毒心肌损伤中的价值

目的探讨脑钠肽前体(NT-proBNP)及肌钙蛋白I(cTnI)在老年急性有机磷农药中毒(AOPP)心肌损伤中的变化及病情判断、评估中的临床价值。方法 102例老年患者按入院时中毒的程度分为轻度中毒24例(轻度组),中度中毒38例(中度组),重度中毒40例(重度组)。于患者入院后4 h、3 d、7 d抽取静脉血4 ml,同步测定NT-proBNP、cTnI、肌酸激酶(CK)、肌酸激酶同工酶(CK-MB)值,与同期40例健康查体者(对照组)比较;合并发生中间型综合征(IMS)33例(IMS组),未发生IMS 69例(非IMS组),比较对照组、IMS组和非IMS组血清各项指标水平及心电监护情况。结果中、重度组老年AOPP患者的血清NT-proBNP、cTnI、CK、CK-MB较对照组显著升高(P<0.05),且随中毒程度和病情加重而升高,各组间两两比较差异均有统计学意义(P<0.05),血清NT-proBNP的敏感性和特异性均高于cTnI、心肌酶谱。IMS组入院后4 h内检测值显著高于非IMS组,差异均有统计学意义(P<0.05);IMS组较非IMS组出现心电图异常的比例更高。结论老年AOPP患者中毒越重,血清cTnI、NT-proBNP升高越显著,血清NT-proBNP检测可以更详细地反映心肌的损害程度,早期联合检测可以更好地协助老年AOPP临床分级、病情判断、指导救治和预后评估。     

Accidental organophosphate insecticide intoxication in children: a reminder

Misuse of organophosphate insecticides, even in case of domestic application, can be life threatening. We report the case of siblings admitted with respiratory distress, pinpoint pupils and slurred speech. The symptoms appear after spraying the skin by insecticides. Plasma pseudocholinesterase level appeared to be very low, consistent with acute intoxication with organophosphate insecticide.Management of organophosphate poisoning consists of airway management, administration of oxygen and fluid, as well as atropine in increasing doses and pralidoxime. Decontamination of the patient's skin and the removal of the patient's clothes are mandatory in order to avoid recontamination of the patient as well as the surrounding healthcare personnel.Plasma pseudocholinesterase analysis is a cheap and an easy indicator for organophosphate insecticides intoxications and could be used for diagnosis and treatment monitoring.     

Oxime therapy and outcomes in human organophosphate poisoning: an evaluation using meta-analytic techniques

OBJECTIVE: The status of oximes in human organophosphate poisoning is controversial. This analysis compares the outcomes of therapy with or without oximes. DESIGN: Quantitative analysis using meta-analytic techniques. METHODS: Controlled trials of oximes in human organophosphate poisoning were identified by search of MEDLINE and TOXLINE (1966 to May 2005) and review of published articles. MEASUREMENTS AND MAIN RESULTS: Of the 3,122 articles on organophosphate poisoning identified by electronic search, 116 related to oxime use in human organophosphate poisoning. Seven trials, including two randomized controlled trials, compared oximes with standard medical care. Varying dosage schedules of pralidoxime or obidoxime were used. The effects of oxime therapy on mortality rate, mechanical ventilation, incidence of intermediate syndrome, and need for intensive care therapy were analyzed and expressed as risk difference (positive values indicating oxime harm). The random effects estimator was reported because of underlying heterogeneity of treatment effects between study types. No statistically significant association of oxime therapy was demonstrated for either mortality (risk difference 0.09, 95% confidence interval -0.08 to 0.27), ventilatory requirements (risk difference 0.16, 95% confidence interval -0.07 to 0.38), or the incidence of intermediate syndrome (risk difference 0.16, 95% confidence interval -0.12 to 0.45), although point estimates of effect suggested harm. An increased need for intensive care therapy (risk difference 0.19, 95% confidence interval 0.01 to 0.36) was apparent with oxime therapy. CONCLUSIONS: Based on the current available data on human organophosphate poisoning, oxime was associated with either a null effect or possible harm. The lack of current prospective randomized controlled trials, with appropriate patient stratification, mandates ongoing assessment of the role of oximes in organophosphate poisoning.     

Compartment syndrome: when it is least expected

Compartment syndrome, if not identified and acted upon early, will result in irreversible damage to neuromuscular soft tissues. Therefore, orthopaedic nurses must be aware of the risks, signs and symptoms, unusual circumstances, and appropriate medical and nursing interventions with this syndrome. Usually compartment syndrome is considered to occur with fractures of the tibia, the forearm, or in vascular injuries or burns where there is significant edema. Not as common are compartment syndromes that occur after intramedullary nailing, in the thigh or upper arm, or in the presence of fracture blisters. These unexpected compartment syndromes each occurred only once in the author's many years as an orthopaedic clinical nurse specialist at a major trauma center. However, in each case, the situation and actions were significant. Compartment syndrome will be reviewed with supporting current literature. Each scenario will then be analyzed in terms of the particular considerations surrounding the diagnosis, treatment and nursing implications with the compartment syndrome.     

Food Poisoning Due to Methamidophos-Contaminated Vegetables

Background: Organophosphate poisoning is well known for its characteristic symptoms and signs, but food poisoning caused by pesticide-contaminated food is seldom reported. Case Report: We report three incidents of food poisoning that resulted from exposure to the organophosphate insecticide methamidophos in vegetables. These outbreaks caused a cholinergic syndrome in 4 patients. The cholinergic overactivity led us to suspect organophosphate food poisoning. All patients recovered well following appropriate therapy. The clinical diagnosis of organophosphate poisoning was confirmed by reduced levels of erythrocytes and plasma cholinesterase and the presence of methamidophos in the vegetable leftovers. The implicated vegetables and levels of methamidophos were: Ipomoea batatas 255 ppm, Gynura bicolor 110 ppm, and red cabbage 26.3 ppm. Since methamidophos is normally applied to vegetables during planting, improper selection and/or overuse of pesticide or improper harvest times may explain the occurrence of these high residue levels of methamidophos.     

Respiratory failure in acute organophosphorus pesticide self-poisoning

BACKGROUND: Acute organophosphorus (OP) pesticide poisoning is a major clinical problem in the developing world. Textbooks ascribe most deaths to respiratory failure occurring in one of two distinct clinical syndromes: acute cholinergic respiratory failure or the intermediate syndrome. Delayed failure appears to be due to respiratory muscle weakness, but its pathophysiology is unclear. AIM: To describe the clinical patterns of OP-induced respiratory failure, and to determine whether the two syndromes are clinically distinct. DESIGN: Prospective study of 376 patients with confirmed OP poisoning. METHODS: Patients were observed throughout their admission to three Sri Lankan hospitals. Exposure was confirmed by butyrylcholinesterase and blood OP assays. RESULTS: Ninety of 376 patients (24%) required intubation: 52 (58%) within 2 h of admission while unconscious with cholinergic features. Twenty-nine (32%) were well on admission but then required intubation after 24 h while conscious and without cholinergic features. These two syndromes were not clinically distinct and had much overlap. In particular, some patients who required intubation on arrival subsequently recovered consciousness but could not be extubated, requiring ventilation for up to 6 days. DISCUSSION: Respiratory failure did not occur as two discrete clinical syndromes within distinct time frames. Instead, the pattern of failure was variable and overlapped in some patients. There seemed to be two underlying mechanisms (an early acute mixed central and peripheral respiratory failure, and a late peripheral respiratory failure) rather than two distinct clinical syndromes.     

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.     

The Effects of Fresh Frozen Plasma on Cholinesterase Levels and Outcomes in Patients with Organophosphate Poisoning

Objective: The aim of this study is to determine the effects of fresh frozen plasma, as a source of cholinesterase, on butyrylcholinesterase (BuChE; plasma or pseudo cholinesterase) levels and outcomes in patients with organophosphate poisoning. Materials and Methods: This prospective study was performed at the Department of Intensive Care of Erciyes University Medical School. Over 2 yrs, patients admitted to the ICU for OP poisoning were entered into the study. OP poisoning was diagnosed on the basis of history and BuChE levels. All patients received atropine. Fresh frozen plasma was given to 12 patients. The study was approved by the Ethical Committee, and verbal informed consent was obtained. Results: Thirty‐three patients were included in the study. BuChE levels measured at admission and the pralidoxime and atropine doses administered were not different between groups (p > 0.05). Although intermediate syndrome developed in 28.6% of patients receiving pralidoxime, there were no intermediate syndrome cases in patients receiving plasma prior to developing intermediate syndrome. The mortality rates were 14.3% in the pralidoxime group and 0% in the plasma + atropine + pralidoxime group. Two patients received plasma after developing the intermediate syndrome, and one patient who received only atropine died. BuChE levels of fresh frozen plasma were 4069.5 ± 565.1 IU/L. Every two bags of plasma provided an increase in BuChE levels of approximately 461.7 ± 142.1 IU/L. Conclusion: Fresh frozen plasma therapy increases BuChE levels in patients with organophosphate poisonings. The administration of plasma may also prevent the development of intermediate syndrome and related mortality. Plasma (fresh frozen or freshly prepared) therapy may be used as an alternative or adjunctive treatment method in patients with organophosphate pesticide poisoning, especially in cases not given pralidoxime. Further randomized controlled and animal studies are required to infer a definitive result.     

急性有机磷中毒的急诊急救护理

目的探讨急性有机磷中毒急诊急救的综合护理,寻求提高抢救成功的对策,降低死亡率。方法对本院急诊科2002年1月至2007年3月收治的92例急性有机磷中毒患者的临床资料进行回顾分析,对中毒途径、中毒程序、服药量、中毒至就诊时间及各种处理措施等因素进行分析。结果早期彻底洗胃,合理维持阿托品化和应用呼吸机是有效的处理措施。全组治愈87例（94．6％）,死亡5例（5．4％）。呼吸循环衰竭、阿托品中毒为主要死亡原因。结论有效的护理措施、预防并及时处理并发症和辅助方法的恰当选用是提高存活率的关键。     

Food poisoning

Food poisoning is encountered throughout the world. Many of the toxins responsible for specific food poisoning syndromes are no longer limited to isolated geographic locations. With increased travel and the ease of transporting food products, it is likely that a patient may present to any emergency department with the clinical effects of food poisoning. Recognizing specific food poisoning syndromes allows emergency health care providers not only to initiate appropriate treatment rapidly but also to notify health departments early and thereby prevent further poisoning cases. This article reviews several potential food-borne poisons and describes each agent's mechanism of toxicity, expected clinical presentation, and currently accepted treatment.     

Recovery from ultra-high dose organophosphate poisoning after "in-the-field" antidote treatment: potential lessons for civil defense

Organophosphate poisoning is associated with a high mortality rate due to respiratory failure, dysrhythmias, and multi-organ failure. We report two cases of survival after “in-the field” antidote treatment of very severe organophosphate poisonings. Two patients orally ingested large amounts of the organophosphorous agent oxydemeton-methyl in suicide attempts, resulting in the hypercholinergic syndrome in both. Resuscitation included early administration of antidote by emergency medical personnel as well as high-dose atropine. Plasma levels of pseudo cholinesterase were initially very low in both patients. Long-term mechanical ventilation was necessary, and both patients developed aspiration pneumonia. At discharge, no major neurological deficits were present. Prompt antidote treatment and aggressive supportive emergency and intensive care unit therapy contribute to improved survival after acute organophosphate poisoning. We believe that in cases of mass poisonings—for example, terrorist activity—therapy must be available on the scene as soon as possible. This also may require decentralized antidote storage.     

急性有机磷农药中毒早期血胆碱酯酶变化与临床中毒程度关系的探讨——附96例临床分析

目的：探讨急性有机磷农药中毒早期血胆碱酯酶变化与临床中毒程度的.减少误、漏诊的发生及避免对病情估计不足,方法：回顾性将近2年本院收治急性有机磷农药中毒96例,按临床中毒程度分轻、中重度中毒3组,把就诊和确诊时用纸片法测得的血胆碱酯酶活性与其临床中毒程度相比较,观察血胆碱酯酶活性变化与临床中毒程度关系。结果：22例血胆碱酯酶变化与临床中毒程度明显不相符。结论：急性有机磷农药中毒早期,血胆碱酯酶活性变化在诊断及估计病情时只能作参考;对可疑中毒者不能因血胆碱酯酶正常而作出否定的结论;对诊断明确,血胆碱酯酶活性正常而症明显及血胆碱酯酶活性严重下降而下着状轻微者,上均不能麻痹大意。