PURPOSE: Organophosphorus (OP) pesticides are differentiated into 3 groups according to their toxicity. The differences in chemical composition of each OP pesticide determines its toxicokinetic characteristics. There are few human studies that address the clinical results of poisoning according to the OP pesticide. In this study, we aimed to examine the differences in clinical features among self-poisoning from 4 highly toxic OP pesticides. METHODS: The 4 kinds of OP poisonings included 17 cases of Dichlorvos, 17 cases of EPN, 17 cases of methidathion, and 13 cases of phosphamidon. We set primary outcomes as GCS, atropine dose required, duration of patient need for atropine, proportion who required ventilation, duration on ventilation, and the interval from ingestion to ventilation. Secondary outcomes were the proportion of OP-induced delayed neuropathy, duration of ICU stay, and proportion who required additional infusion of pralidoxime chloride (PAM). RESULTS: The EPN group required the largest amount of atropine, the longest duration of atropine use, the longest duration for support of mechanical ventilation, and the longest ICU stay. Furthermore the proportion who required additional PAM and neuropathy were in the EPN group. However, the EPN group had the longest interval from ingestion to ventilatory support. Meanwhile, the Dichlorvos group exhibited comparatively mild clinical features. CONCLUSION: Throughout this study, we found different clinical features to each OP pesticide poisoning. It can be explained by differences in chemical composition, which determined the speed of aging, the reactivation rate of OPenzyme, the metabolism, the fat solubility, and other characteristics of the pesticides.
Aging ; Atropine ; Dichlorvos ; Eating ; Humans ; Organophosphorus Compounds ; Organothiophosphorus Compounds ; Pesticides ; Phosphamidon ; Pralidoxime Compounds ; Respiration, Artificial ; Solubility ; Ventilation

PURPOSE: Extremely hazardous pesticides are classified as World Health Organization (WHO) hazard class Ia. However, data describing the clinical course of WHO class Ia OP (organophosphate) poisonings in humans are very scarce. Here, we compare the clinical features of patients who ingested hazard class Ia OPs. METHODS: This retrospective observational case study included 75 patients with a history of ingesting ethyl p-nitrophenol thio-benzene phosphonate (EPN), phosphamidon, or terbufos. The patients were divided according to the chemical formulation of the ingested OP. Data regarding mortality and the development of complications were collected and compared among groups. RESULTS: There were no differences in the baseline characteristics and severity scores at presentation between the three groups. No fatalities were observed in the terbufos group. The fatality rates in the EPN and phosphamidon groups were 11.8% and 28.6%, respectively. Patients poisoned with EPN developed respiratory failure later than those poisoned with phosphamidon and also tended to require longer mechanical ventilatory support than phosphamidon patients. The main cause of death was pneumonia in the EPN group and hypotensive shock in the phosphamidon group. Death occurred later in the EPN group than in the phosphamidon group. CONCLUSION: Even though all three drugs are classified as WHO class Ia OPs (extremely hazardous pesticides), their clinical courses and the related causes of death in humans varied. Their treatment protocols and predicted outcomes should therefore also be different based on the chemical formulation of the OP.
Cause of Death ; Classification ; Clinical Protocols ; Humans* ; Mortality ; Organophosphates* ; Pesticides ; Phosphamidon* ; Pneumonia ; Poisoning* ; Respiratory Insufficiency ; Retrospective Studies ; Shock ; World Health Organization

Purpose: Dichlorvos has been in widespread use as an organophosphate (OP) insecticide compound. The purpose of this study was to access the epidemiology and clinical features of dichlorvos in Korea. Methods: This was a 38 multi-center prospective study of dichlorvos poisoning using surveys, a structural reporting system and review of hospital records from August 2005 to July 2006. A total of 54 patients with acute dichlorvos poisoning on a national basis were enrolled. We analyzed the epidemiologic characteristics and clinical manifestations of dichlorvos poisoning. In addition, the clinical features of dichlorvos poisoning were compared with others OP compounds. Results: During the study period, compounds involving pure OP poisoning were dichlorvos (22.7%), methidathion (8.4%), and phosphamidon (6.7%). In acute dichlorvos poisoning, all ingestion routes were oral. Intentional poisoning involved 74.1% of cases. The common initial complaints involved gastrointestinal (64.8%), systemic (61.1%), central or peripheral nervous system (53.7%), and respiratory symptoms (50.0%). The median arrival time to hospital after dichlorvos poisoning was 2.6 hours and mean hospitalization duration was 7.1 days. 2-PAM was administered in 35 patients in mean doses of 6.3 g/day intravenously. Atropine was administered in 30 patients with a mean dose of 62.8 mg/day (maximal 240 mg/day). Overall mortality rate for dichlorvos poisonings were 14.8% (8/54). Immediate causes for death included sudden cardiac arrest or ventricular dysrhythmias (50%), multi-organ failure (25%), acute renal failure (12.5%), and unknown causes (12.5%). Conclusion: When compared to previous reports, dichlorvos poisoning displayed relatively moderate severity. The presence of a lower GCS score, altered mental status, serious dysrhythmias, systemic shock, acute renal failure, and respiratory complications upon presentation were associated with a more serious and fatal poisoning.
Acute Kidney Injury ; Atropine ; Death, Sudden, Cardiac ; Dichlorvos ; Eating ; Hospital Records ; Hospitalization ; Humans ; Korea ; Organothiophosphorus Compounds ; Peripheral Nervous System ; Phosphamidon ; Pralidoxime Compounds ; Prospective Studies ; Shock

BACKGROUND: Intermediate myasthenia syndrome(IMS) is thought to have clinical importance because it may cause sudden respiratory failure during the recovery phase of a cholinergic crisis of organophosphate poisoning. We designed this study to identify the prevalence, the inducing agent, clinical predictor, and the proposed treatment of IMS. METHODS: Patients who had admitted with the diagnosis of acute organophosphate poisoning from 1992 to 1998 at two teaching hospitals were enrolled in this study. We selected the cases of IMS based on a review of medical records using modified He's criteria. RESULTS: Twelve(12) out of 110 patients with acute organophosphate poisoning were diagnosed for a prevalence at 10.9%. The drug inducing IMS were identified as dichlorvos, fenthion, EPN, methidathion, and phosphamidon. The occurrence of IMS was not related to either the initial treatment with atropine and pralidoxime, or the level of serum cholinesterase. Complications were pneumonia, sepsis, pancreatitis, and pseudomembranous colitis, etc. Eleven(11) patients were discharged without sequelae, and one patient was discharged as a hopeless care. CONCLUSION: This study suggests that IMS is not rare, so close observation is required to detect IMS in organophosphate-poisoning patients. Also, more studies are required to find predictors and treatments.
Atropine ; Cholinesterases ; Diagnosis ; Dichlorvos ; Enterocolitis, Pseudomembranous ; Fenthion ; Hospitals, Teaching ; Humans ; Medical Records ; Organophosphate Poisoning ; Pancreatitis ; Phosphamidon ; Pneumonia ; Prevalence ; Respiratory Insufficiency ; Sepsis