pralidoxime and Syndrome

A 33-year-old female ingested an unknown quantity of malathion in a suicide attempt. Cholinergic signs consistent with severe organ, phosphate intoxication developed and were treated within 6 hours of ingestion. Intravenous atropine and a continuous infusion of pralidoxime (400 mg/h) were administered. Prolonged depression of plasma and red blood cell cholinesterases were documented. Despite an initial clinical improvement and the presence of plasma pralidoxime concentrations exceeding 4 microg/mL, the patient developed profound motor paralysis consistent with the diagnosis of Intermediate Syndrome. In addition to the dose and frequency of pralidoxime administration, other factors including persistence of organophosphate in the body, the chemical structure of the ingested organophosphate, and the time elapsed between ingestion and treatment may limit the effectiveness of pralidoxime as an antidote in organophosphate ingestions. This case study suggests that these factors should be taken into account in assessing the risk of Intermediate Syndrome after intentional organophosphate ingestions.

Topics: Adult; Antidotes; Cholinesterase Inhibitors; Cholinesterase Reactivators; Female; Humans; Infusions, Intravenous; Insecticides; Malathion; Paralysis; Pralidoxime Compounds; Syndrome

A dimethoate-poisoned woman gradually developed a moderately severe cholinergic crisis that was readily treated by atropine. After being symptom-free for nearly two days, she suffered from sudden life-threatening respiratory paresis and weakness of the facial, extraocular, neck flexor and proximal limb muscles. Muscarinic symptoms were absent. Cholinesterase inhibition was severe, and EMG revealed marked decrements at low rates of repetitive nerve stimulation, and increments at a high rate. The clinical course was compatible with the Intermediate Syndrome. This syndrome seems due to persistent cholinesterase inhibition presumably leading to combined pre- and postsynaptic impairment of neuromuscular transmission. Inadequate pralidoxime therapy is proposed but not established as contributory. Prolonged monitoring of respiratory function in patients poisoned by particular organophosphate agents is mandatory.

Topics: Adult; Antidotes; Atropine; Cholinesterase Inhibitors; Cholinesterase Reactivators; Dimethoate; Electromyography; Female; Humans; Neuromuscular Diseases; Pralidoxime Compounds; Respiratory Paralysis; Synaptic Transmission; Syndrome; Ventilators, Mechanical

Seventy two patients admitted to the Intensive Care Unit following ingestion of organophosphorus compounds were studied prospectively with two different doses of pralidoxime (PAM). One group received 1 gm immediately after admission and no further PAM and the other group received infusion of PAM, 1 gm 8 hourly for four days (total 12 gms). The incidence of type II paralysis or intermediate syndrome was 47%. We observed a higher incidence in the 4 days of infusion of PAM group (61%) (20 patients) as compared to the single Bolus dose group (39%) (13 patients). Relative risk 1.48 (confidence interval = 0.9-2.4).

Topics: Adult; Cholinesterase Reactivators; Dose-Response Relationship, Drug; Double-Blind Method; Drug Administration Schedule; Drug Overdose; Female; Humans; Infusions, Intravenous; Male; Organophosphate Poisoning; Paralysis; Pralidoxime Compounds; Prospective Studies; Respiratory Paralysis; Syndrome

Topics: Aged; Bradycardia; Cholinesterase Inhibitors; Cholinesterase Reactivators; Cholinesterases; Combined Modality Therapy; Diagnosis, Differential; Diagnostic Errors; Fatal Outcome; Humans; Hypertension; Male; Organophosphate Poisoning; Poisoning; Pralidoxime Compounds; Pulmonary Edema; Respiration, Artificial; Respiratory Paralysis; Syndrome

The authors report 2 cases of organophosphate poisoning which developed intermediate syndrome. The first case was a man who took an organophosphate insecticide, monocrotophos, and developed severe organophosphate poisoning. Respiratory support was needed. He was treated with atropine and 2-PAM. Weakness of neck muscles, proximal limb and respiratory muscle developed in the 3rd day after ingestion. By supportive treatment and careful monitoring, however, he recovered after 11 days of the poisoning. The second case was a lady who took dicrotophos. She developed severe organophosphate poisoning for which respiratory support was also needed High dose of atropine, but without 2-PAM, was administered. She developed bulbar palsy, proximal muscle and respiratory weakness 3 day after the ingestion. Ventilation support was needed for 13 days before weaning was successful. This report did not support an efficacy of pralidoxime (2-PAM) in alleviation of the intermediate syndrome, but aims to alert physicians to recognize the intermediate syndrome for which adequate respiratory care is the crucial key for its management.

Topics: Adult; Atropine; Female; Humans; Insecticides; Male; Muscle Weakness; Organophosphate Poisoning; Paralysis; Pralidoxime Compounds; Respiratory Insufficiency; Syndrome; Thailand; Time Factors

An acute poisoning in a 44-y-old female who ingested 50 ml of ethyl parathion concentrate (25 g) is described. She was treated by gastric lavage, administration of pralidoxime and atropine, and mechanical ventilation. As signs of intoxication disappeared at day 3, treatment was discontinued. The patient had a relapse of acute cholinergic crisis at day 4, and the same treatment was applied again. The acute poisoning phase was followed by an intermediate syndrome and delayed distal polyneuropathy. The clinical course of this severe ethyl parathion poisoning was favorable after 40 d.

Topics: Acute Disease; Adult; Atropine; Cholinesterase Reactivators; Drug Overdose; Drug Therapy, Combination; Female; Gastric Lavage; Humans; Insecticides; Muscles; Parathion; Peripheral Nervous System Diseases; Pralidoxime Compounds; Recurrence; Respiration, Artificial; Suicide, Attempted; Syndrome; Treatment Outcome

Ten patients with intermediate syndrome (IMS) after acute organophosphorus (OP) pesticides poisoning were observed. The occurrence rate of IMS was 5.4% among total inpatients of acute OP poisoning in the same period. The majority of IMS cases were of severe oral OP poisoning. Seven to 68 hours after poisoning there were initial signs including motor weakness of muscles innervated by the 9th and 10th cranial nerves (e.g. dysphagia, hoarse voice). The neck flexor muscles and proximal limb muscles were also involved. Patients with respiratory muscle paralysis usually required urgent tracheal intubation and mechanical ventilation. The IMS in this group persisted for 6-30 days (mean 13 days) with no fatality. The relevant kinds of pesticide, the development and regression of IMS, and the treatment and possible mechanism of IMS were discussed.

Topics: Adult; Antidotes; Atropine; Cholinesterase Reactivators; Deglutition Disorders; Female; Hoarseness; Humans; Insecticides; Male; Middle Aged; Organophosphorus Compounds; Pralidoxime Compounds; Respiration, Artificial; Respiratory Paralysis; Syndrome