The spectrum of intermediate syndrome following acute organophosphate poisoning: a prospective cohort study from Sri Lanka.

Intermediate syndrome (IMS) is a major cause of death from respiratory failure following acute organophosphate poisoning. The objective of this study was to determine repetitive nerve stimulation (RNS) predictors of IMS that would assist in patient management and clinical research.Seventy-eight cons...

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Main Authors: Pradeepa Jayawardane, Andrew H Dawson, Vajira Weerasinghe, Lakshman Karalliedde, Nicholas A Buckley, Nimal Senanayake
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2008-07-01
Series:PLoS Medicine
Online Access:http://europepmc.org/articles/PMC2459203?pdf=render
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author Pradeepa Jayawardane
Andrew H Dawson
Vajira Weerasinghe
Lakshman Karalliedde
Nicholas A Buckley
Nimal Senanayake
author_facet Pradeepa Jayawardane
Andrew H Dawson
Vajira Weerasinghe
Lakshman Karalliedde
Nicholas A Buckley
Nimal Senanayake
author_sort Pradeepa Jayawardane
collection DOAJ
description Intermediate syndrome (IMS) is a major cause of death from respiratory failure following acute organophosphate poisoning. The objective of this study was to determine repetitive nerve stimulation (RNS) predictors of IMS that would assist in patient management and clinical research.Seventy-eight consenting symptomatic patients with organophosphate poisoning were assessed prospectively with daily physical examination and RNS. RNS was done on the right and left median and ulnar nerves at 1, 3, 10, 15, 20, and 30 Hz. The study was conducted as a prospective observational cohort study in the Central Province, Sri Lanka. IMS was diagnosed in ten out of 78 patients using a priori clinical diagnostic criteria, and five of them developed respiratory failure. All ten patients showed progressive RNS changes correlating with the severity of IMS. A decrement-increment was observed at intermediate and high frequencies preceding the onset of clinical signs of IMS. As the patient developed clinical signs of IMS, decrement-increment was progressively noted at low and intermediate frequencies and a combination of decrement-increment and repetitive fade or severe decrement was noted at high frequencies. Severe decrement preceded respiratory failure in four patients. Thirty patients developed forme fruste IMS with less severe weakness not progressing to respiratory failure whose RNS was characterized by decrement-increment or a combination of decrement-increment and repetitive fade but never severe decrements.Characteristic changes in RNS, preceding the development of IMS, help to identify a subgroup of patients at high risk of developing respiratory failure. The forme fruste IMS with the characteristic early changes on RNS indicates that IMS is a spectrum disorder. RNS changes are objective and precede the diagnosis and complications of IMS. Thus they may be useful in clinical management and research.
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spelling doaj.art-0140874f193449ec9e6a4fe36c9f481f2022-12-21T23:55:20ZengPublic Library of Science (PLoS)PLoS Medicine1549-12771549-16762008-07-0157e14710.1371/journal.pmed.0050147The spectrum of intermediate syndrome following acute organophosphate poisoning: a prospective cohort study from Sri Lanka.Pradeepa JayawardaneAndrew H DawsonVajira WeerasingheLakshman KarallieddeNicholas A BuckleyNimal SenanayakeIntermediate syndrome (IMS) is a major cause of death from respiratory failure following acute organophosphate poisoning. The objective of this study was to determine repetitive nerve stimulation (RNS) predictors of IMS that would assist in patient management and clinical research.Seventy-eight consenting symptomatic patients with organophosphate poisoning were assessed prospectively with daily physical examination and RNS. RNS was done on the right and left median and ulnar nerves at 1, 3, 10, 15, 20, and 30 Hz. The study was conducted as a prospective observational cohort study in the Central Province, Sri Lanka. IMS was diagnosed in ten out of 78 patients using a priori clinical diagnostic criteria, and five of them developed respiratory failure. All ten patients showed progressive RNS changes correlating with the severity of IMS. A decrement-increment was observed at intermediate and high frequencies preceding the onset of clinical signs of IMS. As the patient developed clinical signs of IMS, decrement-increment was progressively noted at low and intermediate frequencies and a combination of decrement-increment and repetitive fade or severe decrement was noted at high frequencies. Severe decrement preceded respiratory failure in four patients. Thirty patients developed forme fruste IMS with less severe weakness not progressing to respiratory failure whose RNS was characterized by decrement-increment or a combination of decrement-increment and repetitive fade but never severe decrements.Characteristic changes in RNS, preceding the development of IMS, help to identify a subgroup of patients at high risk of developing respiratory failure. The forme fruste IMS with the characteristic early changes on RNS indicates that IMS is a spectrum disorder. RNS changes are objective and precede the diagnosis and complications of IMS. Thus they may be useful in clinical management and research.http://europepmc.org/articles/PMC2459203?pdf=render
spellingShingle Pradeepa Jayawardane
Andrew H Dawson
Vajira Weerasinghe
Lakshman Karalliedde
Nicholas A Buckley
Nimal Senanayake
The spectrum of intermediate syndrome following acute organophosphate poisoning: a prospective cohort study from Sri Lanka.
PLoS Medicine
title The spectrum of intermediate syndrome following acute organophosphate poisoning: a prospective cohort study from Sri Lanka.
title_full The spectrum of intermediate syndrome following acute organophosphate poisoning: a prospective cohort study from Sri Lanka.
title_fullStr The spectrum of intermediate syndrome following acute organophosphate poisoning: a prospective cohort study from Sri Lanka.
title_full_unstemmed The spectrum of intermediate syndrome following acute organophosphate poisoning: a prospective cohort study from Sri Lanka.
title_short The spectrum of intermediate syndrome following acute organophosphate poisoning: a prospective cohort study from Sri Lanka.
title_sort spectrum of intermediate syndrome following acute organophosphate poisoning a prospective cohort study from sri lanka
url http://europepmc.org/articles/PMC2459203?pdf=render
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