title: Is oxygen required before atropine administration in organophosphorus or carbamate pesticide poisoning? - A cohort study.
abstract: BACKGROUND
  Early and adequate atropine administration in organophosphorus (OP) or carbamate insecticide poisoning improves outcome. However, some authors advise that oxygen must be given before atropine due to the risk of inducing ventricular dysrhythmias in hypoxic patients. Because oxygen is frequently unavailable in district hospitals of rural Asia, where the majority of patients with insecticide poisoning present, this guidance has significant implications for patient care. The published evidence for this advice is weak. We therefore performed a patient cohort analysis to look for early cardiac deaths in patients poisoned by anticholinesterase pesticides.
  
  
  METHODS
  We analysed a prospective Sri Lankan cohort of OP or carbamate-poisoned patients treated with early atropine without the benefit of oxygen for evidence of early deaths. The incidence of fatal primary cardiac arrests within 3 h of admission was used as a sensitive (but non-specific) marker of possible ventricular dysrhythmias.
  
  
  RESULTS
  The cohort consisted of 1957 patients. The incidence of a primary cardiac death within 3 h of atropine administration was 4 (0.2%) of 1957 patients. The majority of deaths occurred at a later time point from respiratory complications of poisoning.
  
  
  CONCLUSIONS
  We found no evidence of a high number of early deaths in an observational study of 1957 patients routinely given atropine before oxygen that might support guidance that oxygen must be given before atropine. The published literature indicates that early and rapid administration of atropine during resuscitation is life-saving. Therefore, whether oxygen is available or not, early atropinisation of OP- and carbamate-poisoned patients should be performed.
authors.affiliation: Pharmacology, Toxicology and Therapeutics, University/BHF Centre for Cardiovascular Science, University of Edinburgh , UK.
authors.forename: L A
authors.initials: LA
authors.lastname: Konickx
authors.forename: K
authors.initials: K
authors.lastname: Bingham
authors.forename: M
authors.initials: M
authors.lastname: Eddleston
mesh_terms: D000328:Adult; D000931:Antidotes / Q000008:administration & dosage / Q000627:therapeutic use; D001285:Atropine / Q000008:administration & dosage / Q000627:therapeutic use*; D002219:Carbamates / Q000506:poisoning*; D002800:Cholinesterase Inhibitors / Q000506:poisoning; D015331:Cohort Studies; D005260:Female; D006323:Heart Arrest / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D062025:Organophosphate Poisoning / Q000628:therapy*; D010100:Oxygen / Q000008:administration & dosage*; D010575:Pesticides / Q000506:poisoning*; D011446:Prospective Studies; D012151:Resuscitation / Q000379:methods; D013188:Sri Lanka / Q000453:epidemiology; D013997:Time Factors
chemical_list: D000931:Antidotes; D002219:Carbamates; D002800:Cholinesterase Inhibitors; D010575:Pesticides; D001285:Atropine; D010100:Oxygen
keywords: Atropine; Carbamate; Organophosphorus; Oxygen; Ventricular dysrhythmia