title: Bystander capability to activate speaker function for continuous dispatcher assisted CPR in case of suspected cardiac arrest.
abstract: The European Resuscitation Council Guidelines 2015 recommend bystanders to activate their mobile phone speaker function, if possible, in case of suspected cardiac arrest. This is to facilitate continuous dialogue with the dispatcher including (if required) cardiopulmonary resuscitation instructions. The aim of this study was to measure the bystander capability to activate speaker function in case of suspected cardiac arrest.
  
  
  
  In 87days, a systematic prospective registration of bystander capability to activate the speaker function, when cardiac arrest was suspected, was performed. For those asked, "can you activate your mobile phone's speaker function", audio recordings were examined and categorized into groups according to the bystanders capability to activate speaker function on their own initiative, without instructions, or with instructions from the emergency medical dispatcher. Time delay was measured, in seconds, for the bystanders without pre-activated speaker function.
  
  
  
  42.0% (58) was able to activate the speaker function without instructions, 2.9% (4) with instructions, 18.1% (25) on own initiative and 37.0% (51) were unable to activate the speaker function. The median time to activate speaker function was 19s and 8s, with and without instructions, respectively.
  
  
  
  Dispatcher assisted cardiopulmonary resuscitation with activated speaker function, in cases of suspected cardiac arrest, allows for continuous dialogue between the emergency medical dispatcher and the bystander. In this study, we found a 63.0% success rate of activating the speaker function in such situations.
authors.affiliation: Prehospital Emergency Medical Services, Region Zealand, Denmark. Electronic address: alvilda.steensberg@gmail.com.
authors.forename: Alvilda T
authors.initials: AT
authors.lastname: Steensberg
authors.affiliation: Prehospital Emergency Medical Services, Region Zealand, Denmark.
authors.forename: Mette M
authors.initials: MM
authors.lastname: Eriksen
authors.affiliation: Prehospital Emergency Medical Services, Region Zealand, Denmark.
authors.forename: Lars B
authors.initials: LB
authors.lastname: Andersen
authors.affiliation: Prehospital Emergency Medical Services, Region Zealand, Denmark.
authors.forename: Ole M
authors.initials: OM
authors.lastname: Hendriksen
authors.affiliation: Prehospital Emergency Medical Services, Region Zealand, Denmark.
authors.forename: Heinrich D
authors.initials: HD
authors.lastname: Larsen
authors.affiliation: Production, Research & Innovation, Region Zealand, Denmark.
authors.forename: Gunnar H
authors.initials: GH
authors.lastname: Laier
authors.affiliation: Prehospital Emergency Medical Services, Region Zealand, Denmark.
authors.forename: Thomas
authors.initials: T
authors.lastname: Thougaard
mesh_terms: D000328:Adult; D000368:Aged; D016887:Cardiopulmonary Resuscitation; D040421:Cell Phone; D004631:Emergency Medical Service Communication Systems; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D058687:Out-of-Hospital Cardiac Arrest / Q000628:therapy*; D011446:Prospective Studies; D012042:Registries; D013997:Time Factors
keywords: Dispatcher-assisted-cardiopulmonary resuscitation; Out-of-hospital cardiac arrest; Speaker function; Telephone-CPR