title: Dispatcher-assisted compression-only cardiopulmonary resuscitation provides best quality cardiopulmonary resuscitation by laypersons: A randomised controlled single-blinded manikin trial.
abstract: BACKGROUND
  High-quality cardiopulmonary resuscitation (CPR) by laypersons is a key determinant of both outcome and survival for out-of-hospital cardiac arrest. Dispatcher-assisted CPR (telephone-CPR, T-CPR) increases the frequency and correctness of bystander-CPR but results in prolonged time to first chest compressions. However, it remains unclear whether instructions for rescue ventilation and/or chest compressions should be recommended for dispatcher-assisted CPR.
  
  
  OBJECTIVE
  The aim of this study was to evaluate both principles of T-CPR with respect to CPR quality.
  
  
  METHODS
  Randomised controlled single-blinded manikin trial.
  
  
  METHODS
  University Hospital of Cologne, Germany, 1 July 2012 to 30 September 2012.
  
  
  METHODS
  Sixty laypersons between 18 and 65 years. Medically educated individuals, medical professionals and pregnant women were excluded. Participants were asked to resuscitate a manikin and were randomised into three groups: not dispatcher-assisted (uninstructed) CPR (group 1; U-CPR; n = 20), dispatcher-assisted compression-only CPR (group 2; DACO-CPR; n = 19) and full dispatcher-assisted CPR with rescue ventilation (group 3; DAF-CPR; n = 19).
  
  
  METHODS
  Specific parameters of CPR quality [i.e. no-flow-time (NFT) as well as compression and ventilation parameters] were analysed. To compare different groups we used Student's t test and P less than 0.05 was considered significant.
  
  
  RESULTS
  Initial NFT was lowest in the DACO-CPR group (mean 21.3 ± 14.4%), followed by dispatcher-assisted full CPR (mean 49.1 ± 8.5%) and by unassisted CPR (mean 55.0 ± 12.9%). Initial NFT covering the time of instruction was lower in DACO-CPR (12.1 ± 5.4%) as compared to dispatcher-assisted full CPR (20.7 ± 8.1%). Compression depth was similar in all three groups: 40.6 ± 13.0 mm (unassisted CPR), 41.0 ± 12.2 mm (DACO-CPR) and 38.8 ± 15.8 mm (dispatcher-assisted full CPR). Average compression frequency was highest in the DACO-CPR group (65.2 ± 22.4 min) compared with the unassisted CPR group (35.6 ± 24.2 min) and the dispatcher-assisted full CPR group (44.5 ± 10.8 min). Correct rescue ventilation was given in 3.1 ± 11.1% (unassisted CPR) and 1.6 ± 16.1% (dispatcher-assisted full CPR) of all ventilation attempts.
  
  
  CONCLUSIONS
  Best quality of CPR was achieved by DACO-CPR because of superior compression frequencies and reduced NFT. In contrast, the full dispatcher-assisted CPR with a longer initial instructing phase (initial NFT) did not result in enhanced CPR quality or an optimised compression depth.
authors.affiliation: From the Department for Anaesthesiology and Intensive Care Medicine, University Hospital of Cologne (OS, WAW, RS, BWB, JH); and Department of Anaesthesiology and Intensive Care Medicine, St Elisabeth-Hospital, Cologne, Germany (TW).
authors.forename: Oliver
authors.initials: O
authors.lastname: Spelten
authors.forename: Tobias
authors.initials: T
authors.lastname: Warnecke
authors.forename: Wolfgang A
authors.initials: WA
authors.lastname: Wetsch
authors.forename: Robert
authors.initials: R
authors.lastname: Schier
authors.forename: Bernd W
authors.initials: BW
authors.lastname: Böttiger
authors.forename: Jochen
authors.initials: J
authors.lastname: Hinkelbein
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D016887:Cardiopulmonary Resuscitation / Q000379:methods*; D004632:Emergency Medical Services; D005260:Female; D005392:First Aid; D006801:Humans; D008297:Male; D008348:Manikins; D008875:Middle Aged; D058687:Out-of-Hospital Cardiac Arrest; D011446:Prospective Studies; D012119:Respiration; D016037:Single-Blind Method; D013689:Telephone; D013990:Tidal Volume; D055815:Young Adult