title: Mechanical chest compressions improved aspects of CPR in the LINC trial.
abstract: OBJECTIVE
  We studied resuscitation process metrics in patients with out-of-hospital cardiac arrest enrolled in a randomized trial comparing one protocol designed to best use a mechanical CPR device, with another based on the 2005 European Resuscitation Council guidelines for manual CPR.
  
  
  METHODS
  We analyzed clinical data, ECG signals, and transthoracic impedance signals for a subset of the patients in the LUCAS in Cardiac Arrest (LINC) trial, including 124 patients randomized to mechanical and 82 to manual CPR. Chest compression fraction (CCF) was defined as the fraction of time during cardiac arrest that chest compressions were administered.
  
  
  RESULTS
  Patients in the mechanical CPR group had a higher CCF than those in the manual CPR group [0.84 (0.78, 0.91) vs. 0.79 (0.70, 0.86), p < 0.001]. The median duration of their pauses for defibrillation was also shorter [0 s (0, 6.0) vs. 10.0 s (7.0, 14.3), p < 0.001]. Compressions were interrupted for a median of 36.0 s to apply the compression device. There was no difference between groups in duration of the longest pause in compressions [32.5s vs. 26.0 s, p = 0.24], number of compressions received per minute [86.5 vs. 88.3, p = 0.47], defibrillation success rate [73.2% vs. 81.0%, p = 0.15], or refibrillation rate [74% vs. 77%, p = 0.79].
  
  
  CONCLUSIONS
  A protocol using mechanical chest compression devices reduced interruptions in chest compressions, and enabled defibrillation during ongoing compressions, without adversely affecting other resuscitation process metrics. Future emphasis on optimizing device deployment may be beneficial.
authors.affiliation: Physio-Control, Inc., 11811 Willows Road NE, Redmond, WA 98052, USA. Electronic address: alex.esibov@physio-control.com.
authors.forename: Alexander
authors.initials: A
authors.lastname: Esibov
authors.affiliation: Physio-Control, Inc., 11811 Willows Road NE, Redmond, WA 98052, USA.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Banville
authors.affiliation: Physio-Control, Inc., 11811 Willows Road NE, Redmond, WA 98052, USA.
authors.forename: Fred W
authors.initials: FW
authors.lastname: Chapman
authors.affiliation: Regional Ambulance Service Utrecht, Jan van Eyck Lane 6, 3723 BC Bilthoven, Utrecht, The Netherlands.
authors.forename: René
authors.initials: R
authors.lastname: Boomars
authors.affiliation: South Western Ambulance Service NHS Foundation Trust, Abbey Ct, Exeter EX2 7HY, England, United Kingdom.
authors.forename: Martyn
authors.initials: M
authors.lastname: Box
authors.affiliation: Department of Surgical Sciences/Anaesthesiology and Intensive Care Medicine, Uppsala University, Akademiska sjukhuset entrence 70, 1 tr, Uppsala, Sweden.
authors.forename: Sten
authors.initials: S
authors.lastname: Rubertsson
mesh_terms: D000368:Aged; D016887:Cardiopulmonary Resuscitation / Q000379:methods*; D004554:Electric Countershock; D005260:Female; D006336:Heart Massage / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D058687:Out-of-Hospital Cardiac Arrest / Q000628:therapy*; D013909:Thorax
keywords: Cardiopulmonary resuscitation (CPR); Chest compression fraction; Defibrillation; Mechanical CPR; Out-of-hospital cardiac arrest (OHCA); Perishock pause