title: Are two or four hands needed for elderly female bystanders to achieve the required chest compression depth during dispatcher-assisted CPR: a randomized controlled trial.
abstract: BACKGROUND
  Rescuers are often unable to achieve the recommended 5-6 cm CC depth. The physical limitations of elderly bystanders may affect the quality of CC; thus, we investigated new strategies to improve CC performance.
  
  
  METHODS
  We performed a randomized controlled trial in December 2013. Sixty-eight lay rescuers aged 50-75 were randomized to intervention or control pairs (males and females separately). Each pair performed 8 min of DA-CPR on a manikin connected to a PC. Each participant in every pair took turns performing CCs in cycles of 2 min and switched as advised by the dispatcher. In the middle of every 2-min cycle, the dispatcher asked the participants of the intervention group to perform the Andrew's manoeuvre (to push on the shoulders of the person while he/she performed CCs to achieve deeper CC). Data on the quality of the CCs were analysed for each participant and pair.
  
  
  RESULTS
  The CC depth in the intervention group increased by 6.4 mm (p = 0.002) compared to the control group (54.2 vs. 47.8 mm) due to a significant difference in the female group. The CC depth in the female intervention and control groups was 51.5 and 44.9 mm.
  
  
  CONCLUSIONS
  The largest group of out-of-hospital cardiac arrest occurred in males over the age of 60 at home, and accordingly, the most likely witness, if any, is the spouse or family member, most frequently an older woman. There is a growing body of evidence that female rescuers are frequently unable to achieve sufficient CC depth compared to male rescuers. In some instances, the adequate depth of the CCs could only be reached using four hands, with the second pair of hands placed on the shoulders of the rescuer performing CPR.
  
  
  CONCLUSIONS
  Andrew's manoeuvre (four-hands CC) during the simulated DA-CPR significantly improved the performance of elderly female rescuers and helped them to achieve the recommended CC depth.
authors.affiliation: Department of Disaster Medicine, Lithuanian University of Health Sciences, Eiveniu 4-512, Kaunas, LT, 50161, Lithuania. asta@smp.lt.
authors.forename: Asta
authors.initials: A
authors.lastname: Krikscionaitiene
authors.affiliation: Department of Surgery, Lithuanian University of Health Sciences, Kaunas, Lithuania.
authors.forename: Zilvinas
authors.initials: Z
authors.lastname: Dambrauskas
authors.affiliation: International Academies of Emergency Dispatch, Bristol, UK.
authors.forename: Tracey
authors.initials: T
authors.lastname: Barron
authors.affiliation: Department of Disaster Medicine, Lithuanian University of Health Sciences, Eiveniu 4-512, Kaunas, LT, 50161, Lithuania.
authors.forename: Egle
authors.initials: E
authors.lastname: Vaitkaitiene
authors.affiliation: Department of Disaster Medicine, Lithuanian University of Health Sciences, Eiveniu 4-512, Kaunas, LT, 50161, Lithuania.
authors.forename: Dinas
authors.initials: D
authors.lastname: Vaitkaitis
mesh_terms: D000368:Aged; D016887:Cardiopulmonary Resuscitation / Q000379:methods*; D035641:Chest Wall Oscillation / Q000592:standards*; D003299:Cooperative Behavior; D004631:Emergency Medical Service Communication Systems; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D058687:Out-of-Hospital Cardiac Arrest
keywords: Basic life support; Bystander; CPR quality; Chest compressions; Dispatcher-assisted CPR; Four-hands CC; Manikin