title: A comparison of CPR delivery with various compression-to-ventilation ratios during two-rescuer CPR.
abstract: BACKGROUND
  The number of chest compressions required for optimal generation of coronary perfusion pressure remains unknown although studies examining compression-to-ventilation ratios higher than 15:2 (C:V) in animals have reported higher C:V to be superior for return of spontaneous circulation and neurologic outcome. We examined human performance of two-rescuer CPR using various C:V.
  
  
  METHODS
  Thirty six EMT-Basic students in their final week of training performed two-rescuer CPR using C:V of 15:2, 30:2, 40:2, 50:2, and 60:2 on a recording resuscitation manikin. Compression and ventilation variables were recorded by computer while the number of pauses for ventilations and the hands-off time (time not spent performing chest compressions) were abstracted by hand. Data were analyzed by ANOVA and significant differences from the standard treatment of C:V = 15:2 were assessed by Tukey's HSD post hoc test.
  
  
  RESULTS
  The number of compressions delivered per minute increased with increasing C:V while the hands-off time and pauses for ventilations decreased. All comparisons were significantly different from C:V = 15:2 (P < 0.001). The ventilation numbers decreased with increasing C:V although mean minute volume exceeded 1l for all C:V.
  
  
  CONCLUSIONS
  A 15:2 compression-to-ventilation ratio when performed during two-rescuer CPR results in 26s of hands off time each minute while only delivering 60 compressions. Alternative C:V ratios of 30:2, 40:2, 50:2, and 60:2 all exceed the AHA recommended 80 compressions/min while still delivering a minute volume in excess of 1l.
authors.affiliation: University of Pittsburgh, Department of Emergency Medicine and the Affiliated Emergency Medicine Residency, 230 McKee Place, Suite 500, Pittsburgh, PA 15213, USA. hostlerdp@upmc.edu
authors.forename: David
authors.initials: D
authors.lastname: Hostler
authors.forename: Guy
authors.initials: G
authors.lastname: Guimond
authors.forename: Clifton
authors.initials: C
authors.lastname: Callaway
mesh_terms: D016887:Cardiopulmonary Resuscitation / Q000379:methods*; D006336:Heart Massage / Q000379:methods*; D006801:Humans; D008348:Manikins; D012121:Respiration, Artificial; D013647:Task Performance and Analysis