title: What is the optimal chest compression depth during out-of-hospital cardiac arrest resuscitation of adult patients?
abstract: BACKGROUND
  The 2010 American Heart Association guidelines suggested an increase in cardiopulmonary resuscitation compression depth with a target >50 mm and no upper limit. This target is based on limited evidence, and we sought to determine the optimal compression depth range.
  
  
  RESULTS
  We studied emergency medical services-treated out-of-hospital cardiac arrest patients from the Resuscitation Outcomes Consortium Prehospital Resuscitation Impedance Valve and Early Versus Delayed Analysis clinical trial and the Epistry-Cardiac Arrest database. We calculated adjusted odds ratios for survival to hospital discharge, 1-day survival, and any return of circulation. We included 9136 adult patients from 9 US and Canadian cities with a mean age of 67.5 years, mean compression depth of 41.9 mm, and a return of circulation of 31.3%, 1-day survival of 22.8%, and survival to hospital discharge of 7.3%. For survival to discharge, the adjusted odds ratios were 1.04 (95% CI, 1.00-1.08) for each 5-mm increment in compression depth, 1.45 (95% CI, 1.20-1.76) for cases within 2005 depth range (>38 mm), and 1.05 (95% CI, 1.03-1.08) for percentage of minutes in depth range (10% change). Covariate-adjusted spline curves revealed that the maximum survival is at a depth of 45.6 mm (15-mm interval with highest survival between 40.3 and 55.3 mm) with no differences between men and women.
  
  
  CONCLUSIONS
  This large study of out-of-hospital cardiac arrest patients demonstrated that increased cardiopulmonary resuscitation compression depth is strongly associated with better survival. Our adjusted analyses, however, found that maximum survival was in the depth interval of 40.3 to 55.3 mm (peak, 45.6 mm), suggesting that the 2010 American Heart Association cardiopulmonary resuscitation guideline target may be too high.
  
  
  BACKGROUND
  http://www.clinicaltrials.gov. Unique identifier: NCT00394706.
authors.affiliation: From the Department of Emergency Medicine and Ottawa Hospital Research Institute, University of Ottawa, Ottawa, Ontario, Canada (I.G.S., C.V.); Clinical Trials Center, Department of Biostatistics (S.P.B., G.N.) and Department of Medicine (G.N.), University of Washington, Seattle, WA; University of Washington-Harborview Center for Prehospital Emergency Care, Seattle, WA (G.N.); Division of Emergency Medicine, Department of Family and Community Medicine (S.C.), and Division of Emergency Medicine, Department of Medicine (L.J.M.), University of Toronto, Toronto, Ontario, Canada; Rescu, Li Ka Shing Knowledge Institute, St Michael's Hospital, Toronto, Ontario, Canada (S.C., L.J.M.); Department of Emergency Medicine, University of Pittsburgh, Pittsburgh, PA (C.W.C., D.H.); Department of Emergency Medicine, University of British Columbia, Vancouver, British Columbia, Canada (J.C.); Department of Emergency Medicine, Medical College of Wisconsin, Milwaukee, WI (T.P.A.); Department of Emergency Medicine, University of California, San Diego, CA (D.P.D.); Camas Fire Department, Camas, WA (C.F.); Central Washington University, Ellensburg, WA (J.A.S.); Departments of Emergency Medicine and Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX (A.H.I.). istiell@ohri.ca.
authors.forename: Ian G
authors.initials: IG
authors.lastname: Stiell
authors.affiliation: From the Department of Emergency Medicine and Ottawa Hospital Research Institute, University of Ottawa, Ottawa, Ontario, Canada (I.G.S., C.V.); Clinical Trials Center, Department of Biostatistics (S.P.B., G.N.) and Department of Medicine (G.N.), University of Washington, Seattle, WA; University of Washington-Harborview Center for Prehospital Emergency Care, Seattle, WA (G.N.); Division of Emergency Medicine, Department of Family and Community Medicine (S.C.), and Division of Emergency Medicine, Department of Medicine (L.J.M.), University of Toronto, Toronto, Ontario, Canada; Rescu, Li Ka Shing Knowledge Institute, St Michael's Hospital, Toronto, Ontario, Canada (S.C., L.J.M.); Department of Emergency Medicine, University of Pittsburgh, Pittsburgh, PA (C.W.C., D.H.); Department of Emergency Medicine, University of British Columbia, Vancouver, British Columbia, Canada (J.C.); Department of Emergency Medicine, Medical College of Wisconsin, Milwaukee, WI (T.P.A.); Department of Emergency Medicine, University of California, San Diego, CA (D.P.D.); Camas Fire Department, Camas, WA (C.F.); Central Washington University, Ellensburg, WA (J.A.S.); Departments of Emergency Medicine and Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX (A.H.I.).
authors.forename: Siobhan P
authors.initials: SP
authors.lastname: Brown
authors.affiliation: From the Department of Emergency Medicine and Ottawa Hospital Research Institute, University of Ottawa, Ottawa, Ontario, Canada (I.G.S., C.V.); Clinical Trials Center, Department of Biostatistics (S.P.B., G.N.) and Department of Medicine (G.N.), University of Washington, Seattle, WA; University of Washington-Harborview Center for Prehospital Emergency Care, Seattle, WA (G.N.); Division of Emergency Medicine, Department of Family and Community Medicine (S.C.), and Division of Emergency Medicine, Department of Medicine (L.J.M.), University of Toronto, Toronto, Ontario, Canada; Rescu, Li Ka Shing Knowledge Institute, St Michael's Hospital, Toronto, Ontario, Canada (S.C., L.J.M.); Department of Emergency Medicine, University of Pittsburgh, Pittsburgh, PA (C.W.C., D.H.); Department of Emergency Medicine, University of British Columbia, Vancouver, British Columbia, Canada (J.C.); Department of Emergency Medicine, Medical College of Wisconsin, Milwaukee, WI (T.P.A.); Department of Emergency Medicine, University of California, San Diego, CA (D.P.D.); Camas Fire Department, Camas, WA (C.F.); Central Washington University, Ellensburg, WA (J.A.S.); Departments of Emergency Medicine and Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX (A.H.I.).
authors.forename: Graham
authors.initials: G
authors.lastname: Nichol
authors.affiliation: From the Department of Emergency Medicine and Ottawa Hospital Research Institute, University of Ottawa, Ottawa, Ontario, Canada (I.G.S., C.V.); Clinical Trials Center, Department of Biostatistics (S.P.B., G.N.) and Department of Medicine (G.N.), University of Washington, Seattle, WA; University of Washington-Harborview Center for Prehospital Emergency Care, Seattle, WA (G.N.); Division of Emergency Medicine, Department of Family and Community Medicine (S.C.), and Division of Emergency Medicine, Department of Medicine (L.J.M.), University of Toronto, Toronto, Ontario, Canada; Rescu, Li Ka Shing Knowledge Institute, St Michael's Hospital, Toronto, Ontario, Canada (S.C., L.J.M.); Department of Emergency Medicine, University of Pittsburgh, Pittsburgh, PA (C.W.C., D.H.); Department of Emergency Medicine, University of British Columbia, Vancouver, British Columbia, Canada (J.C.); Department of Emergency Medicine, Medical College of Wisconsin, Milwaukee, WI (T.P.A.); Department of Emergency Medicine, University of California, San Diego, CA (D.P.D.); Camas Fire Department, Camas, WA (C.F.); Central Washington University, Ellensburg, WA (J.A.S.); Departments of Emergency Medicine and Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX (A.H.I.).
authors.forename: Sheldon
authors.initials: S
authors.lastname: Cheskes
authors.affiliation: From the Department of Emergency Medicine and Ottawa Hospital Research Institute, University of Ottawa, Ottawa, Ontario, Canada (I.G.S., C.V.); Clinical Trials Center, Department of Biostatistics (S.P.B., G.N.) and Department of Medicine (G.N.), University of Washington, Seattle, WA; University of Washington-Harborview Center for Prehospital Emergency Care, Seattle, WA (G.N.); Division of Emergency Medicine, Department of Family and Community Medicine (S.C.), and Division of Emergency Medicine, Department of Medicine (L.J.M.), University of Toronto, Toronto, Ontario, Canada; Rescu, Li Ka Shing Knowledge Institute, St Michael's Hospital, Toronto, Ontario, Canada (S.C., L.J.M.); Department of Emergency Medicine, University of Pittsburgh, Pittsburgh, PA (C.W.C., D.H.); Department of Emergency Medicine, University of British Columbia, Vancouver, British Columbia, Canada (J.C.); Department of Emergency Medicine, Medical College of Wisconsin, Milwaukee, WI (T.P.A.); Department of Emergency Medicine, University of California, San Diego, CA (D.P.D.); Camas Fire Department, Camas, WA (C.F.); Central Washington University, Ellensburg, WA (J.A.S.); Departments of Emergency Medicine and Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX (A.H.I.).
authors.forename: Christian
authors.initials: C
authors.lastname: Vaillancourt
authors.affiliation: From the Department of Emergency Medicine and Ottawa Hospital Research Institute, University of Ottawa, Ottawa, Ontario, Canada (I.G.S., C.V.); Clinical Trials Center, Department of Biostatistics (S.P.B., G.N.) and Department of Medicine (G.N.), University of Washington, Seattle, WA; University of Washington-Harborview Center for Prehospital Emergency Care, Seattle, WA (G.N.); Division of Emergency Medicine, Department of Family and Community Medicine (S.C.), and Division of Emergency Medicine, Department of Medicine (L.J.M.), University of Toronto, Toronto, Ontario, Canada; Rescu, Li Ka Shing Knowledge Institute, St Michael's Hospital, Toronto, Ontario, Canada (S.C., L.J.M.); Department of Emergency Medicine, University of Pittsburgh, Pittsburgh, PA (C.W.C., D.H.); Department of Emergency Medicine, University of British Columbia, Vancouver, British Columbia, Canada (J.C.); Department of Emergency Medicine, Medical College of Wisconsin, Milwaukee, WI (T.P.A.); Department of Emergency Medicine, University of California, San Diego, CA (D.P.D.); Camas Fire Department, Camas, WA (C.F.); Central Washington University, Ellensburg, WA (J.A.S.); Departments of Emergency Medicine and Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX (A.H.I.).
authors.forename: Clifton W
authors.initials: CW
authors.lastname: Callaway
authors.affiliation: From the Department of Emergency Medicine and Ottawa Hospital Research Institute, University of Ottawa, Ottawa, Ontario, Canada (I.G.S., C.V.); Clinical Trials Center, Department of Biostatistics (S.P.B., G.N.) and Department of Medicine (G.N.), University of Washington, Seattle, WA; University of Washington-Harborview Center for Prehospital Emergency Care, Seattle, WA (G.N.); Division of Emergency Medicine, Department of Family and Community Medicine (S.C.), and Division of Emergency Medicine, Department of Medicine (L.J.M.), University of Toronto, Toronto, Ontario, Canada; Rescu, Li Ka Shing Knowledge Institute, St Michael's Hospital, Toronto, Ontario, Canada (S.C., L.J.M.); Department of Emergency Medicine, University of Pittsburgh, Pittsburgh, PA (C.W.C., D.H.); Department of Emergency Medicine, University of British Columbia, Vancouver, British Columbia, Canada (J.C.); Department of Emergency Medicine, Medical College of Wisconsin, Milwaukee, WI (T.P.A.); Department of Emergency Medicine, University of California, San Diego, CA (D.P.D.); Camas Fire Department, Camas, WA (C.F.); Central Washington University, Ellensburg, WA (J.A.S.); Departments of Emergency Medicine and Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX (A.H.I.).
authors.forename: Laurie J
authors.initials: LJ
authors.lastname: Morrison
authors.affiliation: From the Department of Emergency Medicine and Ottawa Hospital Research Institute, University of Ottawa, Ottawa, Ontario, Canada (I.G.S., C.V.); Clinical Trials Center, Department of Biostatistics (S.P.B., G.N.) and Department of Medicine (G.N.), University of Washington, Seattle, WA; University of Washington-Harborview Center for Prehospital Emergency Care, Seattle, WA (G.N.); Division of Emergency Medicine, Department of Family and Community Medicine (S.C.), and Division of Emergency Medicine, Department of Medicine (L.J.M.), University of Toronto, Toronto, Ontario, Canada; Rescu, Li Ka Shing Knowledge Institute, St Michael's Hospital, Toronto, Ontario, Canada (S.C., L.J.M.); Department of Emergency Medicine, University of Pittsburgh, Pittsburgh, PA (C.W.C., D.H.); Department of Emergency Medicine, University of British Columbia, Vancouver, British Columbia, Canada (J.C.); Department of Emergency Medicine, Medical College of Wisconsin, Milwaukee, WI (T.P.A.); Department of Emergency Medicine, University of California, San Diego, CA (D.P.D.); Camas Fire Department, Camas, WA (C.F.); Central Washington University, Ellensburg, WA (J.A.S.); Departments of Emergency Medicine and Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX (A.H.I.).
authors.forename: James
authors.initials: J
authors.lastname: Christenson
authors.affiliation: From the Department of Emergency Medicine and Ottawa Hospital Research Institute, University of Ottawa, Ottawa, Ontario, Canada (I.G.S., C.V.); Clinical Trials Center, Department of Biostatistics (S.P.B., G.N.) and Department of Medicine (G.N.), University of Washington, Seattle, WA; University of Washington-Harborview Center for Prehospital Emergency Care, Seattle, WA (G.N.); Division of Emergency Medicine, Department of Family and Community Medicine (S.C.), and Division of Emergency Medicine, Department of Medicine (L.J.M.), University of Toronto, Toronto, Ontario, Canada; Rescu, Li Ka Shing Knowledge Institute, St Michael's Hospital, Toronto, Ontario, Canada (S.C., L.J.M.); Department of Emergency Medicine, University of Pittsburgh, Pittsburgh, PA (C.W.C., D.H.); Department of Emergency Medicine, University of British Columbia, Vancouver, British Columbia, Canada (J.C.); Department of Emergency Medicine, Medical College of Wisconsin, Milwaukee, WI (T.P.A.); Department of Emergency Medicine, University of California, San Diego, CA (D.P.D.); Camas Fire Department, Camas, WA (C.F.); Central Washington University, Ellensburg, WA (J.A.S.); Departments of Emergency Medicine and Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX (A.H.I.).
authors.forename: Tom P
authors.initials: TP
authors.lastname: Aufderheide
authors.affiliation: From the Department of Emergency Medicine and Ottawa Hospital Research Institute, University of Ottawa, Ottawa, Ontario, Canada (I.G.S., C.V.); Clinical Trials Center, Department of Biostatistics (S.P.B., G.N.) and Department of Medicine (G.N.), University of Washington, Seattle, WA; University of Washington-Harborview Center for Prehospital Emergency Care, Seattle, WA (G.N.); Division of Emergency Medicine, Department of Family and Community Medicine (S.C.), and Division of Emergency Medicine, Department of Medicine (L.J.M.), University of Toronto, Toronto, Ontario, Canada; Rescu, Li Ka Shing Knowledge Institute, St Michael's Hospital, Toronto, Ontario, Canada (S.C., L.J.M.); Department of Emergency Medicine, University of Pittsburgh, Pittsburgh, PA (C.W.C., D.H.); Department of Emergency Medicine, University of British Columbia, Vancouver, British Columbia, Canada (J.C.); Department of Emergency Medicine, Medical College of Wisconsin, Milwaukee, WI (T.P.A.); Department of Emergency Medicine, University of California, San Diego, CA (D.P.D.); Camas Fire Department, Camas, WA (C.F.); Central Washington University, Ellensburg, WA (J.A.S.); Departments of Emergency Medicine and Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX (A.H.I.).
authors.forename: Daniel P
authors.initials: DP
authors.lastname: Davis
authors.affiliation: From the Department of Emergency Medicine and Ottawa Hospital Research Institute, University of Ottawa, Ottawa, Ontario, Canada (I.G.S., C.V.); Clinical Trials Center, Department of Biostatistics (S.P.B., G.N.) and Department of Medicine (G.N.), University of Washington, Seattle, WA; University of Washington-Harborview Center for Prehospital Emergency Care, Seattle, WA (G.N.); Division of Emergency Medicine, Department of Family and Community Medicine (S.C.), and Division of Emergency Medicine, Department of Medicine (L.J.M.), University of Toronto, Toronto, Ontario, Canada; Rescu, Li Ka Shing Knowledge Institute, St Michael's Hospital, Toronto, Ontario, Canada (S.C., L.J.M.); Department of Emergency Medicine, University of Pittsburgh, Pittsburgh, PA (C.W.C., D.H.); Department of Emergency Medicine, University of British Columbia, Vancouver, British Columbia, Canada (J.C.); Department of Emergency Medicine, Medical College of Wisconsin, Milwaukee, WI (T.P.A.); Department of Emergency Medicine, University of California, San Diego, CA (D.P.D.); Camas Fire Department, Camas, WA (C.F.); Central Washington University, Ellensburg, WA (J.A.S.); Departments of Emergency Medicine and Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX (A.H.I.).
authors.forename: Cliff
authors.initials: C
authors.lastname: Free
authors.affiliation: From the Department of Emergency Medicine and Ottawa Hospital Research Institute, University of Ottawa, Ottawa, Ontario, Canada (I.G.S., C.V.); Clinical Trials Center, Department of Biostatistics (S.P.B., G.N.) and Department of Medicine (G.N.), University of Washington, Seattle, WA; University of Washington-Harborview Center for Prehospital Emergency Care, Seattle, WA (G.N.); Division of Emergency Medicine, Department of Family and Community Medicine (S.C.), and Division of Emergency Medicine, Department of Medicine (L.J.M.), University of Toronto, Toronto, Ontario, Canada; Rescu, Li Ka Shing Knowledge Institute, St Michael's Hospital, Toronto, Ontario, Canada (S.C., L.J.M.); Department of Emergency Medicine, University of Pittsburgh, Pittsburgh, PA (C.W.C., D.H.); Department of Emergency Medicine, University of British Columbia, Vancouver, British Columbia, Canada (J.C.); Department of Emergency Medicine, Medical College of Wisconsin, Milwaukee, WI (T.P.A.); Department of Emergency Medicine, University of California, San Diego, CA (D.P.D.); Camas Fire Department, Camas, WA (C.F.); Central Washington University, Ellensburg, WA (J.A.S.); Departments of Emergency Medicine and Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX (A.H.I.).
authors.forename: Dave
authors.initials: D
authors.lastname: Hostler
authors.affiliation: From the Department of Emergency Medicine and Ottawa Hospital Research Institute, University of Ottawa, Ottawa, Ontario, Canada (I.G.S., C.V.); Clinical Trials Center, Department of Biostatistics (S.P.B., G.N.) and Department of Medicine (G.N.), University of Washington, Seattle, WA; University of Washington-Harborview Center for Prehospital Emergency Care, Seattle, WA (G.N.); Division of Emergency Medicine, Department of Family and Community Medicine (S.C.), and Division of Emergency Medicine, Department of Medicine (L.J.M.), University of Toronto, Toronto, Ontario, Canada; Rescu, Li Ka Shing Knowledge Institute, St Michael's Hospital, Toronto, Ontario, Canada (S.C., L.J.M.); Department of Emergency Medicine, University of Pittsburgh, Pittsburgh, PA (C.W.C., D.H.); Department of Emergency Medicine, University of British Columbia, Vancouver, British Columbia, Canada (J.C.); Department of Emergency Medicine, Medical College of Wisconsin, Milwaukee, WI (T.P.A.); Department of Emergency Medicine, University of California, San Diego, CA (D.P.D.); Camas Fire Department, Camas, WA (C.F.); Central Washington University, Ellensburg, WA (J.A.S.); Departments of Emergency Medicine and Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX (A.H.I.).
authors.forename: John A
authors.initials: JA
authors.lastname: Stouffer
authors.affiliation: From the Department of Emergency Medicine and Ottawa Hospital Research Institute, University of Ottawa, Ottawa, Ontario, Canada (I.G.S., C.V.); Clinical Trials Center, Department of Biostatistics (S.P.B., G.N.) and Department of Medicine (G.N.), University of Washington, Seattle, WA; University of Washington-Harborview Center for Prehospital Emergency Care, Seattle, WA (G.N.); Division of Emergency Medicine, Department of Family and Community Medicine (S.C.), and Division of Emergency Medicine, Department of Medicine (L.J.M.), University of Toronto, Toronto, Ontario, Canada; Rescu, Li Ka Shing Knowledge Institute, St Michael's Hospital, Toronto, Ontario, Canada (S.C., L.J.M.); Department of Emergency Medicine, University of Pittsburgh, Pittsburgh, PA (C.W.C., D.H.); Department of Emergency Medicine, University of British Columbia, Vancouver, British Columbia, Canada (J.C.); Department of Emergency Medicine, Medical College of Wisconsin, Milwaukee, WI (T.P.A.); Department of Emergency Medicine, University of California, San Diego, CA (D.P.D.); Camas Fire Department, Camas, WA (C.F.); Central Washington University, Ellensburg, WA (J.A.S.); Departments of Emergency Medicine and Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX (A.H.I.).
authors.forename: Ahamed H
authors.initials: AH
authors.lastname: Idris
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016887:Cardiopulmonary Resuscitation / Q000379:methods* / Q000401:mortality / Q000592:standards*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D058687:Out-of-Hospital Cardiac Arrest / Q000175:diagnosis* / Q000401:mortality / Q000628:therapy*; D011446:Prospective Studies; D015996:Survival Rate / Q000639:trends
keywords: cardiopulmonary resuscitation; emergency medical services; heart arrest