title: Quality of cardiopulmonary resuscitation during out-of-hospital cardiac arrest.
abstract: BACKGROUND
  Cardiopulmonary resuscitation (CPR) guidelines recommend target values for compressions, ventilations, and CPR-free intervals allowed for rhythm analysis and defibrillation. There is little information on adherence to these guidelines during advanced cardiac life support in the field.
  
  
  OBJECTIVE
  To measure the quality of out-of-hospital CPR performed by ambulance personnel, as measured by adherence to CPR guidelines.
  
  
  METHODS
  Case series of 176 adult patients with out-of-hospital cardiac arrest treated by paramedics and nurse anesthetists in Stockholm, Sweden, London, England, and Akershus, Norway, between March 2002 and October 2003. The defibrillators recorded chest compressions via a sternal pad fitted with an accelerometer and ventilations by changes in thoracic impedance between the defibrillator pads, in addition to standard event and electrocardiographic recordings.
  
  
  METHODS
  Adherence to international guidelines for CPR.
  
  
  RESULTS
  Chest compressions were not given 48% (95% CI, 45%-51%) of the time without spontaneous circulation; this percentage was 38% (95% CI, 36%-41%) when subtracting the time necessary for electrocardiographic analysis and defibrillation. Combining these data with a mean compression rate of 121/min (95% CI, 118-124/min) when compressions were given resulted in a mean compression rate of 64/min (95% CI, 61-67/min). Mean compression depth was 34 mm (95% CI, 33-35 mm), 28% (95% CI, 24%-32%) of the compressions had a depth of 38 mm to 51 mm (guidelines recommendation), and the compression part of the duty cycle was 42% (95% CI, 41%-42%). A mean of 11 (95% CI, 11-12) ventilations were given per minute. Sixty-one patients (35%) had return of spontaneous circulation, and 5 of 6 patients discharged alive from the hospital had normal neurological outcomes.
  
  
  CONCLUSIONS
  In this study of CPR during out-of-hospital cardiac arrest, chest compressions were not delivered half of the time, and most compressions were too shallow. Electrocardiographic analysis and defibrillation accounted for only small parts of intervals without chest compressions.
authors.affiliation: National Competence Center for Emergency Medicine, Ulleval University Hospital, Oslo, Norway.
authors.forename: Lars
authors.initials: L
authors.lastname: Wik
authors.forename: Jo
authors.initials: J
authors.lastname: Kramer-Johansen
authors.forename: Helge
authors.initials: H
authors.lastname: Myklebust
authors.forename: Hallstein
authors.initials: H
authors.lastname: Sørebø
authors.forename: Leif
authors.initials: L
authors.lastname: Svensson
authors.forename: Bob
authors.initials: B
authors.lastname: Fellows
authors.forename: Petter Andreas
authors.initials: PA
authors.lastname: Steen
mesh_terms: D000368:Aged; D016887:Cardiopulmonary Resuscitation / Q000379:methods / Q000592:standards*; D004632:Emergency Medical Services / Q000592:standards*; D004634:Emergency Medical Technicians; D004739:England; D005260:Female; D019983:Guideline Adherence / Q000706:statistics & numerical data*; D006323:Heart Arrest / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009664:Norway; D009719:Nurse Anesthetists; D017410:Practice Guidelines as Topic; D013548:Sweden