title: Effects of uninterrupted chest compressions on the rescuer's physical condition.
abstract: OBJECTIVE
  Recent guidelines have emphasized the need for uninterrupted chest compressions. The purpose of this study was to evaluate the rescuer's tolerability of uninterrupted chest compressions.
  
  
  METHODS
  Twenty-five healthy subjects performed uninterrupted chest compressions for 7 minutes at a rate of 100 compressions per minute using a training manikin. The quality of chest compressions was assessed in terms of the total number and percentage of chest compressions, compression depth, recoil distance, and duty cycle. Correct chest compression was defined as a depth of 38 to 51 mm. Physiological and laboratory parameters were measured before and after the procedure. Fatigue was measured using a numerical rating scale. Data were compared before and after the procedure.
  
  
  RESULTS
  The participants were 10 emergency physicians and 15 medical students. The compression rate was nearly 100 compressions per minute. The number and percentage of correct compressions decreased gradually after 3 minutes. The compression depth decreased significantly after 2 minutes. The recoil distance and duty cycle were unchanged over 7 minutes. Systolic blood pressure, pulse rate, respiratory rate, numerical rating scale, serum lactate, adrenalin, and noradrenalin increased significantly after the procedure. Noradrenalin levels measured before the procedure were significantly and negatively correlated with the total number and percentage of correct compressions (r = -0.587, P = .004; r = -0.549, P = .008, respectively).
  
  
  CONCLUSIONS
  Performing uninterrupted chest compressions for 7 minutes is an arduous procedure. Higher noradrenalin levels before the procedure might be associated with incorrect chest compressions.
authors.affiliation: Advanced Medical Emergency and Critical Care Center, Yamaguchi University Hospital, Ube, Yamaguchi 755-8505, Japan.
authors.forename: Yohei
authors.initials: Y
authors.lastname: Otsuka
authors.affiliation: Department of Stress and Bio-response Medicine, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi 755-8505, Japan.
authors.forename: Shunji
authors.initials: S
authors.lastname: Kasaoka
authors.affiliation: Department of Stress and Bio-response Medicine, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi 755-8505, Japan. Electronic address: yasutaka-ygc@umin.ac.jp.
authors.forename: Yasutaka
authors.initials: Y
authors.lastname: Oda
authors.affiliation: Advanced Medical Emergency and Critical Care Center, Yamaguchi University Hospital, Ube, Yamaguchi 755-8505, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Nakahara
authors.affiliation: Advanced Medical Emergency and Critical Care Center, Yamaguchi University Hospital, Ube, Yamaguchi 755-8505, Japan.
authors.forename: Ryo
authors.initials: R
authors.lastname: Tanaka
authors.affiliation: Advanced Medical Emergency and Critical Care Center, Yamaguchi University Hospital, Ube, Yamaguchi 755-8505, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Todani
authors.affiliation: Advanced Medical Emergency and Critical Care Center, Yamaguchi University Hospital, Ube, Yamaguchi 755-8505, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Miyauchi
authors.affiliation: Advanced Medical Emergency and Critical Care Center, Yamaguchi University Hospital, Ube, Yamaguchi 755-8505, Japan.
authors.forename: Kotaro
authors.initials: K
authors.lastname: Kaneda
authors.affiliation: Advanced Medical Emergency and Critical Care Center, Yamaguchi University Hospital, Ube, Yamaguchi 755-8505, Japan.
authors.forename: Yoshikatsu
authors.initials: Y
authors.lastname: Kawamura
authors.affiliation: Advanced Medical Emergency and Critical Care Center, Yamaguchi University Hospital, Ube, Yamaguchi 755-8505, Japan; Department of Stress and Bio-response Medicine, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi 755-8505, Japan.
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Tsuruta
mesh_terms: D000328:Adult; D001794:Blood Pressure / Q000502:physiology; D004837:Epinephrine / Q000097:blood; D005221:Fatigue / Q000209:etiology / Q000503:physiopathology; D005260:Female; D006336:Heart Massage; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D007773:Lactates / Q000097:blood; D008297:Male; D008348:Manikins; D009638:Norepinephrine / Q000097:blood; D005082:Physical Exertion / Q000502:physiology; D056152:Respiratory Rate / Q000502:physiology; D013997:Time Factors
chemical_list: D007773:Lactates; D009638:Norepinephrine; D004837:Epinephrine