title: The impact of airway management on quality of cardiopulmonary resuscitation: an observational study in patients during cardiac arrest.
abstract: BACKGROUND
  Minimising interruptions in chest compressions is associated with improved survival from cardiac arrest. Current in-hospital guidelines recommend continuous chest compressions after the airway is secured on the premise that this will reduce no flow time. The aim of this study was to determine the effect of advanced airway use on the no flow ratio and other measures of CPR quality.
  
  
  METHODS
  Consecutive adult patients who sustained an in-hospital cardiac arrest were enrolled in this prospective observational study. The quality of CPR was measured using the Q-CPR device (Phillips, UK) before and after an advanced airway device (endotracheal tube [ET] or laryngeal mask airway [LMA]) was inserted. Patients receiving only bag-mask ventilation were used as the control cohort. The primary outcome was no flow ratio (NFR). Secondary outcomes were chest compression rate, depth, compressions too shallow, compressions with leaning, ventilation rate, inflation time, change in impedance and time required to successfully insert airway device.
  
  
  RESULTS
  One hundred patients were enrolled in the study (2008-2011). Endotracheal tube and LMA placement took similar durations (median 15.8 s (IQR 6.8-19.4) vs. LMA median 8.0s (IQR 5.5-15.9), p=0.1). The use of an advanced airway was associated with improved no flow ratios (endotracheal tube placement (n=50) improved NFR from baseline median 0.24 IQR 0.17-0.40) to 0.15 to (IQR 0.09-0.28), p=0.012; LMA (n=25) from median 0.28 (IQR 0.23-0.40) to 0.13 (IQR 0.11- 0.19), p=0.0001). There was no change in NFR in patients managed solely with bag valve mask (BVM) (n=25) (median 0.29 (IQR 0.18-0.59) vs. median 0.26 (IQR 0.12-0.37), p=0.888). There was no significant difference in time taken to successfully insert the airway device between the two groups.
  
  
  CONCLUSIONS
  The use of an advanced airway (ETT or LMA) during in-hospital cardiac arrest was associated with improved no flow ratio. Further studies are required to determine the effect of airway devices on overall patient outcomes.
authors.affiliation: Heart of England NHS Foundation Trust, Birmingham Heartlands Hospital, Birmingham B9 5SS, United Kingdom; University of Birmingham, School of Clinical and Experimental Medicine, Birmingham B15 2TT, United Kingdom.
authors.forename: Joyce
authors.initials: J
authors.lastname: Yeung
authors.affiliation: Heart of England NHS Foundation Trust, Birmingham Heartlands Hospital, Birmingham B9 5SS, United Kingdom; University of Warwick, Warwick Medical School, Coventry CV4 7AL, United Kingdom.
authors.forename: Mehboob
authors.initials: M
authors.lastname: Chilwan
authors.affiliation: University of Southampton, Faculty of Medicine, SO16 6YD, United Kingdom.
authors.forename: Richard
authors.initials: R
authors.lastname: Field
authors.affiliation: Heart of England NHS Foundation Trust, Birmingham Heartlands Hospital, Birmingham B9 5SS, United Kingdom.
authors.forename: Robin
authors.initials: R
authors.lastname: Davies
authors.affiliation: Heart of England NHS Foundation Trust, Birmingham Heartlands Hospital, Birmingham B9 5SS, United Kingdom; University of Birmingham, School of Clinical and Experimental Medicine, Birmingham B15 2TT, United Kingdom.
authors.forename: Fang
authors.initials: F
authors.lastname: Gao
authors.affiliation: Heart of England NHS Foundation Trust, Birmingham Heartlands Hospital, Birmingham B9 5SS, United Kingdom; University of Warwick, Warwick Medical School, Coventry CV4 7AL, United Kingdom. Electronic address: g.d.perkins@warwick.ac.uk.
authors.forename: Gavin D
authors.initials: GD
authors.lastname: Perkins
mesh_terms: D000328:Adult; D000368:Aged; D058109:Airway Management / Q000379:methods*; D016887:Cardiopulmonary Resuscitation / Q000592:standards*; D004632:Emergency Medical Services; D005260:Female; D006323:Heart Arrest / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D006113:United Kingdom
keywords: Airway management; Cardiac arrest; Cardiopulmonary resuscitation