title: Speaking valves in tracheostomised ICU patients weaning off mechanical ventilation--do they facilitate lung recruitment?
abstract: BACKGROUND
  Patients who require positive pressure ventilation through a tracheostomy are unable to phonate due to the inflated tracheostomy cuff. Whilst a speaking valve (SV) can be used on a tracheostomy tube, its use in ventilated ICU patients has been inhibited by concerns regarding potential deleterious effects to recovering lungs. The objective of this study was to assess end expiratory lung impedance (EELI) and standard bedside respiratory parameters before, during and after SV use in tracheostomised patients weaning from mechanical ventilation.
  
  
  METHODS
  A prospective observational study was conducted in a cardio-thoracic adult ICU. 20 consecutive tracheostomised patients weaning from mechanical ventilation and using a SV were recruited. Electrical Impedance Tomography (EIT) was used to monitor patients' EELI. Changes in lung impedance and standard bedside respiratory data were analysed pre, during and post SV use.
  
  
  RESULTS
  Use of in-line SVs resulted in significant increase of EELI. This effect grew and was maintained for at least 15 minutes after removal of the SV (p < 0.001). EtCO2 showed a significant drop during SV use (p = 0.01) whilst SpO2 remained unchanged. Respiratory rate (RR (breaths per minute)) decreased whilst the SV was in situ (p <0.001), and heart rate (HR (beats per minute)) was unchanged. All results were similar regardless of the patients' respiratory requirements at time of recruitment.
  
  
  CONCLUSIONS
  In this cohort of critically ill ventilated patients, SVs did not cause derecruitment of the lungs when used in the ventilator weaning period. Deflating the tracheostomy cuff and restoring the airflow via the upper airway with a one-way valve may facilitate lung recruitment during and after SV use, as indicated by increased EELI.
  
  
  BACKGROUND
  Anna-Liisa Sutt, Australian New Zealand Clinical Trials Registry (ANZCTR).
  ACTRN12615000589583. 4/6/2015.
authors.affiliation: Critical Care Research Group, The Prince Charles Hospital, Brisbane, Australia. anna-liisa.sutt@health.qld.gov.au.|School of Medicine, University of Queensland, Brisbane, Australia. anna-liisa.sutt@health.qld.gov.au.|Speech Pathology Department, The Prince Charles Hospital, Brisbane, Australia. anna-liisa.sutt@health.qld.gov.au.
authors.forename: Anna-Liisa
authors.initials: AL
authors.lastname: Sutt
authors.affiliation: Critical Care Research Group, The Prince Charles Hospital, Brisbane, Australia.|Physiotherapy Department, The Prince Charles Hospital, Brisbane, Australia.
authors.forename: Lawrence R
authors.initials: LR
authors.lastname: Caruana
authors.affiliation: Critical Care Research Group, The Prince Charles Hospital, Brisbane, Australia.|Science & Engineering Faculty, Queensland University of Technology, Brisbane, Australia.
authors.forename: Kimble R
authors.initials: KR
authors.lastname: Dunster
authors.affiliation: Allied Health Collaborative, Metro North HHS, Brisbane, Australia.|School of Applied Psychology, Menzies Health Institute Queensland, Griffith University, Brisbane, Australia.
authors.forename: Petrea L
authors.initials: PL
authors.lastname: Cornwell
authors.affiliation: School of Medicine, University of Queensland, Brisbane, Australia.|Critical Care Research Group, Sunshine Coast University Hospital, Brisbane, Australia.
authors.forename: Chris M
authors.initials: CM
authors.lastname: Anstey
authors.affiliation: Critical Care Research Group, The Prince Charles Hospital, Brisbane, Australia.|School of Medicine, University of Queensland, Brisbane, Australia.
authors.forename: John F
authors.initials: JF
authors.lastname: Fraser
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D003142:Communication; D005260:Female; D006801:Humans; D007362:Intensive Care Units / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D012121:Respiration, Artificial / Q000009:adverse effects / Q000379:methods* / Q000706:statistics & numerical data; D013060:Speech / Q000502:physiology*; D014139:Tracheostomy / Q000009:adverse effects / Q000379:methods* / Q000706:statistics & numerical data; D015300:Ventilator Weaning / Q000009:adverse effects / Q000379:methods*
keywords: Communication; FRC; Lung recruitment; Mechanical ventilation; Speaking valve; Tracheostomy