title: Effort to Breathe with Various Spontaneous Breathing Trial Techniques. A Physiologic Meta-analysis.
abstract: Spontaneous breathing trials (SBTs) are designed to simulate conditions after extubation, and it is essential to understand the physiologic impact of different methods.
  
  
  
  We conducted a systematic review and pooled measures reflecting patient respiratory effort among studies comparing SBT methods in a meta-analysis.
  
  
  
  We searched Medline, Excerpta Medica Database, and Web of Science from inception to January 2016 to identify randomized and nonrandomized clinical trials reporting physiologic measurements of respiratory effort (pressure-time product) or work of breathing during at least two SBT techniques. Secondary outcomes included the rapid shallow breathing index (RSBI), and effort measured before and after extubation. The quality of physiologic measurement and research design was appraised for each study. Outcomes were analyzed using ratio of means.
  
  
  
  Among 4,138 citations, 16 studies (n = 239) were included. Compared with T-piece, pressure support ventilation significantly reduced work by 30% (ratio of means [RoM], 0.70; 95% confidence interval [CI], 0.57-0.86), effort by 30% (RoM, 0.70; 95% CI, 0.60-0.82), and RSBI by 20% (RoM, 0.80; 95% CI, 0.75-0.86). Continuous positive airway pressure had significantly lower pressure-time product by 18% (RoM, 0.82; 95% CI, 0.68-0.999) compared with T-piece, and reduced RSBI by 16% (RoM, 0.84; 95% CI, 0.74-0.95). Studies comparing SBTs with the postextubation period demonstrated that pressure support induced significantly lower effort and RSBI; T-piece reduced effort, but not the work, compared with postextubation. Work, effort, and RSBI measured while intubated on the ventilator with continuous positive airway pressure of 0 cm H2O were no different than extubation.
  
  
  
  Pressure support reduces respiratory effort compared with T-piece. Continuous positive airway pressure of 0 cm H2O and T-piece more accurately reflect the physiologic conditions after extubation.
authors: 1 Department of Anesthesiology and.|2 Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario, Canada.
authors: Michael C
authors: MC
authors: Sklar
authors: 3 Interdepartmental Division of Critical Care Medicine, University of Toronto, Ontario, Canada.|2 Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario, Canada.
authors: Karen
authors: K
authors: Burns
authors: 4 Department of Medicine, Division of Respiratory Diseases and Tuberculosis, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand.
authors: Nuttapol
authors: N
authors: Rittayamai
authors: 2 Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario, Canada.
authors: Ashley
authors: A
authors: Lanys
authors: 2 Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario, Canada.|5 Department of Anaesthesia and Intensive Care, University of Foggia, Foggia, Italy.
authors: Michela
authors: M
authors: Rauseo
authors: 2 Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario, Canada.
authors: Lu
authors: 0000-0002-7512-1865
authors: L
authors: Chen
authors: 2 Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario, Canada.|6 Sorbonne Universités, UPMC Univ Paris 06, INSERM, UMRS_1158 Neurophysiologie Respiratoire Expérimentale et Clinique, Paris, France.
authors: Martin
authors: M
authors: Dres
authors: 2 Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario, Canada.|7 Department of Critical Care Medicine, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.
authors: Guang-Qiang
authors: GQ
authors: Chen
authors: 3 Interdepartmental Division of Critical Care Medicine, University of Toronto, Ontario, Canada.|8 Division of Respirology, Department of Medicine, University Health Network and Mount Sinai Hospital, Toronto, Ontario, Canada; and.
authors: Ewan C
authors: EC
authors: Goligher
authors: 3 Interdepartmental Division of Critical Care Medicine, University of Toronto, Ontario, Canada.|9 Department of Critical Care Medicine, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada.
authors: Neill K J
authors: NKJ
authors: Adhikari
authors: 3 Interdepartmental Division of Critical Care Medicine, University of Toronto, Ontario, Canada.|2 Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario, Canada.
authors: Laurent
authors: L
authors: Brochard
authors: 3 Interdepartmental Division of Critical Care Medicine, University of Toronto, Ontario, Canada.|2 Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario, Canada.
authors: Jan O
authors: JO
authors: Friedrich
mesh_terms: D006801:Humans; D012119:Respiration; D014939:Work of Breathing / Q000502:physiology*
keywords: mechanical ventilation; pressure time product; weaning; work of breathing