Ventilation Literature Summaries

OVERVIEW

  • summaries of key papers from the ventilation literature
  • NIV
  • ARDS
  • Tracheostomy
  • Weaning

NON-INVASIVE VENTILATION (NIV)

Lightowler JV1 Wedzicha JA, Elliott MW, Ram FS. Non-invasive positive pressure ventilation to treat respiratory failure resulting from exacerbations of chronic obstructive pulmonary disease: Cochrane systematic review and meta-analysis. BMJ. 2003 Jan 25;326(7382):185. [PMC140272]

  • 8 studies
  • patients with hypercapnic respiratory failure from an exacerbation of COPD
  • NIV vs standard care
    -> reduced mortality
    -> reduced need for intubation

Masip J, Roque M, Sánchez B, Fernández R, Subirana M, Expósito JA. Noninvasive ventilation in acute cardiogenic pulmonary edema: systematic review and meta-analysis. JAMA. 2005 Dec 28;294(24):3124-30. [PMID 16380593]

  • systematic review (15 trials)
  • CPAP vs BIPAP in APO
    -> decreased mortality in CPAP group

Mehta S et al. Randomized, prospective trial of bilevel versus continuous positive airway pressure in acute pulmonary edema. Crit Care Med. 1997 Apr;25(4):620-8. [PMID 9142026]

  • BIPAP vs CPAP
  • APO -> prematurely terminated after only 27 patients as increased risk of MI in BIPAP group
  • criticisms: unmatched groups with a higher incidence of patients with chest pain in BIPAP group

Other indications for NIV with less compelling evidence =

  • -> pneumonia in the immunosuppressed
  • -> isolated chest trauma with rib #’s + regional analgesia
  • -> acute-on-chronic hypercapnic respiratory failure due to chest wall deformity or neuromuscular disease
  • -> acute asthma

Nava S et al. Noninvasive ventilation to prevent respiratory failure after extubation in high-risk patients. Crit Care Med. 2005 Nov;33(11):2465-70. [PMID 16276167]

  • MRCT
  • n = 97
  • inclusion criteria: ventilated for more than 48 hours + risk of developing post extubation respiratory failure (hypercapnia, CHF, weak cough, secretion retention, co-morbidities, upper airway obstruction)
  • extubation to NIV for atleast 8 hours VS extubation to O2
    -> significant reduction in re-intubation rate
    -> extubate high risk patients to NIV (data no so convincing for extubating everyone to NIV)

Esteban, A. et al (2004) “Noninvasive Positive-Pressure Ventilation for Respiratory Failure after Extubation” NEJM 350:2452-60

  • MRCT
  • 37 centers (8 countries)
  • n = 221
  • extubated after at least 48 hours of MV who developed respiratory failure within 48 hours -> NIV vs standard medical therapy
    -> trial stopped early because of increased mortality in NIV group (risk of death: NIV group 25% and invasive group 14% -> absolute risk increase = 11% -> NNH 10)
    -> in unselected patients NIV didn’t prevent re-intubation, it delayed it and was associated with a higher rate of death!

Weaknesses

  • waited until respiratory failure developed prior to instituting NIV
  • unselected patients
  • contamination from cross over to the NIV group

Ferrer M et al. Non-invasive ventilation after extubation in hypercapnic patients with chronic respiratory disorders: randomised controlled trial. Lancet. 2009 Sep 26;374(9695):1082-8 [PMID 19682735]

  • RCT
  • single center (Spain)
  • n = 106
  • inclusion criteria: ventilated with chronic respiratory disorders and hypercapnia (>45mmHg) after a successful spontaneous breathing trial -> NIV for 24 hours vs O2
  • primary end point: avoidance of respiratory failure after extubation
    -> respiratory failure less likely in patients assigned to NIV (ARR 33% -> NNT 3)
    -> NIV group had a lower 90 day mortality (ARR 20% -> 5)

Weaknesses

  • ICU length of stay not changed -> it could be argued that you should just keep them ventilated for longer and wait until their hypercapnic respiratory failure resolves!

ACUTE RESPIRATORY DISTRESS SYNDROME (ARDS)


TRACHEOSTOMY

Griffiths J et al. Systematic review and meta-analysis of studies of the timing of tracheostomy in adult patients undergoing artificial ventilation. BMJ. 2005 May 28;330(7502):1243 [PMC558092]

  • systematic review of randomized and controlled studies looking at early tracheostomy VS later tracheostomy VS prolonged endotracheal intubation
  • 15,950 articles -> 5 papers analysed
  • n = 406
    -> no difference in mortality or risk of pneumonia
    -> significant difference in duration of MV and ICU stay

WEANING

Brochard L et al. Comparison of three methods of gradual withdrawal from ventilatory support during weaning from mechanical ventilation. Am J Respir Crit Care Med. 1994 Oct;150(4):896-903. [PMID 7921460]

  • RCT
  • n = 109
  • inclusion criteria: deemed ready for weaning, failed to sustain 2 hours on a T piece
  • SIMV vs PSV vs further T piece sessions
    -> significant increase in number of patients successfully weaned on PSV

Esteban A et al. A comparison of four methods of weaning patients from mechanical ventilation. Spanish Lung Failure Collaborative Group. N Engl J Med. 1995 Feb 9;332(6):345-50. [PMID 7823995]

  • -> one daily spontaneous breathing trials are equally as effective as multiple daily trials
  • -> spontaneous breathing trials led to extubation 3 times more rapidly than SIMV and 2 times as quickly as PSV

Girard TD et al. Efficacy and safety of a paired sedation and ventilator weaning protocol for mechanically ventilated patients in intensive care (Awakening and Breathing Controlled trial): a randomised controlled trial. Lancet. 2008 Jan 12;371(9607):126-34 [PMID 18191684]

  • 4 Centers is North American
  • RCT – 2003-2006
  • inclusion criteria: > 18 years, on MV for > 12 hours
  • exclusion criteria: post cardiac arrest, moribund, > 2 weeks ventilatory support, severe dementia, co-enrolled in another trial
  • intervention = SBT vs SAT -> SBT
  • primary end points = ventilator free days
  • secondary end points = delirium, 28 day -> 1 year mortality, length of stay in ICU and hospital
  • n = 334 (powered of 80%)
  • intention to treat analysis
  • Results
    -> reduction in ventilator free days
    -> reduced mortality at 1 year
    -> similar delirium rates but less coma
    -> increased risk of extubation
    -> however, risk of re-intubation same in control arm
    -> higher rate of successful extubation
    -> lower trachestomy rate

Strengths

  • protocolised
  • multi-centre

Weaknesses

  • not blinded
  • not generalisable to Australasia (North America has Ventilator Technician)
  • surgical patients not enrolled
  • sedation time and practice not recorded

CCC 700 6

Critical Care

Compendium

Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also the Innovation Lead for the Australian Centre for Health Innovation at Alfred Health and Clinical Adjunct Associate Professor at Monash University. He is a co-founder of the Australia and New Zealand Clinician Educator Network (ANZCEN) and is the Lead for the ANZCEN Clinician Educator Incubator programme. He is on the Board of Directors for the Intensive Care Foundation and is a First Part Examiner for the College of Intensive Care Medicine. He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives.

After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia’s Northern Territory, Perth and Melbourne. He has completed fellowship training in both intensive care medicine and emergency medicine, as well as post-graduate training in biochemistry, clinical toxicology, clinical epidemiology, and health professional education.

He is actively involved in in using translational simulation to improve patient care and the design of processes and systems at Alfred Health. He coordinates the Alfred ICU’s education and simulation programmes and runs the unit’s education website, INTENSIVE.  He created the ‘Critically Ill Airway’ course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of litfl.com, the RAGE podcast, the Resuscitology course, and the SMACC conference.

His one great achievement is being the father of two amazing children.

On Twitter, he is @precordialthump.

| INTENSIVE | RAGE | Resuscitology | SMACC

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