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. 2021 Mar 4;2021(3):CD010172. doi: 10.1002/14651858.CD010172.pub3

Stephan 2015.

Study characteristics
Methods RCT, parallel‐group design, multicentre study
Participants Total number of randomized participants: 830
Setting: 6 ICUs; France
Inclusion criteria: patients who had undergone cardiothoracic surgery and had failed a SBT, or had pre‐existing risk factors for post‐extubation acute respiratory failure, or had failed extubation
Exclusion criteria: obstructive sleep apnoea, tracheostomy, do‐not‐intubate status, delirium, nausea and vomiting, bradypnoea, impaired consciousness, haemodynamic instability
Baseline characteristics
Intervention group (HFNC):

  • Age, mean (95% CI): 63.8 (62.5 to 65.2) years

  • Gender M/F: 273/141

  • BMI, mean (95% CI): 28.3 (27.8 to 28.8) kg/m2

  • SAPS II, mean (95% CI): 29.0 (27.8 to 30.1)

  • PaCO2,mean (95% CI): 38.7 (38.1 to 39.4) mmHg

  • PaO2/FiO2, mean (95% CI): 196 (187 to 204) mmHg

  • Respiratory rate, mean (95% CI): 22.8 (22.1 to 23.5) breaths/min


Control group (BiPAP):

  • Age, mean (95% CI): 63.9 (62.6 to 65.2) years

  • Gender, M/F: 278/138

  • BMI, mean (95% CI): 28.2 (27.6 to 28.7) kg/m2

  • SAPS II, mean (95% CI): 28.8 (27.7 to 30.0)

  • PaCO2, mean (95% CI): 39.1 (38.4 to 39.8) mmHg

  • PaO2/FiO2, mean (95% CI): 203 (195 to 212) mmHg

  • Respiratory rate, mean (95% CI): 23.3 (22.6 to 24.0) breaths/min
Interventions Intervention group (HFNC):

  • Randomized, n = 414; losses, n = 0; analysed, n = 414

  • Details: HFNC; Optiflow system at initial flow rate of 50 L/min. Delivered continuously


Control group (NIV: BiPAP):

  • Randomized, n = 416; losses, n = 0; analysed, n = 416

  • Details: BiPAP; pressure support started at 8 cm H2O to achieve exhaled tidal volume of 8 mL/kg and respiratory rate < 25 breaths per minute, via full face mask and ventilator specifically designed for BiPAP or an ICU ventilator. BiPAP was delivered for 2 hours initially, then for approximately 1 hour every 4 hours, or more if needed.


Initial FiO2 in both groups was 50%, adjusted to maintain SaO2 at 92% to 98%
Outcomes Treatment failure (defined as reintubation for MV, switch to other study treatment, or premature study treatment discontinuation), duration of respiratory support, respiratory variables, dyspnoea, comfort, skin breakdown, respiratory and extrapulmonary complications, number of bronchoscopies, mortality in ICU
Note:

  • respiratory variables and respiratory rate reported at baseline, 1 hour, and 6 to 12 hours. For meta‐analysis in the review, data were taken at 6 to 12 hours.

  • we did not include data for duration of respiratory support because of differences in method of use, with HFNC used continuously and BiPAP used for approximately one hour at four‐hourly windows.
Notes Funding/declarations of interest: study authors did not report any funding sources. They disclosed no conflicts of interest.
Study dates: June 2011 to January 2014
Risk of bias
Bias Authors' judgement Support for judgement
Random sequence generation (selection bias) Low risk Computer‐generated random sequence in blocks of 2 or 4
Allocation concealment (selection bias) Unclear risk Use of opaque envelopes but no further details
Blinding of participants and personnel (performance bias)
All outcomes Unclear risk Blinding was not possible. Although we expected that this would not influence outcome data, we could not be certain of this.
Blinding of outcome assessors (objective outcomes) Low risk Blinding of outcome assessors was not described; we did not anticipate that this would influence the assessment of objective outcome measures.
Blinding of outcome assessors (subjective measures) Low risk Participants were outcome assessors for dyspnoea and comfort; we did not expect this to influence the outcome data. We did not know if outcome assessors for skin breakdown and other complications were blinded, however, complications were predefined to reduce bias.
Incomplete outcome data (attrition bias)
All outcomes Low risk No losses
Selective reporting (reporting bias) Low risk NCT01458444. Study registered retrospectively in October 2011 (although early in study period). All relevant outcomes were reported as stated in protocol.
Other bias Low risk No other sources of bias identified