Respiratory failure & ventilation
High flow nasal cannula and low level continuous positive airway pressure have different physiological effects during de novo acute hypoxemic respiratory failure
Main finding · Tidal volume under HFNC vs under low-level CPAP (4 cmH2O); ability of CPAP tidal volume to predict HFNC tidal volumeResult — go to the resultSpearman r 0.50Authors' conclusion
Among ICU patients with de novo AHRF, tidal volume under HFNC was mostly protective. Tidal volume during CPAP at 4 cmH2O did not predict tidal volume during HFNC. Such low-level CPAP was associated with increased tidal volume, minute ventilation, end-expiratory volume, and oxygenation.
Study context
- Population
- ICU patients with de novo acute hypoxemic respiratory failure (AHRF) treated with high flow nasal cannula (HFNC)
- Participants
- 29 patients
- Exposure
- Low-level continuous positive airway pressure (CPAP) vs HFNC
- Outcome
- Ability of tidal volume under low-level CPAP to predict tidal volume under HFNC (Bland-Altman analysis)
Methodological detailssingle-centre, crossover (HFNC then CPAP), electrical impedance tomography
- Single-centre
- Crossover (HFNC then CPAP)
- Electrical impedance tomography
Main finding
As reported in the abstract
Tidal volume under HFNC vs under low-level CPAP (4 cmH2O); ability of CPAP tidal volume to predict HFNC tidal volume
Spearman r
0.50
P = 0.005
By group
- Bland-Altman bias (limits of agreement - 1.1 to 5.9 mL.kg- 1)
- 2.4 mL.kg- 1
- Tidal volume under HFNC 4–8 mL.kg- 1 PBW
- 20 (69%)
- Tidal volume under HFNC >9 mL.kg- 1 PBW
- 5 (17%)
- CPAP tidal volume >11.5 mL.kg- 1 PBW predicting HFNC tidal volume >9 mL.kg- 1 PBW: sensitivity
- 80%
- CPAP tidal volume >11.5 mL.kg- 1 PBW predicting HFNC tidal volume >9 mL.kg- 1 PBW: specificity
- 96%
Observational data: associations, not effects.
Further findings
Tidal volume distribution under HFNC
- Tidal volume between 4 and 8 mL.kg- 1 PBW
- 20 (69%)
- Tidal volume exceeding 9 mL.kg- 1 PBW
- 5 (17%)
Minute ventilation, end-expiratory lung volume, oxygenation, respiratory distress, comfort
- CPAP associated with increased minute ventilation, end-expiratory lung volume and oxygenation vs HFNC
- CPAP decreased signs of respiratory distress in the most severe patients
- CPAP associated with lower comfort vs HFNC
Original publication
High flow nasal cannula and low level continuous positive airway pressure have different physiological effects during de novo acute hypoxemic respiratory failure. Ann Intensive Care. Published 23 November 2024. doi:10.
Composed by AI from the published abstract and checked against it. How Briefs are made →