Hypoxemia
Conditions
Keywords
asymmetrical nasal cannula, hypoxemia, DUET
Brief summary
High-flow nasal cannula (HFNC) therapy is increasingly used in the management of acute respiratory failure. Its clinical application has been largely investigated in chronic obstructive pulmonary disease (COPD) patients but only marginally in patients experiencing acute respiratory failure after extubation. Promising data have been published in vitro about new asymmetrical high flow nasal cannula, named 'Optiflow + DUET'. Positive airway pressure, that dynamically changes with breathing, and clearance of anatomical dead space are the key mechanisms of noninvasive respiratory support with nasal high flow. Pressure mainly depends on flow rate and nare occlusion. The hypothesis is that an increase in asymmetrical occlusion of the nares leads to an improvement in dead-space clearance resulting in a reduction in re-breathing and breathing work.
Detailed description
A prospective cross-over RCT on the effects of 'Optiflow + DUET' as compared to convetional symmetrical high flow cannula and Venturi mask.
Interventions
DEVICESymmetrical high flow nasal cannula (HFNO)
After a 'baseline' trial using Venturi Mask, within the first 120 minutes after extubation, and assessing a PaO2/FiO2 ratio \< 300, patients will be randomly assigned to a first 1h-phase of 'conventional HFNO' or 'DUET HFNO'. At the end of each session several clinical parameters (i.e. DUS, EIT, ABGs, comfort, VAS) will be collected. Specifically, Gas-flow rate will be set at a maximum of 60 L/min, temperature at a maximum of 37°C, while FiO2 will be adjusted to maintain SpO2 between 92 and 98%.
DEVICEAsymmetrical high flow nasal cannula (DUET HFNO)
After a 'baseline' trial using Venturi Mask, within the first 120 minutes after extubation, and assessing a PaO2/FiO2 ratio \< 300, patients will be randomly assigned to a first 1h-phase of 'DUET HFNO' vs 'conventional HFNO'. At the end of each session several clinical parameters (i.e. DUS, EIT, ABGs, comfort, VAS) will be collected. Specifically, Gas-flow rate will be set at a maximum of 60 L/min, temperature at a maximum of 37°C, while FiO2 will be adjusted to maintain SpO2 between 92 and 98%. A 5-10min 'washout' phase using VM, between different interfaces, will be allowed.
Sponsors
University of Padova
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
SUPPORTIVE_CARE
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* age \>18 years old; * invasive mechanical ventilation \> 24h; * acute respiratory failure within 120 minutes after extubation (defined during a spontaneous trial using Venturi mask and assessing a PaO2/FiO2 ratio \< 300; * absence of Sars-Cov-2 positivity; * absence of cardiological or long-term respiratory disease
Exclusion criteria
* pregnancy * tracheostomy * non-invasive ventilation after extubation * second tracheal intubation * contraindications for EIT belt * facial or nose abnormalities
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Lung aeration | Last 10 minutes of 1 hour-trial | To evaluate changes, between arms, in lung aeration (as assessed by the end-expiratory lung impedance (delta EELI) through EIT. |
| Breathing effort | Last 10 minutes of 1 hour-trial | To evaluate changes, between arms, in breathing effort (as assessed by diaphragm ultrasound (DUS)). |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Breathing heterogeneity | Last 10 minutes of 1 hour-trial | To evaluate changes, between arms, in ventilation distribution (as assessed by pendelluft (yes/not), respiratory rates/min, tidal volume (ml), global inhomogeneity index through EIT) |
| Comfort | Last 10 minutes of 1h-trial | To evaluate changes in comfort, between arms, as assessed by NRS scale |
| Minute ventilation (MV) (L/min) | Last 10 minutes of 1 hour-trial | To evaluate breathing pattern |
| Gas exchange | Last 10 minutes of 1h-trial | To evaluate changes, between arms, in gas exchange (as assessed by PaO2 mmHg, pCO2 mmHg, pH through ABGs) |
| Dyspnea | Last 10 minutes of 1h-trial | To evaluate changes in dyspnea, between arms, as assessed by VAS scale |
| corrected MV (L/min) | Last 10 minutes of 1 hour-trial | To evaluate breathing pattern |
Countries
Italy
Outcome results
None listed