Respiratory Failure With Hypoxia
Conditions
Keywords
noninvasive ventilation, PEEP, respiratory failure
Brief summary
To investigate the physiological effects of high positive end-expiratory pressure (PEEP) during noninvasive ventilation in patients with hypoxemic respiratory failure, and to elucidate the mechanisms underlying high PEEP-induced improvement in oxygenation.
Interventions
PROCEDUREhigh PEEP
First, PEEP was set at 5 cmH₂O, and inspiratory pressure was adjusted to achieve a target tidal volume of 6-8 mL/kg. Fraction of inspired oxygen (FiO₂) was titrated to maintain peripheral oxygen saturation (SpO₂) between 88% and 92%. Subsequently, PEEP was increased in 5 cmH₂O increments every 10-20 minutes from the initial value of 5 cmH₂O. Once PEEP reached 20 cmH₂O or above, increments were made every 3-5 minutes until the recruitment level was achieved (i.e., PEEP was increased stepwise from 5 to 10, 15, 20, 25, and 30 cmH₂O). Inspiratory pressure was adjusted concurrently to maintain a constant pressure difference. Throughout the procedure, physiological parameters-including respiratory rate, oxygenation, work of breathing, and others-were collected.
Sponsors
Chongqing Medical University
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
BASIC_SCIENCE
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 100 Years
Healthy volunteers
No
Inclusion criteria
1. Age ≥ 18 years 2. PaCO₂ ≤ 50 mmHg 3. PaO₂/FiO₂ ≤ 300 mmHg 4. Use of a noninvasive ventilator with esophageal pressure monitoring capability (e.g., Mindray SV70) -
Exclusion criteria
1. Respiratory failure caused by heart failure, asthma, or acute exacerbation of chronic obstructive pulmonary disease (COPD) (COPD as a comorbidity may be included) 2. Pneumothorax 3. Patients who refuse to participate in this trial -
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Oxygenation | From enrollment to 2 hours post-intervention | The changes of SpO2/FiO2 from 5 to 30 cmH2O of PEEP. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Respiratory rate | From enrollment to 2 hours post-intervention | Changes of respiratory rate from 5 to 30 cmH2O of PEEP |
| Blood pressure | From enrollment to 2 hours post-intervention | Changes of blood pressure from 5 to 30 cmH2O of PEEP |
| Heart rate | From enrollment to 2 hours post-intervention | Changes of heart rate from 5 to 30 cmH2O of PEEP |
| Diaphragmatic excursion | From enrollment to 2 hours post-intervention | Changes in diaphragmatic excursion across PEEP levels from 5 to 30 cmH₂O. Diaphragmatic excursion refers to the movement of the thoracic diaphragm during breathing, as assessed by ultrasound. |
| Diaphragm thickening fraction | From enrollment to 2 hours post-intervention | Changes in diaphragm thickening fraction across PEEP levels from 5 to 30 cmH₂O. Diaphragm thickening fraction is calculated based on the change in diaphragm thickness from end-expiration to end-inspiration (\[end-inspiration - end-expiration\]/end-expiration), as assessed by ultrasound. |
| Work of breathing | From enrollment to 2 hours post-intervention | Changes in work of breathing across PEEP levels ranging from 5 to 30 cmH₂O were assessed by monitoring esophageal pressure with an esophageal balloon catheter. |
| Electrical impedance tomography of the lung | From enrollment to 2 hours post-intervention | Changes in lung electrical impedance tomography were recorded across PEEP levels ranging from 5 to 30 cmH₂O. The electrical impedance tomography belt was placed around the chest at the level of the 4th to 5th intercostal spaces, and data were collected after the patient's breathing had stabilized. |
| Tidal volume | From enrollment to 2 hours post-intervention | Changes of tidal volume from 5 to 30 cmH2O of PEEP |
Countries
China
Contacts
CONTACTJun Duan
CONTACTYiwei Min
PRINCIPAL_INVESTIGATORJun Duan, MD
First Affiliated Hospital of Chongqing Medical University
Outcome results
None listed