Acute Respiratory Failure
Conditions
Brief summary
Stable patient with ARF spontaneously breathing light sedation (not too awake but with stable breathing pattern) and EAdi \>8 uV. Four modes of mechanical ventilation were performed under different support level for the measuring of EAdi, air way pressure and other parameters.
Detailed description
1. Mode NAVA spontaneous breathing select a NAVA level that gives peak pressure about 9-10 cm H2O assist keep NAVA level for 15 minutes, do ZAM breaths every 3 minutes (make sure not to disturb the patient). Insp Hold after every ZAM. Increase NAVA level by 50% and repeat the protocol when patient's breathing has stabilized (only one increase).Do ZAM breaths every 3 minutes (make sure not to disturb the patient). Insp Hold after every ZAMAt the end of protocol (minute 15) do one end-inspiratory hold-maneuver and one end-expiratory occlusion. 2. Mode N- PSV spontaneous breathing :PS level of 8-10 cmH2O, keep PS level for 15 minutes, do ZAM every 3 minutes (make sure not to disturb patient). Inspiratory Hold after every ZAM。At the end of protocol (minute 15) do one end-inspiratory hold-maneuver and one end-expiratory occlusion.Increase PS by 50% and repeat protocol when patient's breathing has stabilized (only 1 increase). Do ZAM every 3 minutes (make sure not to disturb patient). Inspiratory Hold after every ZAM.At the end of protocol (minute 15) do one end-inspiratory hold-maneuver and one end-expiratory occlusion. Make record of RR, Vt, Flow, Ti during both periods. 3. Mode VCV no spontaneous breathing：Set Vt, Ti and RR to match the breathing pattern observed during NAVA 4. Mode PCV no spontaneous breathing-do ZAM after each PS level：Increase PSV level from 8 to 20 in steps of 1 cmH2O every 2 minutes.
Interventions
OTHERdifferent modes of mechanical ventilation
Four different ventilation modes were performed one by one and respiratory parameters were recorded.
Sponsors
Southeast University, China
Study design
Allocation
NON_RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
OTHER
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 85 Years
Healthy volunteers
No
Inclusion criteria
* Stable patient with acute respiratory failure on invasive mechanical ventilation Can tolerate pressure support ventilation light sedation with RASS between -2 and 1
Exclusion criteria
* EAdi\<8 uV contraindication for nasogastric tube insertion neuromuscular disease affecting spontaneous breathing lack of informed consent, and patients included in other intervention study
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Predicted transpulmonary pressure | 6 hours | Transpulmonary pressure calculated from airway pressure by Prediction formula |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| patient-ventilator breath contribution | 6 hours | An index for quantifying the respective patient and ventilator breath contributions |
| inspiratory flow | 6 hours | the inspiratory flow measured by the ventilator |
Countries
China
Outcome results
None listed