ARDS
Conditions
Brief summary
The investigators conducted a prospective physiological observation study on ARDS population, described their physiological and EIT indexes with various PEEP titration methods, and also compared and analyzed those indexes to determine whether there were differences among various PEEP titration methods.The objective of this study was to explore and uncover the physiological differences in response to optimal PEEP in different ways，and analyzed the correlation of the optimal PEEP in these different ways.
Interventions
DEVICEEsophageal pressure catheter
Esophageal pressure was monitored with an esophageal pressure catheter
Sponsors
West China Hospital
Study design
Observational model
CASE_ONLY
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Inclusion criteria
* Intubated and mechanical ventilated patients in ICU within 48 hours * Be over 18 years old * With moderate-severe ARDS (PaO2 /FIO2 ,200 mm Hg)
Exclusion criteria
* Severe chronic obstructive pulmonary diseases * Pulmonary bulla(\>1CM) or pneumothorax or pneumomediastinum or subcutaneous emphysema * Pregnancy * BMI≥35kg/m2 * Suspected pulmonary vascular hemorrhage * Disturbance of consciousness or intracranial hypertension * Severe cardiac dysfunction (New York Heart Association Class III or IV, acute -Coronary syndrome or persistent ventricular tachyarrhythmia), cardiogenic shock or after major cardiac surgery * Hemodynamic instability (i.e., mean arterial pressure \[MAP\]\<60 mm Hg despite vasopressor use * The medical team considering short periods of high pressure to be unsafe * Contraindications for placement of esophageal pressure catheters (e.g., esophageal varix or fracture of skull base) * Contraindications for EIT monitoring (including pacemaker, or cutaneous diseases which limiting electrode placement) * Agonal stage or end-stages of diseases
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| the selected PEEP values | through study completion, an average of 1 year | 1\. Method-specific selected PEEP values * Description: The principal endpoint was the set of 15 method-specific selected PEEP values determined for each patient. * Unit of Measure: cmH₂O |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| SpO2/FiO2 at each selected PEEP | baseline, within 5 minutes after the PV-tool measurement, and within 5 minutes after each increment and decrement of PEEP during the PEEP adjustment process | SpO2/FiO2 measured at each selected PEEP. This study will separately measure peripheral oxygen saturation (SpO₂, unit: %) and fraction of inspired oxygen (FiO₂, unit: %). Because both measurements share the same unit (%), they will not be reported as separate outcome measures. Instead, they will be aggregated into a single reported value: the SpO₂/FiO₂ ratio (dimensionless). At each selected positive end-expiratory pressure (PEEP) level, the ratio will be calculated as S/F = SpO₂ (%) ÷ FiO₂ (%), and this ratio will be recorded as the final outcome measure. |
| respiratory system compliance value at each selected PEEP | baseline, within 5 minutes after the PV-tool measurement, and within 5 minutes after each increment and decrement of PEEP during the PEEP adjustment process | This study will directly record the respiratory system compliance value as measured and displayed by the ventilator (unit: mL/cmH₂O) at each selected PEEP. |
| plateau pressure at each selected PEEP | baseline, within 5 minutes after the PV-tool measurement, and within 5 minutes after each increment and decrement of PEEP during the PEEP adjustment process | At each selected positive end-expiratory pressure (PEEP) level, plateau pressure will be directly recorded from the ventilator after performing an inspiratory hold maneuver. This value is displayed by the ventilator in cmH₂O |
| Driving Pressure at each selected PEEP | baseline, within 5 minutes after the PV-tool measurement, and within 5 minutes after each increment and decrement of PEEP during the PEEP adjustment process | At each selected positive end-expiratory pressure (PEEP) level, plateau pressure (Pplat, unit: cmH₂O) will be measured via the ventilator, and the corresponding PEEP value (unit: cmH₂O) will be recorded. Driving pressure (ΔP) is calculated as the difference between the two: ΔP = Pplat - PEEP (unit: cmH₂O). |
| End-inspiratory Transpulmonary Pressure (PTPi) at each selected PEEP | baseline, within 5 minutes after the PV-tool measurement, and within 5 minutes after each increment and decrement of PEEP during the PEEP adjustment process | After placement of an esophageal pressure catheter, the ventilator will monitor esophageal pressure (Pes) and airway pressure. At each selected positive end-expiratory pressure (PEEP) level, an end-inspiratory hold maneuver will be performed. The end-inspiratory transpulmonary pressure (PTPi) is calculated as the difference between the airway plateau pressure (Pplat) measured during the hold and the corresponding esophageal pressure (Pes): PTPi = Pplat - Pes (unit: cmH₂O). |
| End-expiratory Transpulmonary Pressure (PTPe) at each selected PEEP | baseline, within 5 minutes after the PV-tool measurement, and within 5 minutes after each increment and decrement of PEEP during the PEEP adjustment process | After placement of an esophageal pressure catheter, the ventilator will monitor esophageal pressure (Pes) and airway pressure. At each selected positive end-expiratory pressure (PEEP) level, an end-expiratory hold maneuver will be performed. The end-inspiratory transpulmonary pressure (PTPe) is calculated as the difference between the PEEP measured during the hold and the corresponding esophageal pressure (Pes): PTPe = PEEP - Pes (unit: cmH₂O). This calculated value is the single reported outcome measure |
| transpulmonary driving pressure at each selected PEEP | baseline, within 5 minutes after the PV-tool measurement, and within 5 minutes after each increment and decrement of PEEP during the PEEP adjustment process | After placement of an esophageal pressure catheter, the ventilator will monitor transpulmonary pressures. At each selected PEEP level, end-inspiratory transpulmonary pressure (PTPi) and end-expiratory transpulmonary pressure (PTPe) are obtained during inspiratory and expiratory hold maneuvers, respectively. Both are measured in cmH₂O. Transpulmonary driving pressure is calculated as the difference: ΔPtp = PTPi - PTPe (unit: cmH₂O). |
| EIT-derived Regional Ventilation Parameters at each selected PEEP level | baseline, within 5 minutes after the PV-tool measurement, and within 5 minutes after each increment and decrement of PEEP during the PEEP adjustment process | Using electrical impedance tomography (EIT), the lung is divided into four regions of interest (ROI I to ROI IV) from ventral to dorsal. For each ROI, the percentage of tidal impedance variation relative to total tidal impedance variation is recorded (% of total). unit: cmH₂O |
| the center of ventilation (COV) at each selected PEEP level | baseline, within 5 minutes after the PV-tool measurement, and within 5 minutes after each increment and decrement of PEEP during the PEEP adjustment process | the center of ventilation (COV) is calculated as the position of the ventilation center along the ventral-dorsal axis, expressed as a percentage (0% = ventral, 100% = dorsal). this parameter is measured in % |
| CL HP% (overdistension region) at each selected PEEP level | baseline, within 5 minutes after the PV-tool measurement, and within 5 minutes after each increment and decrement of PEEP during the PEEP adjustment process | Using electrical impedance tomography (EIT)，based on regional compliance analysis，CL HP% represent the percentage of lung regions showing a decrease in compliance at high PEEP due to overdistension (unit: %). |
| CL LP% (collapse region) at selected PEEP | baseline, within 5 minutes after the PV-tool measurement, and within 5 minutes after each increment and decrement of PEEP during the PEEP adjustment process | Using electrical impedance tomography (EIT)，based on regional compliance analysis，CL LP% represent the percentage of lung regions showing a decrease in compliance at low PEEP due to collapse (unit: %). |
Countries
China
Outcome results
None listed