PEEP and Spontaneous Breathing During ARDS

Not Applicable

Completed

• Conditions: Acute Respiratory Distress Syndrome
• Interventions: Other: Mechanical Ventilation

• Registration Number: NCT04241874
• Lead Sponsor: Fondazione Policlinico Universitario Agostino Gemelli IRCCS

Brief Summary

Prospective, physiological study to systematically assess the effects of high positive end-expiratory pressure (PEEP) with and without inspiratory synchronization in patients with moderate to severe acute respiratory distress syndrome (ARDS) exhibiting intense inspiratory effort while on assisted ventilation.

Detailed Description

This prospective, physiological, randomized, cross-over study will be conducted in the 20-bed general ICU of the Fondazione Policlinico Universitario A. Gemelli IRCCS, Roma, Italy. Patients with ARDS will be screened for eligibility. ARDS will be defined according to the Berlin Definition.

Intubated patients fulfilling ARDS criteria, undergoing assisted ventilation as per clinical decision and exhibiting intense inspiratory effort (occlusion pressure equal or greater than 13 cmH2O) will be enrolled.

Patients will be placed in a 30°-45° head up position during all study phases. According to our institution protocol, pressure support setting will be selected by the attending physician to target a predefined tidal volume range of 6-8 mL/kg of predicted body weight (PBW) (female PBW \[kg\] = 45.5 + 0.91 \[cm of height - 152.4\]; male PBW \[kg\] = 50 + 0.91 \[cm of height - 152.4\]).The lowest pressure support level allowed will be 7 cmH2O, even if Vt \<8 ml/Kg PBW is not achieved.

In each patient, four different ventilator settings will be applied in a random order. Each step will last 45 minutes.

Study Timeline

• Study First Submitted: 2020-01-22
• Study First Submitted QC: 2020-01-22
• Study First Posted: 2020-01-27
• Study Start: 2021-05-01
• Primary Completion: 2022-06-15
• Study Completion: 2022-06-15
• Status Verified: 2022-09
• Last Update Submitted: 2022-09-04
• Last Update Posted: 2022-09-07

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 16

Inclusion Criteria

• (a) ARDS according to the Berlin definition (ratio of arterial partial pressure of oxygen to fraction of inspired oxygen (PaO2/FiO2) ≤ 300 mmHg);
• (b) assisted ventilation, as prescribed by the attending physician
• (c) intense inspiratory effort, defined as a negative deflection in the airway pressure equal or greater than 13 cmH2O in the first breath recorded during an end-expiratory occlusion

Exclusion Criteria

Pregnancy, clinically documented barotrauma, contraindication to electrical impedance tomography (EIT) use (e.g., presence of pacemaker or automatic implantable cardioverter defibrillator), impossibility to place the EIT belt in the right position (e.g., presence of surgical wounds dressing), and any contraindication to the insertion of a nasogastric tube (eg, recent upper-gastrointestinal surgery, esophageal varices), chest tubes with active air leaks, fever.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Low PEEP and full inspiratory synchronization	Mechanical Ventilation	PEEP = 5 cmH2O + clinically selected pressure support (PSVclin)
High PEEP and full inspiratory synchronization	Mechanical Ventilation	PEEP = 15 cmH2O + clinically selected pressure support (PSVclin)
Low PEEP and inspiratory desynchronization	Mechanical Ventilation	PEEP = 5 cmH2O + bilevel positive airway pressure (Respiratory rate 15 breaths/minute, inspiratory time=1 sec, Inspiratory pressure=PSVclin+PEEP, PS=0 cmH2O)
High PEEP and inspiratory desynchronization	Mechanical Ventilation	PEEP = 15 cmH2O + bilevel positive airway pressure (Respiratory rate 15 breaths/minute, inspiratory time=1 sec, Inspiratory pressure=PSVclin+PEEP, PS=0 cmH2O)

Primary Outcome Measures

Name	Time	Method
Inspiratory effort	45 minutes	The negative deflection in esophageal pressure during inspiration

Secondary Outcome Measures

Name	Time	Method
Work of breathing	45 minutes	Esopghageal pressure pressure-time product per minute
Alveolar recruitment	45 minutes	Change in end-expiratory lung impedance, assessed by electrical impedance tomography
Tidal volume	45 minutes	Average Tidal volume received by the patient
Dynamic transpulmonary driving pressure	45 minutes	The average positive swing in transpulmonary driving pressure during tidal breathing
Respiratory rate	45 minutes	Respiratory rate per minute
Regional Tidal volume distribution	45 minutes	Distribution of tidal volume in the different lung zones, assessed by electrical impedance tomography
Oxygenation	45 minutes	Ratio of PaO2 to FiO2
Respiratory mechanics	45 minutes	Respiratory mechanics assessed by end-inspiratory occlusion
Lung mechanics	45 minutes	Respiratory mechanics assessed by esophageal pressure monitoring during an end-inspiratory occlusion
Carbon dioxide	45 minutes	Blood carbon dioxide, as assessed by arterial blood gas analysis
Pendelluft	45 minutes	Occurrence of intra-tidal shift of gas within different lung regions at beginning of inspiration

Trial Locations

Locations (1)

Fondazione Policlinico Universitaro A. Gemelli IRCCS; 🇮🇹 Rome, Italy