Lowering PEEP: Weaning From High PEEP Setting

Not Applicable

Completed

• Conditions: Mechanical Ventilation Complication
• Interventions: Other: decrease the positive end expiratory pressure (PEEP); Other: shunt assessment; Other: mechanical features assessment

• Registration Number: NCT04429399
• Lead Sponsor: University of Bari

Brief Summary

The perfusion of the deeply different areas coexisting in ARDS lung generates two type of venus-admixure : true shunt and shunt effect. Briefly, true shunt and shunt effect are related to non-aerated and poorly-ventilated lung areas perfusion respectively. Practically, it is not possible to quantify the true shunt and the shunt-effect directly, but we can measure the "total-shunt", i.e. the sum of two kind of venus-admixured. As it is known from classical physiology, the effects of FiO2 variations on PaO2 are deeply different depending on the type of venous admixures. In the case of a patient with virtually only true shunt, any FiO2 variation will not modify the PaO2. On the other hand, in a patient with virtually only a shunt effect, increasing the FiO2 the PaO2 will progressively increase. Indeed, ventilating a patient presenting only a shunt effect (without true shunt) with pure oxygen will generate a "normal" P/F ratio. In patients ventilated with high PEEP levels it is difficult to predict based on the P/F ratio the relative amount of true shunt and shunt effect. However, patients presenting a significant shunt effect when ventilated with higher PEEP level would likely have "unstable" poorly aerated lung areas that need PEEP to remain opened. In those patients, a PEEP-weaning protocol based on the P/F ratio could induce significant alveolar de-recruitment and clinical deterioration. On the contrary, patients with less shunt effect would be likely less prone to alveolar de-recruitment and would benefice from PEEP decrease.

Detailed Description

the investigators set up a study to test the hypothesis that patients presenting a significant shunt effect when ventilated with higher PEEP levels could be prone to significant alveolar de-recruitment at the PEEP weaning attempt. To do so, the investigator has to measure the total shunt at higher PEEP level in patients ready to be weaned from the PEEP (according to the Mercat protocol), at three FiO2 levels (i.e. 0,3, 0,6 and 1). The shunt effect is quantified as the difference in total shunt between FiO2 0,3 and .The hypothesis of this study is that the shunt effect could predict alveolar de-recruitment when weaning PEEP.

Study Timeline

• Study Start: 2019-09-21
• Study First Submitted: 2020-06-04
• Study First Submitted QC: 2020-06-10
• Study First Posted: 2020-06-12
• Primary Completion: 2021-06-21
• Status Verified: 2022-01
• Study Completion: 2022-01-01
• Last Update Submitted: 2022-01-20
• Last Update Posted: 2022-01-21

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 20

Inclusion Criteria

• Age major than 18
• 1-2 days since the beginning of mechanical ventilation
• Moderate or severe ARDS

Exclusion Criteria

• Patients with a story of chronic obstructive pulmonary disease (COPD)
• Patients with asthma
• Patients with neurological disease
• Patients with heart disease
• Patients with cardiopulmonary.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Low positive end-expiratory pressure Ventilation	shunt assessment	patient ventilated fixing low level of positive end expiratory pressure
High positive end-expiratory pressure Ventilation	decrease the positive end expiratory pressure (PEEP)	patient ventilated fixing high level of positive end expiratory pressure
High positive end-expiratory pressure Ventilation	mechanical features assessment	patient ventilated fixing high level of positive end expiratory pressure
High positive end-expiratory pressure Ventilation	shunt assessment	patient ventilated fixing high level of positive end expiratory pressure
Low positive end-expiratory pressure Ventilation	mechanical features assessment	patient ventilated fixing low level of positive end expiratory pressure

Primary Outcome Measures

Name	Time	Method
de-recruitment	decreasing PEEP from high to low levelthrough study completion, an average of 2 years	the shunt effect cold predict the lung de-recruitment volume

Trial Locations

Locations (1)

Azienda Ospedaliero Universitaria Policlinico; 🇮🇹 Bari, Italy