An interventional study of PSV + sigh (Clinical PEEP and Clinical PEEP + 3 cmH₂O) in Mechanical Ventilation, sponsored by AUSL Romagna Rimini. Completed at 2 sites in Italy. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2025-09-15.
Sponsored by AUSL Romagna Rimini · Not applicable, Interventional, and Diagnostic
The goal of this physiological study is to determine whether ventilator-delivered sigh breaths during pressure support ventilation (PSV) provide a reliable bedside index of lung recruitability and can guide PEEP optimization.The main questions it aims to answer are:
Background and RationaleInvasive mechanical ventilation is often necessary in critically ill adults but may contribute to ventilator-induced lung injury (VILI) if ventilator settings are not individualized. During assisted ventilation (pressure support ventilation, PSV), ongoing patient effort complicates the assessment of PEEP response, PEEP titration, and lung recruitability.Ventilator-delivered sigh breaths (i.e., brief sustained inflations) can improve gas exchange and promote alveolar recruitment, and may permit artifact-free assessment of respiratory mechanics in assisted modes. This study evaluates whether Crs measured at the end of a sigh provides reliable, clinically useful information on recruitability and whether the ratio of Crs during sigh to Crs during an assisted breath (Crs_sigh/Crs_assisted) can guide positive end-expiratory pressure (PEEP) optimization.Primary ObjectiveTo assess lung recruitability during PSV by normalizing Crs measured at the end of a sigh to Crs obtained with an inspiratory hold during an assisted breath.Secondary Objectives
Inclusion criteria:Adults (≥18 years) receiving PSV with the ventilator's sigh function active.Exclusion criteria:
Protocol OverviewEach participant undergoes two sequential, non-randomized steps:
In both steps, a sigh is programmed as a sustained inflation at 30 cmH₂O for 3 seconds (pressure-controlled), per routine practice and prior literature.Sigh Setting
Data CollectionBaseline demographics (age, sex, BMI), comorbidities, and hemodynamics are recorded. At the end of each 15-minute step (baseline and PEEP+3), we perform an end-inspiratory hold and an end-expiratory hold on a tidal assisted breath and measured:
AUSL Romagna Rimini is the lead sponsor of 13 studies on the registry; 5 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Exclusion Criteria:
Pressure support ventilation (PSV) at the clinical PEEP with ventilator-delivered sighs: one sustained inflation at 30 cmH₂O for 3 seconds every minute.
Other: PSV + sigh (Clinical PEEP and Clinical PEEP + 3 cmH₂O)
Pressure support ventilation (PSV) with PEEP set 3 cmH₂O above the clinical PEEP, with ventilator-delivered sighs: one sustained inflation at 30 cmH₂O for 3 seconds every minute.
Other: PSV + sigh (Clinical PEEP and Clinical PEEP + 3 cmH₂O)
Each patient undergoes two sequential 15-minute steps: 1) pressure support ventilation at the clinical PEEP and 2) the same settings with PEEP increased by 3 cmH₂O. A ventilator-delivered sigh is programmed as one sustained inflation at 30 cmH₂O for 3 seconds every minute. All other ventilator parameters (trigger sensitivity, pressure support level, mandatory breath timing) remain unchanged. At the end of each step, inspiratory and expiratory holds are performed to collect respiratory mechanics and arterial blood gases; compliance during the sigh is calculated once flow is zero and airway pressure is stable.
Sigh-to-Assisted Breath Respiratory System Compliance Ratio (Crs_sigh/Crs_assisted)
Ratio of respiratory system compliance at the end of a ventilator-delivered sigh to compliance measured during an inspiratory hold on an assisted tidal breath. This normalized metric indexes recruitability during assisted ventilation; higher values indicate greater recruitability. The primary analysis is the within-patient change in the ratio from clinical PEEP to clinical PEEP +3 cmH₂O.
Time frame: End of each 15-minute step within a single study session (clinical PEEP; clinical PEEP +3 cmH₂O).
Patients with unreliable plateau pressure during assisted breaths
Proportion of patients in whom Pplat cannot be reliably measured (non-readable or visually unstable for ≥3 seconds) during inspiratory hold maneuvers in assisted breathing at either study step.
Time frame: Across both 15-minute steps within the single study session.
Association between sigh-derived recruitability index and change in respiratory system compliance
Correlation between the sigh-to-assisted compliance ratio at clinical PEEP and the within-patient change in compliance after PEEP increase
Time frame: End of each 15-minute step within the single study session
Plan to share: No — Data may be shared after reasonable request to the Principal investigator.
This study is completed, as verified in Sep 2025. You cannot join it, but the record below documents what was studied.
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AUSL Romagna Rimini