Acute Respiratory Failure (ARF)
Conditions
Keywords
respiratory mechanics, ARDS, mechanical ventilation
Brief summary
The goal of this study is to learn about the respiratory mechanics in patients undergoing mechanical ventilation. The investigators can achieve this through the offline analysis of data provided by the ventilator. Within the field of respiratory mechanics, the study focuses particularly on the quantification of lung instability. What does lung instability mean? By this definition, the investigators refer to the part of lung tissue that opens during inspiration and then collapses during the subsequent expiration. The more diseased the lung (for example, in the case of viral pneumonia), the greater the quantity of this tissue. How is lung instability measured? In the context of the study analysis, lung instability is measured through the analysis of the low flow pressure-volume loop during ventilation. This graph illustrates how the volume of air in the lungs varies in response to the pressures applied by the ventilator during slow inflation and deflation phases. This maneuver is considered quick and safe and has been an integral part of our clinical practice for several years. Through this maneuver, investigators can examine the range of pressures provided by the ventilator during tidal ventilation. To assess lung instability, hysteresis is analyzed, which represents a distinctive characteristic of the pressure-volume loop. Greater hysteresis indicates a higher degree of lung instability. During the study, investigators will record not only hysteresis but also classical respiratory mechanics parameters (for example, elastance of the respiratory system, i.e., how stiff the lung is), parameters regarding gas exchange (blood oxygen and carbon dioxide levels), biometric data (for example, height and weight), and imaging (CT scans, lung ultrasound, and electrical impedance tomography) to relate them to the degree of lung instability.
Interventions
None listed
Sponsors
Fondazione IRCCS Policlinico San Matteo di Pavia
Study design
Observational model
CASE_ONLY
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
18 Years to 90 Years
Healthy volunteers
No
Inclusion criteria
* patients undergoing passive mechanical ventilation
Exclusion criteria
* hemodynamic instability * confirmed intracranial hypertension
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Statistical prevalence of respiratory system instability , defined as indexed lung hysteresis at PEEP lower than 10 cmH2O. | up to 45 months | Lung instability is defined as indexed hysteresis \> 100. Where: * Hysteresis (ml) is calculated as the area enclosed between inspiratory and expiratory limb of the low flow pressure volume loop. * indexed hysteresis corresponds to the hysteresis area normalized for the applied driving pressure (plateau pressure minus PEEP) |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Description of classical respiratory mechanics related to lung instability | up to 45 months | Correlate respiratory system compliance (measured as tidal volume divided by driving pressure) with the degree of lung instability (ie indexed hysteresis) |
Countries
Italy
Contacts
Primary ContactMarco Pozzi, MD
Outcome results
None listed