Lung Ultrasound, PEEP and Overdistension (LUPO) (LUPO)

April 23, 2022 updated by: Paolo Persona, University of Padova

Lung Ultrasound for Diagnosis of Lung Overdistension in Acute Hypoxaemic Respiratory Failure

The investigators suppose that lung sliding could be reduced in the same lung region moving from less ventilated to overinflated condition. This is supported by theoretical arguments by some authors but so far it has not been demonstrated.

The investigators suppose that speckle tracking applied to LUS is able to demonstrate a reduction or abolition in pleural sliding when lung tissue is overinflated by higher PEEP after lung recruitment maneuver. The overinflation is diagnosed by Electric Impedance Tomography (EIT) and mechanical respiratory measurements (reduction in compliance as ratio between tidal volume over difference between plateau pressure and PEEP) and localized by EIT.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Lung ultrasonography (LUS) is a rapid, easy and non-invasive bedside tool for the detection of specific ultrasound patterns, associated with several pulmonary and pleural disorders. The main limitation of studies assessing lung recruitability and lung monitoring during mechanical ventilation is the lack of detection of lung overinflation: the A pattern doesn't change if the lung tissue is completely re-aerated or is overinflated. Considering this, the investigators could not use LUS to guide lung recruitment due to the risk of lung damage. Speckle tracking echocardiography is a gray-scale based technique used for quantification of myocardial strain to provide a quantitative, objective measure of left ventricle (LV) systolic function.

The investigators suppose that lung sliding could be reduced in the same lung region moving from less ventilated to overinflated condition. This is supported by theoretical arguments by some authors but so far it has not been demonstrated.

The investigators suppose that speckle tracking is able to demonstrate a reduction or abolition in pleural sliding when lung tissue is overinflated by higher PEEP after lung recruitment maneuver. The overinflation is diagnosed by EIT and mechanical respiratory measurements (reduction in compliance as ratio between tidal volume over difference between plateau pressure and PEEP) and localized by EIT.

Primary endpoint: agreement between LUS and EIT to diagnose lung overdistension in Acute Hypoxaemic Respiratory failure patients during a PEEP trial.

Patients are ventilated in pressure controlled mode with a tidal volume of 6 mL/kg predicted body weight (PBW), respiratory rate (RR) is maintained as set per clinical management, I:E = 1:2, PEEP level is set at 5 cmH2O and inspiratory fraction of O2 (FiO2) at 100% before starting the protocol.

To check the presence of areas with reduced or absent pleural sliding not depending on overdistention, and to exclude absence of lung pulse due to pneumothorax, a basal LUS examination is performed before recruiting manoeuvre (RM): the ultrasound linear probe (12 megahertz, GE) is positioned parallel into the 4th-5th right intercostal space next to the sternal margin for the first acquisition; then other two acquisitions along the intercostal space from the medial part to the lateral side of the thorax are recorded; the procedure is repeated on the left side resulting in a final acquisition of 3 ultrasound clips of 10 seconds for each hemithorax. If the presence of pneumothorax is suspected or diagnosed (absence of lung pulse), the patient is excluded from the study according to exclusion criteria.

Then at the same level, marked with a dermographic pen, the EIT belt is positioned and a basal assessment of lung impedance is recorded.

After that a 40x40 RM is performed, setting a PEEP of 40 cmH2O for 40 seconds on continuous positive airway pressure mode mode. If hemodynamic instability or decrease in oxygen saturation occurs during the maneuver, RM is interrupted and previous ventilator settings restored until stability is obtained and the patient discharged from the protocol. If the presence of pneumothorax is suspected or diagnosed (absence of lung pulse), the patient is excluded from the study according to exclusion criteria and clinically managed.

Ventilation is then set again in volume controlled mode with a tidal volume of 6 ml/kg and a PEEP set to reach a maximum plateau pressure of 30 cmH20. I:E ratio and RR are left unchanged.

A decremental PEEP trial is performed reducing PEEP value of 2 cmH2O, static compliance is calculated with an inspiratory pause of 3 seconds just before PEEP modification, and a registration of EIT is acquired for each PEEP level. The PEEP trial starts with the maximum PEEP level (PEEPmax, which is 30 cmH2O minus the pressure generated by 6 ml/kg of tidal volume) and stops at 2 cmH2O less than the best PEEP (PEEPmin), identified according to the static compliance value.

At the same time ultrasound linear probe is transversely set 1 cm above or below the EIT belt and clips recorded at each PEEP level as described above (Fig.2). A total of 6 LUS clips for each level of PEEP is recorded.

Once best PEEP is identified, LUS clips are encoded stored on an external memory stick.

EIT images

Ultrasound setting pre-defined are fixed. Clips are analyzed using GE software and longitudinal speckle tracking applied for each pleural clip. A-lines are numbered per clip Measurements Maximal strain, strain rate and time to peak are calculated and stored by a second investigator blinded to respiratory maneuvers. Differences between parameters calculated on basal and on PEEP trial clips are analyzed.

EIT session is analyzed by dedicated software and lung impedance assessed; each LUS clip is matched with correspondent part of EIT image considered two Region of Interest on the upper part of each hemithorax.

Intra-observer variability on speckle-tracking is assessed by intra-class coefficient correlation; correlation between speckle tracking values and PEEP level is assessed by Spearman correlation test; receiving operating characteristic (ROC) curve (Youden's index) is calculated to predict the accuracy of speckle tracking for predicting hyperinflation. EIT and LUS clips are compared with Cohen's K.

A-lines are numbered at different level of PEEP to investigate if the number of A-lines could be related to lung overdistention

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
30

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Italy
      • Padova, Italy, 35100
        • Azienda Ospedaliera Universita di Padova

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Sampling Method

Probability Sample

Study Population

Mechanically ventilated patients with acute hypoxemic respiratory failure (AHRF) or acute respiratory distress syndrome (ARDS) according to the Berlin definition (P/F ratio 100-300 with at least PEEP 5 cmH2O)

Description

Inclusion Criteria:

  • Age > 18 years
  • BMI < 35 kg/m2

Exclusion Criteria:

  • Presence or history of pneumothorax, absence of lung pulse
  • Pregnancy
  • Patients with Pressure arterial O2/FiO2 (PaO2/FiO2) < 100 mmHg with at least 5 cmH2O of PEEP
  • Pacemaker and/or internal cardiac defibrillator
  • Hemodynamic parameters: systolic blood pressure <100 mmHg and >180 mmHg, or if systolic blood pressure is between 100-180 mmHg on high dose of IV continuous infusion of norepinephrine (>0,2 μg/kg/min), or dobutamine (>5 μg/kg/min ), or dopamine (>5 μg/kg/min), or epinephrine (>0,1 μg/kg/min)
  • Hemodynamic instability (systolic blood pressure < 70 mmHg, heart rate increase to >140 bpm or decrease to <60 bpm, appearance of cardiac arrhythmias, (peripheral saturation O2 (SpO2) decrease to < 88%) during RM

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Observational Models: Cohort
  • Time Perspectives: Prospective

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
acute hypoxemic respiratory failure patients
Mechanically ventilated patients with acute hypoxemic respiratory failure (AHRF) with P/F ratio < 300 with at least PEEP 5 cmH2O)
Device: Lung Ultrasound
Echography of Lungs based on artifacts study
Other Names:
  • LUS
Device: Electric impedance tomography
Low alternating electrical currents (usually <5 milliampere at 50-80 kHz) applied through different pair of electrodes on thorax
Other Names:
  • EIT

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
agreement between LUS+Speckle tracking and EIT in diagnosis of lung overdistension
Time Frame: 5 months
LUS with speckle tracking applied and EIT are able to diagnose lung overdistension in the same lung zone
5 months

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
quantification of lung sliding by speckle tracking at different levels of PEEP
Time Frame: 5 months
Speckle tracking applied to LUS is able to quantify lung sliding at different PEEP levels
5 months
correlation between number of A-lines and lung overdistention
Time Frame: 5 months
the number of A-lines per clip at different level of PEEP is related to the lung overdistention diagnosed by EIT
5 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University of Padova

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Study Chair: Paolo Navalesi, MD, University of Padova

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
February 25, 2021

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
April 30, 2021

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
May 15, 2021

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
November 23, 2020

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
November 23, 2020

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
December 1, 2020

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
April 26, 2022

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 23, 2022

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
April 1, 2022

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 0021712

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

Undecided

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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