Comparison of Different Methods to Calculate Pendelluft by Electrical Impedance Tomography in Mechanically Ventilated Patients

July 2, 2024 updated by: University of Sao Paulo General Hospital

Comparison of Different Methods to Calculate Pendelluft by Electrical Impedance Tomography in Patients Undergoing Invasive Mechanical Ventilation Under Pressure Support Mode

The Pendelluft phenomenon is an important cause of lung damage in spontaneously breathing mechanically ventilated patients since it considerably increases the stress on the lung parenchyma in the dependent areas. It can result in a local driving pressure up to three times higher than the global driving pressure. The measurement of Pendelluft is still uncertain in the literature, and although various methods have been proposed, not all have the same meaning in terms of pulmonary overstress and overstrain. This study proposes a comparative analysis of different ways to calculate and estimate the stress imposed on the lung parenchyma by Pendelluft in terms of regional volume and local driving pressure through electrical impedance tomography.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

Respiratory mechanics and regional ventilation will be monitored by electrical impedance tomography (Enlight 1800 and 2100, Timpel). Esophageal and gastric pressures will be obtained by placing an esophageal/gastric balloon cathether (Nutrivent ®), validation concerning position will be done through modified Baydur maneuver (delta esophageal/delta airway pressure = 0.8-1.2). The hardware Pneumodrive will be used to inflate the balloon and store the airway, gastric and esophageal pressures.

Initially the patients will be monitored with EIT for aproximately 30 minutes after pletismography stabilization. Then, an arterial blood-gas sample shall be collected for analysis. Next, three expiratory and three inspiratory pauses of at least two seconds will be realized with intervals of eight respiratory cycles between them, allowing plateau pressure to be recorded and global and regional driving pressure to be estimated. All this data will be stored for later analysis. The same procedures and measurements shall be made sequentially with a 50% higher pressure support and with a 50% lower pressure support.

Study Type

Interventional

Enrollment (Estimated)

15

Phase

  • Not Applicable

Contacts and Locations

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

Study Contact

Study Contact Backup

Study Locations

  • Brazil
      • São Paulo, Brazil, 05403-900
        • Recruiting
        • Instituto do Coração do Hospital das Clínicas da Faculdade de Medicina da USP
        • Contact:
        • Contact:
        • Principal Investigator:
          • Marcelo C Amato, MD, PhD

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

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Patients under invasive mechanical ventilation intubated due to respiratory failure in pressure support mode (weaning phase)

Exclusion Criteria:

  • Age less than 18 years; sedation or neuromuscular blockade; absence of respiratory effort; contraindications to esophageal balloon cathether positioning or electrical impedance tomography belt positioning; presence of pneumothorax or active air leaks; hemodynamic instability; absence of informed consent.

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

  • Primary Purpose: Diagnostic
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Other: Pressure Support Variation
Patients shall be submitted to pressure support variation in a randomly assigned manner. First 30 minutes after plethysmogram stabilization shall be recorded at clinical pressure support. Next, a blood gas sample shall be collected by a nurse or a physician, and three inspiratory pauses of at least 2 seconds shall be performed in between eight respiratory cycles. Next three expiratory pauses shall be performed in between eight respiratory cycles. All data shall be recorded and analysed offline. Subsequently the same sequence of events shall be performed at a 50% higher pressure support and at a 50% lower pressure support. The sequence in which this will happen shall be randomly assigned (first lower PS vs higher PS or first higher PS vs lower PS).
Other: Pressure Support Variation and Calculation of Respiratory Mechanics
Patients will be submitted to different levels of pressure support (PS) in a randomly assigned order. First 30 minutes shall be recorded at the clinical PS. Next, blood gas samples shall be collected. Subsequently, three inspiratory pauses of at least 2 seconds shall be performed with an interval of at least 8 respiratory cycles between them. The same shall be performed with three expiratory pauses. Next, the PS shall be varied to 50% less or 50% more than clinical PS (based on randomization) and the same procedures shall be performed after 30 minutes of data recording (blood gas sample collection, inspiratory and expiratory pauses). All data shall be analyzed offline using a software that will be able to compare three different methods to calculate Pendelluft magnitude based on the literature. After completion of the protocol, ventilatory parameters shall be returned to the original settings. If the patient becomes tachypneic during lower PS, the protocol shall be interrupted.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
1. Magnitude of Pendelluft
Time Frame: During 30 minutes after plethysmogram stabilization at clinical PS, during 30 minutes at 50% lower PS, and during 30 minutes at 50% higher PS
Three differents methods of estimating magnitude of Pendelluft shall be compared using a software based on electrical impedance tomography monitoring (Enlight 2100, Timpel Medical®, Brazil)
During 30 minutes after plethysmogram stabilization at clinical PS, during 30 minutes at 50% lower PS, and during 30 minutes at 50% higher PS
2. Magnitude of Pendelluft during inspiratory pause
Time Frame: During 30 minutes after plethysmogram stabilization at clinical PS, during 30 minutes at 50% lower PS, and during 30 minutes at 50% higher PS
One of the methods of Pendelluft measurement shall be performed during an inspiratory pause for comparison with a normal cycle (without pause).
During 30 minutes after plethysmogram stabilization at clinical PS, during 30 minutes at 50% lower PS, and during 30 minutes at 50% higher PS
3. Magnitude of respiratory effort
Time Frame: During 30 minutes after plethysmogram stabilization at clinical PS, during 30 minutes at 50% lower PS, and during 30 minutes at 50% higher PS
Respiratory effort shall be estimated through expiratory pauses and though recording of esophageal pressure at different pressure support levels. These data shall be compared to Pendelluft magnitude according to the different methods of calculation
During 30 minutes after plethysmogram stabilization at clinical PS, during 30 minutes at 50% lower PS, and during 30 minutes at 50% higher PS

Collaborators and Investigators

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

Sponsor

University of Sao Paulo General Hospital

Investigators

  • Principal Investigator: Marcelo BP Amato, University of Sao Paulo General Hospital

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)

June 11, 2024

Primary Completion (Estimated)

June 11, 2025

Study Completion (Estimated)

June 11, 2025

Study Registration Dates

First Submitted

July 2, 2024

First Submitted That Met QC Criteria

July 2, 2024

First Posted (Actual)

July 10, 2024

Study Record Updates

Last Update Posted (Actual)

July 10, 2024

Last Update Submitted That Met QC Criteria

July 2, 2024

Last Verified

June 1, 2024

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 79317924.0.0000.0068

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

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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