Clinical Trial Details
— Status: Completed
Administrative data
NCT number |
NCT04442815 |
Other study ID # |
EIT and ARF |
Secondary ID |
|
Status |
Completed |
Phase |
|
First received |
|
Last updated |
|
Start date |
December 13, 2019 |
Est. completion date |
May 31, 2021 |
Study information
Verified date |
December 2022 |
Source |
National Cheng-Kung University Hospital |
Contact |
n/a |
Is FDA regulated |
No |
Health authority |
|
Study type |
Observational [Patient Registry]
|
Clinical Trial Summary
Patient-ventilator asynchrony is an important clinical issue in mechanically ventilated
patients. For patients with moderate to severe acute respiratory distress syndrome (ARDS),
various types of patient ventilator asynchrony may lead to injury of the lung. For example,
double cycling may lead to high tidal volume and pendelluft may result in transient
overstretch of dependent lung region. In this project, the investigators will record and
analyze various types of patient-ventilator asynchrony in ARDS patients and analyze the
regional distribution of lung gas and determined their harmful effect via concomitant
recording of EIT and transpulmonary pressure. The results may influence our ventilator
management of ARDS patients.
Description:
Patients and Methods:
Admitted ventilated patients who are greater than 18 years old and fulfilled the Berlin's
diagnostic criteria of moderate to severe ARDS will be selected to enter our study. The
exclusion criteria include (1) patients with metallic materials in the body (including wire,
pin or implanted electrical devices etc.); (2) patients with cutaneous diseases which
prohibited the application of electrode leads to attached the body; (3) severe chronic
obstructive pulmonary diseases; (4) hemodynamically unstable; (5) proved barotrauma
(including pneumothorax or pneumomediastinum etc.); (6) pregnancy; (7) diseases characterized
with increased intracranial pressure; (8) patients or family who refused the informed
consent. All patients who fulfilled the diagnosis of ARDS will receive standard care of low
tidal volume ventilator therapy. The tidal volume 6 ml/Kg will be used. The investigators
expect to enroll at least 20 analyzable cases. Sedation and paralysis are usually used in
moderate to severe ARDS patients and daily interruption of sedation and paralysis is a
standard practice. The investigators will perform recording during daily interruption of
sedation and paralysis, up to 60 minutes period will be recorded during the interruption
period. Recording will be done at least once for registered case and could be repeated in
case of unsatisfactory signals.
Instrumentation In all patients, air flow will be measured using a pneumotachograph (Hamilton
AG, or Hans Rudolf) connected to a differential pressure transducer (MP 45, Validyne Corp.,
Northridge, CA). The flow sensor will be placed between the endotracheal tube and the Y-piece
of the ventilator. Tidal volume will be obtained by integrating the flow signal. Airway
pressure and esophageal pressure will be measured using differential pressure transducers
(P300D, Validyne Corp., Northridge, CA.). An appropriate esophageal pressure signal will be
confirmed according to the standard guideline[27]. All signals are sampled and digitalized at
200 Hz and data are stored in a data acquisition system (MP150, Acqknowledgement, Biopac,
Goleta, CA).
Measurements:
Electrical impedance tomography:
The investigators use a commercial EIT monitor (PulmoVista 500, Drager Medical GmbH, Lubeck,
Germany). An electrode belt with 16 equally spaced electrodes will be placed around the
patient's thorax at the 4th to 5th intercostal space. Impedance data will be acquired by
applying adjacent alternate current injection (50 KHz) and measuring the voltage difference
between the adjacent leads and a finite element method-based, linearized Newton-Raphson
reconstruction algorithm is used to construct the impedance data. The PulmoVista 500 monitor
displays functional EIT images, i.e. relative impedance changes including tidal ventilation
and end-expiratory lung impedance (EELI) changes. During the study phases, EIT data will be
registered at 20-40 Hz and low-pass filtered (35 per minute) and stored for offline analysis.
The individual impedance recording (10 minutes per segment) will be linked into a single file
and impedance calculation will thus be done off-line. The investigators will subdivide the
impedance recordings into ventral to dorsal parts. The investigators define the presence of
pendelluft as the presence of opposite impedance change (△Z) between dependent and
independent zones during a breathing effort. The breath could occur in inspiration phase,
expiratory phase or in transition. Estimation of volume of pendelluft will be determined by
the integrated volume and corresponding impedance change.
Respiratory mechanics:
The investigators will record the peak and plateau airway pressure, total PEEP, flow and the
esophageal pressure. Transpulmonary pressure (PL) will be calculated as the difference
between Paw and Pes calculate the transpulmonary pressure.
Study protocol The investigators target at moderate to severe ARDS patients who are already
under deep sedation with neuromuscular blockade. As daily interruption of sedatives and
muscle relaxant are routinely performed in our ICU, we will record the respiratory mechanics
and EIT data for about one hour which should include both controlled and spontaneous
breathing period.