Acute Lung InjuryNCT01083355
Assessing Respiratory Variability During Mechanical Ventilation in Acute Lung Injury (ALI)
An observational study of Acute Lung Injury and Adult Respiratory Distress Syndrome, run by Boston Medical Center at 1 site in United States.
Trial summary
Healthy biological systems are characterized by a normal range of "variability" in organ function. For example, many studies of heart rate clearly document that loss of the normal level of intrinsic, beat-to-beat variability in heart rate is associated with poor prognosis and early death. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Acute Lung Injury, Adult Respiratory Distress Syndrome
- How many people
- 0 participants
- Where
- 1 siteUnited States
- Study dates
- Mar 2010to Mar 2016
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Patients admitted to adult medical, surgical, and coronary critical care units at Boston Medical Center.
Who may be able to join
- Age > or equal to 18.
- Requires mechanical ventilation.
- Admitted to surgical, medical, or coronary critical care unit
- Triggering ventilator above set rate
- Meets American European consensus definition of acute lung injury: PaO2/FiO2 ratio <300 or SaO2/FiO2 ratio<315; bilateral infiltrates on chest x-ray (CXR); no congestive heart failure (CHF).
Who cannot join
- None
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Assessing Respiratory Variability During Mechanical Ventilation in Acute Lung Injury
Healthy biological systems are characterized by a normal range of "variability" in organ function. For example, many studies of heart rate clearly document that loss of the normal level of intrinsic, beat-to-beat variability in heart rate is associated with poor prognosis and early death.
Unlike the heart, little is known about patterns of respiratory variability in illness. What is known is that, like the heart, healthy subjects have a specific range of variability in breath- to-breath depth and timing. Additionally, in animal models, ventilator strategies that re-introduce normal variability to the breathing pattern significantly reduce ventilator-associated lung injury.
Read more
Critically ill patients requiring mechanical ventilation offer an opportunity to observe and analyze respiratory patterns in a completely non-invasive manner. Current mechanical ventilators produce real-time output of respiratory tracings that can analyzed for variability.
The investigators propose to non-invasively record these tracings from patients ventilated in the intensive care units for mathematical variability analysis. The purpose of these pilot analyses are to: (1) demonstrate the range of respiratory variability present in the mechanically ve ventilated critically ill and (2) demonstrate the ventilator modality that delivers or permits the closest approximation to previously described beneficial or normal levels of variability. Future studies will use this pilot data in order to determine if the observed patterns of respiratory variability in mechanically ventilated critically ill subjects have prognostic or therapeutic implications.
Read the detailed description
Different modes of mechanical ventilation allow different levels of patient control of the respiratory pattern. For example, the most common mode of ventilation, called volume control, gives very little control to the patient in the amount of air taken for each breath. Other modes, such as pressure control, pressure regulated volume control and pressure support, allow more patient control of the volume of air delivered by the ventilator. Newer modes, such as airway pressure release ventilation (APRV), allow completely spontaneous patient respirations. All of these modes allow at least some patient control of respiratory rates.
Studies of natural breathing by healthy subjects have shown normal levels of variability in respiratory rate and tidal volume.1 Variability in physiological processes has been associated with health and the loss of variability can presage the onset of illness. For example, normal humans exposed to LPS (lipopolysaccharide-the potent immune-stimulating cell wall component of bacteria) lose their normal respiratory variability. Thus, physiological variability may represent a "hidden vital sign," the monitoring of which may herald important clinical events. Additionally, re-establishing normal levels of variability has therapeutic benefits in animal models. 2
The variability in respiratory patterns in ill patients has not been well studied. For example, it is currently unclear if critical illness results in deviations from normal variability patterns, if ventilator modes allowing increasing patient control of respiration allow patients to attain greater normalcy of respiratory variability, or if deviations from normal respiratory patterns while on ventilator modes which allow for increased levels of spontaneous breathing have prognostic implications.
The purpose of this pilot study is to record respiratory patterns from the ventilators of patients receiving various modes of mechanical ventilation in order to quantify and compare levels of respiratory variability associated with each mode. Our hypothesis is that APRV, a mode that allows spontaneous respiration, will be associated with respiratory variability patterns that most closely approximate that of normal subjects.
We hope that data derived from this study will inform future observational studies correlating respiratory variability during mechanical ventilation with severity of illness and prognosis.
- Keywords
- Variable ventilation, Pressure regulated volume control ventilation, Airway pressure release ventilation
- Medical subject headings
- Acute Lung Injury, Respiratory Distress Syndrome
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Mechanical ventilation | Critical care patients |
What is being measured
The primary outcome is the main question the study is designed to answer.
The degree of variability in tidal volume (measured as % variation about the mean) stratified by ventilator mode.
Measured: 1 hour
Secondary outcomes (2)
Alternative measures of variability and complexity for each ventilator mode.
Measured: 1 hour
Correlations between clinical parameters such as disease severity, vital signs, sedation levels, and variability.
Measured: 1 hour
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted9 Mar 2010 (estimated)
- Study startMar 2010
- Primary completionMar 2016
- Study completionMar 2016
Why it stopped: No participants were enrolled, no funding obtained to perform study
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Acute Lung InjuryStudies of the same condition, open and under way.
- More trials run by Boston Medical CenterThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Case-control
- Time perspective
- Prospective
- Enrolment
- 0 participants (actual)
Sponsor and investigators
- Lead sponsor
- Boston Medical Center
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Allan J. Walkey, Boston Medical Center
- Investigators
- George O'Connor, MD, Principal investigator, Boston University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT01083355
- Sponsor's protocol ID
- H-29278
- Status last verified
- Mar 2016
- First submitted
- 19 Feb 2010
- Last updated
- 30 Mar 2016
- Results posted
- No
- Data monitoring committee
- No
Publications
Davis JN, Stagg D. Interrelationships of the volume and time components of individual breaths in resting man. J Physiol. 1975 Feb;245(2):481-98. doi: 10.1113/jphysiol.1975.sp010857.
PubMed 1142186
Study at a glance
From the registry record, last updated by the sponsor on 30 Mar 2016. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Assessing Respiratory Variability During Mechanical Ventilation in Acute Lung Injury
- ClinicalTrials.gov ID
- NCT01083355
- Acronym / sponsor ID
- H-29278
- Keywords
- Variable ventilation, Pressure regulated volume control ventilation, Airway pressure release ventilation
- Study type
- Observational
- Recruitment status
- WithdrawnReason stopped: No participants were enrolled, no funding obtained to perform study
- Enrolment
- 0 participants (actual)
- Lead sponsor
- Boston Medical CenterUniversity, hospital or other
- Study start
- Mar 2010
- Primary completion
- Mar 2016 (actual)
- Study completion
- Mar 2016 (actual)
- First posted
- 9 Mar 2010 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Healthy biological systems are characterized by a normal range of "variability" in organ function. For example, many studies of heart rate clearly document that loss of the normal level of intrinsic, beat-to-beat variability in heart rate is associated with poor prognosis and early death.
Unlike the heart, little is known about patterns of respiratory variability in illness. What is known is that, like the heart, healthy subjects have a specific range of variability in breath- to-breath depth and timing. Additionally, in animal models, ventilator strategies that re-introduce normal variability to the breathing pattern significantly reduce ventilator-associated lung injury.
Critically ill patients requiring mechanical ventilation offer an opportunity to observe and analyze respiratory patterns in a completely non-invasive manner. Current mechanical ventilators produce real-time output of respiratory tracings that can analyzed for variability.
The investigators propose to non-invasively record these tracings from patients ventilated in the intensive care units for mathematical variability analysis. The purpose of these pilot analyses are to: (1) demonstrate the range of respiratory variability present in the mechanically ve ventilated critically ill and (2) demonstrate the ventilator modality that delivers or permits the closest approximation to previously described beneficial or normal levels of variability. Future studies will use this pilot data in order to determine if the observed patterns of respiratory variability in mechanically ventilated critically ill subjects have prognostic or therapeutic implications.
Detailed description
Different modes of mechanical ventilation allow different levels of patient control of the respiratory pattern. For example, the most common mode of ventilation, called volume control, gives very little control to the patient in the amount of air taken for each breath. Other modes, such as pressure control, pressure regulated volume control and pressure support, allow more patient control of the volume of air delivered by the ventilator. Newer modes, such as airway pressure release ventilation (APRV), allow completely spontaneous patient respirations. All of these modes allow at least some patient control of respiratory rates.
Studies of natural breathing by healthy subjects have shown normal levels of variability in respiratory rate and tidal volume.1 Variability in physiological processes has been associated with health and the loss of variability can presage the onset of illness. For example, normal humans exposed to LPS (lipopolysaccharide-the potent immune-stimulating cell wall component of bacteria) lose their normal respiratory variability. Thus, physiological variability may represent a "hidden vital sign," the monitoring of which may herald important clinical events. Additionally, re-establishing normal levels of variability has therapeutic benefits in animal models. 2
The variability in respiratory patterns in ill patients has not been well studied. For example, it is currently unclear if critical illness results in deviations from normal variability patterns, if ventilator modes allowing increasing patient control of respiration allow patients to attain greater normalcy of respiratory variability, or if deviations from normal respiratory patterns while on ventilator modes which allow for increased levels of spontaneous breathing have prognostic implications.
The purpose of this pilot study is to record respiratory patterns from the ventilators of patients receiving various modes of mechanical ventilation in order to quantify and compare levels of respiratory variability associated with each mode. Our hypothesis is that APRV, a mode that allows spontaneous respiration, will be associated with respiratory variability patterns that most closely approximate that of normal subjects.
We hope that data derived from this study will inform future observational studies correlating respiratory variability during mechanical ventilation with severity of illness and prognosis.
Study design
- Observational model
- Case-control
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Mechanical ventilation | – | –Critical care patients |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Patients admitted to adult medical, surgical, and coronary critical care units at Boston Medical Center.
Key inclusion criteria (5 listed)
- Age > or equal to 18.
- Requires mechanical ventilation.
- Admitted to surgical, medical, or coronary critical care unit
- Triggering ventilator above set rate
- Meets American European consensus definition of acute lung injury: PaO2/FiO2 ratio <300 or SaO2/FiO2 ratio<315; bilateral infiltrates on chest x-ray (CXR); no congestive heart failure (CHF).
Key exclusion criteria (1 listed)
- None
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
The degree of variability in tidal volume (measured as % variation about the mean) stratified by ventilator mode.
Time frame: 1 hour
2 secondary outcomes
Alternative measures of variability and complexity for each ventilator mode.
Time frame: 1 hour
Correlations between clinical parameters such as disease severity, vital signs, sedation levels, and variability.
Time frame: 1 hour
Results and safety
The study was withdrawn before enrolling participants, so there are no results.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 30 Mar 2016.
- Background: PubMed 1142186Davis JN, Stagg D. Interrelationships of the volume and time components of individual breaths in resting man. J Physiol. 1975 Feb;245(2):481-98. doi: 10.1113/jphysiol.1975.sp010857.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
George O'Connor, MD principal investigator
Boston University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Acute Lung Injury and Adult Respiratory Distress Syndrome, run by Boston Medical Center at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: withdrawn, as of the sponsor's last update on 30 Mar 2016. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study was withdrawn before enrolling participants, so there are no results.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
The degree of variability in tidal volume (measured as % variation about the mean) stratified by ventilator mode. (time frame: 1 hour). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT01083355, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 30 Mar 2016.