Critical IllnessSMARTNCT03019133
Trial to Evaluate the Effects of Sound Modulation on Critically Ill Patients
A study testing Sound reduction and Sound masking in people with Critical Illness and Physiological Stress, run by Brian Gehlbach at 1 site in United States.
Trial summary
The goal of the project is to determine the effects of noise masking and noise reduction on stress related physiological parameters in critically ill patients admitted to the intensive care unit. Read more about this study
- Who is it for?
- Ages 18 to 99 years
- Conditions the study is for
- Critical Illness, Physiological Stress, Delirium
- What is being tested?
- Sound reduction and Sound masking
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 120 participants
- Where
- 1 siteUnited States
- Study dates
- Dec 2016to 31 Dec 2024
- Phase
- Interventional
- 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 to 99 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Subjects aged 18-99 years who are expected to receive care on an adult critical care unit for at least 24 hours
Who cannot join
- Admission for drug overdose or with a known substance abuse disorder
- Untreated sleep apnea disorder, narcolepsy, REM sleep behavior disorder, parasomnia, restless leg syndrome or other sleep disorder
- Use of hearing aids, or known significant conductive or sensory hearing loss
- Ventilator support via an endotracheal tube
- Use of vasopressors
- Unresponsive or delirious
- Subjects with known Dementia, Parkinson's disease, or other neurodegenerative disorder
- Subjects with a pacemaker or who have received cardiac transplant
Trial locations and contacts
1 site in 1 country.
United States1 site
University of Iowa Hospitals and Clinics
Iowa City, Iowa, 52242
About this study
Official title: Prospective Randomized Controlled Trial to Compare and Analyze the Effects of Sound Masking and Reduction Techniques on Heart Rate and Blood Pressure Variability in Critically Ill Patients
The goal of the project is to determine the effects of noise masking and noise reduction on stress related physiological parameters in critically ill patients admitted to the intensive care unit.
Read the detailed description
Sleep deprivation is common in critically ill patients in the intensive care unit (ICU) and may impair recovery. While noise is widely cited as the most common cause of sleep disruption in the ICU setting, its contribution to sympathetic activity in critically ill patients is not known. This is an important knowledge gap, because noise initiates a sequence of physiological changes including vasoconstriction, raised diastolic blood pressure, pupil dilatation and muscle tension. Furthermore, noise is implicated in sympathetic arousals, resulting in a release of adrenaline which prevents relaxation and consequently prevents the patient from falling asleep.
The investigators plan to study the effect of noise masking and noise reduction on stress related physiological parameters in critically ill patients admitted to the ICU. Subjects will be randomized into 3 separate groups: control, noise reduction, and noise masking. The investigators will compare the heart rate and blood pressure variability between and within the groups to determine the effects of treatment assignment on these variables. Non-invasive measurements obtained from the bedside monitor will be collected using physiological data acquisition software.
- Conditions
- Critical Illness, Physiological Stress, Delirium, Sleep Deprivation
- Being tested
- Sound reduction, Sound masking
- Keywords
- Heart rate, Blood pressure variability
- Medical subject headings
- Critical Illness, Delirium, Sleep Deprivation
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Sound reductionDevice
Subjects will wear noise reduction headphones between the hours of 8:00 pm and 8:00 am.
Sound maskingDevice
Subjects will wear wear headphones playing relaxing music between the hours of 8:00 pm and 8:00 am.
| Study group | Role | What they receive |
|---|---|---|
| Usual Care | No intervention | Usual care will be provided. |
| Sound reduction | Active comparator | Use of noise reduction headphones. Pro For Sho safety ear muffs with a noise reduction rate of 34dB will be used. Receives: Device: Sound reduction |
| Sound masking | Active comparator | Use of headphones and relaxing music. Sennheiser HD 280 pro headphones will be used for sound masking. Receives: Device: Sound masking |
What is being measured
The primary outcome is the main question the study is designed to answer.
Nocturnal LF/HF ratio (a.u.)
The effect of group assignment on nocturnal (8pm to 8am) low frequency/high frequency (LF/HF) ratio will be determined.
Measured: Day 1 of study
Secondary outcomes (8)
Nocturnal heart rate (bpm)
The effect of group assignment on nocturnal (8pm to 8am) heart rate will be determined.
Measured: Day 1 of study
Nocturnal RMSSD (ms)
The effect of group assignment on nocturnal (8pm to 8am) root mean square of sequential differences of RR intervals (RMSSD) will be determined.
Measured: Day 1 of study
Nocturnal blood pressure (mm Hg)
The effect of group assignment on nocturnal (8pm to 8am) blood pressure (mean arterial pressure) will be determined.
Measured: Day 1 of study
Incidence of ICU delirium
The effect of group assignment on the incidence of ICU delirium as assessed by the CAM-ICU will be determined.
Measured: Assessed at the time of ICU discharge up to a maximum of 28 days after enrollment, and averaging 4 days after enrollment
Hospital length of stay (days)
The effect of group assignment on hospital length of stay will be assessed.
Measured: Assessed at the time of hospital discharge up to a maximum of 28 days after enrollment, and averaging 6 days after enrollment.
ICU length of stay (days)
The effect of group assignment on ICU length of stay will be assessed.
Measured: Assessed at the time of ICU discharge up to a maximum of 28 days after enrollment, and averaging 4 days after enrollment.
Hospital mortality (%)
The effect of group assignment on in-hospital mortality will be assessed.
Measured: Assessed at the time of hospital discharge up to a maximum of 28 days after enrollment, and averaging 6 days after enrollment.
Discharged home (%, versus discharge to another health care facility or died)
The effect of group assignment on being discharged directly to home (versus to another skilled care facility or died) from the hospital will be assessed.
Measured: Assessed at the time of hospital discharge up to a maximum of 28 days after enrollment, and averaging 6 days after enrollment.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted12 Jan 2017 (estimated)
- Study startDec 2016
- Primary completion31 Dec 2024
- Study completion31 Dec 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Critical IllnessStudies of the same condition, open and under way.
- 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
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Supportive care
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 120 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Brian Gehlbach
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor-investigator, Brian Gehlbach, University of Iowa
- Investigators
- Brian K Gehlbach, MD, Principal investigator, Faculty
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03019133
- Sponsor's protocol ID
- 201609843
- Acronym
- SMART
- Status last verified
- Mar 2025
- First submitted
- 19 Dec 2016
- Last updated
- 6 Apr 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: As this is a pilot study, there are no definite plans for sharing individual participant data at this time.
Study at a glance
From the registry record, last updated by the sponsor on 6 Apr 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Prospective Randomized Controlled Trial to Compare and Analyze the Effects of Sound Masking and Reduction Techniques on Heart Rate and Blood Pressure Variability in Critically Ill Patients
- ClinicalTrials.gov ID
- NCT03019133
- Acronym / sponsor ID
- SMART / 201609843
- Conditions
- Critical Illness, Physiological Stress, Delirium, Sleep Deprivation
- Keywords
- Heart rate, Blood pressure variability
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 120 participants (estimated)
- Lead sponsor
- Brian GehlbachUniversity, hospital or other
- Study start
- Dec 2016
- Primary completion
- 31 Dec 2024 (actual)
- Study completion
- 31 Dec 2024 (actual)
- First posted
- 12 Jan 2017 (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.
The goal of the project is to determine the effects of noise masking and noise reduction on stress related physiological parameters in critically ill patients admitted to the intensive care unit.
Detailed description
Sleep deprivation is common in critically ill patients in the intensive care unit (ICU) and may impair recovery. While noise is widely cited as the most common cause of sleep disruption in the ICU setting, its contribution to sympathetic activity in critically ill patients is not known. This is an important knowledge gap, because noise initiates a sequence of physiological changes including vasoconstriction, raised diastolic blood pressure, pupil dilatation and muscle tension. Furthermore, noise is implicated in sympathetic arousals, resulting in a release of adrenaline which prevents relaxation and consequently prevents the patient from falling asleep.
The investigators plan to study the effect of noise masking and noise reduction on stress related physiological parameters in critically ill patients admitted to the ICU. Subjects will be randomized into 3 separate groups: control, noise reduction, and noise masking. The investigators will compare the heart rate and blood pressure variability between and within the groups to determine the effects of treatment assignment on these variables. Non-invasive measurements obtained from the bedside monitor will be collected using physiological data acquisition software.
Study design
- Primary purpose
- Supportive care
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Usual Care | No intervention | –Usual care will be provided. |
| Sound reduction | Active comparator | Device: Sound reductionUse of noise reduction headphones. Pro For Sho safety ear muffs with a noise reduction rate of 34dB will be used. |
| Sound masking | Active comparator | Device: Sound maskingUse of headphones and relaxing music. Sennheiser HD 280 pro headphones will be used for sound masking. |
Who may qualify
- Ages
- 18 to 99 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (1 listed)
- Subjects aged 18-99 years who are expected to receive care on an adult critical care unit for at least 24 hours
Key exclusion criteria (8 listed)
- Admission for drug overdose or with a known substance abuse disorder
- Untreated sleep apnea disorder, narcolepsy, REM sleep behavior disorder, parasomnia, restless leg syndrome or other sleep disorder
- Use of hearing aids, or known significant conductive or sensory hearing loss
- Ventilator support via an endotracheal tube
- Use of vasopressors
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Sound reductionSubjects will wear noise reduction headphones between the hours of 8:00 pm and 8:00 am. | Device | Sound reduction |
| Sound maskingSubjects will wear wear headphones playing relaxing music between the hours of 8:00 pm and 8:00 am. | Device | Sound masking |
Primary outcome
Nocturnal LF/HF ratio (a.u.)
Time frame: Day 1 of study
The effect of group assignment on nocturnal (8pm to 8am) low frequency/high frequency (LF/HF) ratio will be determined.
8 secondary outcomes
Nocturnal heart rate (bpm)
Time frame: Day 1 of study
Nocturnal RMSSD (ms)
Time frame: Day 1 of study
Nocturnal blood pressure (mm Hg)
Time frame: Day 1 of study
Incidence of ICU delirium
Time frame: Assessed at the time of ICU discharge up to a maximum of 28 days after enrollment, and averaging 4 days after enrollment
Hospital length of stay (days)
Time frame: Assessed at the time of hospital discharge up to a maximum of 28 days after enrollment, and averaging 6 days after enrollment.
ICU length of stay (days)
Time frame: Assessed at the time of ICU discharge up to a maximum of 28 days after enrollment, and averaging 4 days after enrollment.
Hospital mortality (%)
Time frame: Assessed at the time of hospital discharge up to a maximum of 28 days after enrollment, and averaging 6 days after enrollment.
Discharged home (%, versus discharge to another health care facility or died)
Time frame: Assessed at the time of hospital discharge up to a maximum of 28 days after enrollment, and averaging 6 days after enrollment.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 6 Apr 2025.
- Individual participant dataSharing planned: No. As this is a pilot study, there are no definite plans for sharing individual participant data at this time.
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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.
Brian K Gehlbach, MD principal investigator
Faculty
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Sound reduction and Sound masking in people with Critical Illness and Physiological Stress, run by Brian Gehlbach 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 1 inclusion and 8 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: finished, as of the sponsor's last update on 6 Apr 2025. 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 is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
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?
Nocturnal LF/HF ratio (a.u.) (time frame: Day 1 of study). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 6 Apr 2025.