Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT05291832 |
| Other study ID # |
001 |
| Secondary ID |
|
| Status |
Completed |
| Phase |
N/A
|
| First received |
|
| Last updated |
|
| Start date |
February 22, 2022 |
| Est. completion date |
July 19, 2022 |
Study information
| Verified date |
August 2022 |
| Source |
Brain.fm, Inc. |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Interventional
|
Clinical Trial Summary
Induction and emergence from propofol can be a difficult process for patients and healthcare
workers, and long recovery times in particular can limit the rate of care. A double-blinded
randomized controlled trial with 220 patients undergoing elective colonoscopy or endoscopy is
proposed to test the impact of perioperative music on patient experience and recovery from
propofol anaesthesia. Patients will be assigned at random to hear either rhythmic auditory
stimulation (music designed to drive neural oscillations) or spectrally-matched noise (sound
that produces the same levels of activity at the cochlea but not expected to drive neural
entrainment). Bone-conduction headphones will be administered in pre-operation waiting and
will play music (or matched noise) until propofol administration ceases, at which time the
music (or noise) will be switched: Pre- and post-operational music is designed to be sedative
and stimulative, respectively, created with methods that drive auditory entrainment to
promote those states. Outcome measures will be recovery time and the patient's subjective
experience (taken via survey).
Description:
INTRODUCTION
Can perioperative music improve the patient experience, and speed recovery from propofol
anaesthesia?
Difficulties around induction and emergence from general anesthesia are a burden on
healthcare workers, and central to a patient's experience. Anxiety prior to a procedure, and
confusion upon regaining consciousness, are common experiences that negatively affect both
patients and staff. Presurgical anxiety can result in difficulty with intubation and longer
presurgical delay periods, burdening nurses and slowing the pace of care. Postsurgically, the
duration and quality of a patient's recovery from anesthesia affects healthcare providers and
patients, both of whom want to minimize the time spent in the recovery room. Lengthy recovery
periods may involve amnesic episodes, delirium, agitation, cognitive dysfunction or other
emergence phenomenon, which place strain on patients and staff. Longer recoveries also place
strain on the patient's caretaker (e.g., relatives waiting to take them home) and burden the
healthcare facility, which may be limited in how quickly procedures can occur based on space
available in the recovery area.
Perioperative music has been used effectively to control anxiety and pain (Bringman et al.
2009, Gooding et al. 2012, Tan et al. 2012, Fu et al. 2019,. 2020, 2021), but in these
studies the music is chosen to be either relaxing or familiar, with no regard for how it
drives brain activity. Prior work has focused on the pre-operative period, and has not
considered how stimulative music might be used to kickstart cognition following emergence
from anaesthesia. Binaural beats (a type of sound therapy that drives neural entrainment) has
been recommended for perioperative use (Padmanabhan et al. 2012), but for relaxation only
rather than stimulation. Indeed, no work has been done to distinguish music for induction and
emergence, or to provide stimulative music to aid recovery from the unconscious state.
Sound is a powerful neuromodulator, and the auditory system can be used to drive neural
activity conducive to a variety of mental states. Part of this effect may be due to how sound
(and some music in particular) affects neural oscillations (Will & Berg 2007, Large 2010,
Tierney et al. 2014), arousal systems (Thompson et al. 2001, Dillman et al. 2007, Gingras et
al. 2014) and dopamine levels (Suttoo et al. 2004, Moraes et al. 2018). Propofol recovery is
known to be accelerated by activating the brain's arousal systems via drugs (Chemali et al.
2012) or direct electrical stimulation (Bastos et al. 2021), and music targeting arousal is
used to improve cognitive function in humans (Gupta et al. 2018, Woods et al. 2021). Auditory
stimulation developed specifically to drive the brain in different ways (Brain.fm music) may
be useful perioperatively, and different music may be useful for induction and emergence from
anaesthesia.
LITERATURE REVIEW
Propofol recovery Propofol is a widely used general anesthetic agent for ambulatory
procedures, but recovery from propofol is not well understood, and the time a patient spends
in the recovery room following a procedure may vary widely (Gupta et al. 2004, Shraag et al.
2018). Following return to consciousness (usually characterized by opening the eyes), a
patient may experience cognitive deficits or a variety of emergence phenomena such as
delirium, aggravation, or amnesia, which are a burden on healthcare workers and likely to be
a negative experience for the patient themselves (Lindqvist et al. 2014, Munk et al. 2016,
Metterlein et al. 2021). Recovery from propofol can be sped up by activating arousal systems
in the brain, for example with methylphenidate (Chemali et al. 2012) or direct thalamic
stimulation (Bastos et al. 2021), and by stimuli that have particular arousal value: for
example, speaking a patient's name as opposed to other words is more effective at waking
patients from propofol, reducing wake-up times by ~20% and reducing time in PACU by ~8% (Jung
et al. 2017). Somewhat surprisingly, rather than having negative effects, using arousing
stimuli to speed emergence from anaesthesia has been associated with a reduction in emergence
delirium in children (Byun et al. 2017). Auditory stimuli like music can also be used to
modulate arousal (Husain et al. 2002, Hilz et al. 2014), and sound is commonly used in waking
up from sleep. It thus seems likely that stimulating music could be used to speed recovery
from general anaesthesia; this point has been noted by others recently but work in this area
is still lacking (Seyedalshohadaei et al. 2021).
Perioperative music The role of music in a perioperative setting has largely been confined to
anxiety and analgesia, where there is strong evidence for its effectiveness (Bringman et al.
2009, Gooding et al. 2012, Tan et al. 2012, Fu et al. 2019,. 2020, 2021). In a recent example
of one such study, Muddanna et al. (2021) tested effects of relaxing music before and during
cataract surgery in 165 patients, and found lowered postoperative BP in the test group, along
with 48% of the test group reporting feeling 'not at all' or 'a little' anxious (lower
ratings of anxiety), versus 30% of the control group. In another study, with 322 patients,
Bringman et al. (2009) found that pre-surgical relaxing music was more effective at reducing
anxiety than midazlolam (an orally-administered anxiolytic drug). Headsets to reduce anxiety
have been tested in clinical settings (Johnson et al. 2012), but use only
commercially-available (i.e., not purposely-designed) music, and focus only on relaxation.
Post-operative music has also been found beneficial: in a recent meta-analysis of more than
70 studies, Hole et al. (2015) found strong effects on anxiety, pain, and patient
satisfaction, and highly recommended the use of music following surgeries. However, these
studies again focus on relaxing music, often of the patient's choice, and in none of these
studies was stimulative music used to reduce the duration and difficulty of a patient's
emergence from anaesthesia. Studies involving both pre- and post-operative music (Billar et
al. 2020, Kappen et al. 2021) use the same music on either side of the procedure, typically
with the aim of reducing stress throughout the perioperative period, rather than aiding
induction and emergence specifically.
One reason for a lack of interest thus far in stimulative 'wake-up' music may be that music
is indeed so effective as an anxiolytic that work in the area has gravitated there. Another
possibility is that the use of music to boost arousal or cognition is not widely appreciated,
despite having been demonstrated in other contexts such as aiding attentive work (Thompson et
al. 2001, Schellenberg et al. 2002, Cassidy et al. 2007), mitigating fatigue (Terry et al.
2020), or improving level-of-consciousness in patients with head trauma (Yekefallah et al.
2021). Finally, the way patients typically return to consciousness in practice may not appear
to require external stimulation, since a nurse or doctor will come around to patients at
intervals to rouse them (i.e., no 'alarm clock' is needed). However, whether the patient then
is able to function cognitively and maintain consciousness (i.e., whether they do in fact
wake up when roused), will depend on their neurological state at that time.
Auditory neuromodulation Sound stimuli can modulate brain activity by driving coordinated
activity (i.e., entrainment) of neural populations well beyond auditory cortex (Will & Berg
2007, Large 2010, Tierney et al. 2014). This effect is used to drive the brain into states
conducive to activities such as sleep (Ngo et al. 2013) or attention (Calderone et al. 2014).
Perhaps related to its effect on oscillations, music also can be used to modulate arousal
levels bidirectionally (Thompson et al. 2001, Dillman et al. 2007, Gingras et al. 2014).
During emergence from propofol, neural oscillations are returning from an altered dynamical
state, and changes include increases in beta power (Breshears et al. 2010), an oscillatory
band associated with wakefulness and focus (Zanos et al. 2018). Auditory stimuli can be used
to shape oscillatory power and may be useful to drive the brain emerging from general
anaesthesia. Hunt et al. 2021 used personalized entrainment music (designed to drive
oscillations to inhibit pain) on patients with chronic pain, and found a greater improvement
than when patients listened to music of their own choosing, demonstrating that the effects of
music were due to entrainment rather than affect (emotion or familiarity). Similarly, music
designed for sustained attention via entrainment particularly aids listeners with more
ADHD-like symptoms (whose oscillatory activity is known to be different), and hightens
activity in task-related functional networks (Woods et al. 2021).
In this study we will test music designed to be maximally effective for induction and
emergence from propofol (Brain.fm music). The induction (pre-operative) music is designed to
induce slow-wave activity and sleep, and has been shown to relax listeners significantly more
than commercially-available relaxing music in a pilot study (unpublished). The emergence
music (recovery; post-operative) has been shown to drive beta oscillations and improve focus,
and as being rated higher in arousal than commercially-available focus music (Woods et al.
2021).
RATIONALE No study to date has explored the possibility of using stimulating music to shorten
recovery times from general anaesthesia. One possible reason is that stimulating music is
often jarring, which may produce a negative experience for the patient. It may perhaps have
been unclear what this music should be, or how it can in practice be delivered during
emergence from anaesthesia but not before that point (i.e., stimulating music would be
counterproductive during induction). Another reason may be due to practical limitations
around placing headphones on the unconscious patient and impacting their situational
awareness upon waking. These limitations are overcome in this study, first by having
developed a highly-arousing music that drives neural activity strongly, but which is not
jarring (i.e., does not have negative emotional valence) by imposing rapid amplitude
modulations on music, and secondly by administering this music via bone-conduction headphones
which are convenient to place and do not obscure the ear canal. These innovations in content
and delivery of music make it possible to test if music can ease a patient's induction and
emergence from general anaesthesia, which is a point of concern for both patients and
healthcare providers.
The main innovation of this study is to test stimulative music on recovery post-operatively,
but we include relaxing music pre-operatively for three reasons: 1) The patient has a reason
to apply the headphones themselves (in pre-op waiting), which stay on throughout their
procedure. This familiarity with the device might be beneficial for their experience during
emergence from anaesthesia. 2) To improve the perioperative experience with a unified music
program for the patient; since stimulating music would be counterproductive pre-operatively,
relaxing music is used instead. 3) There is some evidence that pre-operative music can reduce
the level of anaesthetic agent required during a procedure by reducing anxiety and lowering
arousal (LePage et al. 2001, IIkaya et al. 2014; with propofol: Koelsch et al. 2011). Such
effects could lead to a faster trajectory of recovery and better patient experience.
The use of relaxing music pre-operatively is thus expected to improve outcome measures, in
particular the patient experience more so than recovery times. In the case that the music
condition improves patient satisfaction, further studies will be required to explore the
contributions of the pre- or post-operative music. However, in the case of improved recovery
times, the stimulative music during emergence is more likely to be responsible, and would
constitute the first such use of music in a healthcare setting.
RESEARCH QUESTION
Can perioperative music improve the patient experience, and speed recovery from propofol
anaesthesia?
OBJECTIVES AND HYPOTHESES
PRIMARY OBJECTIVE AND HYPOTHESIS
Primary Objective:
The primary objective of this study is to explore whether perioperative music-developed to
aid induction and emergence from general anaesthesia-can speed recovery times, while
maintaining or increasing patient satisfaction with the experience of induction and
emergence.
Primary Hypothesis:
If rhythmic auditory stimulation (music developed to drive neural oscillations) improves
patient satisfaction with induction and emergence, and speeds recovery from propofol, then
these measures should be significantly improved compared to non-rhythmic auditory stimulation
(spectrally-matched noise) delivered in the same manner (i.e., through bone-conduction
headphones, presented as a recommended aid by a healthcare worker).
STUDY DESIGN
Blind study involving two hundred and twenty (220) participants undergoing elective upper
endoscopy or colonoscopy, placed in one of two arms at random. Both groups will receive audio
stimulation through bone conduction headphones, starting in the presurgical suite < 2 minutes
before application of IV, and ending in the PACU (recovery area) prior to discharge. One
group (the test group) will hear Brain.fm music (music designed to be maximally effective for
induction and emergence from propofol); the other group (the control group) will hear noise
that has been spectrally matched to the Brain.fm music (i.e., contains the same energy at the
same frequencies, but is not rhythmic). This control stimulus will be similar to pink noise,
which is often used as an auditory stimulus in experiments and is also used by the public to
relax and focus. Being spectrally matched to the test music, it will stimulate the cochlea to
the same extent and have similar effects in terms of masking (degree of overlap with other
sound in the environment).
Bone-conduction headphones will be wireless (bluetooth); audio will be transmitted from an
iPad mini attached to the patient's bed (hung from an IV hook; in the clinic only one hook is
used for an IV and several are unused); each patient has a given bed from presurgery to
recovery. The bone-conduction headphones weigh 26 grams and are low-profile, suitable for
lying down (AfterShokz 'Aeropex' model); the iPad mini device size is 5.3" x 7.7".
Staff are required to interact with patients and study equipment with regard to this study at
five timepoints:
Headphones applied, audio begins. In the presurgical waiting suite, after the patient has
changed into their gown, and just prior to (< 2 minutes) starting the IV. This timing is
intended so that the audio will be maximally novel and effective while the IV is being
started (a highly anxiety-inducing event for many patients). At this interaction point, the
patient is given the bone-conduction device, shown how to wear it, and told it will be on
throughout their procedure. They are told they may remove ask to have the device removed by
staff at any time if the device or sound is causing discomfort (if they do so, the audio is
stopped by staff upon removing the headphones; if this occurs in pre-op their data is
excluded from analysis). If they choose to leave it on, they will wake up with it on, and
upon waking should leave the device on until they are ready to leave the PACU (unless the
device or sound are causing discomfort). They are told that when they take off the device
they will be given a very short questionnaire.
Change of audio from sedative to stimulative. After the procedure, propofol is ceased and the
attending nurse or anaesthesiologist presses a button on the iPad to switch the audio from
sedative to stimulative. After this, the patient is wheeled into PACU.
When wakefulness is noted by staff in PACU, a button is pressed on the iPad. This may be
staff confirming wakefulness after an attempt to rouse a patient, or may be staff noticing
wakefulness in a patient who has been awake for some seconds or minutes already. As such this
measure will not capture the exact wake-up time, but this noise in the data should be
hypothesis-independent and non-biasing (i.e., staff will not be more frequently checking on
patients with one experimental condition over another; conditions are blinded from the
staff).
Headphones removed, audio stopped by staff. After return to consciousness the headphones
should stay on until participants are ready to leave the PACU, but the patient may ask to
remove them at any time When a patient's headphones are removed (either by request or prior
to discharge), the staff will stop the audio, and the three-question survey which appears on
the iPad (see Outcome Measures below) will be presented to patients at that point; they are
given the option to take it at that pointor any time until they leave the PACU. In the event
that a patient asks that their headphones are removed well in advance of leaving the PACU,
staff can follow the same procedure, and the data will show that the audio was stopped well
before the discharge/headphone-return time. If a patient removes their headphones
unsupervised (i.e., staff find a patient with headphones off and do not know how long they
have been off), then that patient will be excluded from the dataset.
At the time of discharge (i.e., when the patient leaves their bed), the headphones and iPad
are recovered, and a button is pressed on the iPad closing that patient's session. This time
is considered the patient's time of discharge.
Randomization between the control and test conditions is implemented by the experiment
program on the iPad, which draws a condition at random for each new participant and logs the
time of day at each interaction point (the start of audio, switch of audio, wakefulness,
headphone removal / playback end, survey completion, and return of equipment). The experiment
is double-blinded since the condition a given patient hears is unknown to staff or patient.
Since pre-appointment (recruitment) materials do not refer to music but only to auditory
stimulation, patients given the noise condition have no indication it is a control condition.
Volume levels are locked to a low, comfortable level, matched across conditions. The
bone-conduction device does not obstruct the ear; this in conjunction with a low volume level
will ensure patients retain situational awareness and can communicate easily with staff.
The headphones are wiped down with a sterilizing alcohol swab upon being returned to staff,
and are placed onto a charging base station. iPads are returned to a charging base station
accompanying the headphones. Headphones and iPads are uniquely paired by bluetooth, and so
each pair will be labeled (e.g., the headphone set labeled '3' must be used with the iPad
labeled '3').
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