What might an interactive music therapy service bring to the adult intensive care unit? A suggested service based on data from a scoping review

Individual music listening in intensive care units (ICU) has more frequently reported benefits for reducing anxiety and pain. There may be benefits in reducing heart rate and respiratory rate. There is a lack of research in the ICU setting that examines the effects of active music-based interventions, for example, where patients play instruments as part of structured exercises for cognitive or physical rehabilitation or improvise music with a Health and Care Professions Council (HCPC) registered Music Therapist in ways that may benefit emotional well-being in addition to physical and cognitive function, including management of deconditioning. The search string of the present scoping review was used on 25 January 2022 and then again for PubMed on 24 June 2023 and brought up any research using music or music therapy in the intensive care setting. Out of 139 titles, 45 full texts were included, with a total of 3,441 participants. Forty-three studies meeting the inclusion criteria used pre-recorded music, ranging from cassette to CDs, audio files, and MP3, most often delivered using headphones, some with audio pillows. All interventions were passive (listening) except for one, which delivered music played live. More research is needed into the workings of active and receptive music therapy in the adult ICU.


Introduction
Annually, more than 250,000 patients are admitted to the intensive care unit (ICU) in the United Kingdom alone (NHS Digital, 2023;NICE, 2022).While the age range of patients admitted to an adult ICU lies between 18 and 95 years (Zimmerman et al., 2013), reasons for admission can vary that is, elective surgery, emergency surgery and/or medical (Zimmerman et al., 2013).Patients suffering from critical illness or potentially recovering from life-threatening situations in the ICU are subject to different procedures, impacting length, intensity, and impact of the stay.Post Intensive Care Syndrome, general discomfort and other associated problems like delirium or depression are often related to an ICU stay, especially after discharge.
ICUs are described as hostile environments where patients are exposed to unfamiliar sounds and sensations while receiving life-saving care (NHS Digital, 2023).This can impact both the patient and next of kin during their stay.Reasons for this include the extreme medical environment, the uncertainty between life and death of the patient, and the visual and auditory stimuli impacting the patient.Senses connect us to the environment and are an important part of our interaction between the mind, body, and the world around us.The intensity of perception through the senses differs per-patient, however, and can have a significant impact on quality of stay, well-being, and recovery.The perception of sound and the associated auditory soundscapes created in the ICU through machines, procedures, and other patients have a significant impact on the way the patient is informed by the environment, judging whether it is safe, where they are safe, and how to react to stimuli (Truax, 1984).Unlike vision, auditory perception is permanent, since the patient cannot choose to close their ears as they can their eyes, therefore, being exposed to the complex soundscapes of the ICU (Luetz et al., 2019).Recent research indicates that changes in sound levels can have a more disruptive effect on patient well-being than continuous sound, in particular, differences between lower and higher noise pressure levels incorporating medical devices and alarms (Jaiswal et al., 2017).
Against this backdrop, the use of organized sound in the form of musical listening interventions has been associated with an increase in well-being and connectedness to the 'real' world outside of the ICU for both patients and next of kin (Almerud and Petersson, 2003;Chou and Vieira, 2020).A recent systematic review of RCTs and meta-analysis focused on the stress response of ICU patients and included 25 studies (Erbay Dalli et al., 2022).Music interventions were found to reduce anxiety levels concerning psychological stress.However, regarding physiological stress, it was found that music only had an effect on systolic blood pressure level (pressure in the arteries when the heart beats, i.e., the first number when measuring blood pressure) and no effect on diastolic blood pressure (pressure in the arteries when the heart rests between beats, i.e., the second number when measuring blood pressure), respiration rate, or heart rate.Multiple music sessions were reported to be more effective than a single session, and all but one delivered pre-recorded music for listening.
A Cochrane review that included 14 predominantly music-listening RCTs (805 participants) found the music intervention to have a positive effect on hemodynamics (how blood flows through the vessels), when compared to care as usual (Bradt and Dileo, 2014).Listening to music was found to consistently reduce respiratory rate and systolic blood pressure, suggesting a relaxation response.Furthermore, a reduced sedative and analgesic intake for patients was found in the music intervention group.The review concludes that music listening may have a beneficial effect on anxiety in mechanically ventilated patients.
Sufficient sleep as well as moments of calm are crucial for a good recovery (Luetz et al., 2019;Sayilan et al., 2020).As the ICU does not provide a calm and natural environment, sleep is often affected and associated with anxiety (Sayilan et al., 2020).Interventions aiming at alleviating sleep deprivation and anxiety often focus on pharmacological interventions, artificially sedating the patient in order to implement a sleep pattern (Hardin, 2009;Sayilan et al., 2020).While sleep can be induced, eliminating anxiety is a much tougher challenge (Hardin, 2009).Anxiety is seen as a key component of lack of sleep and the uncertainty of the patient's medical outcome (Hardin, 2009) -music therapy can be seen as a nonpharmacological alternative.
Music-based therapies and interventions can profoundly improve patients' anxiety and sleep quality.Receptive and interactive music therapy in the ICU, even though still lacking an evidence-based foundation in the ICU, has been promising in evoking empathy and resonance, strengthening positive emotions, relieving stress, psychological distorting, and tension, as well as evoking memories, physical and cognitive engagement (Browning et al., 2020;Erbay Dalli et al., 2022;Messika et al., 2019) across the life span.
Due to the nature of the ICU, an interactive music-based therapeutic intervention may prove difficult to implement, as patients are often immobile, non-responsive or sedated (Zimmerman et al., 2013), and so less able to access the instruments, respond with their playing to that of the therapist, and track musical interactions as coherent musical dialogue.Against this backdrop, receptive music therapy can be administered either live, by inviting Music Therapists to the ICU to play for the patients, or allowing Music Therapists to administer listening to music through headphones.Both methods must be patient-informed, as playing random music either through headphones or live can irritate or even aggravate the patient and associated pain and anxiety sensations (O'Callaghan, 1996).In cases where the patient is non-responsive, next of kin serve as a point of reference as to their preferred music.A recent systematic review and meta-analysis has shown that music interventions can have a reducing effect on anxiety and stress, as well as promote better sleep (Erbay Dalli et al., 2022).Their elegant study, however, even though defining music therapy, has not focused on music-based therapeutic interventions as provided by trained Music Therapists, and so does not help inform on what benefits there might be from their skill sets in the administration of music for ICU patients.
The aims of this scoping review are to identify any (interactive) music-based interventions that have been explored specifically in ICU settings, their intervention types, aims and outcomes, in order to inform clinical music therapy and research services at any hospital with an ICU.We aimed to identify how music-based interventions have been used in this setting, whether delivered by Music Therapists, and their potential benefits.

Search strategy
The review was undertaken by two researchers (AS and ACJ).Searches were conducted, duplicates were removed, and the remaining papers were imported into Rayyan (an artificial intelligence [AI]-powered tool for systematic reviews).Initial screening of titles and abstracts was conducted, and any conflicts were resolved between the two reviewers -as was the case for the full-text reviews (See Figure 1

Inclusion and exclusion criteria
Title and abstract screening excluded protocols, paediatric populations, literature reviews, thesis, foreign language and papers unavailable through our specified databases, inter-library loans, and ResearchGate.

Inclusion and data extraction
Out of 139 titles, 45 full texts were included (Table 1), with a total of 3,441 participants.One feasibility study was included, as it reported treatment-related effects on delirium (Johnson et al., 2018).The following data were extracted from the included articles: study design, aims and sample size, setting and country, whether delivery of music intervention by a Music Therapist was reported, intervention type, equipment, frequency and duration, outcome measures, and findings.

Delirium
Prevention or reduction in delirium was reported in two studies (Browning et al., 2020;Johnson et al., 2018).

Deconditioning and muscle strength
One study comparing exercise performance with and without music found significant improvements in the music group in upper and lower limb muscle groups, including grip strength (Liang et al., 2022).A Music Therapist was consulted on the music selection but did not deliver the intervention.

Delivery of music
All data synthesis including listening duration, equipment and Music Therapist involvement can be seen in Table 2 (Appendices).Some of the included literature reported input from a Music Therapist in delivering live music for guided imagery or accompanied song, describing how the therapist was able to match tempo, volume and intensity to the patients' heart and respiratory rate (Golino et al., 2019).There was input from Music Therapists reported on design aspects of interventions, such as music selection (Gullick and Kwan, 2015;Liang et al., 2022;Mateu-Capell et al., 2019), composition (Messika et al., 2019), or study design, but little on intervention delivery (Golino et al., 2019;Hansen et al., 2018).
Duration of delivery was not always clearly reported, but when stated ranged from 10 min of live harp music (Chiasson et al., 2013) to 60 min music listening broken into 20 min before, during and after suctioning (Mateu-Capell et al., 2019) and twice daily with an average listening time of 79.8 min (Gullick and Kwan, 2015).Many studies delivered single sessions, and several spanned a number of days, including 7 consecutive days for head trauma (Yekefallah et al., 2021) and 6 consecutive days with traumatic brain injury (Froutan et al., 2020), 5.7 days for stress reduction (Gullick and Kwan, 2015) and twice daily for 3 days (Beaulieu-Boire et al., 2013).
Listening equipment ranged from cassettes played through headphones (Barnason et al., 1995;Updike, 1990) to MP3 players and audio pillows (Mateu-Capell et al., 2019).Not all papers stated the device or whether headphones or a speaker were used.other disciplines such as occupational therapy could not access such interventions, provided they had adequate support and/or training from a Music Therapist -this is another area of research to explore.It has been reported that music-based interventions delivered to brain injury survivors in neurorehabilitation by a Music Therapist may bring added benefits in some areas (Magee et al., 2017), and that their skills bring added value to multidisciplinary teams with that patient population (Magee, 2019).One study included in this review stated the importance of having a Music Therapist in ICU but did not describe their input in their study (Miller et al., 2021).
Potential for active music therapy for rehabilitation and/or reducing deconditioning.Rehabilitation on ICU using active musicbased interventions could be explored for helping to prevent and treat deconditioning, including muscle tone and strength and respiratory weakness (Gosselink et al., 2012).Some stroke rehabilitation research has reported equal benefits in sensory-motor recovery compared to usual care, in addition to less fatigue and enhanced mood and cognitive function that are not found in usual care (Grau-Sánchez et al., 2018).Such interventions have been delivered as part of usual care in the acute and subacute setting, where feasibility and acceptability were well rated, and there was possibly an improvement in patient mood (Street et al., 2020;Thompson et al., 2022).Based on this, a reasonable hypothesis might be to try some music-based exercises with ICU patients to help manage deconditioning and combine the benefits of passive (music listening) and active approaches to also help manage stress and anxiety.
Music listening as part of usual care: feasibility and implementation research.As can be seen from the scoping review and other literature reviews, music interventions have not been explored on ICUs in the United Kingdom, so it is not known how they would fit into their health systems, or what effect they might have on health service delivery and patient outcomes, including length of stay.However, the literature and related research provide enough detail to inform on the setting up of a service delivering patient-preferred music, targeting a number of factors experienced by patients on ICU, including anxiety and pain.
In the form of feasibility and implementation research, or service evaluation and audit, a Music Therapist could deliver music-listening interventions but also train research nurses or other nursing staff to compile and deliver patient-preferred music playlists.They could collect data on patient experience, undertake co-design work with patients, their relatives and staff to develop delivery methods in a range of ICU settings and measure effects on pain and anxiety, delirium and sleep, using standardized measures, which could be done as part of usual care depending on availability of research nurses.
Bio-data-driven music listening for arousal adjustment.Systems have been developed to deliver pre-recorded music in medical settings that are driven by bio-data such as heart rate (Sice et al., 2020).Music is selected by these systems that have been processed using algorithms and mapped onto an arousal valance.Arousal can then be adjusted or maintained based on a live heart rate stream from the user, feeding the system, starting with music that is matched to the user's existing heart rate.X-system delivers music in this way and could be costed for research purposes.

Conclusion
Some music-listening research has been reported in ICU settings, but little on guided and active music-based therapeutic interventions administered by a Music Therapist.This makes it somewhat problematic to fully establish, based on this review, what a service implemented by Music Therapists using active interventions would look like.Some of the singlesession studies included in this review indicate that there are benefits from this potentially cost-effective passive listening approach, but more needs to be revealed about the benefits from this and active music therapy interventions for patients in short-and longer-term ICU stays.While we believe -and some evidence in this review suggests -that receptive music listening is better than no music intervention at all, it may be of importance for a Music Therapist to be part of the ICU and hospital environment.Their expertise and training may compliment medical professionals in providing the best care for the patient and in turn improving well-being, recovery, and patient experience.

Figure 1 .
Figure 1.Flow diagram for the review.

Table 2 .
All included full texts.
placed in the ceiling above the participants' beds and is a newly developed method where the sound is centred around the patient (Soundfocus.dk).The music, MusiCure, was especially composed and developed for critically ill patients in ICU by Niels Eje (Musi-Cure.com).The intervention consisted of four pieces of soothing music, in terms of soft wind, bird twitter, ocean sound and music instruments.

Table 2 .
(Continued) Western classical music (e.g.Erik Satie's Trios Gymnopedies, Mozart's Piano Concerto no.26), Chinese classical music (e.g.bamboo flute, rain, and tears), music of natural sounds, Relax Your Mood, or religious music (Buddhist or Christian).All 60-80 beats per min.Control group participants had a 30 min rest between 4:00 and 4:30 pm while wearing headphones, while patients in the intervention group were listening to music Three types of music were used, including Chinese classical music (e.g.bamboo flute), religious music (e.g.Buddha Bar IV-Tibet), and Western classical music (e.g.