The Effect of Music Intervention on Analgesia During Bed Baths in the Immediate Postoperative Period of Cardiac Surgery: A Randomized Clinical Trial

Abstract

Background

Pain is a significant complication following cardiac surgery. While pharmacological treatments are standard, non-pharmacological interventions like music offer a promising, low-cost adjunct for pain management.

Objective

To evaluate the effect of a music intervention on pain and vital signs during the first postoperative bed bath for patients recovering from cardiac surgery.

Methods

This study was a single-blind, randomized controlled trial involving 38 patients who had undergone Coronary Artery Bypass Grafting (CABG). Patients were allocated to either an experimental group (n = 19), which listened to self-selected music via headphones, or a control group (n = 19), which wore headphones with no audio. The primary outcome, pain, was measured using the Numerical Rating Scale (NRS) and the Wong-Baker FACES Scale (WBS) during and after the bed bath.

Results

The music intervention group demonstrated a statistically significant reduction in pain scores both during and after the bath. Compared to the control group, the experimental group’s pain scores decreased by a mean of 2.41 points on the NRS (P < 0.001) and 2.11 points on the WBS (P < 0.001). Furthermore, a significant reduction in heart rate (P = 0.019) was observed in the experimental group.

Conclusion

Music intervention effectively reduced pain and stabilized heart rate during a potentially painful routine procedure in the immediate postoperative period of cardiac surgery.

Keywords

thoracic surgery pain pain management music medicine pain measurement nursing care

Introduction

Cardiovascular diseases (CVDs) accounted for approximately 32% of all global deaths in 2019.¹ Coronary Artery Disease (CAD) is the most prevalent type of CVD in Brazil and is associated with reduced blood flow in conditions such as angina and Acute Myocardial Infarction (AMI).² Imaging examinations, including Coronary Computed Tomography Angiography (CCTA), are crucial for diagnosing CAD. Treatment for CAD is typically based on a three-pronged approach: clinical intervention, percutaneous coronary intervention (PCI), and coronary artery bypass grafting (CABG) surgery. The primary goals of therapy are to improve patient survival and alleviate clinical symptoms.^3-5

CABG surgery is an invasive procedure that requires intensive care during the immediate postoperative period (IPO) to prevent complications and manage pain effectively.⁶ Postoperative surgical pain, resulting from intraoperative tissue damage, varies in intensity depending on the surgical site and extent, the patient’s preoperative anxiety, and the perioperative analgesic management. This pain is often more severe in open thoracic surgeries, procedures requiring cardiopulmonary bypass, and in female, younger, or obese patients.⁷ It is typically most intense within the first 24 hours after surgery.⁸ The management of pain following thoracic surgeries has unique challenges, making a multidisciplinary approach essential.⁹ In this context, one of the responsibilities of the nursing staff is to perform the first bed bath for patients in the IPO of CABG surgery. While this is a fundamental aspect of patient care, it can also be a significant factor in increasing pain and causing hemodynamic instability.¹⁰

Effective management of postoperative pain is critical, as inadequate control can lead to chronic pain, immunosuppression, infections, and delayed surgical wound healing.⁷ Proper pain management can help mitigate the stress response, facilitate early mobilization, and enhance the patient’s quality of life.⁸ It is important to note that pain can be treated using both pharmacological and non-pharmacological methods. The latter are frequently employed due to their lower cost, minimal adverse effects, and significant potential for pain reduction.¹¹

In many instances, patients continue to experience moderate to severe postoperative pain, which is linked to an increased risk of delayed hospital discharge, postoperative complications, the development of persistent chronic pain, and a negative impact on their quality of life in the immediate postsurgical period. Opioids are the primary therapeutic option for managing acute postoperative pain and represent the second most common reason for prescribing these medications. However, opioid use is often associated with adverse effects, including itching, nausea, vomiting, drowsiness, urinary retention, and, in some cases, delirium.¹²

Consequently, there is a growing interest in the development and implementation of non-pharmacological interventions aimed at minimizing postoperative pain and reducing the reliance on opioids.^12-14 Music has significant potential as an effective therapeutic and clinical tool, offering an accessible and low-cost alternative, particularly in a society marked by a heavy dependence on medication, as it has no side effects.^14-16

Studies have demonstrated the effectiveness of using music as a non-pharmacological nursing intervention for relieving postoperative pain, reducing anxiety, and promoting a greater sense of tranquility.^16-18 The literature also supports the use of music as an adjuvant therapy for pain control, highlighting its positive effects on relaxation, pain and anxiety reduction, and stress mitigation in cardiac surgery patients. The influence of music on the central nervous system creates a distraction effect, which is reflected in the feeling of relaxation experienced by patients as they focus on the musical tones rather than the sensation of pain or their surrounding environment.^18,19

Furthermore, music can be applied therapeutically and in a targeted manner by certified music therapists. These professionals utilize specific protocols, as demonstrated in a randomized clinical trial involving 31 patients in Intensive Care Units undergoing burn dressing changes. This study evaluated the effectiveness of two music therapy protocols—music-based imagery and alternative engagement with music—in alleviating pain, anxiety, and muscle tension. The results showed significant reductions in pain levels before, during, and after the dressing changes (P < 0.05), as well as a significant decrease in anxiety and muscle tension during the painful procedure (P < 0.05).¹⁹

The postoperative period for cardiac surgery can induce physical and psychological symptoms that negatively affect a patient’s quality of life. Therefore, nurses must stay informed about the development of strategies to help patients cope with stress and fear, with the goal of reducing or preventing these issues, which directly or indirectly promotes better health and quality of life after surgery.²⁰

This study is justified by its potential to provide data supporting the use of music to alleviate pain in patients in the IPO of CABG surgery. The null hypothesis of this study is that the use of music during the bed bath will have no effect on reducing pain in patients in the IPO of CABG surgery. The alternative hypothesis is that the use of music will have a positive effect on reducing pain in this same population.

Therefore, the present study aims to evaluate the effect of a music intervention on pain and changes in vital signs in patients undergoing a bed bath in the immediate postoperative period of cardiac surgery.

Based on the foregoing, the research question is: What is the effect of using music on pain relief in post-cardiac surgery patients during their bed bath?

Method

Study Design and Location

This is a randomized, controlled, masked clinical trial conducted in the Cardiac Intensive Care Unit (ICU) of a private hospital in Natal, Rio Grande do Norte (RN), Brazil. The study adhered to the standards recommended by the Consolidated Standards of Reporting Trials (CONSORT).²¹

Participants

The study sample consisted of patients in the IPO of CABG surgery who were hospitalized in the cardiology ICU of the study site and scheduled for their first post-surgical bed bath. Inclusion criteria were: patients aged 18 years or older who had undergone CABG, were scheduled for a bed bath within the first 24 postoperative hours, and who either enjoyed listening to music or did not associate it with negative experiences. A score of 14 or 15 on the Glasgow Coma Scale (GCS) was also required for inclusion.

Exclusion criteria included patients with self-reported decreased auditory acuity, those who did not follow the institutional bed bath protocol, those with hemodynamic instability, or those whose analgesic prescriptions did not comply with the institutional protocol for the CABG postoperative period. Patients with a history of other associated heart surgeries or who had previously undergone heart surgery were also excluded. Participant attrition was recorded by the researchers during data collection, and these cases were excluded from the final results.

The study employed a probabilistic, simple random sampling method. The sample size was calculated using the G*Power software (version 3.1.9.2), based on the study by Liu and Petrini (2015). The calculation considered a Cohen’s effect size of 0.80, a test power of 0.80, and a significance level of 5% (P-value <0.05). The sample was initially composed of 42 patients divided into a Control Group (CG) and an Experimental Group (EG). However, four patients withdrew from the study, resulting in a final sample of 38 participants. The main researcher randomized the patients using the website https://www.randomization.com.

Data Collection Instruments

The data collection instrument was developed by the main researcher but was not previously validated. It was organized into four parts: (1) Part one: Collected patient identification, sociodemographic and clinical data, musical preferences, and surgical and post-surgical information; (2) Part two: Recorded vital signs and pain level assessments before the bed bath; (3) Part three: Assessed the pain level after the changing of sheets and dressings; and (4) Part four: Recorded vital signs and pain level assessments 10 minutes after the bed bath.

The pain level was assessed using the Numerical Rating Scale (NRS)²² and the Wong-Baker FACES Scale (WBS).²³ The WBS was included because the researcher also observed pain intensity during the intervention at the time of the bed bath, and a patient’s facial expression of pain might diverge from their self-reported pain intensity. Vital signs were recorded by observing the multiparameter monitor.

Intervention

Participants in the control group received a bed bath while wearing headphones without any music. Participants in the experimental group received a bed bath while listening to music of their choice through headphones. The sound intensity was chosen by the participants in the EG to ensure comfort, ranging from 40 to 60 decibels (dB). The headphones were sanitized with 70% alcohol before and after each use, and disposable protectors were used over the padded region to avoid direct contact with the ear. The institution has a standard bed bath protocol, which all professionals followed using standardized techniques.

The headphones used were the JBL TUNE500BT model, which the manufacturer describes as lightweight (155 g), padded, over-ear, wireless, without noise cancellation, and with a 16-hour battery life and Bluetooth connectivity. The headphones were connected to the researchers’ smartphones, and music was played through a paid subscription to a music app (Spotify). Music selection was performed as follows: after a participant indicated their preferred musical genre to the first researcher (R1), a search was conducted in the app, which provided a playlist characterizing that style. The same playlist for a chosen genre was used consistently, and the same pair of headphones was used for all participants.

To reduce bias and ensure masking, the researchers were organized as follows: the main researcher (R1) was responsible for participant allocation, randomization, instructing the participant about the procedure, and applying the headphones. The second researcher (R2) administered the data collection instrument at three time points: before, during, and 10 minutes after the completion of the bed bath. At these three points, R2 assessed the individual’s pain intensity using the scales mentioned before and recorded vital signs from the multiparametric monitor. This evaluator (R2) was masked, as they were unaware of the group to which the patient had been assigned. It is also noteworthy that the patients and the professionals performing the bed bath were unaware of the patient’s group assignment.

Data Collection Procedures

Data collection was carried out by two master’s students from the Postgraduate Program in Nursing at the Federal University of Rio Grande do Norte (PGENF/UFRN). The researchers conducted three meetings, totaling 20 hours, at the data collection site to standardize the collection stages and calibrate the investigation of the phenomenon.

In the first meeting, the data collection protocol was reviewed, and the data collection instrument was calibrated to clarify any potential doubts during its completion. The patient entry flowchart for those with indications for CABG surgery was also reviewed. In the second meeting, procedures for using, sanitizing, and storing the headphones were discussed. Finally, the institution’s protocols were demonstrated in the teaching sector where the research was conducted, and the completion and simulation of data collection were practiced.

Data collection occurred from February to December 2021 and was organized into two phases. In Phase 1, the main researcher (R1) approached potential participants, explained the purpose of the study, and detailed the benefits and risks of participation. Participants were then asked to read and sign the Informed Consent Form (ICF).

In Phase 2, before the bed bath began, the second researcher (R2) administered the first and second parts of the data collection instrument. At this stage, the initial assessment of pain intensity and the first recording of vital signs were performed. After the bed bath started, specifically after head hygiene was completed, R1 gave the headphones to the participants and began the musical intervention for the EG participants only, playing the music chosen by the individual. After the sheets and dressings were changed, the third stage was completed: assessment of pain during the bed bath and the second recording of vital signs. Ten minutes after the conclusion of the bed bath, the fourth and final stage was recorded: assessment of pain and the last recording of vital signs.

The intervention was administered once, during the first postoperative bed bath, for approximately 30 minutes. It began after the head was cleaned and concluded 10 minutes after the bed bath was finished.

Statistical Analysis

A descriptive analysis was performed using absolute and relative frequency distributions, as well as measures of central tendency and dispersion. The Student’s t-test and Analysis of Variance (ANOVA) were used to compare the CG and the EG regarding the clinical variables studied. ANOVA and Chi-squared (X²) tests were applied when comparing the classification of isolated clinical variables for the EG and CG, with Fisher’s exact test used when necessary. A significance level of 5% was adopted. The effect size for ANOVA was considered small when less than 0.30, medium when between 0.30 and 0.49, and large when above 0.50.

Ethical Aspects

The study was approved on February 4, 2021, by the Research Ethics Committee of the Federal University of Rio Grande do Norte, Brazil, under opinion number 4.523.917. The study protocol was registered with the Brazilian Clinical Trials Registry (ReBEC), with the approval registration number RBR-69w6f5z. This study complies with the Declaration of Helsinki of 1964 and Resolution 466/12 of the National Health Council. The participation of individuals was guaranteed through the signing of the ICF.

Results

Figure 1 depicts the flow diagram of the research steps adapted from the CONSORT 2010 guidelines.

Figure 1.

Diagram With Research Steps Adapted From CONSORT (2010)

The sample consisted of 38 patients who were randomly allocated as follows: 21 to the control group and 17 to the experimental group. There were no statistically significant differences between the groups with regard to sociodemographic, clinical, and surgical data, as shown in Table 1.

Table 1.

Baseline: Sociodemographic, Clinical and Surgical Characterization of the Research Participants. Natal, RN/Brazil, 2022

Characterization	Group		P-value
	Control	Experimental
	n (%)	n (%)
Gender
Male	17 (80.95)	14 (82.35)	1.000
Female	4 (19.05)	3 (17.65)
Age range
Up to 64 years	12 (57.14)	11 (64.71)	0.635
Over 64 years	9 (42.86)	6 (35.29)
Civil status
Married/Stable union	14 (66.67)	11 (64.71)	0.932
Divored	4 (19.05)	4 (23.53)
Single	3 (14.29)	2 (11.76)
Education level
No formal education	2 (9.52)	2 (11.76)	0.823
Elementary	10 (47.62)	7(41.18)
High school	4 (19.05)	6 (35.29)
Graduated higher education	5 (23.81)	2 (11.76)
Diabetes
Yes	10 (47.62)	5 (29.41)	0.254
No	11 (52.38)	12 (70.59)
Hypertension
Yes	10 (47.62)	10 (58.82)	0.492
No	11 (52.38)	7 (41.18)
Transoperative complications
Yes	1 (4.76)	---	1.000
No	20 (95.24)	17 (100)
Use of cardiopulmonary bypass
Yes	---	3 (17.65)	0.081
No	21 (100)	14 (82.35)
Vasoactive drug use
Yes	19 (90.48)	13 (76.47)	0.378
No	2 (9.52)	4 (23.53)
Total	21 (100)	17 (100)

The musical preferences of the participants were predominantly religious music and Brazilian popular music (MPB), with 7 participants (18.42%) choosing each. Following this, 5 participants (13.16%) preferred romantic music, 4 (10.53%) chose brega, 3 (7.89%) chose classical, 3 (7.89%) were eclectic, and 2 (5.26%) chose forró. Only one participant each (2.63%) chose sertanejo, pop, rock, or pagode. Three participants (7.89%) chose other musical styles.

The average sound intensity chosen by participants in the experimental group for comfort was 50 decibels (dB), with a minimum of 40 dB and a maximum of 60 dB. There was no statistical difference (P = 0.730) when comparing the variation in sound level, and the Shapiro-Wilk test confirmed the normality of the data when comparing the EG and CG.

Table 2 shows the minimum, maximum, mean, standard deviation, and P-values from the Student’s t-test for clinical variables, comparing the groups at three time points: before, during, and after the bed bath. A significance level of 5% was used.

Table 2.

Clinical Variables of the Control and Experimental Groups and the Times Studied, Natal/RN, Brazil, 2022

Variables	Group	Min	Max	Mean	Effect	SD^a	P-value
Before
HR^b	Control	77.00	113.00	93	-	10.22	0.928
HR^b	Experimental	69.00	110.00	93	-	11.98	0.928
RR^c	Control	12.00	31.00	19	-	5.28	0.560
RR^c	Experimental	14.00	28.00	20	-	4.04	0.560
SPO₂^d	Control	89.00	98.00	95	-	2.64	0.621
SPO₂^d	Experimental	90.00	100.00	95	-	2.62	0.621
Temperature	Control	34.00	37.30	35.9	-	0.94	0.477
Temperature	Experimental	31.70	37.30	35.6	-	1.31	0.477
Numerical rating scale	Control	0.00	8.00	3.71	-	2.70	0.660
Numerical rating scale	Experimental	0.00	10.00	3.29	-	3.14	0.660
Wong-baker FACES scale	Control	0.00	6.00	3.05	-	1.63	0.696
Wong-baker FACES scale	Experimental	0.00	6.00	2.82	-	1.88	0.696
During
HR^b	Control	66.00	111.00	91	0.11	12.14	0.732
HR^b	Experimental	70.00	109.00	90	0.11	13.25	0.732
RR^c	Control	11.00	29.00	18	0.48	4.51	0.160
RR^c	Experimental	13.00	25.00	19	0.48	3.39	0.160
SPO₂^d	Control	85.00	99.00	94	0.16	3.16	0.629
SPO₂^d	Experimental	89.00	99.00	94	0.16	2.56	0.629
Temperature	Control	33.40	36.90	35.6	0.44	0.90	0.200
Temperature	Experimental	34.40	37.20	35.3	0.44	0.64	0.200
Numerical rating scale	Control	0.00	8.00	3.05	0.75	2.52	0.030
Numerical rating scale	Experimental	0.00	6.00	1.35	0.75	2.00	0.030
Wong-baker FAAfterCES scale	Control	0.00	8.00	3.52	1.17	1.89	0.001
Wong-baker FAAfterCES scale	Experimental	0.00	4.00	1.53	1.17	1.50	0.001
After
HR^b	Control	70.00	115.00	91	0.16	11.25	0.614
HR^b	Experimental	69.00	108.00	89	0.16	12.79	0.614
RR^c	Control	11.00	28.00	18	0.27	3.82	0.413
RR^c	Experimental	12.00	29.00	19	0.27	4.29	0.413
SPO₂^d	Control	86.00	98.00	94	0.15	3.03	0.651
SPO₂^d	Experimental	90.00	99.00	94	0.15	2.63	0.651
Temperature	Controle	35.00	37.00	36.0	0.25	0.77	0.443
Temperature	Experimental	34.50	37.20	35.8	0.25	0.83	0.443
Numerical rating scale	Control	0.00	8.00	2.52	0.82	2.46	0.015
Numerical rating scale	Experimental	0.00	5.00	0.88	0.82	1.41	0.015
Wong-baker FACES scale	Control	0.00	6.00	2.67	1.13	2.13	0.001
Wong-baker FACES scale	Experimental	0.00	4.00	0.71	1.13	1.21	0.001

^aSD: standard deviation

^bHR: heart rate

^cRR: respiratory rate

^dSpO2: oxygen saturation.

A statistically significant difference (P < 0.05) was identified when comparing the Numerical Rating Scale and the Wong-Baker FACES Scale between the CG and EG during and after the bed bath. The group that listened to music reported the lowest pain scores on both scales. This finding is supported by the large effect sizes observed for both pain scales during and after the bed bath. This result indicates that music was effective in reducing the pain of patients in the IPO of CABG surgery while undergoing a bed bath.

No significant differences were observed between the groups for HR, RR, temperature, and SpO₂ at any time point during the bed bath, suggesting music had no effect on these physiological parameters in this context.

However, when comparing clinical variables within each group over time, some statistically significant differences emerged, as shown in Table 3.

Table 3.

Comparison of Clinical Variables Within the Control and Experimental Groups, Natal/RN, Brazil, 2022

Variable	Moment	Control group		Experimental group
Variable	Moment	Mean (SD*)	P-value	Mean (SD*)	P-value
HR^a	T₀^b	92.86 (10.22)	0.485	92.53 (11.98)	0.019
	T ₁ ^c	90.95 (12.14)		89.53 (13.25)
	T ₂ ^d	90.81 (11.25)		88.82 (12.79)
RR^e	T₀^b	19.14 (5.28)	0.290	20.06 (4.04)	0.733
	T₁^c	17.57 (4.51)		19.47 (3.39)
	T₂^d	18.14 (3.82)		19.24 (4.29)
SPO₂^f	T₀^b	94.57 (2.64)	0.121	95.00 (2.62)	0.256
	T₁^c	93.71 (3.16)		94.18 (2.56)
	T₂^d	93.81 (3.03)		94.24 (2.63)
Temperature	T₀^b	35.91 (0.94)	0.050	35.65 (1.31)	0.137
	T₁^c	35.65 (0.90)		35.31 (0.64)
	T₂^d	36.08 (0.77)		35.88 (0.83)
Numerical rating scale	T₀^b	3.71 (2.70)	0.062	3.29 (3.14)	0.001
	T₁^c	3.05 (2.52)		1.35 (2.00)
	T₂^d	2.52 (2.46)		0.88 (1.41)
Wong-baker FACES scale	T₀^b	3.05 (1.63)	0.158	2.82 (1.88)	<0.001
	T₁^c	3.52 (1.89)		1.53 (1.50)
	T₂^d	2.67 (2.13)		0.71 (1.21)

*SD: standard deviation.

^aHR: heart rate.

^bT_0: Time before bed bath.

^cT₁: Time during the bed bath.

^dT₂: Time 10 min after bed bath.

^eRR: respiratory rate.

^fSpO₂: oxygen saturation.

Means followed by the same letter do not differ statistically from each other. The Bonferroni Test was applied at the significance level of 5%.

In the experimental group, statistically significant changes were observed for several variables. The heart rate (HR) showed a significant reduction (P = 0.019), with the mean decreasing from 92.53 bpm before the bed bath to 88.82 bpm 10 minutes after the procedure. This suggests that the music intervention contributed to a reduction in HR. The statistical difference was even more pronounced for the pain scales over time within the experimental group (P < 0.001).

All patients (100%) were on a standardized analgesia protocol for the IPO of CABG, which included dipyrone 1 gram (g) every 4 hours, with morphine sulfate available as needed. Dipyrone was substituted with paracetamol for patients with an allergy. In this context, only one patient (2.63%) in the experimental group used paracetamol due to a dipyrone allergy. Another patient (2.63%) in the control group required an additional dose of morphine sulfate before the bed bath. The other 37 participants (97.37%) followed the standard analgesia protocol, using 1g of dipyrone every 4 hours without needing additional morphine.

Discussion

The demographic profile of the participants in this study, characterized by a predominance of older, male patients, is consistent with findings from other studies on cardiac surgery conducted in the South and Northeast of Brazil, as well as in the United States and the United Kingdom.^24,25

Older age is a known risk factor for an increased incidence of coronary artery disease and heart failure. In this context, surgical revascularization is often offered as a strategy to prevent coronary events and improve patient survival. Therefore, surgical indications should not be dismissed for elderly patients, despite the inherent risks associated with age-related fragility and the postoperative period. Research indicates a reduction in mortality among the elderly when an ideal surgical technique is selected, which can decrease surgical time, minimize blood loss, and reduce interleukin induction. Consequently, the decision to proceed with surgery must be based on a thorough evaluation by the multidisciplinary team and respect for the patient’s autonomy.^26,27

The average sound intensity chosen by participants in this study was 50 dB. This differs slightly from other studies, such as an analysis in Spain where the average ranged from 60 to 80 dB,²⁸ and another clinical trial that set a standard sound level of 65 dB for all participants.²⁹ While some investigations suggest that patient-selected volume enhances comfort, it is important to note that many studies do not report details about the volume or type of music used.^29-31

In the present study, the most frequently chosen musical styles were Catholic and Protestant religious music and Brazilian Popular Music (MPB). In contrast, a randomized clinical trial in Spain found that participants preferred pop-rock.²⁸ Although music with a slower tempo (lower frequency) has demonstrated significant therapeutic potential in minimizing pain, allowing patients to choose their preferred music is crucial for respecting their cultural background and personal preferences, thereby providing a more comfortable experience.^28,32,33

Numerous studies have described the capacity of music to relieve postoperative pain and anxiety. This effect is thought to occur through several mechanisms, including distraction, activation of the brain’s reward system, promotion of positive affect, and relaxation. The musical pieces can be chosen by either the participant or the researcher, and there is currently no consensus on the specific musical attributes that best promote analgesia. When chosen by the participant, the music is often described as pleasant, relaxing, familiar, or slow-paced. When selected by the researcher, it is typically classified as classical, baroque, sedative, or relaxing music.^34,35

Consistent with our results, a systematic review and meta-analysis of 14 randomized clinical trials found that participant-chosen music had a significantly greater analgesic effect on chronic pain than researcher-selected music. Similarly, our trial allowed participants to select their own music. The convergence of these findings reinforces the hypothesis that personalizing the musical intervention according to the patient’s preferences is a promising and effective strategy.³⁶

An individual’s musical preference is an affective response to an auditory stimulus. In modern research, it is often measured through preferred musical attributes, which are frequently categorized into three dimensions: excitement (the perceived energy of the music), valence (the positive or negative emotions elicited), and depth (the intellectual and emotional complexity).³⁴

Further evidence reinforces the clinical importance of using a patient’s preferred music in the perioperative context. A randomized clinical trial in Türkiye with 117 participants demonstrated that patients who listened to their favorite music for 15 minutes before surgery had significantly lower postoperative anxiety levels, improved hemodynamic parameters, and greater overall satisfaction. Although that study found no significant differences in pain scores, it highlighted the role of musical and cultural preferences in managing patients’ emotional responses, which aligns with the therapeutic potential demonstrated in our study.³⁷

The styles most preferred by the experimental group in our study were generally slow, a characteristic considered important for therapeutic effects. This complements the necessity of respecting the patient’s choice. However, gaps remain in the literature regarding which specific styles are most effective.^32,38,39 A randomized clinical trial in the Netherlands with 548 participants evaluated the efficacy of five genres (electronic, rock, classical, urban, and pop) on pain tolerance. They found significantly positive results when individual musical preference was considered, independent of the genre itself.⁴⁰

A meta-analysis evaluating the effect of music on patients undergoing cardiac surgery reported an average pain reduction of 1.26 points, which was considered a significant finding. The results of our analysis complement and strengthen this evidence, confirming that music can reduce pain in patients during the postoperative period of cardiac surgery.⁴¹

The pain levels reported in our study before the intervention (mean NRS scores of 3.71 for the CG and 3.29 for the EG) are similar to the analgesic administration thresholds reported in other studies.^29,42 For example, a clinical trial in Germany identified a pain score of 3 as a trigger for analgesia, while a study in Turkey used a score of 5.²⁹ This highlights the need for nursing teams to implement robust pain management protocols that include adjuvant therapies like music. In our study, music proved to be a simple, cost-effective, and safe method for reducing pain during nursing care, as evidenced by the lower pain scores in the EG after the bed bath.

A key limitation of this study is that we did not measure the use and dosage of analgesics between the groups after the musical intervention was applied. This restricts our understanding of the medium- and long-term analgesic effects of music and its potential to reduce the frequency or dosage of pain medication.

Pain is a common postoperative symptom that can become persistent if analgesic measures are insufficient. While symptom reduction occurred in both groups after the bed bath, the experimental group clearly benefited more from the musical intervention.⁴³ This aligns with a comprehensive meta-analysis demonstrating that music interventions significantly reduce pain, associated emotional distress, opioid use, and physiological parameters like heart rate and blood pressure. These effects are observed across various clinical settings and age groups, suggesting that music’s analgesic properties may operate through multiple mechanisms, including distraction from nociceptive stimuli, emotional regulation, and modulation of the autonomic nervous system. Music appears to activate descending inhibitory pain pathways, contributing to reduced pain perception and greater patient comfort.⁴⁴

Our finding of a significant reduction in heart rate in the group that received the music intervention is consistent with a study in China involving patients undergoing thoracic surgery.⁴⁵ In contrast, an RCT in Egypt reported a significant reduction in pain (P = 0.043) but only a borderline reduction in HR (P = 0.063) after a musical intervention.⁴⁶ It is theorized that the rhythm of music can synchronize with bodily rhythms, decreasing sympathetic activity and increasing vagal tone, which in turn lowers the heart rate.⁴⁷

Similar effects have been described with environmental music therapy (AMT) in surgical and pediatric ICUs. In these settings, music therapists use live music, including improvisations and patient-preferred songs, in 30-minute sessions. The results showed significant reductions in patients’ pain perception and a positive impact on sleep quality and their perception of the hospital environment. These findings highlight the potential of music therapy as a complementary intervention in ICUs to promote comfort and reduce stress.⁴⁸

Given the results of this study, we recommend that future research explore different aspects of musical intervention as an analgesic resource in the postoperative period of cardiac surgery. Future studies could investigate variables such as the ideal duration of the intervention and the influence of different music genres. Furthermore, it would be relevant to evaluate the effects of musical interventions in specific subgroups, such as different age groups or patients with comorbidities. Finally, multicenter studies with larger samples and long-term follow-up are needed to generalize these results and support the inclusion of patient-preferred recorded music as a standard complementary practice in pain management protocols for the immediate postoperative period.

Clinical Implications

The findings of this study can contribute to both clinical research and professional practice. They provide a basis for nurses to develop and implement pain management protocols that include music as a non-pharmacological intervention. Furthermore, these results should encourage new studies that replicate this intervention in different nursing practices, with diverse patient populations, and at various time points during the surgical recovery process. It is recommended that future research investigate the combined effect of music with other complementary therapies and analgesics. Additionally, future studies should explore the impact of music on more specific cardiological parameters, assess the degree of patient satisfaction following the intervention, and evaluate the nursing team’s perceptions of using this therapy.

Limitations

This study has several limitations that should be considered. First, the findings are limited to adults and older adults, as a pediatric population was not included. The results are also specific to the context of a single private hospital and may not be generalizable to other settings.

The intervention itself was limited to a single, 20-minute application of music during the first bed bath. The study also did not involve a trained music therapist who could have optimized the intervention by making more individualized choices regarding frequency, sound intensity, musical selections, and application method based on each patient’s clinical needs.

A further limitation is the scarcity of current studies that specifically use music during a bed bath, which makes it difficult to compare our findings directly with existing literature. Finally, we did not measure the use and dosage of analgesics consumed by participants after the intervention, which prevents a full assessment of music’s potential to reduce medication reliance.

Conclusion

The use of music during a bed bath effectively reduced patient-reported pain, as measured by both the Numerical Rating Scale and the Wong-Baker FACES Scale, in the immediate postoperative period of CABG surgery. Therefore, the study’s alternative hypothesis is accepted, and the null hypothesis is rejected. The musical intervention, delivered via headphones at approximately 50 dB, proved to be a valid, low-cost tool that can contribute to more humanized patient care.

Furthermore, the study may have been biased by the inclusion of patients who reported zero pain on the Numerical Rating and Wong-Baker FACES scales. The bath itself promotes relaxation, which may have masked a more pronounced effect of the music on physiological variables. The study was also impacted by the COVID-19 pandemic, which caused the suspension of elective surgeries at various times. This extended the data collection period and resulted in a smaller final sample size.

Footnotes

ORCID iDs

Sabrina Daiane Gurgel Sarmento

Naryllenne Maciel de Araújo

Kauanny Vitoria Gurgel dos Santos

Karena Cristina da Silva Leal

Fernanda de Castro Teixeira

Kátia Regina Barros Ribeiro

Daniele Vieira Dantas

Rodrigo Assis Neves Dantas

Ethical Considerations

The study was approved on February 4, 2021 by the institutional review board of the Federal University of Rio Grande do Norte, Brazil (opinion no. 4.523.917). The study protocol was registered on the Brazilian Registry of Clinical Trials (ReBEC), obtaining approval under registration no. RBR-69w6f5z. The study complies with the Declaration of Helsinki of 1964 and Resolution 466/12 of the National Health Council of Brazil, and all participants provided written informed consent by signing the ICF.

Consent to Participate

All individuals provided voluntary, written informed consent by signing the informed consent form before their inclusion in the study.

Funding

The authors received no financial support for the research, authorship, and/or publication of this article.

Declaration of Conflicting Interests

The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Data Availability Statement

Study data is available from the corresponding author upon reasonable request.*

Clinical Trial Registration

Brazilian Registry of Clinical Trials (ReBEC): RBR-69w6f5z URL:

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