Acta Anaesthesiol Scand 2013; ••: ••–••
Printed in Singapore. All rights reserved
© 2013 The Acta Anaesthesiologica Scandinavica Foundation
Published by Blackwell Publishing Ltd.
ACTA ANAESTHESIOLOGICA SCANDINAVICA
doi: 10.1111/aas.12100
Perioperative music may reduce pain and fatigue in
patients undergoing laparoscopic cholecystectomy
M. Graversen and T. Sommer
Department of Surgery, Randers Region Hospital, Randers, Denmark
Background: Acute post-operative pain is a predictor in the
development of chronic pain after laparoscopic cholecystectomy.
Music has been shown to reduce surgical stress. In a randomized, clinical trial, we wanted to test the hypothesis that perioperative and post-operative soft music reduces pain, nausea,
fatigue and surgical stress in patients undergoing laparoscopic
cholecystectomy as day surgery.
Method: The study was performed in otherwise healthy
Danish patients eligible for day surgery. Ninety-three patients
were included and randomized to either soft music or no music
perioperatively and post-operatively. Using visual analog score
pain, nausea and fatigue at baseline, 1 h, 3 h, 1 day and 7 days
after surgery were recorded. C-reactive protein and cortisol
were sampled before and after surgery.
Results: Music did not lower pain 3 h after surgery, which was
the main outcome. The music group had less pain day 7
(P = 0.014). Nausea was low in both groups and was not affected
E
very year, around 7500 laparoscopic cholecystectomies are performed in Denmark. The course of
surgery has changed dramatically since the introduction of laparoscopic approach to gallbladder surgery
in 1985.1 Prior to the laparoscopic approach, postoperative pain was a substantial problem, and
patients were often admitted for several days. Today,
the laparoscopic approach is a standard procedure
and often performed as day surgery. Usually,
laparoscopic cholecystectomy (LC) only lasts about
30–45 min. Patients are discharged 3–6 h after
surgery without any restraints on their level of
physical activity. Post-operative pain is a main side
effect to LC and influences the patient’s satisfaction
and convalescence after surgery. In patients with a
history of gallstone attacks, a modified and hypersensitive pain perception from the area of the gall
bladder can be measured in the brain,2 and because
strong and acute post-operative pain is a predictor
for chronic pain development,3,4 early multimodal
pain management is important in the post-operative
by music. The music group experienced less fatigue at day 1
(P = 0.042) and day 7 (P = 0.015). Cortisol levels decreased
during surgery in the music group (428.5–348.0 nmol/l), while it
increased in the non-music group (443.5–512.0 nmol/l); still, the
difference between the two groups were only significant using
general linear models as post-hoc analysis. Soft music did not
affect C-reactive protein levels.
Conclusion: Soft music did not reduce pain 3 h after laparoscopic cholecystectomy. Soft music may reduce later postoperative pain and fatigue by decreasing the surgical stress
response.
Accepted for publication 8 February 2013
© 2013 The Acta Anaesthesiologica Scandinavica Foundation
Published by Blackwell Publishing Ltd.
setting.5 In several studies, music has been used to
decrease post-operative pain and discomfort.
Nilsson et al. demonstrated that perioperative and
post-operative music reduced post-operative pain
in patients undergoing variceal surgery or open
inguinal herniotomy.6,7 Furthermore, Leardi et al.
demonstrated a decrease in cortisol levels when
patients were exposed to perioperative music.8
However, Migneault et al. did not find any beneficial
effects from intraoperative music on changes in cortisol levels.9 During heart surgery, music reduces
anxiety and pain,10,11 and in patients undergoing
colonoscopy, one meta-analysis concluded that
music reduces stress, pain and anxiety,12 while
another meta-analysis concluded that soft music
improved the overall experience of patients.13
A Cochrane review in 200614 concluded that
music may modify surgical pain intensity; however,
differences between studies in surgical procedures,
techniques, music media, scoring systems and
heterogeneous study groups made comparisons
1
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M. Graversen and T. Sommer
difficult. No study has been performed in patients
undergoing laparoscopic surgery.
In a randomized, clinical trial with patients
undergoing LC, the aim of this study was to evaluate
the impact of soft music on post-operative pain,
nausea, fatigue and surgical stress as measured by
changes in cortisol- and C-reactive protein (CRP)
levels. Our hypothesis was that listening to soft
music reduces the levels of post-operative pain,
nausea and fatigue. Furthermore, we anticipated
that listening to soft music may reduce surgical
stress.
Methods
The study conforms to the Helsinki declaration,
was approved by The Danish National Committee
on Biomedical Research Ethics (Ref: 20080031,
approved 01.08.2008) and registered at http://
www.clinicaltrials.gov protocol record 20080031.
From September 1, 2008 until March 1, 2011, all
patients scheduled for LC were invited to participate
in the study. Inclusion criteria were ⱖ 18 years of
age and uncomplicated cholecystolithiasis (no prior
cholecystitis, cholangitis or choledocholithiasis).
Exclusion criteria were: pregnancy; conversion to
open surgery; systemic steroid; or daily morphine
treatment, a history of gastrointestinal surgery
within the past 2 weeks or if the patient was incapable of understanding the given information. Furthermore, patients were excluded if they were
admitted to the hospital after surgery.
Randomization
The study was designed as a randomized, clinical
trial. Each day of surgery, an envelope was picked
containing information whether or not music
should be used for all patients that day (like ‘flip a
coin’). The unit nurse was responsible for the randomization, and the staff nurses registered the patient
data. The scheme of randomization was kept secret
until data from all patients were collected.
Surgery
Pneumoperitoneum of 12 mmHg was created by the
use of a Veress needle, and two 12-mm and two
5-mm ports were used. A standard LC was performed, and the gall bladder was removed from the
abdomen through the epigastric or umbilical port
site. Carefully, the abdomen of all patients was completely desufflated. At the port sites, 40 ml bupivacaine 0.25% was injected subcutaneously. Lesions
of the gallbladder with bile contamination or other
2
surgical complications were registered. In case of
bile contamination, thorough peritoneal lavage was
performed. All patients received standard postoperative analgesic treatment with ibuprofen
400 mg ¥ 4 and paracetamol 1 g ¥ 4 for 3 days.
Amount of anesthetics and fluids administered
during surgery were recorded as well.
Intervention and outcome assessment
A music pillow with an integrated mp3 music
player with soft music from Musicure® (Gefion
Records, Copenhagen, Denmark – a company that
designs music to reduce stress) was placed behind
the patient’s head before surgery and used until
discharge from the day surgery department. In cases
where patients were randomized to non-music, the
pillow was placed, but the player was not started.
Primary end point: The primary end point was
post-operative pain 3 h post-operatively measured
by using the visual analog scale 0–10 (VAS). In addition, pain was estimated 1 h post-operatively using
VAS and by phone after 1 and 7 days using the
numeric rating scale (NRS) where 0 = no symptoms
and 10 was worst degree of symptoms.
Secondary end points: These were symptomatic
nausea and fatigue as measured on a 0–10 VAS/
NRS. Patients were monitored at baseline just prior
to surgery, 1 and 3 h post-operatively in the day
surgery unit, while 1- and 7-day follow-up was done
by phone. VAS was used in the day surgery unit,
while NRS where used at follow-up by phone. CRP
and cortisol levels were sampled for analysis before
and 2 h after surgery.
Perioperative data regarding length of surgery,
pre-operative waiting period, post-operative mobilization and discharge, bile leakage, consultant/
junior surgeon, anesthetics, and morphine usage
was recorded.
Statistical analysis
Sample size was calculated by collecting VAS scores
for pain 3 h after surgery in 60 patients undergoing
a standard LC with the same setup as in this study.
The Mann–Whitney rank-sum test was used to
detect a minimal difference between the two groups
of 50% and types 1 and 2 errors of 0.05 and 0.20,
respectively. Inclusion of 35 patients in each group
was adequate according to the power calculation.
The Mann–Whitney rank-sum test was used when
evaluating difference in pain, fatigue, nausea, cortisol and CRP levels between the two groups. The
chi-square (Fisher’s exact) test was used for dichotomized data. Post-hoc, the pre- to post-operative
Soft music in laparoscopic cholecystectomy
Fig. 1. Flowchart from inclusion to randomization. n = 93.
changes of CRP and cortisol levels were tested using
Generalized Linear Models. Two-tailed P-values of
less than 0.05 were considered statistically significant. Statistical analyses were performed in STATA
version 10.1 (StataCorp, College Station, TX, USA).
Results are presented as per-protocol analysis, as we
did not think that music would be the reason for
admission after surgery or any malfunction of the
mp3 player.
Results
Patient data
During the study period, 204 consecutive patients
underwent LC in our day surgery unit, 93 were
enrolled in the study to compensate for likely dropouts. Five patients were excluded due to lack of
randomization, four due to defect music pillow, one
due to laparotomy and finally eight due to admission – five in the music group and three in the nonmusic group (Fig. 1). Data from 75 patients were
analyzed, 40 patients randomized in the music
group and 35 patients in the non-music group
(Fig. 1). The groups had similar baseline characteristics (Table 1). The two groups received similar
amounts of anesthetics and fluids during surgery
and same amounts of morphine in recovery. Junior
surgeons performed the majority of operations in
both groups (Table 2).
Pain, fatigue and nausea
In the music group, no difference was found regarding the primary end point (VAS score 3 h postoperatively), but less pain was recorded at day 7.
Furthermore, the music group experienced less
fatigue at days 1 and 7 (Table 3). No differences were
recorded in nausea.
Table 1
Patient characteristics.
Variable
Music, n = 40
Non-music, n = 35
Gender, male/female
Smokers, male/female
BMI (kg/m2)
Age (years)
ASA (I/II)
12/28
3/13
27 (25–31)
50 (35–57)
28/12
8/27
4/12
26 (24–33)
44 (36–58)
25/10
Data are reported as number of patients, or medians and interquartile ranges.
ASA, American Society of Anesthesiologists; BMI, body mass
index.
Cortisol/CRP
Pre- and post-operative cortisol and CRP levels
were not different in the two groups. In the music
group, cortisol decreased after surgery from 428.5
to 348.0 nmol/l, while it increased in the non-music
group from 443.5 to 512.0 nmol/l (Fig. 2). CRP did
not change in the music group from 1.90 to
1.60 nmol/l and in the non-music group from 1.45
to 1.25 nmol/l (Fig. 3). Using Generalized Linear
Models for the comparisons, findings were
statistically significant when comparing the pre- to
postoperative cortisol level changes between the
two groups (P < 0.001), while that was not the case
for CRP (P = 0.292).
Mobilization/discharge data
No differences were observed regarding surgery
time, mobilization time, or discharge time even
though patients in the non-music group waited
longer pre-operatively than patients in the music
group (122 vs. 90 min, P = 0.035) (Table 2).
Discussion
The main findings of this study show that soft music
did not decrease post-operative pain 3 h after
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M. Graversen and T. Sommer
Table 2
Anesthetic and surgical factors. n = 75.
Variable
Surgical factors
Surgery (min)
Waiting (min)
Mobilization (min)
Discharge (min)
Bile leakage
Consultant surgeon
Admissions
Anesthetic usage
Remifentanil (mg)
Propofol (mg)
Droperidol (mg)
Isotonic NaCl (l)
Morphine (mg)
Music, n = 40
75
90
150
255
5
8
5
3.38
670.50
1.25
900
10.0
Non-music, n = 35
(63–99)
(65–140)
(115–190)
(195–290)
75
122
155
237
9
5
3
(2.60–4.61)
(576.25–890.75)
(0.625–1.25)
(500–1000)
(5.3–15.0)
3.40
706.50
1.25
900
8.0
P-value
(60–90)
(80–157)
(120–210)
(200–285)
0.550
0.035*
0.643
0.551
0.235
0.552
0.723
(2.75–3.93)
(591.25–890.50)
(0.625–1,25)
(500–1000)
(3.5–10.0)
0.642
0.897
0.690
0.878
0.147
Data are reported as number of patients, or medians and interquartile ranges.
*Statistically significant (P < 0.05).
Table 3
Pain, fatigue and nausea at baseline and after surgery.
Variable
Pain (VAS 1–10)
Baseline
1h
3h
1 day
7 days
Fatigue (VAS 1–10)
Baseline
1h
3h
1 day
7 days
Nausea (VAS 1–10)
Baseline
1h
3h
1 day
7 days
Music, n = 40
Non-music, n = 35
P-value
0.00
3.00
2.00
3.00
0.00
(0.00–1.00)
(1.00–5.00)
(0.25–3.00)
(1.00–5.00)
(0.00–1.25)
0.00
3.00
2.00
3.00
1.00
(0.00–2.00)
(2.00–4.00)
(1.00–3.00)
(2.00–5.00)
(1.00–2.00)
0.537
0.927
0.207
0.542
0.014*
1.00
5.00
5.00
3.00
0.00
(0.00–3.00)
(2.25–8.00)
(3.00–7.00)
(0.75–5.00)
(0.00–1.25)
2.00
6.00
5.00
4.00
1.00
(0.00–4.00)
(4.50–8.00)
(3.00–7.00)
(2.00–6.00)
(0.00–3.00)
0.425
0.115
0.632
0.042*
0.015*
0.00
0.00
0.00
0.00
0.00
(0.00–0.00)
(0.00–0.00)
(0.00–0.00)
(0.00–0.00)
(0.00–0.00)
0.00
0.00
0.00
0.00
0.00
(0.00–0.00)
(0.00–0.00)
(0.00–0.00)
(0.00–0.00)
(0.00–0.00)
0.522
0.809
0.950
0.817
0.150
Data are reported as median and (interquartile range).
*Statistically significant (P < 0.05).
VAS, visual analog scale.
surgery. However, decreased post-operative pain 7
days after LC, and fatigue 1 and 7 days after surgery
were observed. Furthermore, there seemed to be a
significant difference in the pre- to post-operative
cortisol level in patients randomized in the music
group compared with patients in the non-music
group; however, this finding was based on post-hoc
analysis, and final conclusions regarding these
changes should be modest. As demonstrated in
other studies,15 CRP did not change in the early
period of laparoscopically induced surgical stress.
Overall pain and fatigue levels in the two groups
4
were quite low, indicating that the impact of soft
music may have minor clinical relevance in patients
undergoing minimal invasive surgery. There was no
difference in the level of pain during the stay in the
day surgery unit as demonstrated by the equal VAS
scores and use of analgesics. The fact that more
patients in the non-music group had gallbladder
lesion during surgery could have induced more
pain; however, in case of gallbladder lesion during
surgery, our routine is to clean up the abdomen
completely by peritoneal lavage, thus minimizing
additional pain.
Soft music in laparoscopic cholecystectomy
Fig. 2. Cortisol levels (nmol/l) before and 2 h after surgery in the
two groups. n = 75 (40 exposed to music and 35 not exposed to
music). Data are reported as medians and interquartile ranges.
*Statistically significant (P < 0.001).
Fig. 3. C-reactive protein (CRP) levels (nmol/l) before and 2 h
after surgery in the two groups. n = 75 (40 exposed to music and
35 not exposed to music). Data are reported as medians and interquartile ranges.
The non-music group waited longer for surgery,
which may have caused higher levels of stress;
however, pre-operative cortisol levels in the two
groups were comparable. A recent study has demonstrated that post-operative pain may be associated
with the length of waiting.16 Per protocol, we
excluded patients who were admitted after surgery
because we wanted to test soft music therapy in day
surgery patients and admission could have a great
impact on results, distorting the day surgery focus.
There was no difference in admission rates between
the two groups. Because we excluded admitted
patients, we have no post-operative data on the
admitted patients, making it impossible to evaluate
any impact on outcome.
We used only one type of music from Musicure®,
which has been designed for use in perioperative
settings and used in other studies.17 Sounds from
the music pillow could be heard from a small distance. Therefore, we chose to randomize days and
not patients, as the sound could have affected measurements of patients randomized to non-music
group, lying in the same ward. Any discomfort
known from headsets/earphones was also avoided
by using the music pillow, as it allowed the patient
to rest in different positions without decreasing the
sound of music or shutting out the external sounds
at the unit. The music pillow was tested and considered comfortable by the patients and staff prior to
the study as well.
Scoring the patients at days 1 and 7 was done
blinded. However, we did not note if the patients
made any remarks about the music to the nurse,
which may have biased the scoring, but overall, the
study design did not allow blinding. It has been
shown in several randomized, clinical trials that
pre- or post-operative music may decrease anxiety18,19,20 and thereby maybe also the level of the
surgical stress response measured by reduced
changes in cortisol level during/after surgery, as
reported by Leardi et al.,8 Nilsson21 and Nilsson
et al.22 However, as stated by Nilsson in a comprehensive review from 2008, this effect has only
been documented in 50% of 42 randomized, clinical
trials.18
There is no consensus whether music should be
used pre-operatively, intraoperatively or postoperatively. We wanted to achieve the maximum
effect from soft music, and therefore, our patients
were exposed to music throughout the operation
until discharge. The beneficial effects of music
throughout the stay is demonstrated by BinnsTurner et al. in women undergoing mastectomy,
where music reduces anxiety, mean arterial blood
pressure and pain.23
Another factor that could have been of interest
was the feedback from the patient and staff, allowing us to determine any changes of pain, anxiety or
fatigue related to the music. If a patient or the staff
disliked the music, it may have imposed stress and
anxiety on the patient. Conversely, if the patient
could choose the music genre, it may have reduced
the level of stress, as demonstrated earlier.8 We tried
to minimize any disapproval of the music genre, as
5
M. Graversen and T. Sommer
we used music specifically developed to be soft and
comfortable in a perioperative setting.
The effect of music in humans is subject to
ongoing investigation probably because of minimal
adverse effects. The way music is affecting cerebral
activity including moods is complex and not fully
understood. It involves increasing the levels of neurotransmitters such as dopamine, glutamate and
perhaps also noradrenaline, when listening to
music. Dopamine levels affect moods, while glutamate is crucial in learning and memory functions.24
Särkämo et al. found that music influence the cerebral plasticity after stroke.25 Music has a powerful
effect on our moods and emotions, and the calming
and relaxing effect is used a great deal in commercial settings such as supermarkets, retail stores,
Internet sites and the entertainment industry to
make people feel comfortable and relaxed when
waiting for a specific service. Waiting periods in the
hospital are known to cause anxiety in patients
undergoing surgery,26 and music may be a simple
and cost-effective intervention that should be tested
in well-designed randomized, clinical trials. Patient
perceptions should be compared with objective data
indicating surgical stress like cortisol, prolactin or
interleukins previously used to measure stress in
laparoscopic gallbladder surgery.15
In conclusion, we could not show that soft music
decreased pain 3 h after LC; however, there may be
an effect on the surgical stress causing a decrease in
fatigue and later pain. Larger studies should be conducted with focus on changes in stress hormones as
primary end points in combination with desired
symptomatic effects from soft music in the perioperative setting.
Acknowledgements
The study was supported by J Klein og Hustrus Mindelegat.
Conflict of interest: The authors have no conflicts of interest.
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Address:
Martin Graversen
Vestre Ringgade 216
3. th, 8000 Aarhus
Denmark
e-mail: [email protected]
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