INTRODUCTION

Anxiety is an abnormal, overwhelming feeling of apprehension and fear, which leads physiological changes such as excess perspiration, hypertension and tachycardia. It is due to doubts about the reality and nature of the threat or because of the lack of self-confidence on the ability to deal with it ^1,2.

There is currently a growing interest in alleviating the anxiety of patients ³in any situation occurring in the hospital environment.

Musical intervention is a therapeutic resource that is increasingly being used as adjuvant therapy, to promote relaxation, emotional and spiritual comfort, distraction, feeling of well-being and pain relief ⁴.

Music has always been linked to the social life of humans, fulfilling different social functions ⁵. One of these functions is the application of music in medicine. In a hospital setting, music therapy has proven effective, mainly as a way to reduce anxiety ⁶.

When talking about music therapy, we mean how music can be used in a studied and controlled way to modulate the responses of the people who listen to it. These effects can be refreshing and sedative, anxiolytic, analgesic, etc. ⁷.

In an anxiety situation, breathing is usually blocked. Music can act as a guide to accompany and control breathing and help focus attention on the relaxation exercise ⁷, improving motivation and positive feelings of self-control against pain ⁸.

Several studies have shown the interaction between anxiety and pain. Anxiety is the most common form of impairment of subjective well-being in patients with chronic pain, highlighting the situational anxiety caused by situations such as invasive procedures ⁹.

Patients attending the pain unit frequently have stress and anxiety when undergoing an interventional technique.

A quiet and comfortable environment, without noise pollution, together with proper patient placement on the procedure table, are key points of care during the performance of an interventional technique. It requires knowledge of the health personnel, as well as being familiar with the programmed interventional technique. The interventional technique that will be performed, the drugs that will be administered, age, height, weight, patient history and safety measures (body position, the perfect functioning of the procedure table, the standards for patient protection and the anticipation of the needed equipment) should also take into account.

MATERIAL AND METHODS

Description of the study variables

The variables included in the study are the following:

• - Dependent variable: level of anxiety: measured according to the visual analog scale (Figure 1) at the following time-points: pre-intervention, intra-intervention and post-intervention (interventional technique). This scale is a modification used in a study conducted by Sepúlveda-Vildósola (2014).

• - Independent variable: interventional technique to be performed according to the indication and diagnosis assessed during the medical visit at the Pain Unit of the Sagrat Cor University Hospital in Barcelona.

• - Secondary variables: age (years), sex of the patient, work activity of the patient (active, inactive, pensioner or unemployed), level of education (primary, high school or university), diagnosis and interventional technique to perform and if this is performed for the first time, anxiolytic treatment in a chronic or timely manner, registration of vital signs (heart rate in beats per minute, oxygen saturation by pulse oximetry and non-invasive systolic and diastolic blood pressure in millimeters of mercury) in the preintervention, at 2, 5, 7, 10, 13, 15 and 20 minutes and post-intervention (interventional technique), pain severity according to the visual analog scale (VAS) and patient satisfaction level according to a Likert type scale.

Fig. 1. Escala visual análoga modificada para medir nivel de ansiedad (^{Sepúlveda-Vildósola, 2014}). 

RESULTS

A total of 80 subjects have been recruited for the present study, 71.6% were women. The average age of the subjects was 66.7 (SD 14) years, 49.4% have completed high school and 64.2% are pensioners.

A total of 60.5% of subjects are not undergoing anxiolytic therapy.

59% of study participants have radicular low back pain and have undergone an epidural block.

The interventional technique was performed for the first time in 33.3% of the subjects.

When comparing sex, age, work activity, level of education, diagnosis and interventional technique, prior treatment with anxiolytics, undergoing the technique for the first time, vital signs (heart rate, oxygen saturation and blood pressure), pain assessment according to the VAS and assessment of anxiety according to the modified visual analog scale before the interventional technique. No statistically significant difference was found between the patients in the control group and those who underwent music therapy intervention. That is, the groups are homogeneous and therefore comparable (Table 1).

Table I. Variables collected before intervention 

The intra-intervention VAS value in the control group was 5.83 (SD 3.2) and in the music therapy group it was lower, with a VAS value of 5.0 (SD 2.2). This difference is not statistically significant (F = 1.614, p = 0.208).

In the control group, the value of the intra-intervention modified visual analog scale (anxiety) was 4.3 (SD 3.1) and in the music therapy group it was lower, with a value of 3.0 (SD 2.0). This difference is statistically significant (F = 4.83, p = 0.031) (Figure 2).

Fig. 2. Intra-intervention results. 

The same happens regarding the post-intervention VAS value. In the control group the post-intervention VAS value was 3.7 (SD 3.3) and in the music therapy group it was lower, with an VAS value of 3.1 (SD 2.4). This difference is not statistically significant (F = 0.755, p = 0.387).

In the control group the value of the post-intervention modified visual analog scale (anxiety) was 2.7 (SD 2.8) and in the music therapy group it was lower, with a value of 1.3 (SD 1.5). This difference is statistically significant (F = 7.427, p = 0.008) (Figure 3).

Fig. 3. Post-intervention results. 

81.5% of the total subjects that participated in the study consider that they are very satisfied and 18.5% are satisfied that they have received enough information about the technique that has been performed.

95.1% of the total subjects who participated in the study consider that they are very satisfied and 4.9% are satisfied, since health professionals have given them confidence and security.

The subjects of the intervention group report that with the use of music therapy a relaxed environment has been created and 80% are considered very satisfied and the remaining 20% considered themselves satisfied.

DISCUSSION

Because patients attending the Pain Unit frequently present with anxiety, the purpose of this study was to demonstrate the importance of reducing the level of anxiety before performing an interventional technique at the Pain Unit.

Music therapy consists of an interaction between the healthcare professional, the patient, the music and the means used to offer it ². Its purpose is to provide physiological, social, psychological and intellectual benefits to the patients to whom it is applied, reducing anxiety, which is associated with a state of negative stress, and increasing well-being ¹⁵.

A quiet and comfortable environment, without noise pollution, together with proper patient placement on the procedure table are key points of care during the performance of an interventional technique.

The International Association for the Study of Pain (IASP) defines pain as "an unpleasant experience associated with actual or potential tissue damage, it has sensory, emotional, cognitive and social components" ¹⁶. We have applied music therapy on the emotional component to reduce anxiety to an interventional technique ¹⁷.

To date, published studies ^{18,19,20,21,22,23,24,25}concerning anxiety, pain and music therapy have been performed in groups of patients undergoing endoscopy, cystoscopy and colposcopy, biopsy (breast, prostate), cures of burned patients, patients transplanted, women in labor and postpartum, surgeries (hip, knee, cardiac) and their postoperative, cancer patients and palliative care, patients undergoing extracorporeal shock wave lithotripsy, patients with multiple sclerosis, patients undergoing radiological procedures (nephrostomies, catheterizations) or other procedures (aesthetic, ophthalmological, dental, pleural). A decrease in anxiety levels and pain severity thanks to music therapy was found in all of them, either through a decrease in the requirements of anxiolytic and/or analgesic drugs.

We decided to use the modified visual analog scale of Sepúlveda-Vildósola ²as a measure of anxiety level for several reasons: it is a scale that was used to assess the level of anxiety to a potentially stressful and painful technique; it is an easily understandable tool that can be completed quickly; and it adjusts to the times used in the performance of an interventional technique at the Pain Unit of the Sagrat Cor University Hospital in Barcelona.

The results obtained regarding the level of anxiety are similar to the studies of Bringuier ¹⁰and Sepúlveda-Vildósola ². These authors studied the level of anxiety in the pediatric population (7-16 years) who presented postoperative pain ¹⁰or who was given intravenous chemotherapy ². Both situations, obviously painful, generate a level of pre-, intra- and post-intervention anxiety.

We consider both studies extrapolated to the adult population, since in the age range (7-16 years), the subjects understand and express their anxiety levels, being almost comparable to the patients attending the Pain Unit of the Sagrat Cor University Hospital of Barcelona for the performance of an interventional technique.

In our study, through the use of music therapy, we found a clinically relevant improvement in pain severity measured by the VAS and a significant decrease in the anxiety measured by the modified visual analog scale at both intra-intervention and post-intervention (interventional technique) in the music therapy group.

Likewise, patients feel very satisfied about the information received and consider the confidence and security provided by health professionals as very satisfactory. In addition, the music therapy group considers that the relaxed atmosphere created by the music is in general very satisfactory.

Therefore, after assessing the results obtained in the present study, we consider that music therapy is an excellent therapeutic tool, easy to use, accessible and economical, with no adverse effects, which can be used as an adjunct in interventional techniques at the Pain Unit.

However, we cannot attribute the success of these results exclusively to music therapy. There are other external factors that may have influenced and that we must take into account (comfortable environment, area free of noise pollution, knowledge of health professionals and area where the interventional technique is performed).

For the future, according to the results obtained, we consider applying music therapy as a comprehensive part in the performance of interventional techniques at the Pain Unit of the Sagrat Cor University Hospital in Barcelona.