Effects of Patient-Controlled Music Therapy During Coronary Angiography on Procedural Pain and Anxiety Distress Syndrome

Patients who undergo coronary angiography may experience harmful stress. Research suggests that music therapy improves the level of comfort in patients; the authors determine the effect of patient-controlled music on the psychophysiological stress response to coronary angiography.Undergoing invasive procedures, such as coronary angiography, can be acutely stressful for many patients. Many factors contribute to patients’ level of stress: previous experience, pain, anxiety, unfamiliar environment, and fear. Stress produces a physiological and biochemical response that is unique for each person with respect to duration, intensity, and overall impact. This response is elicited when stressors, such as pain or anxiety or a combination thereof, are physically and psychologically demanding for the patient. The psychophysiological stress response involves activation of the hypothalamic-pituitary-adrenal axis and the sympathetic nervous system and is characterized by increased heart rate, blood pressure, and cardiac output. The degree of the physiological stress response reflects the stress perceived and experienced. Obviously, this response increases the workload on a cardiovascular system that may already be compromised.Stress can be reduced by either removing the source of the stress or by mediating its effect through supportive interventions. Pain and anxiety are 2 common stressors in patients with cardiovascular conditions. Anxiety is an emotional state characterized by feelings of tension, nervousness, worry, apprehension, and heightened activity of the autonomic nervous system. Spielberger1 differentiates between state anxiety as a transitory emotional condition and trait anxiety as a stable predisposition to anxiety. Anxiety may bring about coping mechanisms to reduce the impact of the stress; but too much anxiety may interfere with cognitive ability to cope and lead to feelings of helplessness. Some anxiety is expected and may be beneficial during coronary angiography procedures, because it indicates that the patient is confronting and attuned to the demands of the procedure and event. However, high anxiety may cause or potentiate an imbalance and create an unhealthy stress response. High anxiety, measured physiologically and with the State-Trait Anxiety Inventory (STAI), has been reported in cardiac patients in coronary care units2–5 and after surgery.6,7 Most nurses have observed that pain can cause or potentiate the level of anxiety. Pain during angiographic procedures may be associated with sheath insertion, immobilization, injection of contrast material, and balloon inflation. At Kingston General Hospital, Kingston, Ontario, patients are routinely administered an anxiolytic agent (ie, lorazepam) to help alleviate anxiety during the procedure and a local anesthetic at the time of sheath insertion to alleviate pain. Despite these pharmacological measures and the usual supportive care provided by the nurses, indications of anxiety often occur in patients even during the procedure. Nonpharmacological interventions, such as music therapy, have not yet been incorporated into usual care.Ideally, supportive care interventions should enhance patients’ ability to physically and cognitively (behaviorally) cope with the stress. Although the evidence is varied, the available research suggests that music therapy is an intervention that may be effective in mediating or reducing pain and anxiety. Music therapy is a nonpharmacological intervention that purportedly improves level of comfort and enhances well-being in patients by engaging the affective, cognitive, and sensory mechanisms.8,9Studies exploring the effectiveness of music therapy have produced mixed results. Stevens10 examined patients’ response to music during operative procedures involving spinal, epidural, or local infiltration anesthesia: 75% of the patients rated the music as helpful, relaxing, and supportive. Participants stated that listening to music helped counterbalance the feeling of depersonalization associated with being in the hospital environment. Palakanis et al11 reported the effect of music on patients’ anxiety during flexible sigmoidoscopy. They found that music was an effective anxiolytic; state anxiety scores were significantly less in the group of patients who listened to self-selected tapes during procedures than in patients who received the standard protocol. Conversely, music in combination with muscle relaxation was ineffective in reducing anxiety in patients admitted to a coronary care unit with unstable angina or acute myocardial infarction.6 Good12 reviewed the effects of music and relaxation on postoperative pain and concluded that relaxation and music were effective in reducing affective and observed pain in most studies but were less effective in reducing opioid intake and sensory pain. Methodological problems, such as inadequate sample size, poor measurement of pain, and no assurance of pretest equivalence reduced the validity of the study results reviewed by Good. Good recommended that randomized controlled trials be conducted within various clinical contexts to determine the effectiveness of music therapies on relevant outcomes for patients.The purpose of this research was to determine the effect of patient-controlled music on the psychophysiological stress response to coronary angiography. The null hypothesis was that there would be no difference in levels of anxiety and pain, as measured by the patients’ own assessments and physiological monitoring, in patients who were offered the opportunity to listen to a self-selected audiotape of music before, during, and after coronary angiography in comparison to patients who were offered conventional care alone.A pretest-posttest control group experimental study was conducted at Kingston General Hospital, a university-affiliated teaching hospital, between March 1999 and June 2000. This hospital is a tertiary cardiology referral center with a yearly diagnostic volume of approximately 1400 cases and an interventional volume of approximately 600 cases. The study took place in the cardiovascular laboratory. Registered nurses, cardiovascular technicians, and cardiologists provided patients’ care.Patients were eligible for inclusion if they were undergoing, for the first time, diagnostic coronary angiography or a percutaneous intervention procedure; able to speak and read English; cognitively oriented to person, place, and time; and had no major auditory deficits. On the basis of the effectiveness of music therapy in lowering state anxiety in previous studies with patients who had myocardial infarction,3,4 we estimated a sample size of 120 patients for a power of 80% and a significance α of .05.Patients were approached for participation during their outpatient cardiology clinic visit before the procedure or while in the hospital. A research assistant contacted potential participants, described the study, and sought consent. Patients scheduled for either diagnostic coronary angiography or a percutaneous intervention procedure who consented were immediately randomized to a control or experimental group by selecting a randomly generated group number sealed in an opaque envelope. The research protocol was reviewed and approved by the local research ethics board.Participants randomized to the control group received the standard care reflective of current practice. This care included a physical assessment before the procedure, an explanation about the procedure, routine administration of an anxiolytic (ie, lorazepam) and a local anesthetic, and administration of other medications, such as nitroglycerin, as needed.Participants randomized to the experimental group were provided, in addition to the usual care, the opportunity to listen before, during, and after the procedure to a self-selected audiocassette tape via earphones. Music therapy began after the questionnaires were completed before the procedure, continued as the patient desired during the procedure, and ended just before the patient completed the questionnaire after the procedure. The use of earphones was pretested during the angiographic procedure to ensure that it did not affect the patient’s ability to follow verbal instructions during the procedure.Data were collected from the questionnaires completed by the patients before and after the procedure and from each patient’s record. Anxiety and pain were measured at baseline and after the procedure, just before removal of the arterial sheath. Apical heart rate and systolic and diastolic blood pressure were measured 4 times: (1) at baseline before the questionnaire was administered and on the patient’s arrival at the holding area of the cardiovascular laboratory, (2) before the start of the procedure, immediately after sheath insertion, (3) at the end of the angiographic procedure and before transfer from the procedure table, and (4) after the procedure, immediately before sheath removal.Anxiety was measured by using the STAI-Form Y-1.1 The state anxiety scale measure reflects the subject’s level of anxiety at a particular moment in time. The scale consists of 20 statements with responses on a 4-point Likert scale. Half of the items relate to the presence of apprehension, worry, or tension, and the remaining items reflect the absence of such states. The total score is the weighted sum of the 20 responses and ranges from 20 to 80: low anxiety (20–30), moderate anxiety (40–59), and high anxiety (60–80). The test-retest reliability correlation reported for the state scale was 0.16 to 0.62. This low correlation was expected because the STAI is designed to measure situational anxiety. Alpha reliability coefficients obtained to measure internal consistency are reported as 0.91 to 0.93.Pain was measured by using a visual analog scale and a descriptor scale (Figure 1). The visual analog scale is a unidimensional scale for quantifying intensity and is used extensively to measure such unpleasant symptoms as pain, fatigue, and dyspnea.The visual analog scale used in this study was 10 cm long, anchored with pain intensity extremes of no pain to worst possible pain. Interval level data were obtained by measuring the centimeters from the low end of each scale to the subject’s mark. The descriptor scale contained 6 categorical descriptions of pain.13An external cardiac monitor was used to measure heart rate indirectly. Blood pressure was measured indirectly with a pressure dynamometer at baseline and after the procedure but before sheath removal. Blood pressure was measured directly via arterial pressure monitoring after sheath insertion and at the end of the angiographic procedure. Information on medications and complications was abstracted from patients’ records.All questionnaire and chart abstraction data were entered into a Microsoft Access database. All data from questionnaires were entered twice to ensure accuracy of data entry. Data were analyzed by using the SAS 8.5 statistical software package (SAS Institute, Cary, NC). To compare the groups at baseline, we performed an analysis of variance for continuous variables and a χ2 test for categorical variables. To determine the effect of the intervention on levels of anxiety and pain, we performed an analysis of covariance, to control for baseline levels of anxiety and pain. Post hoc we performed a correlational and forward regression analysis to determine the relationships between anxiety and pain and the factors that contributed to elevated levels of anxiety. We used the conventional P less than .05 level of significance.We asked 129 patients to participate; of these, 113 (87.6%) agreed to participate and were randomized to the control (n=55) and experimental (n=58) groups. We have complete data on 107 patients. Six patients (4 control, 2 experimental) were not included because the procedure was canceled after their enrollment or they could not complete all the questionnaires because of complications. Enrolled patients, in both groups, were similar at baseline with respect to age, sex, and type of diagnostic procedure performed (Table 1). As expected, both groups included slightly more men than women. Diagnostic angiography was the most common procedure with a mean duration, defined as the time from placement on the procedure table to the end of the procedure, of approximately 45 minutes. Participants in the intervention group selected a variety of music, predominantly softer, more relaxing music (eg, classical, soft rock, relaxation, and “easy” country).Both at baseline and after the procedure, no significant differences were apparent between groups in levels of state anxiety or pain intensity, and no differences were detected in change scores (Table 2). With use of the analysis of covariance and control for preintervention anxiety levels, we found no difference between groups in anxiety after the procedure (F=0.86, P=.36). Patients reported moderate levels of state anxiety before the procedure. Anxiety decreased after the procedure. Patients in both groups received an anxiolytic (lorazepam) before the procedure but few received additional doses, and 43.9% (n=47) received nitroglycerin or other medications such as heparin. The standardized Cronbach coefficient α for the anxiety scale was 0.92 at baseline and 0.89 after the procedure. Angiographic procedures were not associated with postprocedural pain; most patients (n=86, 80.4%) reported no pain after the procedure.F3Heart rate and blood pressure (systolic and mean) were not significantly different at baseline, before the procedure but after sheath insertion, at the end of the procedure, or after the procedure but before sheath removal (Figure 2). Heart rate increased and peaked at the end of the procedure, and blood pressure (systolic and mean) peaked at the beginning of the procedure, after the insertion of the sheath. The changes in heart rate and blood pressure (systolic, diastolic, and mean) were not significantly different at the 4 measurement points.Post hoc, we determined the relationships between levels of anxiety and pain before and after the procedure (Table 3). Significant moderate correlations were found between anxiety before the procedure and pain before the procedure, anxiety after the procedure, and pain after the procedure. Pain before the procedure and pain after the procedure also had a moderate significant correlation. The forward stepwise regression confirmed that anxiety and pain before the procedure were predictive of anxiety after the procedure (R2=0.24, F=13.52, P<.001).Patient-controlled music therapy had no significant effect on state anxiety (as measured with the STAI), pain intensity, heart rate, or blood pressure, and it did not decrease the use of additional pharmacological measures to control pain and anxiety. Patients commented favorably on the use of music. Statements included comments such as: “I loved the music—it helped me to relax,” “I enjoyed listening while I had to wait on the table,” and “The music was very calming as I was so nervous about the procedure.” Many patients in the experimental group requested the music during sheath removal. Some patients in the control group expressed disappointment when they were not assigned to the intervention group. These patients were offered the opportunity to listen to the music tape during sheath removal. The nurses also reported that the music seemed to have a calming influence and, at times, they sought it out for patients not enrolled in the study. Although we did not find significant differences in the selected outcome measures, the intervention seemed to be enjoyed and appreciated by patients in the experimental group. Further study and validation of this point are needed.The major strength of this study was in its design as a randomized experimental trial. The intervention was conceptually sound because it was grounded in the principles of the psychophysiological stress response and based on evidence of the effectiveness of music therapy in other clinical populations. The study did have limitations. First, the strength of the intervention, that is, the ability of the music therapy to decrease anxiety and pain, may have been influenced by the use of existing pharmacological measures and the short duration of the intervention. Second, the selected outcome measures of pain, anxiety, and changes in heart rate and blood pressure may not have been sensitive enough to detect differences or may not have been the best measures to use. Third, we estimated the effect size on the basis of studies in hospital patients with myocardial infarctions. These patients were not undergoing an invasive acute procedure and, consequently, are different.Thus, our study may not have had enough power to detect a difference if a difference truly existed (ie, probability of a type I error more likely). Using our mean scores and SDs for the changes in levels of anxiety from before to after the procedure, we did a post hoc power analysis. On the basis of this analysis, the estimated sample size required to determine a difference, with a power of 80% and an α of .05 was 240 subjects (ie, 120 per group). Future research could address these limitations.The purpose of this research was to determine the effectiveness of patient-controlled music therapy in decreasing anxiety and pain in patients undergoing coronary angiographic procedures for the first time. The findings indicated that patients do experience a psychophysiological response to an invasive procedure, but no significant differences in level of anxiety, level of pain, heart rate, or blood pressure were found in patients who participated in the music therapy intervention.Before the angiographic procedure, patients reported moderate levels of anxiety, with scores of 39 to 40 on the STAI scale. Moderate levels of anxiety have been reported in patients after myocardial infarction and in conjunction with other procedures. After the procedure, these levels decreased in both groups, with no significant difference in the amount of the decrease. Our findings support those reported in the literature and our assumption that having an angiographic procedure is a stressful event for most patients.In our study, patients reported pain before or after the procedure. We measured pain at baseline, before the insertion of the sheath and and at the end of the angiographic procedure, before the removal of the sheath. removal is a The of our was such that we did not measure patients’ reported pain during sheath removal. This post hoc analysis indicated that the intensity of anxiety and pain at baseline was with the intensity of anxiety and pain after the procedure, levels of anxiety and pain after the procedure did not significantly with each This suggests that a of patients may who and experience pain during angiography. this such as pain and anxiety are the procedure, patients who are pain may be more and patients who are more may be more of their pain. we that state anxiety is influenced by trait anxiety. We did not measure the level of trait anxiety at The correlations after the procedure are not as However, the low levels of reported pain and anxiety after the procedure that associated with of an invasive procedure is stress Further study could the effectiveness of music therapy in patients with levels of anxiety or pain at baseline, because therapies may be more effective in this of heart increased and peaked at the end of the procedure. Blood pressure increased and peaked after the procedure after the sheath insertion, and decreased to baseline in heart rate and blood pressure are predominantly controlled by the autonomic nervous system and as such are to of the sympathetic nervous system when patients experience a stressful Music therapy has reduced heart rate and blood pressure in other patients and did not occur in this study. We that arterial blood pressure was measured indirectly at baseline and after the procedure, but was measured directly during the procedure. and do different arterial blood because measure pressure and measure However, when mean arterial pressure is as in this study, with different the are more was this intervention not effective in mediating the stress response for these Music therapy of its effect through and of from stressful this study, patients’ ability to and their may have been influenced by (ie, the table, and the and by an and anxiety about the procedure Although patients reported that the music was it did not decrease the level of anxiety after the procedure when the event was we did not determine patients’ perceived anxiety levels during the procedure. we could have asked patients to their experience and rate their level of anxiety as has been in other that if patients were more or more a physiological response of increased heart rate and blood pressure would We found no differences in heart rate and blood pressure, measured either directly or the procedure. Heart rate increased the procedure and to blood pressure much the Patients in this study routinely received anxiolytic a are used as muscle These at the and levels of the nervous system to various levels of of the nervous system. many patients received nitroglycerin for relaxation of These or in combination influence and cardiac response and, consequently, may have the effect of the music intervention. The routine use of in these patients may have the sympathetic response to by the of heart rate and cardiac The of music may not have been enough to influence the psychophysiological response when pharmacological were would be to the effectiveness and of various of pharmacological and nonpharmacological for the of anxiety in patients undergoing we selected the outcomes of pain and anxiety as the variables on the basis of previous intervention studies in other and our of the psychophysiological response to stress. the of an invasive the patient’s cognitive of the experience is also The comments by the patients and the nurses support this studies could the effectiveness of music therapy on cognitive such as with care, with of pain and patients undergoing diagnostic angiography or percutaneous intervention procedure for the first time (1) experience high levels of anxiety before the procedure and moderate levels of anxiety after the procedure, (2) pain before and after the procedure, and (3) have a cardiovascular psychophysiological stress response heart rate, increased blood during the procedure. A patient-controlled music intervention had no effect on postprocedural pain and anxiety, as measured in this study. Future research could the effectiveness of different of pharmacological in conjunction with music therapy and the effectiveness of music therapy in patients with levels of anxiety pain before the procedure. it no and patients music therapy to be an supportive care intervention for patients undergoing invasive coronary angiographic the support and of the nurses, cardiovascular technicians, and cardiologists in Kingston General cardiovascular and the outpatient cardiology We also the of audiocassette tape by of and for this research was provided by the of care and the Kingston General research