Methods: Scientific articles published between January 2002 and April 2022 were scanned in ScienceDirect, Scopus, PubMed, Web of Science, Google Scholar, Mendeley, Wiley Online Library databases. The keywords "open heart surgery," "cardiovascular surgery," "non-pharmacological," "complementary medicine," and "pain" were used in Turkish and English language. As a result of the search, 7,952 studies were identified and analyzed. Research data were obtained from 49 scientific articles.
Results: The total sample size of the studies included in the analysis was 3,097. The total effect size was found to be 3.070, with a 95% confidence interval of 2.522 at the lower limit and 3.736 at the upper limit. Non-pharmacological pain methods in open heart surgery included positive environmental experience, distraction, massage therapy, hand massage, foot massage, acupuncture therapy, lavender essential oil inhalation, cold application, music therapy, breathing and relaxation exercises, neurolinguistic programming, guided visualization, imagery, therapeutic touch, osteopathic treatment, and transcutaneous electrical nerve stimulation.
Conclusion: The pain of patients who underwent open heart surgery with non-pharmacological methods combined with pharmacological methods was three times less than those without non-pharmacological methods. Based on these findings, non-pharmacological methods are recommended for use due to their ease of application, and low side effects.
Pain is a common problem which occurs after many surgical operations. It is more common in patients undergoing cardiovascular operations.[2] Despite the use of benzodiazepines and opioids, patients undergoing cardiac surgery may experience high-intensity pain. This leads to increased patient demand for opioids.[3] However, postoperative pain and serious side effects of opioid use also pose a clinical challenge after cardiothoracic surgery.[3,4] Satisfactory pain relief is a fundamental right of every patient with pain. Non-pharmacological methods (NPMs) of pain management are methods that do not replace pharmacological methods and can be used in conjunction with pharmacological pain interventions to improve patients" pain relief.[5,6] They are independent nursing practices that can be applied alone or in combination with analgesics, have no side effects, can be used as needed, can be easily taught to patients, do not impose an economic burden, can be easily applied and their effects can be observed immediately. Therefore, non-pharmaceutical interventions are considered means of improving pain relief and reducing opioid use, and many guidelines recommend the use of multimodal pain management strategies using both pharmacological and non-pharmacological interventions.[3,5 ,6]
Non-pharmacological pain management methods used in the studies include cognitive and behavioral methods including distraction, listening to music, relaxation, imagery, breathing techniques, meditation, hypnosis, physical or skin stimulation methods including hot/cold applications, massage, position changes and transcutaneous electrical nerve stimulation (TENS), acupuncture, acupressure, therapeutic touch, and environmental or emotional methods such as touch, reassurance or interior decoration of the room.[6-8]
Non-pharmacological methods such as kinesiotaping, TENS, and cold application improve respiratory functions and can provide less pain during deep breathing and coughing exercises or the use of a spirometer.[9 -14] I n o pen h eart s urgery, by applying music and aromatherapy at different times and methods, starting from the preoperative period and in the postoperative period, vital signs can improve, physical and psychological comfort can be achieved, anxiety levels can decrease, and pain intensity can decrease.[15 -24] Therapeutic touch, osteopathic manipulative treatment, individual exercise programs, neurolinguistic programming and guided visualization methods can be effective in increasing life skills, accelerating functional recovery, increasing comfort, supporting early recovery, and reducing pain and tension.[25 -31] In addition to all these methods, it is possible to reduce the pain intensity, analgesic needs, and opioid and non-opioid drug intake of individuals after open heart surgery by using non-pharmacological methods such as acupuncture, reflexology, massage, and Benson relaxation exercises.[32-36]
There is a limited number of studies investigating whether non-pharmacological methods have an effect on pain in patients undergoing open heart surgery compared to pharmacological methods. In the present study, we, therefore, aimed to examine the effect of non-pharmacological methods on pain relief in patients undergoing open heart surgery compared to pharmacological methods through a systematic review and meta-analysis.
This systematic review was conducted according to the Cochrane guidelines and was reported using the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA). This study is registered in the PROSPERO (The International Prospective Register of Systematic Reviews) database with protocol number CRD42024499619.
Literature search
This meta-analysis utilized ScienceDirect, Scopus, PubMed, Web of Science, Google Scholar, Mendeley, Wiley Online Library databases. Two researchers evaluated all included studies independently. The literature review was completed on April 25th, 2022. Studies were recorded via Microsoft Excel Program. When the inclusion criteria of the studies were met by two independent researchers, they were included in the meta-analysis. In case of disagreement, third reviewers reviewed the documents until a consensus was reached ( Figure 1).
Figure 1. Flowchart of the meta-analysis.
Eligibility criteria
The inclusion criteria of the study included articles and research articles covering patients who underwent open heart surgery between January 2002 and April 2022, full-text studies, studies in English and Turkish languages, and studies containing non-pharmacological pain methods. Quantitative analysis values, access to full texts, and having full statistical results for calculating the effect size were also included in the inclusion criteria for the study.
Exclusion criteria
Editorials, Letters to the Editor, Experience Reports, studies with inappropriate publication years, qualitative studies, theses and abstracts of conference proceedings were excluded. In addition, studies with duplication were not included in the meta-analysis.
Statistical analysis
Statistical analysis was performed using the licensed software Comprehensive Meta-Analysis Academic/Non-profit Pricing version 3.0. The data of all articles meeting the inclusion criteria and decided to be included in the study were entered into the CMA software, and the heterogeneity status of the articles was evaluated. Effect sizes, study weights, 95% confidence intervals, and overall effect size of all studies were calculated under the random effects model in group analyses with a p value of <0.05 in the heterogeneity test and under the fixed effects model in group analyses with a p value of >0.05. The " R.R. a nd O R" v alues were taken as a basis for evaluating the overall effect size in the analyses performed for binary data. Heterogeneity test was applied to determine the effect of non-pharmacological methods on pain in patients undergoing open heart surgery in the articles included in the study. The I2 statistic was used to quantify heterogeneity. Using accepted guidelines, an I2 between 0 and 40% was considered to exclude heterogeneity, 30 and 60% moderate heterogeneity, 50 and 90% substantial heterogeneity, and 75 and 100% considerable heterogeneity. As a result of the heterogeneity test, a p value was set less than 0.05 (p<0.001) and the Q (115.944) value was greater than the value corresponding to the 49 df (degrees of freedom) value in the χ2 table ( χ2 (0.95)=34.764 for df=49). As a result of the individual studies included in the analysis, it was determined that the studies examined in the meta-analysis application had a heterogeneous structure. The Cohen's d coefficient was used to compare means and calculate the overall effect size, and this coefficient was converted to the OR coefficient to compare the effectiveness between sites. The Begg and Mazumdar rank correlation tests and Egger"s regression intercept tests were used for publication bias tests. The statistical significance limit was accepted as p<0.05 in evaluating the overall effect. The kappa (k) statistic was used in the IBM SPSS version 22.0 software (IBM Corp., Armonk, NY, USA) for inter-rater agreement.
Table 1. Assessment details of all studies that underwent quality assessment (n=49)
The sample size of the studies included in the analysis was 3,097. All 49 studies included in the meta-analysis, which evaluated the effect of nonpharmacological methods on pain in patients undergoing open heart surgery, were research articles published in peer-reviewed journals. The studies included in the study were as follows: Descriptive: 3, Descriptive-Sectional: 1, Randomized-Controlled: 28, Single-Blind Randomized-Controlled: 2, Prospective Single-Blind Randomized-Controlled: 1, Double-Blind Randomized-Controlled: 1, Case-Control: 5, Quasi- Experimental: 3, Crossover Design: 1, Prospective Randomized-Controlled: 4. Sample numbers varied between 10 and 200. The average sample size was 72. The characteristics of each primary study are summarized in Table 1. Non-pharmacological treatments used in studies evaluating pain in open heart surgery are given in Table 2.
Study quality evaluation
As a result of the review of the articles, for the remaining 49 publications, the Joanna Briggs Institute MAStARI Critical Appraisal Tool for Descriptive/Case Series Studies adapted into Turkish by Nahcivan and Secginli[37] was used. The tool has a total of nine items. For each study included in the scope of the review, the fulfillment of each feature included in the nine items in the form was examined, and an evaluation was made by giving 1 point if the relevant feature was met and 0 points if it was not met. These criteria allow for a general evaluation of the aims, sample characteristics, findings, and results of the studies. In the study, the articles belonging to all subgroups were examined independently by two researchers, and the articles with a score of ≥6 in the quality assessment were evaluated as high quality. An inter-coder agreement was found to be 76% based on the quality assessment score. The k value <0 is worse agreement than chance agreement; 0.01-0.20 is insignificant agreement; 0.21-0.40 is poor agreement; 0.41-0.60 is moderate agreement; 0.61-0.80 is good agreement; and 0.81-1.00 is very good agreement or 0.75 and above is excellent, 0.40-0.75 is moderate-good and below 0.40 is poor agreement.[37,38] The k v alue i n t his s tudy ( 0.76) showed excellent inter-coder agreement (Table 1).
Table 2. Non-pharmacological treatments used in studies assessing pain in open heart surgery
Validity, reliability, and bias
Funnel plot, Rosenthal"s Safe N, and Orwin"s Safe N methods were used to demonstrate that the meta-analysis study was reliable and valid and to determine publication bias. The effect sizes of 49 studies examining the effect of nonpharmacological methods on pain in patients undergoing open heart surgery were evaluated according to the funnel scatter plot. In the funnel plot, if the effect sizes of individual studies are inside the funnel lines and symmetrically distributed, it does not cause publication bias; if the effect sizes of individual studies are outside the funnel lines and asymmetrically distributed, it causes publication bias.[38] In line with this information, when Figure 2 is analyzed, it can be said that the effect sizes of the studies are distributed in the graph close to a symmetrical shape ( Figure 2).
When the Begg-Mazumdar and Egger tests for the bias indicators of the funnel plot were evaluated, these values were Begg-Mazumdar Kendall"s tau=0.016, p=0.885 and Egger: bias=0.759 (95% CI: 0.211 to 2.545), p=0.548. In this case, the p value was greater than 0.05 (p=0.885). These findings indicated that there was no bias. In addition, Rosenthal"s fail-safe number data, another test to determine study bias, also supports the data in the funnel plot.
The effect of non-pharmacological methods on pain
In Figure
Deep breathing and coughing exercises, which are practices that accelerate postoperative recovery, also contribute to reducing pain after open heart surgery. When the studies included in the meta-analysis were examined, deep breathing and coughing exercises were found to be effective in reducing pain when applied alone or together with spirometry and relaxation exercises. In addition, the use of these methods can also contribute to the improvement of lung functions.[43,45-47]
Babamohamadi et al.[43] s howed t hat d istraction was an effective nursing intervention in controlling short-term and transient pain. Distraction could be achieved through various techniques including progressive muscle relaxation, meditation and rhythmic breathing (RB), in which patients were asked to close their eyes in a supine position, breathe in through the nose, hold their breath and exhale through the mouth counting from 1 to 3. All patients in the intervention group were instructed to focus solely on their breathing while breathing, and the severity of pain after the intervention was found to be significantly lower in the experimental group compared to the control group. The authors concluded that it might help to reduce the number of analgesic use in these patients.
Considering the studies on massage therapy among non-pharmacological methods, massage therapy showed a positive effect on pain in patients who underwent massage therapy. This method is applied in various ways such as hand, foot, extremity and back massage. While massage practices can be applied alone in open heart surgery, there are also studies in which they are used in combination with methods such as patient education, quiet rest time, and relaxation.[5,25 ,32 -34,44 ,48 -53] Alameri et al.,[5] in their study, applied 10-min foot massage to the experimental group by a research nurse within 30 min after taking opioid pain medication, twice in one day, and reported that pain intensity and anxiety significantly reduced in the experimental group compared to the control group. Another study by Boitor et al.[44] randomized patients to two 20-min hand massages (experimental), two 20-min hand holds (active control), or two 20-min rest periods (passive control/standard care) in addition to standard care, and assessed pain intensity, pain discomfort, anxiety, muscle tension, and vital signs before, after, and 30 min after each intervention. The findings showed that a 20-min hand massage in addition to routine postoperative pain management could simultaneously reduce pain intensity, pain discomfort and anxiety by an average of two points on a 0-10 scale.[44] In the study of Bauer et al.,[48] the efficacy and feasibility of massage therapy in relieving pain, tension and anxiety were evaluated in patients undergoing cardiovascular surgery. The patients were randomized to receive massage therapy or a quiet rest period (control). The authors reported that pain, anxiety and tension significantly reduced in patients receiving massage.
Considering the effects of environmental or emotional methods on pain from the non-pharmacological management used in the studies examined, in Aslan and Tosun"s study,[42] the effects of positive environmental experiences on the patient were examined and pain levels were found to be lower in relation to environmental awareness.
With the kinesiotaping method, the respiratory functions of open heart surgery patients can be improved, the pain intensity can be reduced and, therefore, the use of pharmacological methods can be reduced.[10,14]
The music method, which is frequently used among non-pharmacological methods in open heart surgery patients, has various applications before and after surgery. Music, which is a simple, safe and effective method, can reduce anxiety, pain intensity and the amount of analgesics thanks to its physically and psychologically relaxing effect.[18 -24]
With TENS, a method of electrical nerve stimulation, patients" respiratory functions and pain can be improved after open heart surgery. Thus, opioid analgesic use may also decrease.[45,53-55]
Acupuncture methods are effective methods in reducing pain after open heart surgery and limiting opioid and non-opioid drug intake.[33,35 ,36]
In the reflexology method, pain can be reduced by applying pressure and massage to reflex pressure points. Ice massage or Benson relaxation exercises can also be included in these methods.[32,34]
Cold application is among the methods frequently used in thoracic surgeries. The intensity of pain after open heart surgery can be reduced by the application of cold gel packs. In addition, possible pain during exercise can be reduced by applying cold gel packs before deep breathing and coughing exercises or before using a spirometer.[54 -57]
Aromatherapy can be applied at different time periods before and after extubation in open heart surgery. Studies have shown that aromatherapy improves vital signs and reduces pain and anxiety.[15 -17]
Following open heart disease, the cardiac system is equalized, therapeutic touch, osteopathic manipulative treatment and individual exercise programs appear to increase life skills, accelerate functional recovery, and contribute to pain relief.[26,29-31]
With neurolinguistic programming and guided visualization methods, it can be easier to increase the comfort of patients after open heart surgery, support early recovery, and reduce pain and tension.[25,27 ,28]
After open heart surgery, patients" pain levels can be reduced by informing them about reducing pain, providing training, and providing follow-up by phone after discharge.[58 -60]
The results of the meta-analysis of 49 studies that examined the effect of non-pharmacological methods on pain in patients undergoing open heart surgery and included in the study showed that the effect size of non-pharmacological methods on pain in patients undergoing open heart surgery was statistically significant with a value of 3.070 (W.A; 2.522-3.736; p<0.001) and was above the OR of +1. According to this result, non-pharmacological interventions were three times more effective in reducing the severity of pain in patients undergoing cardiac surgery than those without non-pharmacological methods. In this metaanalysis study, it is thought that non-pharmacological methods used in addition to pharmacological methods are effective on patients" quality of life and may reduce opioid use.
Currently, open heart surgery is among the most frequently performed surgeries and severe pain levels are reported by patients after these surgeries. With effective pain control after open heart surgery, patients" recovery is accelerated and their quality of life increases. In addition, with pain control, complications can be prevented, health care expenditure costs can be reduced, and pain can be prevented from becoming chronic. In addition to pharmacological methods, it is of utmost importance to use non-pharmacological methods in pain control.
Nonetheless, there are some limitations to this meta-analysis. The main limitation is the inclusion of studies in only two languages, English and Turkish. Additionally, pain is a patient-reported condition. Pain varies from person to person. Therefore, non-pharmacological methods used to relieve pain are affected by the individual characteristics of the patients. Furthermore, although it was concluded that pharmacological treatments might be effective in relieving postoperative pain after cardiac surgery when combined with non-pharmacological treatments, its effectiveness on pain, which is a subjective condition, could not be clearly stated. The fact that the research (programming and guided images) was not conducted only with randomized-controlled studies and that more studies are needed in this field are among the limitations to our study. Additional limitations include subjectivity, possible publication bias, and handling of main effects.
However, the main strengths of this metaanalysis include its holistic examination of nonpharmacological pain methods in open heart surgery and its statistical significance. Non-pharmacological pain methods are cost-effective, have few side effects, and are easy to use. Additionally, with the use of nonpharmacological methods, the use of pharmacological methods, particularly opioids, tends to decline.
In conclusion, the use of non-pharmacological methods, as well as pharmacological methods, in pain control in patients undergoing cardiac surgery reduces the probability of pain by three times compared to non-pharmacological methods. Based on our results, using non-pharmacological methods is crucial in relieving patients" pain. Pain is a subjective finding reported by patients. However, it also adversely affects quality of life and recovery. It is, therefore, critical to use non-pharmacological methods to reduce pain in nursing care.
Ethics Committee Approval: As the study was conducted as a meta-analysis study, a literature review model was used. On the basis of the literature review, the approval of the Ethics Committee for research was not obtained, as it did not directly involve an intervention or effect on animals or humans.
Data Sharing Statement: The data that support the findings of this study are available from the corresponding author upon reasonable request.
Author Contributions: Design, analysis or interpretation, literature search, writing: T.Y., M.O., Ç.A.; Data collection or processing: T.Y., M.O.
Conflict of Interest: The authors declared no conflicts of interest with respect to the authorship and/or publication of this article.
Funding: The authors received no financial support for the research and/or authorship of this article.