No. 355-Physiologic Basis of Pain in Labour and Delivery: An Evidence-Based Approach to its Management

The role and outcomes of music therapy during pregnancy: a systematic review of randomized controlled trials

INTRODUCTION

The abundant functions of music and its effects on human's mental and physical health have been verified since ancient times, but rarely received attention as an alternative obstetric intervention.

OBJECTIVE

This study aims to investigate the benefits of music therapy on prenatal and delivery experiences of pregnant women.

METHOD

A systematic search for articles was conducted in electronic databases including CINAHL, Web of Science, PubMed/Medline, and CNKI. A total of 240 articles were identified, and 17 studies were selected for this review. The extracted data included author, year, location, sample size, intervention phase, type of music, music therapy strategy, measuring instruments, and results. The data were organized chronologically based on the publication year of each study.

RESULT

The articles indicated that music therapy has advantages in reducing pain during childbirth, lowering anxiety and stress levels in mothers, improving sleep quality, and increasing fetal movements, basal fetal heart rate, and accelerations.

CONCLUSION

Based on the findings, it can be concluded that music therapy is an effective approach to enhance the experience of pregnant women during pregnancy and delivery. Therefore, its implementation in obstetrical clinical practice is highly recommended.

Nonpharmacological pain relief for labour pain: knowledge, attitude, and barriers among obstetric care providers

Background

Labor pain is considered the worst pain in a woman's life. Hence, pain control should be essential to labor management at any level. There is scarce information, and there are gaps regarding the knowledge, attitude, and barriers to the utilization of nonpharmacological approaches for pain relief in Saudi Arabia. Therefore, the current study aims to evaluate nonpharmacological pain relief (NPPR)-related knowledge, attitudes, and barriers among obstetric care providers in Najran, Saudi Arabia.

Methods

A cross-sectional analytical study was performed at maternity departments in Maternal and Children Hospital (MCH), Najran, Saudi Arabia, from April 1 to May 26 2023. The study involved 186 obstetric care providers (OPCs), physicians (19), nurses (144), and midwives (23). A structured self-reported questionnaire was used to collect data and involves five main sections: demographic data, work-related data, nonpharmacological pain relief-related attitude, perceived barriers, and knowledge quiz. The adjusted odds ratio (AOR) along with 95% CI was estimated to determine the factors associated with nonpharmacological pain relief-related knowledge and attitude using multivariate analysis in the binary logistic regression.

Results

Over three-quarters (79%) of obstetric care providers had adequate knowledge of nonpharmacological pain relief methods. The majority (85.5%) of the participants had a positive attitude toward NPPR in labour pain management, with the mean scores ranging from 3.55-4.23 for all sub-items. Obstetric care providers acknowledged that patient belief, lack of time, and workload were the strongest barriers to offering nonpharmacological pain relief methods for labour pain 67.6%, 64.5%, and 61.3%, respectively. In binary logistic regression analysis, the in-service training related to nonpharmacological pain relief (AOR = 5.871 (2.174-15.857), p = 0.000), (AOR = 3.942 (1.926-11.380), p = 0.013) and years of work experience (AOR = 1.678 (1.080-2.564), p = 0.019), (AOR = 1.740 (1.188-2.548), p = 0.003) were significantly associated with obstetric care providers' knowledge and attitudes regarding nonpharmacological pain relief (p ≤ 0.05).

Conclusion

Although most OPCs have adequate knowledge and a positive attitude regarding NPPR, they need motivational strategies to enhance their utilization. In addition, an effort should be made to decrease OPCs' workload to provide more time for NPPR application and patient education. Training courses and in-service training can play an important role in enhancing NPPR knowledge and attitude and, consequently, its application. Also, in each working unit, the policymakers should provide clear guidelines and policies that enhance and control the utilization of NPPR.

Delivery in a vertical birth chair supported by freedom of movement during labor: A randomized control trial

To evaluate the effect of delivery in a vertical birth chair (VBC) and traditional delivery table (DT) supported by women's movement during labor on the labor process, fetal outcome, maternal hormone levels, birth comfort, and satisfaction. This randomized controlled trial was conducted with 1:1:1 allocation. Group 1: in the VBC in upright position, Group 2: on the DT in supine position, these groups supported by freedom of movement, control group: on the DT in supine position, labor in bed. The duration of second stage of labor was not different between the groups (p = 0.246). The occurrence of instrumental birth, episiotomy, and perineal laceration was also not different among the groups (p = 0.772, p = 0.953, and p = 0.124). The use of uterotonic was observed in control group (p = 0.001). 1 and 5 APGAR scores of newborns were not different in all groups (p = 0.121, p = 0.268). The lowest pain score was observed in Group 1 (p = 0.001). Birth comfort and satisfaction were higher in Group 1 (p = 0.001 and p = 0.001). Decreased postpartum prolactin levels and increased postpartum oxytocin levels were observed in the control and Group 1 (p = 0.004, p = 0.006). Freedom of movement during labor and delivery using VBC in upright position can play birth-promoting and supporting role. There were no negative effects on the fetal outcome.

Effect of Virtual Reality and Music Therapy on the Physiologic Parameters of Pregnant Women and Fetuses and on Anxiety Levels: A Randomized Controlled Trial

INTRODUCTION

Anxiety negatively affects pregnant women and their fetuses. It can cause misleading test readings in electronic fetal monitoring, affect the duration of the first stage of labor, and influence certain aspects related to childbirth. This study aimed to evaluate the effects of virtual reality and music therapy on anxiety levels, maternal and fetal physiologic parameters, and labor and birth outcomes.

METHODS

A total of 343 full-term pregnant women participated in a randomized controlled trial and were divided into 3 parallel groups: music therapy intervention (n = 104), virtual reality intervention (n = 124), and control (n = 115). The interventions were delivered during a nonstress test in the third trimester and during labor. Data were collected from April 2017 to May 2018. Measures included the Spielberger State-Trait Anxiety Inventory, maternal blood pressure, maternal and fetal heart rates, and labor and birth outcomes. The study was registered in the Australian New Zealand Clinical Trial Registry (ACTRN12621001647820).

RESULTS

Women in the music therapy and virtual reality groups had lower levels of anxiety after a nonstress test (P < .001), and the women were more likely to have a reactive nonstress test (P < .001) compared with the control group. After the nonstress test and intervention were complete, the music therapy and virtual reality groups had significant decreases in systolic blood pressure (P < .001), diastolic blood pressure (P < .001), and maternal heart rate (P = .003) compared with the control group. Furthermore, fetuses in the control group were more likely to experience nonreassuring fetal heart rate tracings compared with the music therapy and virtual reality groups, respectively (P = .004).

DISCUSSION

Our findings support the use of music and virtual reality during nonstress tests and labor as nonpharmacologic interventions to reduce anxiety, improve maternal and fetal physiologic parameters, and improve labor and birth outcomes. This research should be replicated in diverse perinatal settings.

A comparison of the effect of Swedish massage with and without chamomile oil on labor outcomes and maternal satisfaction of the childbirth process: a randomized controlled trial

PURPOSE OF STUDY

Massage is widely used as a traditional technique during labor and delivery. The aim of this study was to evaluate the effect of Swedish massage with and without chamomile oil on delivery outcomes.

METHODS

The present study was a randomized clinical trial on 154 primiparous pregnant women who were selected by random sampling method and divided into 3 groups: massage with chamomile oil (n = 53), massage without chamomile oil (n = 51), and control group (n = 50). Data collection tools included demographic and delivery information questionnaire, Visual Analogue Scale (VAS), maternal satisfaction with delivery scale, and Partograph form. In the two intervention groups, Swedish massage techniques (i.e., Effleurage, Petrissage, Vibration, and Superficial stroke) were performed with and without the use of chamomile oil since the active phase of labor (5 cm dilatation), while the control group received only routine labor care during labor.

RESULTS

Swedish massage with chamomile oil significantly reduced the labor pain score, reduced the length of active phase and the second stage of labor, and increased the score of maternal satisfaction with the labor process (P < 0.001). In addition, there was a significant relationship between the type of study groups and the type of delivery (P < 0.043).

CONCLUSION

The results of the study showed that using Swedish massage techniques with or without chamomile oil can improve labor outcomes. Swedish massage using chamomile oil was associated with better results compared to the same massage without using chamomile oil. Clinical trial code IRCT20200513047430N1.

Consistency of Delivery Mode Increases Chinese Mothers' Maternal Satisfaction: The Effect of Perception of Support from Medical Staff and Mothers' Self-Efficacy

Maternal satisfaction is essential for women. Extant research has focused on how a practical delivery method effects maternal satisfaction. This article tried to explore the effect of the consistency of delivery mode between mothers' expectations and their experience of maternal satisfaction and proposed the mediating effect of the perception of support from medical staff and the moderated mediation effect of maternal self-efficacy. Based on two studies, this article found that the consistency of the delivery mode has a positive effect on maternal satisfaction, and women's perception of support from medical staff mediated the above relationship. The maternal perception of self-efficacy has a moderated mediation effect; specifically, for women with a high level of self-efficacy, the positive effect of the consistency of the delivery mode on maternal satisfaction through perception support from medical staff is stronger. This article highlights the importance of the consistency of the delivery mode between women's expectations and the experience of maternal satisfaction and the psychological mechanisms involved. The results extend the theoretical research on ethics in childbirth and provide implications for improving women's maternal satisfaction from medical staff and themselves.

The Effect of Listening to the Recitation of the Surah Al-Inshirah on Labor Pain, Anxiety and Comfort in Muslim Women: A Randomized Controlled Study

This study aimed to identify whether listening to the recitation of the Surah Al-Inshirah (94th Chapter of the Holy Qur'an) during labor had any effect on women's pain, anxiety and comfort levels. Designed as a randomized controlled trial, the study was performed with the participation of 126 pregnant Muslim women. The study showed that listening to the recitation of the Surah Al-Inshirah during labor had positive effects on the women's pain, anxiety and comfort levels. In this respect, it is recommended that based on individuals' religious beliefs, spiritual elements such as surahs, prayers and hymns be integrated into the midwifery care offered during labor.

Virtual reality is beneficial in decreasing pain in labouring women: A preliminary study

BACKGROUND

Women use a range of non-pharmacological pain relief methods to reduce labour pain intensity and to help manage labour pain.

AIMS

The purpose of this intervention study was to determine whether virtual reality would have an effect on labour pain intensity. Virtual reality has been shown to be effective in reducing pain in other acute pain settings.

MATERIALS AND METHODS

This study was an intervention study in labour in a cross-over within-subjects design (Clinical Trials Registry Number: ACTRN12618001776291P). Fourteen participants reported their pain and had their heart rate and blood pressure measured during active labour while using and not using virtual reality.

RESULTS

There were significantly lower reported pain scores (6.14 compared to 7.61, P < 0.001) and maternal heart rate (79.86 beats per minute compared to 85.57, P = 0.033) and mean arterial pressure (88.78 mmHg compared to 92.61 mmHg, P = 0.022) were lower when using virtual reality compared to when not using virtual reality during active labour.

CONCLUSION

This study makes an important contribution to the field of virtual reality in labour and birth. It is consistent with other recent findings of reduced pain in labour and links decreased pain scales to heart rate and blood pressure, the physiological markers of pain.

The barriers to offering non-pharmacological pain management as an initial option for laboring women: A review of the literature

INTRODUCTION

Many women use pharmacological or non-pharmacological pain management (NPPM) during childbirth, however, evidence shows the usage rates of pharmacological pain management are increasing. The shift towards a biomedical approach to birth care opposes the enduring midwifery philosophy of trusting the woman and her body. Identifying midwives’ beliefs and attitudes towards perceived and actual barriers to offering NPPM as an initial option will provide insight into the factors that affect this.

METHODS

This review of the literature sought to understand midwives’ beliefs and attitudes towards the barriers to offering NPPM as an initial option for laboring women. Peer-reviewed journals were searched for primary research that met the inclusion criteria and explored midwives’ beliefs and attitudes towards the barriers to offering NPPM as an initial option for laboring women. Included studies were evaluated for quality according to the Critical Appraisal Skills Programme (CASP) checklists.

RESULTS

Thirteen qualitative studies met the inclusion criteria and four main themes of barriers to midwives offering NPPM emerged: health system-related, health facility-related, health practitioner-related, and health consumer-related barriers.

CONCLUSIONS

The review of the literature highlighted there are barriers that prevent or delay the initial utilization of non-pharmacological methods of pain management in labor by midwives. These findings can be used as a platform to inform further research into this topic.

Acupoint Injection Decreases Anesthetic Cosumption during Combined Spinal-Epidural and Patient-Controlled Epidural Labor Analgesia

OBJECTIVE

To explore if acupoint injection can improve analgesic effects or delivery outcomes in parturients who received combined spinal-epidural analgesia (CSEA) and patient-controlled epidural analgesia (PCEA) for labor analgesia.

METHODS

A total of 307 participants were prospectively collected from July 2017 to December 2019. The participants were randomized into the combined acupoint injection with CSEA plus PCEA group (AICP group, n=168) and CSEA plus PCEA group (CP group, n=139) for labor analgesia using a random number table. Both groups received CSEA plus PCEA at cervical dilation 3 cm during labor process, and parturients of the AICP group were implemented acupoint injection for which bilateral acupoint of Zusanli (ST 36) and Sanyinjiao (SP 6) were selected in addition. The primary outcome was Visual Analogue Scale (VAS) score, and the secondary outcomes were obstetric outcomes and requirement of anesthetics doses. Safety evaluations were performed after intervention.

RESULTS

The VAS scores were significantly lower in the AICP group than in the CP group at 10, 30, 60, and 120 min after labor analgesia (all P<0.05). The latent phase of the AICP group was shorter than that of the CP group (P<0.05). There were less additional anesthetics consumption, lower incidences of uterine atony, fever, pruritus and urinary retention in the AICP group than those in the CP group (all P<0.05).

CONCLUSION

Acupoint injection combined CSEA plus PCEA for labor analgesia can decrease the anesthetic consumption, improve analgesic quality, and reduce adverse reactions in the parturients. (Registration No. ChiMCTR-2000003120).

Midwives and women's experiences of Sterile Water Injections for back pain during labour: An integrative review

BACKGROUND

/ OBJECTIVE: This integrative review summarises original research that explores the experiences and perceptions of midwives and women using sterile water injections (SWI's) during labour.

DESIGN

Integrative review.

METHODS

A robust search strategy was conducted using the following databases: Scopus, Cumulative Index to Nursing and Allied Health (CINAHL), Ovid Medline and PubMed. All articles were assessed for quality using the Joanna Briggs Institute Critical Appraisal Tools (2017) scoring. Whittemore and Knafl's (2005) five stage approach was used to analyse the primary literature related to midwives and women's experiences of sterile water injections (SWI's) for back pain during labour.

FINDINGS

A total of 291 articles were retrieved and 13 papers were included in this review (four qualitative including one case report and nine quantitative) that fulfilled the inclusion criteria. Three overarching themes were identified: 'Assessment, perception and communication of pain', 'Techniques of administration of SWI's' and 'Barriers and resistance to using SWI's'. The 'Assessment, perception and communication of pain' theme included four subthemes: 'balancing the expectation of the injection pain against pain relief'; 'using appropriate language to prepare women'; 'rapid onset and increased pain relief with SWI's in comparison to saline'; and 'midwives high considerations for using SWI's as a form of pain relief'. The 'Techniques of administration of SWI's' theme included two subthemes: 'intradermal is better than subcutaneous injections'; and, 'four injections is better than one'. The 'Barriers and facilitators to using SWI's' theme included four subthemes: 'guidelines and evidence'; 'level of experience'; 'midwifery philosophy challenges'; and 'resistance from colleagues'. For example, 'midwifery philosophy challenges' included midwives being conflicted about providing an invasive, painful procedure as counter-intuitive to supporting women through the pain of labour. Midwives need opportunities to learn and develop skills for using SWI's. Women described feeling more empowered during their labour and appreciated the use of SWI's including the rapid onset of pain relief and the absence of side effects. The ability for women to exert some control over their pain whilst still being able to experience the physical sensations of labour and birth was important.

CONCLUSIONS AND IMPLICATIONS FOR PRACTICE

The review supports the evidence for the use of SWI's however, there is limited evidence available and more information needs to be provided about the benefits of this non-pharmacological technique for back pain during labour. Generalised guidelines are needed to ensure consistent practice in the provision of care for women experiencing back pain during labour.

The Role of Oxytocin and the Effect of Stress During Childbirth: Neurobiological Basics and Implications for Mother and Child

The neuropeptide oxytocin acts as a hormone and a neuromodulator, influencing a multitude of human social behaviors, including reproduction. During childbirth and the postpartum period, it plays a key role in regulating and controlling processes that ensure a safe birth and the health of mother and child. Especially the onset of labor, the progress of labor and initial breastfeeding are mediated by oxytocin. In the maternal brain it controls the initiation of the mother-infant bond and the mother's emotional responses towards her child. In this review we summarize the current state of knowledge about the role of oxytocin during the different aspects and mechanisms of human childbirth, combining research from human and animal studies. Physiological and psychological stress during childbirth and lactation can have negative effects on the progress of labor, breastfeeding and bonding. We discuss how maternity caregivers can support the positive effects of oxytocin and minimize the effects of stress. Furthermore, we highlight aspects of the basic neurobiological principles and connections where further research is needed to improve our understanding of the regulation and the effects of oxytocin to support maternal and infant health.

Reviewing pain management options for patients in active labor

Pain perception and preferences for pain management are unique to each woman in labor. This article provides an overview of the physiology of labor pain, discusses available nonpharmacologic and pharmacologic approaches to managing pain during active labor, and discusses potential benefits and risks for each option.

Comparative Analgesic Effects of Intradermal and Subdermal Injection of Sterile Water on Active Labor Pain

Background

The labor pain is one of the factors encouraging pregnant women for cesarean section delivery. Recently, intradermal and subdermal injection of distilled water has shown to be effective in improving this pain.

Objectives

The present study aimed to determine which method has a greater impact on labor pain reduction.

Methods

In this double-blind, randomized clinical trial, 121 nulliparous women with a gestational age of ≥ 37 weeks were randomly divided into three groups: (1) 0.5 cc sterile water injection subdermally at four sacral points with insulin needles (n = 40); (2) 0.5 cc sterile water injection intradermally (n = 39); and (3) needle contact with the mentioned points as the placebo (n = 42). Before the intervention, the VAS score was measured for labor pain, and it was repeated 10, 30, 60, and 90 min after the intervention. The results were compared between the three groups.

Results

Before the intervention, the mean VAS pain score had no significant difference between the three groups. However, 30, 60, and 90 min after the intervention, the mean pain score was significantly lower in the intradermal and subdermal injection groups than in the control group (P = 0.001); however, the difference between the intradermal and subdermal injection groups was not significant.

Conclusions

The injection of distilled water by either intradermal or subdermal method was associated with a significant reduction in the pain score during labor, but there was no difference between these two methods in terms of decreasing labor pain. As sterile water injection is a safe, effective, and low-cost method, it is proposed to increase the knowledge of midwives and obstetricians about this method.

Impact of Sophrology on cardiopulmonary fitness in teenagers and young adults with a congenital heart disease: The SOPHROCARE study rationale, design and methods

Background

Recent advances in the field of congenital heart disease (CHD) have significantly improved the overall prognosis. Now more attention is being given to health-related quality of life (HRQoL) and promotion of physical activity. Non-invasive relaxation therapy may be effective in cardiac patients concerned with exercise-induced dyspnoea. The SOPHROCARE randomised trial aims to assess the impact of Caycedian Sophrology on cardiopulmonary fitness in adolescents and young adults with CHD.

Methods

The SOPHROCARE trial is a nationwide, multicentre, randomised, controlled study in CHD patients aged from 13 to 25 years old. Patients will be randomised into 2 groups (8 Sophrology group sessions vs. no intervention). The primary outcome is the change in percent predicted maximum oxygen uptake (VO2_max) between baseline and 12-month follow-up. A total of 94 patients in each group is required to observe a significant increase of 10% in VO2_max with a power of 80% and an alpha risk of 5%. The secondary outcomes are: clinical outcomes, cardiopulmonary exercise test parameters (VE/VCO2 slope, ventilatory anaerobic threshold, oxygen pulse, respiratory response to hypercapnia), health-related quality of life score (PedsQL), physical and psychological status.

Conclusion

After focusing on the survival in CHD, current research is opening on secondary prevention and patient-related outcomes. We sought to assess in the SOPHROCARE trial, if a Sophrology program, could improve exercise capacity and quality of life in youth with CHD.

Trial registration

Clinicaltrials.gov (NCT03999320).

Being in charge in an encounter with extremes. A survey study on how women experience and work with labour pain in a Nordic home birth setting

PROBLEM

There is a knowledge gap regarding women's experiences of coping with labour pain when not soliciting or not having access to pharmacological pain relief.

BACKGROUND

How women manage labour pain is complex, multifaceted and only the woman giving birth can assess the experienced pain. Women in the Nordic countries planning for a homebirth have little or no access to pharmacologic pain relief during labour.

AIM

The aim of this study was to explore how women experience and work with labour pain when giving birth in their own home.

METHODS

Quantitative and qualitative data was prospectively collected and altogether 1649 women with a planned homebirth answered closed and open-ended questions about labour pain and birth experience.

RESULTS

While labour pain was often experienced as positive or very positive, the intensity was experienced as severe or the worst imaginable pain. Two main themes arose from the womens´ descriptions of their birth experience regarding labour pain: An encounter with extremes and Being in charge at home.

DISCUSSION

Women perceived labour pain as severe but manageable and were dedicated to completing the birth at home. Being at home enabled the women to exercise autonomy and work with labour pain on their own terms, together with the midwife and support persons.

CONCLUSIONS

This study provides knowledge about women's experiences of labour pain in a home birth setting who used varying strategies to work with labour pain. This is a subject that should be explored further since results could also apply to facility-based birth settings.

The International Childbirth Initiative: 12 steps to safe and respectful MotherBaby-Family maternity care

The ICI has developed a quality assurance program of 12 steps for safe and respectful MotherBaby–Family maternity care that all birthing units can implement.

Virtual Reality Analgesia in Labor: The VRAIL Pilot Study-A Preliminary Randomized Controlled Trial Suggesting Benefit of Immersive Virtual Reality Analgesia in Unmedicated Laboring Women

This pilot study investigated the use of virtual reality (VR) in laboring women. Twenty-seven women were observed for equivalent time during unmedicated contractions in the first stage of labor both with and without VR (order balanced and randomized). Numeric rating scale scores were collected after both study conditions. Significant decreases in sensory pain -1.5 (95% CI, -0.8 to -2.2), affective pain -2.5 (95% CI, -1.6 to -3.3), cognitive pain -3.1 (95% CI, -2.4 to -3.8), and anxiety -1.5 (95% CI, -0.8 to -2.3) were observed during VR. Results suggest that VR is a potentially effective technique for improving pain and anxiety during labor.

Nurses and midwives' experiences of using non-pharmacological interventions for labour pain management: a qualitative study in Ghana

BACKGROUND

Non-pharmacological interventions hold promise in reducing labour pain, with minimal or no harm to the mother, foetus and the progress of labour and are simple and cost-effective. Yet their use has not been adequately explored in clinical settings, especially in sub-Saharan Africa.

METHODS

This was a descriptive phenomenological study. Fifteen (15) nurses and midwives working in labour wards of two hospitals in Ghana were interviewed. Data analysis was guided by the principles of coding by Bailey and the constant comparative approach to generate themes. Ethics approval was obtained from the 37 Military Teaching Hospital Institutional Review Board in Ghana.

RESULTS

Three major themes were identified that described the experiences of nurses and midwives regarding their use of non-pharmacological interventions in managing labour pain. These were familiarity with non-pharmacological interventions, perceived benefits of non-pharmacological interventions, and barriers to the use of non-pharmacological interventions in the management of labour pain.

CONCLUSIONS

While some non-pharmacological pain management interventions were known and used by the nurses and midwives, they were not familiar with a good number of these interventions. Nurses and midwives perceived these interventions to be beneficial yet a number of barriers prevented easy utilisation.

Adhesive pyramidal thorn patches provide pain relief to athletes

Pain in athletes is ideally treated without systemic medicine. Therefore, complementary and alternative medicine, including patch treatments, is often used. The physiologic mechanisms of pain relief produced by patch treatment, however, are not well elucidated. In the present study, we introduce a pyramidal thorn (PT) patch that we developed, demonstrate the effects of this PT patch for the treatment of various types of pain in 300 subjects, and suggest a physiologic mechanism for the pain relief effects. One treatment with the PT patch effectively relieved pain in almost half the subjects evaluated. Except for pain generated deeply under the skin, such as low-back pain, pain was eliminated within four treatments with the PT patch in almost all of the subjects. Interestingly, the pain-sensing region moved along the nerve fibers after each trial. Further, patches without PT also provided some pain relief. We considered that this effect was due to hair deflection on the skin; that is, adhesion of the PT patch activates Merkel cells directly as well as Merkel cell-neurite complexes around the hair follicles by deflecting the hair follicles, whereas adhesion of a patch without PT only activates the Merkel cell-neurite complexes. In any case, patch adhesion stimulates Aβ fibers to alleviate pain. Finally, we found that the pain threshold is increased by electric stimulation, suggesting that the gentle adhesion of a PT patch would be more effective. To our knowledge, this is the first study to demonstrate physiologically the validity of an adherent patch for pain relief.