Effect of acupressure on pain intensity and physiological indices in patients undergoing extracorporeal shock wave lithotripsy: a randomized double-blind sham-controlled clinical trial

Urinary stones are one of the most common reasons individuals seek urology clinics [1], affecting 12% of the general population [2]. Extracorporeal shock wave lithotripsy (ESWL), a non-invasive therapeutic technique using shock waves, is considered the standard treatment for upper urinary tract and kidney stones [3]. Since its first reported use in 1984 [4], ESWL has quickly gained popularity as an alternative to invasive surgeries due to its non-invasiveness [3]. The ESWL is the first-line treatment for kidney stones smaller than 2 cm [5]. However, this method inherently causes significant pain; thus, pain relief is recommended for patients during the procedure [6]. Severe pain might limit the opportunity for applying sufficient energy doses, leading to additional movement and increased respiration rates [7]. Additionally, acute pain may increase the risk of kidney hematoma following stone fragmentation due to increased blood pressure [1].

Pain sources from ESWL include somatic pain (superficial pain resulting from the impact of waves on the skin and muscles) [2] and visceral pain (deep pain resulting from the penetration of shock waves into the capsule and nerves of the kidney) [5]. There is no consensus on a standardized analgesic regimen for optimal pain reduction during lithotripsy [8]. On the one hand, the use of pharmacological regimens, such as nonsteroidal anti-inflammatory drugs (NSAIDs) and opioid medications, during lithotripsy is associated with limitations [9]. Undesirable effects of NSAIDs include allergy, gastrointestinal bleeding, decreased renal blood flow, and even kidney failure [10]. Additionally, the use of opioids may cause various side effects such as nausea, vomiting, low blood pressure, and respiratory depression [11]. Therefore, it is essential to develop non-pharmacological methods to control vital signs and reduce patient pain [12].

In recent years, non-pharmacological methods such as acupressure and acupuncture have gained significant attention [13]. The application of hand and finger pressure at acupuncture points in acupressure is believed to lead to a balanced energy system and a stable state of homeostasis in the body [14]. According to Western theory, the analgesic effect of acupressure can be explained through the endorphin theory (release of a chemical substance effective in pain) and the gate control theory (blocking the transmission of pain signals to higher nerve centers following acupressure stimulation) [15]. Furthermore, acupressure results in pain relief by vasodilation and increasing blood flow, secretion, and release of chemicals such as dopamine and serotonin [16]. Experimental and clinical studies have well supported the effects of acupressure on pain relief, stabilization of physiological indicators, and reduction in analgesic consumption [13, 17]. Also, it has been reported that there is a direct correlation between pain and patient satisfaction [18], and patients undergoing ESWL may need repeated treatment sessions [19]. This non-pharmacological method is effective, safe, and cost-effective, providing pain relief with patient satisfaction without additional equipment [12, 20].

To the best of our knowledge, there have been limited studies on the impact of acupressure on managing complications during ESWL. On the other hand, some available evidence has reported contradictory results regarding the effectiveness of acupressure in different clinical situations [11, 13]. In this study, acupressure at the Qiu point is proposed, and its effectiveness in alleviating colicky pains has been documented in several studies [21, 22]. No studies have been conducted in the existing literature on using acupressure at the Qiu point to manage pain and physiological indices in patients undergoing ESWL, highlighting the necessity for research in this area. Additionally, there appears to be no evaluation of the effects of acupressure on lithotripsy success and patient satisfaction. Considering the importance of managing complications during lithotripsy and the growing interest in complementary therapies, this study aims to examine the impact of acupressure at the Qiu point on pain intensity and physiological indices in ESWL patients. Moreover, patients' satisfaction with acupressure application and the success of lithotripsy were evaluated as secondary outcomes.

This clinical trial examined the effect of acupressure on pain intensity and physiological indicators in patients treated with ESWL. It was found that massaging the Qiu point for 10 min before ESWL reduced pain and increased patient satisfaction.

In our study, the pain-relieving effects of acupressure were not significant at the initial stages of lithotripsy, probably due to the mild pain at the start of treatment with low energy. The more significant reduction in pain at later stages in the acupressure group might be attributed to more time needed to release chemicals and adjust energy flow [16]. According to a meta-analysis in 2023, the potent analgesic effect of acupuncture requires 15–30 min [10]. However, one study found that massaging the Qiu point provided quicker pain relief than sodium parecoxib in the first 10 min [21]. This difference may be related to pain pathogenesis during lithotripsy compared to colicky pain. Stimulating surface pain receptors in the skin and visceral receptors in the peritoneum, muscles, periosteum, and renal capsule are potential sources of pain during ESWL [31].

Traditional Chinese Medicine suggests acupressure clears blockages in meridian channels, restoring balance to the nervous system [32]. The Western theory explains the effect of acupressure on pain reduction through the endorphin theory (the release of pain-relieving chemicals) and the gate control theory (blocking pain message transmission to higher nerve centers following acupressure stimulation) [15]. Moreover, considering psychological pain mechanisms, manually massaging acupuncture points not only adjusts patients' mental states but also reduces pain-causing mediators [33]. Various clinical evidence supports the impact of acupressure in reducing patient pain [16, 17, 25]. Şolt Kirca et al. showed that the pain-relieving effects of acupressure at points LV4 and LI4 last for about 120 min [16]. Corresponding to these findings, Düzel et al. (2023) reported beneficial effects in reducing pain in patients after angiography [34]. However, one study did not find a significant effect of acupressure on the pain of colic patients [11]. The lack of previous studies on the impact of acupressure on pain during ESWL limits the opportunity for further comparison and discussion.

Insufficient pain relief during ESWL leads to undesirable patient movements and increased respiratory effort. This hampers the concentration of energy on the stone and reduces the success of lithotripsy [3]. The lithotripsy operator may also reduce the device's frequency and voltage due to the patient's unbearable and severe pain, resulting in a proportional decrease in lithotripsy success [35]. The most commonly used drug regimens for this purpose include NSAIDs such as diclofenac [36], sodium parecoxib [21], and opioids such as morphine [2]. However, the use of these drugs may be associated with several adverse effects: reduced renal blood flow, renal failure, severe nausea, vomiting, and potentially dangerous complications like respiratory depression, in addition to their high costs [10, 18]. In contrast to the results obtained from drug regimens, studies have reported pain relief resulting from acupressure without adverse effects or with minor side effects [12, 25, 30]. This study examined the impact of acupressure at the Qiu point. This acupuncture point has been identified and introduced recently for relieving colicky pain [22]. The existing evidence reports promising effects on pain relief in patients. Chen et al. showed that the pain-relieving effects of Qiu point massage were faster and more effective than sodium paracoxib in the first 10 min of intervention [21]. The results of a meta-analysis also highlighted the effectiveness of this massage compared to standard treatments for colicky pain [37]. Also, several previous studies have randomly found that cures in the areas around this point are effective in colicky pain. For example, Gul and Gul reported similar pain relief effects after sterile water injection into the restricted triangular area bordered by the 12th rib, the spinal column, and the iliac crest, akin to an intramuscular diclofenac injection [9]. Maldonado Avila et al. found that the infusion of 2% lidocaine into the twelfth thoracic nerve could effectively relieve kidney stone pain [36].

Nociceptive effects are associated with increased blood pressure, respiratory rate, and heart rate [34]. Pain during ESWL increases the risk of kidney hematoma with increased blood pressure [7]. Our study revealed significant effects of acupressure on patients' systolic blood pressure during the peak of shockwave energy, which is not consistent with the study of Düzel et al. [34]. Khoram et al. also found that massaging three points, HT7, EX-HN3, and GB20, effectively reduced anxiety, heart rate, and systolic blood pressure in patients before open-heart surgery [13]. The difference may be due to the different locations of the acupressure points and the employment of multiple points [34], in contrast to a single point used for massage in our study. Differences in outcome assessment duration, sample size, and cultural characteristics of research samples [13] are the other potential reasons for this difference. Moreover, the results of some previous studies are consistent with our findings. Also, Sharifi Rizi et al. found that massaging the HT7 and LI4 points for two minutes effectively reduced pain intensity in patients undergoing bone marrow biopsy. However, it did not significantly affect blood pressure levels. Researchers attributed this result to the short duration of massage and the sympathetic effects caused by anxiety [12]. A study on pain and vital signs resulting from venipuncture did not report the practical impact of acupressure on patients' vital signs [30]. However, the gate control theory justifies the immediate effects of acupressure [20].

The study findings indicated a statistically significant difference in patients' heart rates between 20 and 30-min time intervals after ESWL started. However, these changes were not clinically significant. There was no statistically significant difference in diastolic blood pressure values reported at any time interval. Similarly, Resim et al. did not find a statistically significant difference in the effects of combined midazolam and tramadol with electroacupuncture on patients' heart rates and blood pressure [38]. It is challenging to achieve physiological changes in a short period during painful procedures because the altered values quickly return to baseline levels after the procedure [30]. Therefore, physiological indicators may not be influenced by acupressure interventions. However, further evidence-based studies are required to obtain more precise results.

In the present study, the stone-free rate was 32.86 percent. Success rates in stone fragmentation have been reported at various levels in different studies [39]. Differences in treatment duration, type of device, and study design are all potential sources affecting the variation in the study [6, 40]. Acupressure intervention also increased patient satisfaction. Consistent with our findings, a study by Yildirim et al. (2021) showed that acupressure reduced venipuncture pain and increased patient satisfaction [30]. The results of a meta-analysis also yielded similar findings [18]. According to the findings of the current research, acupressure at the Qiu point does not significantly influence the physiological indices of patients during ESWL. Nevertheless, applying this method as a safe and cost-effective approach leads to pain reduction and increased patient satisfaction during this procedure.

The findings of this study demonstrate that acupressure facilitates better tolerance of ESWL by reducing patients' pain levels. Simultaneously, increases their satisfaction with this intervention method. Therefore, it provides the possibility of delivering higher-energy shock waves for achieving stone-free outcomes. This method is non-invasive, simple, affordable, and easy for pain management in patients. However, definitive conclusions about the impact of acupressure on managing ESWL complications require further multi-center studies with larger sample sizes.