Transcutaneous Nerve Stimulation for Pain Relief During Office Hysteroscopy: A Randomized Controlled Trial

Analgesia Using Transcutaneous Electric Nerve Stimulation in Office Bladder Chemodenervation, a Randomized Controlled Trial

IMPORTANCE

Office bladder chemodenervation, performed via cystoscopy with intradetrusor onabotulinumtoxinA (BOTOX) injections, is a common treatment for overactive bladder/urge urinary incontinence. Transcutaneous electric nerve stimulation (TENS) has shown to provide analgesia during office hysteroscopy. Adjuvant analgesia using TENS during bladder chemodenervation has not been studied.

OBJECTIVE

The primary outcome is a clinically significant (10-mm) difference in pain visual analog scale (VAS) measurements during injections for chemodenervation using active TENS compared with placebo TENS. We hypothesize that active TENS use will significantly change pain VAS scores. Secondary outcomes include 5-point pain Likert scale, satisfaction 10-point scale, and adverse events.

STUDY DESIGN

This was a double-blind randomized control trial of men and women with urinary urge incontinence undergoing office chemodenervation performed in an academic and private setting. Participants were randomized into 2 groups: chemodenervation with active TENS or placebo TENS. Power calculation determined 100 patients would be required detect a difference of 10 mm on pain VAS.

RESULTS

One hundred one (85 female and 16 male) participants were recruited. No differences were noted in the demographics. Participants in the active TENS group reported a difference of greater than 10 mm in pain VAS scores (48 ± 23 vs 31 ± 23, P = 0.01). Satisfaction index scores were high but no difference was noted between groups (8.6 vs 8.7, P = 0.68).

CONCLUSIONS

Most participants were eligible to use TENS units. Transcutaneous electric nerve stimulation is a safe and noninvasive adjuvant analgesia option for patients undergoing this procedure. Lower pain levels and high satisfaction rates suggest that this is an additional analgesic option during outpatient chemodenervation.

High-frequency, high-intensity transcutaneous electrical nerve stimulation compared with opioids for pain relief after gynecological surgery: a systematic review and meta-analysis

OBJECTIVES

Opioids are important for postoperative analgesia but their use can be associated with numerous side effects. Transcutaneous electrical nerve stimulation (TENS) has been used for acute pain treatment and has dose-dependent analgesic effects, and therefore presents an alternative to intravenous (iv) opioids for postoperative pain relief. The aim of this meta-analysis was to compare high-frequency, high-intensity (HFHI or intense) TENS to iv opioids with regard to postoperative pain intensity, recovery time in the Post Anesthesia Care Unit (PACU) and opioid consumption after elective gynecological surgery.

METHODS

We searched Medline, Embase, Web of Science, Cochrane, Amed and Cinahl for RCTs and quasi-experimental studies (2010-2022), and WHO and ClinicalTrials.gov for ongoing/unpublished studies. Meta-analysis and subsequent Trial Sequential Analysis (TSA) was performed for all stated outcomes. Quality of evidence was assessed according to GRADE.

RESULTS

Only three RCTs met the inclusion criteria (362 participants). The surgical procedures involved surgical abortion, gynecologic laparoscopy and hysteroscopy. The applied TENS frequency was 80 Hz and intensity 40-60 mA. There was no difference in pain intensity according to Visual Analogue Scale (VAS) at discharge from PACU between the TENS and opioid group (MD VAS -0.15, 95 % CI -0.38 to 0.09) (moderate level of evidence). Time in PACU was significantly shorter in the TENS group (MD -15.2, 95 % -22.75 to -7.67), and this finding was manifested by TSA (high-level of evidence). Opioid consumption in PACU was lower in the TENS group (MD Morphine equivalents per patient mg -3.42, 95 % -4.67 to -2.17) (high-level of evidence).

CONCLUSIONS

There was no detectable difference in postoperative pain relief between HFHI TENS and iv opioids after gynecological surgery. Moreover, HFHI TENS decreases recovery time and opioid consumption in PACU. HFHI TENS may be considered an opioid-sparing alternative for postoperative pain relief after gynecological surgery.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42021231048.

Exploring the Rules of Related Parameters in Transcutaneous Electrical Nerve Stimulation for Cancer Pain Based on Data Mining

INTRODUCTION

This study aims to investigate the regularity of related parameters in the treatment of cancer pain using transcutaneous electrical nerve stimulation (TENS).

METHODS

A comprehensive literature search was conducted in databases such as PubMed, Cochrane Library, Embase, Web of Science, OVID, CNKI, CBM, VIP, and WANNGFANG from inception up to December 2022. A database was established, and data mining techniques were applied to analyze the relevant TENS parameters.

RESULTS

A total of 27 articles were included, encompassing nine current frequencies, four retention times, four treatment frequencies, and two wave types. On the basis of the analysis of parameter association rules, the most closely related parameter combination for clinical TENS in the treatment of cancer pain was a current frequency of 2/100 Hz, a treatment frequency of once a day, a retention time of 30 min, and the dilatational wave. Moreover, the study involved 22 acupuncture points distributed along 13 meridians. According to the analysis of acupuncture point association rules, Hegu (LI04), Zusanli (ST36), and Sanyinjiao (SP06) were the most closely related acupuncture points and could be used in combination for clinical TENS in cancer pain treatment. Furthermore, cluster analysis was conducted on acupuncture points with a frequency ≥ 5, resulting in three categories: the first category included Sanyinjiao (SP06), Zusanli (ST36), Hegu (LI04), Jiaji point, and Neiguan (PC06); the second category included Ashi point; and the third category included Back shu point.

CONCLUSION

In the treatment of cancer pain using TENS, it is recommended to use a current frequency of 2/100 Hz, a treatment frequency of once a day, a retention time of 30 min, and the dilatational wave. The electrode positions were primarily selected from Ashi point, Back shu point, Sanyinjiao (SP06), Zusanli (ST36), Hegu (LI04), Jiaji point, and Neiguan (PC06) to achieve the best analgesic effect.

Efficacy of Oral Nifedipine, Naproxen, or Placebo for Pain Relief During Diagnostic Hysteroscopy in an Office Setting: A Randomized Pilot Study

STUDY OBJECTIVE

To compare nifedipine, naproxen, or placebo for pain relief during diagnostic hysteroscopy.

DESIGN

Double-blind, randomized controlled pilot study.

SETTING

University hospital.

PATIENTS

Women scheduled for office diagnostic hysteroscopy (n = 60).

INTERVENTIONS

Women received nifedipine (2 tablets of 10 mg), naproxen (2 tablets of 250 mg), or placebo (2 tablets of 500 mg lactose) 30 to 60 minutes prior to hysteroscopy.

MEASUREMENTS AND MAIN RESULTS

Sixty patients were enrolled in the study (21 in the nifedipine group, 19 in the naproxen group, and 20 in the placebo group). The median pain scores during hysteroscope insertion, measured on a Visual Analog Scale (VAS), were 1 (interquartile range (IQR) 0-0), 2 (0-4) and 1 (0-1) in the nifedipine, naproxen and placebo group, respectively (P,14). The median VAS scores during hysteroscopy were 5 (IQR 2-7), 5 (4-8) and 5 (3-7) in the nifedipine, naproxen and placebo group, respectively (P,73). The median VAS scores immediately after hysteroscopy were 2 (IQR 0-4), 3 (0-6) and 3 (1-5) in the nifedipine, naproxen and placebo group, respectively (P,40). The median VAS scores 30 minutes after hysteroscopy were 1 (IQR 0-2), 1 (0-1) and 1 (0-2) in the nifedipine, naproxen and placebo group, respectively (P,63). Hysteroscope insertion failed in 1 case (naproxen group) because of cervica`l stenosis (P,32). Flushes, fatigue and vertigo, 30 minutes after the procedure, were significantly more prevalent in the nifedipine group compared to the naproxen (p < .001, p,03, p,03, respectively) and the placebo group (p < .001, p,01, p,01, respectively). Palpitations occurred only in the nifedipine group (p < .001). The day after the procedure, the headache was most prevalent in the nifedipine group compared to the naproxen group (p,001) and the placebo group (p,001).

CONCLUSION

In our pilot study, pain relief and success rates for office diagnostic hysteroscopy were not significantly different between nifedipine, naproxen, and placebo. Nifedipine was associated with more, albeit tolerable, side-effects.

The dose-dependent effects of transcutaneous electrical nerve stimulation for pain relief in individuals with fibromyalgia: a systematic review and meta-analysis

ABSTRACT

Transcutaneous electrical nerve stimulation (TENS) is a nonpharmacological modality widely used to manage pain; however, its effectiveness for individuals with fibromyalgia (FM) has been questioned. In previous studies and systematic reviews, variables related to dose of TENS application have not been considered. The objectives of this meta-analysis were (1) to determine the effect of TENS on pain in individuals with FM and (2) determine the dose-dependent effect of TENS dose parameters on pain relief in individuals with FM. We searched the PubMed, PEDro, Cochrane, and EMBASE databases for relevant manuscripts. Data were extracted from 11 of the 1575 studies. The quality of the studies was assessed using the PEDro scale and RoB-2 assessment. This meta-analysis was performed using a random-effects model that, when not considering the TENS dosage applied, showed that the treatment had no overall effect on pain (d+ = 0.51, P > 0.050, k = 14). However, the moderator analyses, which were performed assuming a mixed-effect model, revealed that 3 of the categorical variables were significantly associated with effect sizes: the number of sessions (P = 0.005), the frequency (P = 0.014), and the intensity (P = 0.047). The electrode placement was not significantly associated with any effect sizes. Thus, there is evidence that TENS can effectively reduce pain in individuals with FM when applied at high or at mixed frequencies, a high intensity, or in long-term interventions involving 10 or more sessions. This review protocol was registered at PROSPERO (CRD42021252113).

Characterising the Features of 381 Clinical Studies Evaluating Transcutaneous Electrical Nerve Stimulation (TENS) for Pain Relief: A Secondary Analysis of the Meta-TENS Study to Improve Future Research

Background and Objectives: Characterising the features of methodologies, clinical attributes and intervention protocols, of studies is valuable to advise directions for research and practice. This article reports the findings of a secondary analysis of the features from studies screened as part of a large systematic review of TENS (the meta-TENS study). Materials and Methods: A descriptive analysis was performed on information associated with methodology, sample populations and intervention protocols from 381 randomised controlled trials (24,532 participants) evaluating TENS delivered at a strong comfortable intensity at the painful site in adults with pain, irrespective of diagnosis. Results: Studies were conducted in 43 countries commonly using parallel group design (n = 334) and one comparator group (n = 231). Mean ± standard deviation (SD) study sample size (64.05 ± 58.29 participants) and TENS group size (27.67 ± 21.90 participants) were small, with only 13 of 381 studies having 100 participants or more in the TENS group. Most TENS interventions were ‘high frequency’ (>10 pps, n = 276) and using 100 Hz (109/353 reports that stated a pulse frequency value). Of 476 comparator groups, 54.2% were active treatments (i.e., analgesic medication(s), exercise, manual therapies and electrophysical agents). Of 202 placebo comparator groups, 155 used a TENS device that did not deliver currents. At least 216 of 383 study groups were able to access other treatments whilst receiving TENS. Only 136 out of 381 reports included a statement about adverse events. Conclusions: Clinical studies on TENS are dominated by small parallel group evaluations of high frequency TENS that are often contaminated by concurrent treatment(s). Study reports tended focus on physiological and clinical implications rather than the veracity of methodology and findings. Previously published criteria for designing and reporting TENS studies were neglected and this should be corrected in future research using insights gleaned from this analysis.

A virtual reality system for pain and anxiety management during outpatient hysteroscopy-A randomized control trial

BACKGROUND

Visual and acoustic virtual reality (VR) has been increasingly explored as a non-pharmacological tool for pain relief in clinical settings.

OBJECTIVE

We aimed to evaluate the effectiveness of VR as a distraction technique in the management of acute pain during operative hysteroscopy in the outpatient setting.

METHODS

A prospective, open-label, randomized control trial in a tertiary university-affiliated medical centre between April and August 2020. Overall, 82 women were randomly allocated to undergo operative hysteroscopy either with the use of VR (n = 44, study group) or with standard treatment (control group, n = 38). VR was applied throughout the procedure and no anaesthesia was given. The primary outcome measures included self-reported intraoperative pain. Other objectives included vital parameters as pulse rate (PR) and respiratory rate (RR) before and during the first 3 min of the procedure. Pain and anxiety outcomes were measured as numeric rating scores.

RESULTS

The baseline parameters were similar between groups. The mean duration for the procedure was 8.1 ± 3.2 vs. 7.3 ± 6.0 min for the study and the control groups (p = 0.23). There were no statistically significant differences between the reported pain scores during the procedure [median (interquartile range) 5.0 (3.0-7.2) vs. 5.0 (3.0-8.0), respectively; p = 0.67]. While neither intraoperative heart rate nor respiratory rate differed between groups [14.0 (13.0-16.0) vs. 14.0 (11.0-16.5); p = 0.77)], the increase of heart rate was found greater in the VR group [+7.0 (8.5) vs. +1.0 (12.2); p = 0.01].

CONCLUSION

VR was not effective in reducing pain during an outpatient operative hysteroscopy.

SIGNIFICANCE

The use of a Virtual reality system was found ineffective in reducing pain during and after an office operative hysteroscopy without anaesthesia, in a thorough examination of both continuous physiological parameters and women's self-reported measures.

Transcutaneous Electrical Nerve Stimulation for Pain Management of Aspiration Abortion up to 83 Days of Gestation: A Randomized Controlled Trial

OBJECTIVE

To evaluate high-frequency, high-intensity transcutaneous electrical nerve stimulation (TENS) as an inexpensive, noninvasive pain management approach for first-trimester aspiration abortion.

METHODS

We conducted a noninferiority, single-blind, randomized controlled trial of patients seeking aspiration abortion at up to 83 days of gestation. Participants received TENS (placed posteriorly, T10-L1 and S2-S4) or intravenous (IV) sedation (fentanyl, midazolam). The primary outcome was pain with aspiration, as self-reported by visual analog scale (VAS, 100 mm). To detect at least a 15 mm mean difference on the 100 mm VAS with 90% power and a significance level of .05, a total of 90 participants were required.

RESULTS

Between January 2018 and October 2019, we enrolled 109 participants (55 TENS, 54 IV). Participant median gestation was 53 days (range 36-82) in the TENS group and 58 days (range 35-82) in the IV group (P=.65). Group demographics and clinical histories were similar. Intention-to-treat analysis (n=109) yielded noninferior results for the primary outcome (mean difference 4.8 mm, 95% CI -5.9 to 13.5 mm). In the per-protocol analysis, 9 (16%) in the TENS group were excluded after receiving IV sedation; 100 participants were included (46 TENS, 54 IV). Median (range) reported VAS for aspiration was 73 mm (13-97) and 66 mm (0-99) in the TENS and IV groups, respectively (P=.40). With a mean difference of 4.4 mm (95% CI -5.6 to 14.5 mm), we found TENS to be noninferior to IV. Physicians underestimated participant pain, perceiving pain to be 34 mm (6-91) in the TENS group and 25 mm (0-83) in the IV group (P=.003).

CONCLUSION

We found TENS to be a noninferior alternative to IV sedation for aspiration pain during first-trimester abortion. Expanding pain management options can improve quality of and access to abortion. Transcutaneous electrical nerve stimulation could be a standalone or adjunct approach for abortion pain management for those without access to or are ineligible to receive IV sedation due to the lack of sedation practitioner, designated driver, or local restrictions.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, NCT03187002.

Warm distension fluid reduces pain severity in office hysteroscopy: a randomized controlled trial

BACKGROUND

Abnormal uterine bleeding (AUB) affects approximately 14% to 25% of women of reproductive age. The most common use of office hysteroscopy is to evaluate pathologies related to AUB and reproductive health, but office hysteroscopy can also be used for the diagnosis and treatment of other intrauterine pathologies.

OBJECTIVE

Investigate the effects of the temperature of the distension fluid on pain severity in patients undergoing diagnostic office hysteroscopy due to AUB.

DESIGN

Randomized controlled clinical trial.

SETTING

Tertiary care center in Turkey.

PATIENTS AND METHODS

One hundred perimenopausal patients with AUB were randomly allocated according to the temperature of the distension fluid used in office hysteroscopy (37°C or 25°C). Pain intensity was assessed using a visual analog scale (VAS). Six VAS measurements were compared over the course of the hysteroscopy: pre-treatment (VAS-1), at vaginal entry (VAS-2), at the cervical ostium transition (VAS-3), while in the cavity (VAS-4), at the end of the procedure (VAS-5), and 30 minutes after the end of the procedure (VAS-6).

MAIN OUTCOME MEASURE

VAS SAMPLE SIZE: Fifty in each group enrolled, one drop out.

RESULTS

The VAS-3, VAS-4, and VAS-5 scores were significantly lower for patients in the warm fluid group than in the room temperature group (P<.05), whereas the VAS-1, VAS-2, and VAS-6 scores were similar in both groups.

CONCLUSION

The application of warm distension fluid in office hysteroscopy reduces pain severity compared with the application of an unheated fluid.

LIMITATIONS

The main limitations of the study were that a subgroup analysis could not be performed due to an insufficient number of cases, and we were unable to evaluate vasovagal symptoms.

CONFLICT OF INTEREST

None.

Transcutaneous Electrical Nerve Stimulation to Reduce Pain With Medication Abortion: A Randomized Controlled Trial

OBJECTIVE

To evaluate whether high-frequency transcutaneous electrical nerve stimulation (hfTENS) reduces pain during medication abortion.

METHODS

We conducted a randomized, placebo-controlled trial. Participants who were undergoing medication abortion with mifepristone and misoprostol through 70 days of gestation either received active 80 Hz hfTENS or sham to use for a minimum of 60 minutes within 8 hours of misoprostol. Maximum pain on an 11-point numerical rating scale at 8 hours after misoprostol was the primary outcome. We estimated 20 per group for 80% power to detect a 2-point difference and up to 10% attrition. Secondary outcomes included a maximum pain score at 24 hours, additional analgesia use, the difference in score before and after treatment, the experience of side effects, abortion outcomes, and acceptability. We collected data at baseline, time of misoprostol (0-hour), 8-hour and 24 hours using real-time electronic surveys, and at follow-up.

RESULTS

Between June 2019 and March 2020, we screened 251 patients and randomized 40-20 each to hfTENS or sham-with one postrandomization exclusion and two patients lost to follow-up. Baseline characteristics were similar. Median maximum pain scores at 8 hours were 7.0 (interquartile range 3.0) and 10.0 (interquartile range 3.0) for hfTENS and sham, respectively. The distribution of these scores was lower among hfTENS users compared with sham (mean rank 15.17 vs 22.63, P=.036). High-frequency TENS users also experienced a significant reduction in posttreatment pain score (-2.0 [interquartile range 2.5] vs 0 [interquartile range 1.5], P=.008). We found no statistically significant differences in use of additional analgesia, distribution of maximum pain scores at 24 hours, side effects, or measures of acceptability.

CONCLUSION

High-frequency TENS reduced maximum pain scores within 8 hours of misoprostol and reduced pain scores immediately after treatment compared with placebo. High-frequency TENS offers an effective nonpharmacologic option for pain management during medication abortion.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, NCT03925129.

Multicenter, randomized, double-blind, controlled trial of transcutaneous electrical nerve stimulation for pancreatic cancer related pain

BACKGROUND

Up to 80% of patients with pancreatic cancer experience abdominal and back pain. Although pharmacologic medications provide some relief, many report inadequate analgesia and adverse effects. Transcutaneous electrical nerve stimulation (TENS) is a non-invasive physical modality and had been widely applied for pain relieving, yet no study has investigated the effectiveness of TENS for pain in pancreatic cancer.

METHODS

Eligible patients were randomly assigned in a 1:1 ratio to TENS group or control group. The primary outcome was percentage change of numerous rating scale (NRS) after treatment. Secondary outcomes included percentage change of analgesic medication consumption and effect on constipation and poor appetite.

RESULTS

One hundred seventy-one patients were recruited (84 to control group and 87 to TENS group). NRS in TENS group has been largely decreased 77.9% right after treatment and 27.1% in 2 hours, before applying any analgesic medication, while that in control group was slightly downregulated right after treatment but gave a trend to increase at 1, 2, and 3 hours. When comparing both groups, pain was significantly well controlled without analgesic medication supplement in TENS group at 0 hour (difference in mean percent change in NRS = 50.0 [95% CI, 50-51.4], P < .01) and 3 hours (difference in mean percent change in NRS = 134.0 [95% CI, 130.0-142.7], P < .01) after treatment, and this analgesic effect last to 3 weeks after treatment cycle (difference in mean percent change in NRS = 22.5 [95% CI, 17.6-27.3], P < .01) without increase of analgesic medication consumption.

CONCLUSIONS

TENS reduces pain without increase analgesic medication consumption in patients with pancreatic cancer pain. It provides an alternative therapy for pain in pancreatic cancer.

CLINICAL TRIAL REGISTRATION

This study was registered at ClinicalTrials.gov, identifier NCT03331055.

Pain management for in-office hysteroscopy. A practical decalogue for the operator

Hysteroscopy is known to be the gold standard for evaluation of intrauterine pathologies, pre-menopausal and post-menopausal abnormal uterine bleeding and, in addition to this, it is a crucial examination in the infertility work-up. In-office operative hysteroscopy incorporates the outstanding possibility of seeing and treating an intracavitary pathology in the same examination, eliminating all the risk related to anesthesia and reducing procedure-related costs. By now, performing operative procedures in the office setting is recognized as feasible and safe. Over the last 20 years, many efforts have been made to implement the in-office operative approach worldwide. However, for some women, in-office hysteroscopy is still considered a painful experience, with reported discomfort at different steps of the hysteroscopic procedures. Moreover, uneventful and tedious sensations might be increased by a high level of anxiety for such examination. For this reason, despite the feasibility of the in-office approach, many clinicians are still afraid of provoking pain during the procedure and rather not to perform surgical procedures in the office, postponing the removal of the pathology in the operating room. To date, there is no consensus concerning pain management for in-office hysteroscopy and different approaches, pharmacological and non-pharmacological aids, as well as several procedural tips and tricks are utilized. Our purpose is to provide a feasible practical decalogue for the operator, to supply adequate management of pain during in-office hysteroscopic procedures, performing challenging operations, shrinking discomfort, aiming to upgrade both women's and operator's satisfaction.

Electroanalgesia during a carboxytherapy procedure for cellulite: a study protocol for a randomized controlled trial

The aim of the present study is to describe a study protocol to compare different types of analgesic electrical currents on pain intensity and sensory comfort during the application of carboxytherapy for the treatment of cellulite. Seventy five women with the presence of moderate and/or severe gluteal cellulite will be randomly allocated into three groups: carboxytherapy plus transcutaneous electrical nerve stimulation, carboxytherapy plus interferential current or carboxytherapy plus Aussie current. Pain intensity, which is the primary outcome, will be measured by a numeric rating scale (0-10). The secondary outcome is sensory comfort, which will be measured using the visual analogue scale (0-10). Trial registration: Brazilian Clinical Trials Registry: ReBEC (RBR-6z82zb) www.ensaiosclinicos.gov.br/rg/RBR-6z82zb/.

Effects of high-frequency, high-intensity transcutaneous electrical nerve stimulation versus intravenous opioids for pain relief after hysteroscopy: a randomized controlled study

OBJECTIVE

To compare the time spent in the Post-Anesthesia Care Unit (PACU) and the pain-relieving effects of treatment with high-frequency, high-intensity transcutaneous electrical nerve stimulation (TENS) or intravenous (IV) opioids after hysteroscopy.

METHODS

All patients who postoperatively reported a visual analogue scale (VAS) pain score of ≥3 were included in the study. TENS treatment was given with a stimulus intensity between 40 and 60 mA for 1 minute and repeated once if there was insufficient pain relief. In the opioid group, a fractionated dose of 5 mg morphine was administered. If the patient reported insufficient pain relief after the assigned treatment, the patient was reassigned to the other treatment group.

RESULTS

Seventy-four women were randomized to TENS (n=38) or IV opioids (n=36) for treatment. Both groups reported significant pain relief after discharge from the PACU, with a decrease of VAS scores from 5.6 to 1.4 in the TENS group (P<0.001) and 5.1 to 1.3 in the opioid group (P<0.001). There were no significant differences between the groups. When only the responders in both groups, i.e., patients with VAS scores of <3 on respectively assigned treatments, were compared, the TENS responders (n=22) were found to have spent a significantly shorter time in the PACU (91 vs. 69 minutes, P=0.013) compared to the opioid responders (n=20).

CONCLUSION

Using TENS as first line of pain relief may reduce the need for postoperative opioids. In addition, TENS appears preferable as the first line of treatment due to its association with a shorter time spent in the PACU if the patient responds to the treatment.

TRIAL REGISTRATION

Västra Götalandsregionen Identifier: 211261.

Pharmacological and non-pharmacological pain relief for office hysteroscopy: an up-to-date review

In-office hysteroscopy is considered the standard technique for visualization of the uterine cavity and the diagnosis of intrauterine pathologies. Moreover, nowadays, it is possible to treat a vast number of intracavitary diseases in the office, without the need for the inpatient setting. However, in some cases, pain might occur, and this is the most common reason for not completing the procedure. Over the last 20 years, many efforts have been carried out to miniaturize the instrumentation and to improve the techniques in order to avoid discomfort. Nonetheless, hysteroscopy still provokes distress for many patients. For this reason, pharmacological and non-pharmacological treatments for intraoperative and postoperative pain relief have been widely used for in-office hysteroscopy, with different results in various groups of women. The purpose of this review was to analyze the current literature on pharmacological aids (non-steroidal anti inflammatory drugs, cyclooxygenase-2 inhibitors, antispasmodics, local anesthetics, prostaglandins, opioids) and non-pharmacological interventions (transcutaneous electrical nerve stimulation, uterine stretching, uterine pressure, warming of distension medium, hypnosis, music, vocal-local) and to evaluate their impact on the relief from pain experienced during in-office hysteroscopy.

Evaluation and ranking of different interventions for pain relief during outpatient hysteroscopy: A systematic review and network meta-analysis

AIM

To identify the highest-ranked pharmacological and nonpharmacological interventions for pain relief during outpatient hysteroscopy.

METHODS

We conducted an online bibliographic search in different databases from inception till July 2019. We included randomized controlled trials assessing effect of pharmacological and nonpharmacological interventions on pain relief during outpatient hysteroscopy. Our main outcomes were pain scores at different endpoints of the procedure. We applied this network meta-analysis based on the frequentist approach using statistical package 'netmeta' (version 1.0-1) in R.

RESULTS

The review included 39 randomized controlled trials (Women n = 3964). Misoprostol plus intracervical block anesthesia (mean difference [MD] = -3.32, 95% confidence interval [CI] [-6.06, -0.59]), misoprostol (MD = -1.92, 95% CI [-3.04, -0.81]) and IV analgesia (MD = -2.01, 95% CI [-3.27, -0.25]) were effective in reducing pain during the procedure compared to placebo. Ranking probability showed that misoprostol plus intracervical block anesthesia was the highest ranked pharmacological treatment for pain relief during the procedure (P score = 0.92) followed by misoprostol alone (P score = 0.78), and IV analgesia (P score = 0.76). Regarding nonpharmacological treatments, transcutaneous electrical nerve stimulation (TENS) showed a significant pain reduction compared to placebo (MD = -1.80, 95% CI [-3.31, -0.29]). TENS ranked as the best nonpharmacological treatment (P score = 0.80) followed by CO₂ distention (P score = 0.65) and bladder distention (P score = 0.60).

CONCLUSION

Combination of misoprostol plus local anesthesia appears to be the most effective pharmacological approach for pain reduction during and after outpatient hysteroscopy. Nonpharmacological approaches as TENS and bladder distention showed considerable efficacy but should be further investigated.

Updates in office hysteroscopy: a practical decalogue to perform a correct procedure

Nowadays, hysteroscopy is the gold standard for the diagnosis and treatment of intrauterine pathologies as it represents a safe and minimally invasive procedure that allows the visualization of the entire uterine cavity. Numerous technological innovations have occurred over the past few years, contributing to the development and widespread use of this technique. In particular, the new small-diameter hysteroscopes are equipped with an operating channel in which different mechanical instruments can be inserted, and they allow not only to examine the cervical canal and uterine cavity but also to perform biopsies or treat benign diseases in a relatively short time without anesthesia and in an outpatient setting. In this scenario, the operator must be able to perform hysteroscopy in the correct way to make this procedure increasingly safe and painless for the patient. This review aims to describe the ten steps to perform a correct office hysteroscopy, starting from patient counseling to the therapy after the procedure.

Fallopian tubal obstruction is associated with increased pain experienced during office hysteroscopy: a retrospective study

This study aimed at evaluating the pain experienced during office hysteroscopy, with selective tubal cannulation and chromopertubation, by women with and without tubal obstruction in order to determine if such condition would be associated with increased pain during the examination. Women with a history of infertility underwent in-office hysteroscopy with selective chromopertubation using a continuous flow office hysteroscope with a 5 Fr operating channel fitted with a 4 Fr catheter for the injection of methylene blue dye. Experienced pain was recorded on a Visual Analog Scale (VAS) during diagnostic hysteroscopy after access to the uterine cavity. Of 90 women, 58 (66.4%) were found with at least one patent fallopian tube and inserted in the group "any", meanwhile 32 (33.6%) were categorized into group "none" as both tubes were judged obstructed. There was no significant difference between groups in BMI and primary infertility rate, but the difference was significant concerning mean age (32.6 vs. 35.8; p < 0.001). The mean VAS score was 3.34 (± 1.07) in the group "any" and 4.25 (± 1.11) in "none". Comparing the VAS score of the two groups, the difference was significant (p < 0.001). Tubal occlusion may have a potential role in the pain experienced by women undergoing in-office hysteroscopy. Women with bilateral tubal occlusion experienced a higher level of pain compared with patients with at least one patent fallopian tube. Operators may use milder intrauterine pressure of fluid distension medium when these patients are undergoing in-office hysteroscopy to reduce discomfort.

Does Frequency Modulation of Transcutaneous Electrical Nerve Stimulation Affect Habituation and Mechanical Hypoalgesia? A Randomized, Double-Blind, Sham-Controlled Crossover Trial

BACKGROUND

Devices for applying transcutaneous electrical nerve stimulation (TENS) use numerous frequency modulation patterns for decreasing habituation to currents. However, there is no evidence supporting the use of an optimal pattern instead of the others, or even modulated frequencies instead of a fixed frequency.

OBJECTIVE

The objectives of this study were to determine the effects of 3 TENS patterns (fixed frequency, random modulation, and 6-second-6-second [6s-6s] modulation) on habituation, to examine the subjective perception of habituation and comfort, and to determine their effects on the mechanical pain threshold (MPT).

DESIGN

This study was a randomized, double-blind, sham-controlled crossover trial.

SETTING

The study took place in a university research laboratory under attenuated noise conditions at a regulated temperature of 22°C to 26°C.

PARTICIPANTS

Thirty-nine volunteers who were healthy participated in this trial.

INTERVENTION

The participants received 4 different TENS interventions (fixed frequency, random modulation, 6s-6s modulation, and sham) in random order, with a 24-hour washout period, on the radial nerve.

MEASUREMENTS

The main outcome-habituation-was quantified by the increase in current density and the number of times the intensity had to be increased during the session. Secondary outcome variables were subjective perception of habituation and comfort and MPT.

RESULTS

Random modulation reduced the number of times the intensity had to be increased because of habituation compared with no modulation (1.6 times; 95% confidence interval [CI] = 0.7-2.6) and 6s-6s modulation (0.8 times; 95% CI = 0.01-1.6). No differences were observed between interventions in terms of an increase in current density, self-perceived habituation, or self-perceived comfort. MPT increased during the intervention in the random-modulation group (4.4 N; 95% CI = 1.8-7.0) and the no-modulation group (5.9 N; 95% CI = 1.9-10.0); there were no significant changes in the other 2 groups.

LIMITATIONS

The success of masking or blinding procedures of the participants was not assessed.

CONCLUSIONS

Randomly modulated frequencies caused less habituation than nonmodulated frequencies or 6s-6s modulation. Further research on more prolonged (hours-long) interventions in participants with pain is required.

Randomized controlled trial of transcutaneous electrical nerve stimulation for pain relief during transvaginal oocyte retrieval using conscious sedation: study protocol for a randomized controlled trial

Background

Transvaginal oocytes retrieval is an essential step in in-vitro fertilization treatment. There are different pain relief methods, but none has been shown to be superior than the others. Transcutaneous electrical nerve stimulation (TENS) is a non-pharmacological and non-invasive pain relief method. This study aims to compare the pain levels experienced by the women using the conscious sedation and those who had TENS in addition to conscious sedation.

Methods and analysis

This is a double-blinded randomized trial that will be carried out in a university-assisted conception unit. Women who will undergo oocyte retrieval under conscious sedation will be recruited. After randomization, women will be allocated to either the active TENS group or placebo TENS group (the TENS machine will not emit active impulse), in addition to the paracervical block and conscious sedation. The primary outcome is pain levels of women during the retrieval assessed by the visual analog scale. Secondary outcomes include satisfaction of women and postoperative side effects.

Discussion

TENS is an effective non-pharmacological and non-invasive method for pain relief in a number of clinical conditions. Both women and assisted conception unit can benefit if the addition of non-invasive, simple, and low-cost TENS application is proven to be superior than using conscious sedation and paracervical block alone.

Trial registration

ClinicalTrials.gov, NCT03472430. Registered on 3 May 2018.

Electronic supplementary material

The online version of this article (10.1186/s13063-019-3227-5) contains supplementary material, which is available to authorized users.

Transcutaneous Electrical Nerve Stimulation (TENS) in the Emergency Department for Pain Relief: A Preliminary Study of Feasibility and Efficacy

Introduction

Given the high rates of opioid addiction and overdose in the United States, non-opioid means of treating pain are increasingly needed. Transcutaneous electrical nerve stimulation (TENS) therapy is an effective non-opioid modality for treating pain, but has not yet been routinely used in emergency department (ED) settings. In this study we asked the following questions: Are TENS units a feasible treatment for pain in the ED? How effective are TENS units for the management of pain in a general ED population?

Methods

At our institution, we performed a pilot study using TENS units for pain. Patients in the ED were given, at the discretion of the ED provider, TENS units for the treatment of pain. Patients could be included for acute or chronic pain on whatever part of the body that was safe to use with TENS.

Results

A chart review of patients receiving TENS units in the ED (n=110) revealed that TENS was useful in relieving pain, along with other treatments, in 99% of cases. When surveyed, 83% of patients reported a functional improvement while using the TENS, and 100% of patients would recommend a TENS unit to a family or friend. When surveyed, 100% of ED staff observed that TENS units were effective in treating pain for patients, and 97% would want to use them if they themselves were patients.

Conclusion

Overall, in this small pilot study, TENS units appeared to be effective in our ED for reducing pain, when added to standard treatment. Additional studies are needed to determine which conditions are most responsive to TENS therapy, and the magnitude of pain reduction when used alone.

A Comparative Study between Transcutaneous Electrical Nerve Stimulation and Fentanyl to Relieve Shoulder Pain during Laparoscopic Gynecologic Surgery under Spinal Anesthesia: A Randomized Clinical Trail

Background

Traditionally, laparoscopic procedures have been performed under general anesthesia. Spinal anesthesia is an effective alternative to general anesthesia. However, one of the intraoperative complications of performing laparoscopic surgery under spinal anesthesia is shoulder pain. This study aimed to compare the effect of transcutaneous electrical nerve stimulation (TENS) with fentanyl on pain relief in patients who underwent gynecologic laparoscopy under spinal anesthesia.

Methods

We conducted a prospective randomized clinical trial from May 2016 to March 2017. A sample of patients who underwent gynecological laparoscopy under spinal anesthesia was recruited. If they had shoulder pain, they randomly received either transcutaneous electrical nerve stimulation (TENS) or 50 mg of fentanyl. Pain intensity was measured using the single item visual analogue scale (VAS-10 cm) immediately before and 5, 10, 20, and 30 minutes after treatment. Also, the effect of higher doses of analgesia on pain relief was analyzed.

Results

In all, 80 patients (40 patients in each group) were entered into the study. The mean pain intensity score was 9.02 ± 1.32 in the TENS group and 8.95 ± 1.33 in the fentanyl group at baseline (P = 0.80). Repeated measures analysis of variance indicated that there was no significant difference on overall pain scores between the two treatment groups adjusted for age, BMI, total analgesia used, and baseline pain score (F (1, 74) = 1.44, P = 0.23). The use of analgesic drugs in the TENS group was significantly higher than the fentanyl group (P = 0.01). In addition, we found that nine patients (22.5%) complained of nausea/vomiting in the TENS group compared to thirteen patients (32.5%) in the fentanyl group (P = 0.31).

Conclusions

The findings indicated that TENS was not superior to fentanyl for pain relief in laparoscopic surgery. It seems that the correct use of TENS parameters might merit further investigation. This trial is registered with: IRCT2016031216765N3.

Effects of transcutaneous electrical nerve stimulation on pain intensity during application of carboxytherapy in patients with cellulite: A randomized placebo-controlled trial

BACKGROUND

Carboxytherapy may generate local pain that is considered the main limiting factor in clinical practice. Transcutaneous electric nerve stimulation (TENS) is widely used in the control of acute pain; however, the effect of TENS on pain relief during carboxytherapy has not been studied to date.

AIMS

To assess the effect of TENS on pain intensity during carboxytherapy in patients with cellulite in the gluteal region.

PATIENTS/METHODS

This randomized clinical trial was conducted with 84 patients, 18-44 years of age, who had moderate cellulite in the gluteal region, according to Cellulite Severity Scale, but never received carboxytherapy. Patients were randomized into 3 groups: active TENS, placebo TENS, and control group. For the intervention, skin depressions with cellulite were outlined, and the gluteal area to be treated was defined. The subcutaneous injection of CO₂ was performed using 0.30 × 13 mm-needles at a 45° angle, with a controlled flow rate of 100 mL/min maintained for 1 minute at each puncture site. The parameters for TENS were as follows: frequency of 100 Hz and pulse duration of 200 μs; TENS intensity was adjusted until the patient reported strong paresthesia. The visual numeric pain rating scale was used to assess pain intensity after each puncture.

RESULTS

The active TENS group reported lower pain intensity compared to the placebo TENS (P < .0001) and control (P < .0001) groups.

CONCLUSIONS

Transcutaneous electric nerve stimulation (TENS) was effective in reducing pain intensity during carboxytherapy in patients with cellulite in the gluteal region.

Use of electroanalgesia and laser therapies as alternatives to opioids for acute and chronic pain management

The use of opioid analgesics for postoperative pain management has contributed to the global opioid epidemic. It was recently reported that prescription opioid analgesic use often continued after major joint replacement surgery even though patients were no longer experiencing joint pain. The use of epidural local analgesia for perioperative pain management was not found to be protective against persistent opioid use in a large cohort of opioid-naïve patients undergoing abdominal surgery. In a retrospective study involving over 390,000 outpatients more than 66 years of age who underwent minor ambulatory surgery procedures, patients receiving a prescription opioid analgesic within 7 days of discharge were 44% more likely to continue using opioids 1 year after surgery. In a review of 11 million patients undergoing elective surgery from 2002 to 2011, both opioid overdoses and opioid dependence were found to be increasing over time. Opioid-dependent surgical patients were more likely to experience postoperative pulmonary complications, require longer hospital stays, and increase costs to the health-care system. The Centers for Disease Control and Prevention emphasized the importance of finding alternatives to opioid medication for treating pain. In the new clinical practice guidelines for back pain, the authors endorsed the use of non-pharmacologic therapies. However, one of the more widely used non-pharmacologic treatments for chronic pain (namely radiofrequency ablation therapy) was recently reported to have no clinical benefit. Therefore, this clinical commentary will review evidence in the peer-reviewed literature supporting the use of electroanalgesia and laser therapies for treating acute pain, cervical (neck) pain, low back pain, persistent post-surgical pain after spine surgery (“failed back syndrome”), major joint replacements, and abdominal surgery as well as other common chronic pain syndromes (for example, myofascial pain, peripheral neuropathic pain, fibromyalgia, degenerative joint disease/osteoarthritis, and migraine headaches).

Transcutaneous electrical nerve stimulation for postoperative pain control after total knee arthroplasty: A meta-analysis of randomized controlled trials

BACKGROUND

This meta-analysis aimed to evaluate the efficiency and safety of transcutaneous electrical nerve stimulation (TENS) for pain control after total knee arthroplasty.

METHODS

A systematic search was performed in Medline (1966 to June 2017), PubMed (1966 to June 2017), Embase (1980 to June 2017), ScienceDirect (1985 to June 2017), and the Cochrane Library. Only randomized controlled trial (RCT) was included. The fixed/random effect model was used according to the heterogeneity tested by I statistic. Meta-analysis was performed using Stata 11.0 software.

RESULTS

Five RCTs including 472 patients met the inclusion criteria. The present meta-analysis indicated that there were significant differences between groups in terms of visual analogue scale score at 12 hours (average: 3.58 vs 4.34, SMD = -0.260, 95% CI: -0.442 to -0.078, P = .005), 24 hours (average: 3.18 vs 3.52, SMD = -0.244, 95% CI: -0.426 to -0.063, P = .008), and 48 hours (average: 2.70 vs 2.96, SMD = -0.214, 95% CI: -0.395 to -0.033, P = .021) after total knee arthroplasty. Significant differences were found regarding opioid consumption at 12 hours (average: 14.44 vs 18.54, SMD = -0.503, 95% CI: -0.687 to -0.319, P = .000), 24 hours (average: 16.10 vs 18.40, SMD = -0.262, 95% CI: -0.443 to -0.080, P = .005), and 48 hours (average: 12.92 vs 15.12, SMD = -0.183, 95% CI: -0.364 to -0.002, P = .048).

CONCLUSION

TENS could significantly reduce pain and opioid consumption after total knee arthroplasty. In addition, there were fewer adverse effects in the TENS groups. Higher quality RCTs are required for further research.