Analgesic Effect of Transcutaneous Electrical Nerve Stimulation After Laparoscopic Cholecystectomy

Transcutaneous electrical nerve stimulation and catheter-related bladder discomfort following transurethral resection of bladder tumour: A randomised controlled trial

BACKGROUND

Catheter-related bladder discomfort (CRBD) is problematic in patients with a urinary catheter. Transcutaneous electrical nerve stimulation (TENS) is a non-invasive analgesic modality used to relieve various types of pain.

OBJECTIVES

We evaluated the effect of TENS on CRBD after transurethral resection of bladder tumours (TURBT).

DESIGN

A randomised controlled trial.

SETTING

A large university tertiary hospital, from October 2022 to March 2023.

PATIENTS

Patients requiring urinary catheterisation after TURBT.

INTERVENTION

In this randomised controlled trial, patients were randomly allocated to the TENS (n  = 56) or control (n  = 56) groups. CRBD manifests as a burning sensation with an urge to void or discomfort in the suprapubic area. Moderate to severe CRBD was defined as patients self-reporting CRBD symptoms with or without behavioural response, including attempts to remove the urinary catheter, intense verbal reactions, and flailing limbs. TENS was performed from the end of surgery to 1 h postoperatively.

MAIN OUTCOME MEASURE

The primary endpoint was considered moderate to severe CRBD immediately postoperatively. Secondary endpoints included moderate to severe CRBD at 1, 2 and 6 h postoperatively. Additionally, postoperative pain, patient satisfaction, and TENS-related adverse effects were evaluated.

RESULTS

Moderate to severe CRBD immediately postoperatively was significantly less frequent in the TENS group than in the control group: 10 (17.9%) vs. 34 (60.7%); P < 0.001; relative risk (95% CI) = 0.294 (0.161 to 0.536); absolute risk reduction = 0.43; number needed to treat = 2.3. Moderate to severe CRBD differed between the two groups at 1 h postoperatively: 1 (1.8%) vs. 16 (28.6%); P < 0.001; relative risk = 0.06 (95% CI 0.01 to 0.46); absolute risk reduction = 0.27; number needed to treat = 3.7. The TENS group exhibited a significantly lower score for postoperative pain at 1 h (1.8 ± 0.6 vs. 2.2 ± 0.4; P < 0.001, mean difference (95% CI) = 0.4 (0.2 to 0.6) and a higher score for patient satisfaction, 5.0 (4.0 to 6.0) vs. 3.0 (3.0 to 4.0); P < 0.001; median difference (95% CI) = 2.0 (1.0 to 2.0).

CONCLUSIONS

TENS reduced moderate to severe CRBD, decreased postoperative pain, and increased patient satisfaction after TURBT.

CLINICAL TRIAL REGISTRY

Clinical Research Information Service (KCT0007450).

VISUAL ABSTRACT

http://links.lww.com/EJA/B12.

High-frequency, high-intensity TENS compared to standard treatment with opioids for postoperative pain relief after laparoscopic cholecystectomy: A multicentre randomized controlled trial

BACKGROUND

Adverse effects of opioids could prolong the duration of stay in the post-anaesthesia care unit (PACU). This study aimed to assess time in the PACU and the pain-relieving effect of high-frequency, high-intensity transcutaneous electrical nerve stimulation (HFHI TENS) versus standard treatment with intravenous (IV) opioids.

METHODS

Patients undergoing laparoscopic cholecystectomy at two Swedish hospitals were invited to participate. Patients reporting postoperative pain intensity ≥3 according to the Numeric Rating Scale (NRS) in the PACU were randomized to receive standard treatment with IV opioids or HFHI TENS, administered with an intensity of 40-60 mA for 1 min, repeated once if insufficient pain relief. If NRS remained ≥3 after two TENS stimulation the patients received IV opioids.

RESULTS

In total, 163 patients were randomized to receive HFHI TENS (n = 85) or IV opioids (n = 78). There was no difference between the HFHI TENS group versus the opioid group regarding time in the PACU (138 min [SD 69] vs. 142 min [SD 95], mean difference -4.42 [95% CI-30:22], p = 0.74), time to pain relief NRS < 3 (median 10 min) and pain intensity at PACU discharge (NRS 1.7 [SD 1.45] vs. 1.6 [SD 1.20], p = 0.58). In the HFHI TENS group, 39 patients (46%) needed additional treatment with IV opioids. Mean opioid consumption was significantly lower in the HFHI TENS group than in the opioid group (4.5 vs. 11.0 morphine equivalents; p < 0.001).

CONCLUSIONS

HFHI TENS may be an opioid-sparing alternative for postoperative pain relief.

SIGNIFICANCE STATEMENT

In this multicentre, RCT time in the PACU and the pain-relieving effect of HFHI TENS was compared to standard treatment with IV opioids. There were no differences between the groups regarding time in the PACU, time to pain relief and side effects but opioid consumption in the HFHI TENS group was significantly lower. Both groups reported high satisfaction with pain treatment and care. In summary, HFHI TENS should be considered a safe, fast-onsetting, opioid-sparing option for postoperative pain relief.

The Impact of Transcutaneous Electrical Nerve Stimulation (TENS) on Acute Pain and Other Postoperative Outcomes: A Systematic Review with Meta-Analysis

This study aimed to investigate the efficacy and safety of transcutaneous electrical nerve stimulation (TENS) in postoperative acute pain control. PubMed, Scopus, and Cochrane Library were searched on 1-8 December 2022, for randomized controlled trials on the analgesic effects of TENS. The outcomes were pain intensity and opioid use (primary), and postoperative (PO) adverse events, blood pressure, and the duration of hospital stay (secondary); PROSPERO CRD42022333335. A total of 40 articles were included in the meta-analysis. Pain intensity at rest and during coughing for all types of surgeries combined was lower in the TENS group (standardized mean difference (SMD) = -0.51 [-0.61, -0.41], p < 0.00001, 29 studies, and -1.28 [-2.46, -0.09], p-value = 0.03, six studies, respectively). There was a statistically significant decrease in morphine requirements, as well as in the incidence of postoperative nausea and vomiting, dizziness, and pruritus. There was no difference between the groups in postoperative pain intensity during walking, in blood pressure, and only a borderline difference in the length of hospital stay. The subgroup analysis by surgery type did not show significant differences between the groups in pain severity at rest. Thus, TENS has a potential for pain control and postoperative recovery outcomes.

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.

Effects of Patient Education and Distraction Approaches Using Virtual Reality on Pre-operative Anxiety and Post-operative Pain in Patients Undergoing Laparoscopic Cholecystectomy

BACKGROUND

Fear of post-operative pain often contributes to pre-operative anxiety; accordingly, pain and anxiety are among the most common complications in patients undergoing laparoscopic cholecystectomy (LC).

AIM

The present study aimed to determine the effects of patient education and distraction using virtual reality (VR) on pre-operative anxiety and post-operative pain in patients undergoing LC.

METHOD

This randomized clinical trial included 150 patients in the surgery wards of educational hospitals in Mashhad, Iran, in 2020. The participants were randomly assigned to three groups of education, distraction, and control. The education and distraction groups watched two five-minute animations and three 360-degree images of nature using VR glasses 2 hours before and 4 hours after the surgery, respectively. On the other hand, the control group received routine care. Anxiety was measured using Spielberger's State Anxiety Inventory before and half an hour after the intervention. Moreover, the pain was measured using the visual analog scale and McGill Pain Questionnaire.

RESULTS

The results demonstrated a significant reduction in the two VR groups regarding the pre-operative anxiety mean scores, compared with the control group (p < .001). Furthermore, a significant reduction was observed in post-operative pain scores of patients in the two intervention groups compared with the control group (p = .001).

CONCLUSIONS

As evidenced by the results, both VR approaches of patient education and distraction equally decreased pre-operative anxiety and post-operative pain in patients undergoing LC.

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.

Transcutaneous Electric Nerve Stimulation Reduces Pathological Sensation of Mesh One Week after Open Inguinal Hernia Surgery: Follow-Up Results from a Randomized, Double Blind and Placebo-Controlled Trial

Background and Objectives: Quality of life (QoL) and chronic pain are important outcomes following hernia surgery. The long-term effects of Transcutaneous Electric Nerve Stimulation (TENS) on postoperative recovery are not well known. In this trial we investigated the role of TENS on QoL and on the incidence of chronic pain following inguinal hernia repair with mesh. Materials and Methods: A total of 80 male patients with elective primary unilateral hernia Lichtenstein repair were randomly allocated to receive TENS or a placebo-TENS procedure. The TENS group received conventional TENS twice a day on the first and second postoperative days. The intensity was set at 0–0.5 mA in the placebo-TENS group. General and hernia-specific QoL, as well as the incidence of chronic pain were assessed using SF-36v2 and the Carolinas comfort scale. Results: Less sensation of mesh was reported by the TENS group patients one week after surgery. At this time point, the mean sensation score was 6.07 ± 8.88 in the TENS group and 14.08 ± 16.67 in the placebo-TENS group (p = 0.029). Although at two days and one week postoperatively, TENS group patients tended to have less pain, less movement restrictions and better overall hernia-specific QoL, the differences were not statistically significant. At 6 months postoperatively, no incidence of chronic pain was found in either the placebo-TENS or TENS group. Conclusions: Conventional TENS applied in the early postoperative period following inguinal hernia repair with mesh was found to reduce mesh-related foreign body sensation one week after surgery. Promising results were also found for other QoL domains.

Efficacy and Safety of Transcutaneous Electrical Acupoint Stimulation (TEAS) for Postoperative Pain in Laparoscopy: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

OBJECTIVES

This meta-analysis aimed to assess the efficacy and safety of transcutaneous acupoint electrical stimulation (TEAS) for postoperative pain in laparoscopy. The review has been registered on the "INPLASY" website and the registration number is INPLASY202150101.

METHODS

Relevant randomized controlled trials are selected from seven electronic databases (PubMed, the Cochrane Library, Embase, China National Knowledge Infrastructure, Chongqing VIP Information, WanFang Data, and Chinese Biomedical Database) from their inception up to November 30, 2020. Twenty-eight studies were included in this meta-analysis, and the statistical analyses and the exploration of heterogeneity sources were conducted by Stata 15.0 software. Besides, the bias assessment of the included studies was evaluated using the Cochrane risk of bias tool.

RESULTS

In total, 28 RCTs covering 2787 participants were included. The meta-analysis suggested that TEAS can effectively relieve pain in the short term after laparoscopy, reduce the postoperative consumption of rescue analgesics, improve the quality of life of patients, and shorten the length of hospitalization. And no serious adverse events are related to TEAS. Therefore, TEAS is relatively safe and efficacy for clinical application. The most used acupoints were Hegu (LI14), Neiguan (PC6), and Zusanli (ST36).

CONCLUSIONS

TEAS can be recommended as a complementary and alternative therapy for the treatment of postoperative pain after laparoscopy. However, the included RCTs had some methodological limitations. Therefore, larger-size, more rigorous, and higher-quality RCTs are needed in the future to further explore the efficacy and safety of TEAS for postoperative pain after laparoscopy.

Gender response to 10 weeks acupuncture-TENS application on patients who presented with post-injection sciatic pain

Background

Studies to determine gender response to transcutaneous electrical nerve stimulation (TENS) application on individuals who presented with post-injection sciatic pain (PISP) following gluteal injection is not common. A total of 40 subjects comprising 20 males and 20 females who were purposively recruited and conveniently assigned to group A (male) and group B (female) completed the study. Acupuncture-like TENS (AL-TENS) was applied on the 20 male and 20 female subjects, 1 h per session, 3 times per week for the 10 weeks the study lasted.

Result

The pre-intervention baseline scores for the two groups were 8.80 + 1.05 (Female) and 8.60 + 1.27 (Male). The result revealed that after 10 weeks of intervention the VAS scores were 2.60+ 3.28 (p < 0.001) and 2.40 + 3.28 (p < 0.001) for the female and male subjects, respectively. The mean comparison of the female mean VAS scores (2.60 + 3.28) and male VAS scores 2.40 + 3.25 after 10 weeks of AL-TENS intervention shows no statistically significant difference (p > 0.85) in pain intensity (pain perception).

Conclusions

There was no gender variation in pain perception in subjects with post-injection sciatic pain (PISP) following gluteal muscle injection after 10 weeks of AL-TENS application. Therefore, gender-based variation should not be considered when applying AL-TENS as an instrument of intervention in subjects with PISP.

Trial registration

PACTR2018050034082

Transcutaneous Electric Nerve Stimulation Reduces Acute Postoperative Pain and Analgesic Use After Open Inguinal Hernia Surgery: A Randomized, Double-Blind, Placebo-Controlled Trial

In this randomized, double-blind, placebo-controlled trial, we evaluated the role of transcutaneous electrical nerve stimulation (TENS) in the multimodal treatment (nonopioid analgesics and kinesiotherapy) of postoperative pain following open inguinal hernia repair. In total, 80 males participants with elective primary unilateral hernia Lichtenstein repair were randomly allocated to receive TENS or a placebo-TENS procedure. The TENS group received local and segmental conventional TENS on the first and second postoperative days. In the placebo-TENS group, intensity was set at 0 to 0.5mA. Change of pain level at rest, when walking, when standing up from bed, pressure algometry parameters and additional analgesic use were the main outcomes. Reduction of VAS pain score and absolute and relative pain relief were observed in the TENS group following the procedures compared to the placebo-TENS group (P< .001). The pressure pain threshold and maximal tolerable pressure in the hernia side were equal before the TENS procedure in both groups (P= .84), but after the procedure, these were higher in TENS group (P< .001). Additional nonopioid analgesics requirements were lower in the TENS group on the first and second postoperative days (P< .001). TENS is a safe procedure that can reduce postoperative pain and analgesic use after open inguinal hernia repair. The study was registered in the database of clinicaltrials.gov (register number NCT03739060). PERSPECTIVE: This article presents TENS as a safe and effective nonpharmacologic intervention to reduce postoperative pain after open inguinal hernia repair. TENS could be used in daily practice as part of a multimodal postoperative pain treatment, especially for patients suffering from hyperalgesia.

Transcutaneous electrical nerve stimulation is superior than placebo and control for postoperative pain relief

Aim: To determine whether transcutaneous electrical nerve stimulation (TENS) is more efficient than placebo TENS and control groups for pain relief. Design: Randomized, single-blinded, placebo-controlled trial. Setting & participants: A total of 78 adults with postoperative pain, after cholecystectomy, at the University Hospital. They were randomized into active TENS, placebo TENS and control. Intervention: A total of 30-min interventions applied in the first 24 h after the surgery. Outcome: Pain intensity. Results: Pain significantly decreased for both TENS; however, the active TENS was better. A decrease of 2 points or more on the visual analog scale for 53.8% active TENS and 11.5% placebo. Conclusion: There was a greater reduction in pain of important clinical relevance in the active TENS group.

Clinical Trial registration: Brazilian Clinical Trial (REBEC): RBR-6cgx2k.

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

Background

The aim of the study was to compare the pain relieving effect and the time spent in the recovery unit after treatment with high frequency, high-intensity transcutaneous electrical nerve stimulation (TENS) or intravenous (IV) opioids after gynecologic laparoscopic surgery.

Methods

All patients who postoperatively reported visual analogue scale (VAS) pain score ≥ 3 were consecutively included in the study. The TENS treatment was given with a stimulus intensity between 40–60 mA during 1 minute, repeated once if insufficient pain relief. In the opioid group, a maximum dose of 10 mg morphine was given IV. If the patient reported insufficient pain relief (VAS ≥ 3) on the assigned treatment, the patient crossed over to the other treatment group.

Results

Ninety-three women were randomized to TENS (n = 47) or IV opioids (n = 46). Both groups reported significant pain relief at leave from the recovery unit (TENS group: VAS 5.4 to 1.0, P < 0.001; IV opioid group: VAS 5.2 to 1.1, P < 0.001) with no differences between the groups. When only responders, i.e. patients with VAS < 3 after assigned treatment, were compared the TENS responders spent significantly shorter time in the recovery unit (90 vs. 122 minutes, P = 0.008) compared to the responders in the opioid group.

Conclusions

TENS and IV opioids are both effective treatments for pain relief after gynecologic laparoscopic surgery. TENS seems to be preferable for first choice of treatment as the treatment is associated with shorter time spent in recovery unit if the patient responds to the treatment.

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.

Avulsion of the Anterior Inferior Iliac Spine Rehabilitation in a Rural Private Practice

An unusual case is presented of an 11-year-old girl presenting for treatment to a semirural private physical therapy practice, not specializing in pediatric care, following an avulsion fracture of the anterior inferior iliac spine. The patient presented initially non-weight-bearing, with little hip movement due to pain. Following treatment, the patient returned to preinjury status including return to full participation in netball. A review of the literature regarding healing and rehabilitation is described. Concepts of neuromuscular retraining were integrated in the rehabilitation program. Recent evidence demonstrates deficiencies in hip and knee control for girls between 11 and 15 years of age. Evidence suggests that these deficiencies may be a precursor to injury and poor outcomes in lower extremity injuries in this patient group.

Effects of Transcutaneous Electrical Nerve Stimulation at Two Frequencies on Urinary Incontinence in Poststroke Patients: A Randomized Controlled Trial

OBJECTIVE

The objective of this study was to compare the effects of two frequencies of transcutaneous electrical nerve stimulation (TENS) on urinary incontinence caused by stroke.

METHODS

Eighty-one patients with poststroke urinary incontinence were recruited and randomized into the following three groups with a 1:1 ratio: a 20-Hz TENS group, a 75-Hz TENS group, and a no-treatment control group (n = 27 per group). TENS currents were biphasic square waves with pulse durations of 150 μsecs and pulse frequencies of 20 Hz or 75 Hz and were applied for 30 mins once per day for 90 days. The positive electrodes were placed in the region of the second sacral level on opposite sides of the vertebral column; the negative electrodes were placed on the inside of the middle and lower third of the junction between the posterior superior iliac spine and the ischial node. Overactive Bladder Symptom Scores, Barthel Index, urodynamic values, and voiding diary parameters were assessed before and after 90 days.

RESULTS

The patients treated with 20 Hz had superior Overactive Bladder Symptom Scores, Barthel Index totals, urodynamic values, and voiding diary parameters (P < 0.05). In the 75-Hz group, values were statistically improved compared with the no-treatment group (P < 0.05), but the results were significantly inferior to those of the 20-Hz group (P < 0.05).

CONCLUSIONS

Twenty-hertz TENS improved incontinence symptoms and promoted activities of daily living better than 75-Hz TENS. These results will aid future research regarding TENS parameters.

Transcutaneous electrical nerve stimulation for acute pain

BACKGROUND

This is a second update of a Cochrane Review originally published in Issue 2, 2009. Transcutaneous Electrical Nerve Stimulation (TENS) is a non-pharmacological agent, based on delivering low voltage electrical currents to the skin. TENS is used by people to treat a variety of pain conditions.

OBJECTIVES

To assess the analgesic effectiveness of TENS, as a sole treatment, for acute pain in adults.

SEARCH METHODS

We searched the following databases up to 3 December 2014: the Cochrane Central Register of Controlled Trials (CENTRAL), in the Cochrane Library; MEDLINE; EMBASE; CINAHL; and AMED. We also checked the reference lists of included trials.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of adults with acute pain (< 12 weeks) if they examined TENS given as a sole treatment and assessed pain with subjective pain scales. Trials were eligible if they compared TENS to placebo TENS, no treatment controls, pharmacological interventions or non-pharmacological interventions. We excluded trials on experimental pain, case reports, clinical observations, letters, abstracts or reviews. Also we excluded trials investigating the effect of TENS on pain during childbirth (labour), primary dysmenorrhoea or dental procedures. Studies where TENS was given with another treatment as part of the formal trial design were excluded. We did not restrict any articles based on language of publication.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study eligibility and carried out study selection, data extraction, 'Risk of bias' assessment and analyses of data. We extracted data on the following: types of participants and pain condition, trial design and methods, treatment parameters, adverse effects, and outcome measures. We contacted trial authors for additional information if necessary.

MAIN RESULTS

We included 12 trials in the original review (2009) and included no further trials in the first update (2011). An additional seven new trials met the inclusion criteria in this second update. In total, we included 19 RCTs involving 1346 participants at entry, with 11 trials awaiting classification either because the full text was unavailable or information in the full text failed to clarify eligibility. We excluded most trials because TENS was given in combination with another treatment as part of the formal study design or TENS was not delivered using appropriate TENS technique. The types of acute pain included in this Cochrane Review were procedural pain, e.g. cervical laser treatment, venepuncture, screening flexible sigmoidoscopy and non-procedural pain, e.g. postpartum uterine contractions and rib fractures. We pooled data for pain intensity for six trials (seven comparisons) comparing TENS with placebo but the I(2) statistic suggested substantial heterogeneity. Mean difference (MD) with 95% confidence intervals (CIs) on a visual analogue scale (VAS, 100 mm) was -24.62 mm (95% CI -31.79 to -17.46) in favour of TENS. Data for the proportion of participants achieving ≥ 50% reduction in pain was pooled for four trials (seven comparisons) and relative risk was 3.91 (95% CI 2.42 to 6.32) in favour of TENS over placebo. We pooled data for pain intensity from five trials (seven comparisons) but the I(2) statistic suggested considerable heterogeneity. MD was -19.05 mm (95% CI -27.30 to -10.79) in favour of TENS using a random-effects model. It was not possible to pool other data. There was a high risk of bias associated with inadequate sample sizes in treatment arms and unsuccessful blinding of treatment interventions. Seven trials reported minor adverse effects, such as mild erythema and itching underneath the electrodes and participants disliking TENS sensation.

AUTHORS' CONCLUSIONS

This Cochrane Review update includes seven new trials, in addition to the 12 trials reviewed in the first update in 2011. The analysis provides tentative evidence that TENS reduces pain intensity over and above that seen with placebo (no current) TENS when administered as a stand-alone treatment for acute pain in adults. The high risk of bias associated with inadequate sample sizes in treatment arms and unsuccessful blinding of treatment interventions makes definitive conclusions impossible. There was incomplete reporting of treatment in many reports making replication of trials impossible.

Does transcutaneous electrical nerve stimulation (TENS) alleviate the pain experienced during bone marrow sampling in addition to standard techniques? A randomised, double-blinded, controlled trial

AIMS

Bone marrow aspiration and trephine (BMAT) biopsies remain important tests in haematology. However, the procedures can be moderately to severely painful despite standard methods of pain relief. To test the efficacy of transcutaneous electrical nerve stimulation (TENS) in alleviating the pain from BMAT in addition to standard analgesia using a numerical pain rating scale (NRS).

METHODS

70 patients requiring BMAT were randomised (1:1) in a double-blind, placebo-controlled trial. -35 patients received TENS impulses at a strong but comfortable amplitude (intervention group) and 35 patients received TENS impulses just above the sensory threshold (control group) (median pulse amplitude 20 and 7 mA, respectively). Patients and operators were blinded to group allocation. Pain assessments were made using a numerical pain scale completed after the procedure.

RESULTS

No significant difference in NRS pain recalled after the procedure was detected (median pain score 5.7 (95% CI 4.8 to 6.6) in control vs 5.6 (95% CI 4.8 to 6.4) in the intervention group). However, 100% of patients who had previous experience of BMAT and >94% of participants overall felt they benefited from using TENS and would recommend it to others for this procedure. There were no side effects from the TENS device, and it was well tolerated.

CONCLUSIONS

TENS is a safe, non-invasive adjunct to analgesia for reducing pain during bone marrow biopsy and provides a subjective benefit to most users; however, no objective difference in pain scores was detected when using TENS in this randomised controlled study.

CLINICAL REGISTRATION NUMBER

NCT02005354.

The effect of intra-operative transcutaneous electrical nerve stimulation on posterior neck pain following thyroidectomy

Posterior neck pain following thyroidectomy is common because full neck extension is required during the procedure. We evaluated the effect of intra-operative transcutaneous electrical nerve stimulation on postoperative neck pain in patients undergoing total thyroidectomy under general anaesthesia. One hundred patients were randomly assigned to one of two groups; 50 patients received transcutaneous electrical nerve stimulation applied to the trapezius muscle and 50 patients acted as controls. Postoperative posterior neck pain and anterior wound pain were evaluated using an 11-point numerical rating scale at 30 min, 6 h, 24 h and 48 h following surgery. The numerical rating scale for posterior neck pain was significantly lower in the transcutaneous electrical nerve stimulation group compared with the control group at all time points (p < 0.05). There were no significant differences in the numerical rating scale for anterior wound pain at any time point. No adverse effects related to transcutaneous electrical nerve stimulation were observed. We conclude that intra-operative transcutaneous electrical nerve stimulation applied to the trapezius muscle reduced posterior neck pain following thyroidectomy.

Role of transcutaneous electrical nerve stimulation in post-operative analgesia

The use of transcutaneous electrical nerve stimulation (TENS) as non-pharmacological therapeutic modality is increasing. The types of TENS used clinically are conventional TENS, acupuncture TENS and intense TENS. Their working is believed to be based on gate control theory of pain and activation of endogenous opioids. TENS has been used in anaesthesia for treatment of post-operative analgesia, post-operative nausea vomiting and labour analgesia. Evidence to support analgesic efficacy of TENS is ambiguous. A systematic search of literature on PubMed and Cochrane Library from July 2012 to January 2014 identified a total of eight clinical trials investigating post-operative analgesic effects of TENS including a total of 442 patients. Most of the studies have demonstrated clinically significant reduction in pain intensity and supplemental analgesic requirement. However, these trials vary in TENS parameters used that is, duration, intensity, frequency of stimulation and location of electrodes. Further studies with adequate sample size and good methodological design are warranted to establish general recommendation for use of TENS for post-operative pain.