Far-infrared ray patches relieve pain and improve skin sensitivity in myofascial pain syndrome: A double-blind randomized controlled study

ObjectiveMyofascial pain syndrome (MPS) is a common disorder characterized by muscle pain if myofascial trigger points (MTrP) are stimulated. This study evaluated the effectiveness of far-infrared ray (FIR) patches in reducing the severity of pain in patients with MPS.MethodsA double-blind, randomized controlled study involving 125 patients with MPS and 201 MTrPs located in the trapezius muscle. A FIR patch was applied to 98 MTrPs for 24 h in the intervention group (61 patients) and a placebo patch was applied to 91 MTrPs in the control group (57 patients) at the end. Pain intensity was measured using the visual analogue scale (V) while pressure pain threshold (P) and maximal pain tolerance (T) were measured using an algometer before and after treatment.ResultsThe mean age of the patients was 37.16 years old and 67% were female. There was a positive correlation between P and T (p < 0.001). Older Age was associated with higher P and T due to poor skin sensitivity (p < 0.001). V improved significantly in both groups to a similar extent, but only in the intervention group, P and T decreased significantly (which implied better skin sensitivity) (p < 0.05). P and T decreased the most in the female group aged over 35, probably due to thinner skin in this subgroup.ConclusionsFIR and placebo patches were equally effective at relieving pain (with decreased V), but P and T dropped only in the intervention group with FIR patches. This probably resulted from FIR penetrated only to the skin layer and improved skin sensitivity with more blood circulation, but the muscle remained unaffected. Further studies should investigate the effect of longer exposure or higher energy applications.     

Topical lidocaine patch relieves postherpetic neuralgia more effectively than a vehicle topical patch: results of an enriched enrollment study

This study compared the efficacy of topical lidocaine patches versus vehicle (placebo) patches applied directly to the painful skin of subjects with postherpetic neuralgia (PHN) utilizing an ‘enriched enrollment' study design. All subjects had been successfully treated with topical lidocaine patches on a regular basis for at least 1 month prior to study enrollment. Subjects were enrolled in a randomized, two-treatment period, vehicle-controlled, cross-over study. The primary efficacy variable was ‘time to exit'; subjects were allowed to exit either treatment period if their pain relief score decreased by 2 or more categories on a 6-item Pain Relief Scale for any 2 consecutive days. The median time to exit with the lidocaine patch phase was greater than 14 days, whereas the vehicle patch exit time was 3.8 days (P<0.001). At study completion, 25/32 (78.1%) of subjects preferred the lidocaine patch treatment phase as compared with 3/32 (9.4%) the placebo patch phase (P<0.001). No statistical difference was noted between the active and placebo treatments with regards to side effects. Thus, topical lidocaine patch provides significantly more pain relief for PHN than does a vehicle patch. Topical lidocaine patch is a novel therapy for PHN that is effective, does not cause systemic side effects, and is simple to use.     

Abstract 18: Plantar fasciitis: a new treatment approach.

Objective: To evaluate the efficacy of a new approach that shortens the duration of plantar fasciitis treatment. Design: Randomized controlled study. Setting: Outpatient clinic. Participants: 64 patients were randomly assigned to intensive conventional physical therapy (PT) (n=34) or needling and infiltration of the myofascial trigger points at the proximal portion of the medial gastrocnemius muscle (n=30). Interventions: Patients in the PT group received ultrasound and electric stimulation at the origin of the plantar fascia followed by stretching exercises of the gastrocnemius muscle. The other group was treated by needling and infiltration (1% lidocaine) of the taut band at the proximal portion of the medial gastrocnemius muscle of the involved limb(s). Injections were performed at weekly intervals. PT was administered for 3 consecutive days after the injections. Patients were instructed to perform stretching of the gastrocnemius muscles and of the plantar fascia at home twice a day. Main Outcome Measures: Visual analog scale and hindfoot functional test (American Orthopaedic Foot and Ankle Society Hindfoot Questionnaire) were performed before and after treatment by an independent evaluator. Duration of treatment was compared between the 2 groups. Results: Statistically significant reduction of pain and improvement in function were observed in both groups, without any differences between them. The time required to achieve the same improvement was significantly less (80%) in the injected group than in the control group (P<.001). The number of PT sessions needed was also significantly reduced (P<.001). Postinjection soreness and local hematoma were found in 30% of the patients. No local infection or other major complications were noticed in any cases. Conclusions: Although treatment in both groups was equally successful, needling and infiltration of the medial gastrocnemius muscle provided faster pain relief and functional recovery in patients with plantar fasciitis.     

Comparison of effect of premixed lidocaine in propofol with or without ketorolac pretreatment with placebo on reducing pain on injection of propofol: A prospective, randomized, double-blind, placebo-controlled study in adult Korean surgical patients

Background: Pain on injection of propofol is a common adverse event.Objective: The aim of this study was to investigate the effect of a combination of ketorolac pretreatment and premixed lidocaine in propofol compared with placebo on propofol injection pain.Methods: In this prospective, randomized, double-blind, placebo-controlled study, Korean patients scheduled for elective plastic surgery were randomized to 1 of 3 groups. Group A received 15 mg ketorolac in saline IV as pretreatment. Groups B and C received 3 mL saline IV as pretreatment. Sixty seconds after pretreatment, groups A and B received a mixture of lidocaine 1% in propofol 1% at a 1:10 ratio and group C received propofol 1% alone. Pain during propofol injection was assessed on a 4-point scale (0 = none, 1 = mild, 2 = moderate, 3 = severe).Results: Ninety patients (41 men, 49 vvomen; mean age, 41.7 years; mean weight, 63 kg) completed the study. The overall incidence of pain on propofol injection was significantly lower in groups A (16.7%) and B (36.7%) than in group C (83.3%; both, P < 0.001). There was no significant difference in the incidence of pain between groups A and B. However, the patients in group A reported a significantly lower incidence of moderate (0% vs 33.3%; P < 0.001) and severe pain (0% vs 20%; P = 0.024) compared with those in group C. There were no significant differences in the incidences of moderate and severe pain between the B and C groups.Conclusions: In this Korean population, premixed lidocaine in propofol with or without ketorolac pretreatment was associated with significantly less pain when compared with placebo. The combination of ketorolac pretreatment and premixed lidocaine in propofol was more effective in decreasing the incidence of moderate or severe pain compared with placebo.     

Lidocaine for prevention of propofol injection-induced pain: A prospective, randomized, double-blind, controlled study of the effect of duration of venous occlusion with a tourniquet in adults

Background: Many patients experience pain on injection of propofol. The use of lidocaine to prevent propofol injection pain is common. The analgesic effect of pre-injected lidocaine has been found to increase when a tourniquet is used.Objective: The aim of this study was to compare the effectiveness of various venous occlusion times with lidocaine analgesia to prevent pain during propofol injection.Methods: In this prospective, randomized, double-blind, controlled study, women aged 18 to 45 years, classifed as American Society of Anesthesiologists physical sta- tus I or II, who were scheduled to undergo elective surgery under general anesthesia induced with propofol, were randomly assigned to 1 of 5 groups: group 1, 2% lidocaine 20 mg in saline in a total volume of 10 mL and no venous occlusion; group 2, 2% lidocaine 20 mg in saline in a total volume of 10 mL plus venous occlusion for 15 seconds; group 3, 2% lidocaine plus venous occlusion for 30 seconds; group 4, 2% lidocaine plus venous occlusion for 60 seconds; and group 5, saline 10 mL and no venous occlusion. When the first 25% of the calculated propofol dose was administered, patients were asked about propofol-induced pain using a verbal pain scale (0 = no pain; 1 = mild pain; 2 = moderate pain; and 3 = severe pain). All patients and the anesthesiologist who evaluated pain severity were blinded to the study preparation being used.Results: The study comprised 100 women who were randomly divided into 5 groups of 20 patients each. Significantly more patients in group 5 (18 [90%] patients; P < 0.05) reported pain compared with the other treatment groups. In groups 2, 3, and 4, in which venous occlusion was applied, pain was reported during propofol injection in 6 (30%), 7 (35%), and 2 (10%) patients, respectively. The incidence of reported pain was significantly greater in group 1 (lidocaine without venous occlusion) than in group 4 (P < 0.05); however, the incidence of pain was similar in group 1 compared with groups 2 and 3.Conclusions: The present study found that pretreatment with lidocaine 20 mg with or without venous occlusion significantly reduced the incidence and the severity of pain during the injection of propofol when compared with the group with no venous occlusion administered saline. In addition, pretreatment with lidocaine 20 mg plus venous occlusion for 60 seconds significantly reduced the incidence of propofol-induced pain compared with lidocaine without venous occlusion.     

A pain model with a neuropathic somatosensory lesion: Morton neuroma

A randomized, double-blind, three-period cross-over study was performed to characterize the sensory phenotype and pain demographics in patients with Morton neuroma (n = 27) and to explore the effects of local administration (2 mL) of placebo and lidocaine (1 and 10 mg/mL) around the neuroma. Using the pain quality assessment scale (PQAS), the highest rating was seen for unpleasant pain and intensity of deep pain and the lowest for sensitive skin. Ongoing pain was reported in 32% of patients. Patients reported mild to moderate average pain, and that pain had interfered with sleep only marginally. Quantitative sensory testing (QST) measurements in the innervation territory showed hypophenomena or hyperphenomena in all patients, indicating that all had neuropathy. There was no particular QST modality that appeared to be specifically affected. Even the high-dose lidocaine resulted in limited effects on nerve-impulse conduction as judged by the effect on QST variables. However, both doses of lidocaine significantly reduced pain after step-ups, compared to placebo, indicating that lidocaine in this setting affected predominantly impulse generation and not impulse conduction. Following placebo treatment, pain after step-ups was similar in patients with and without hyperalgesia, indicating that the presence of hyperalgesia does not affect the pain intensity evoked by step-ups or walking.     

Myofascial component of cancer pain review

BackgroundPain is a common complaint of cancer patients, experienced by 38%–85% of patients. Some studies have shown a high incidence of myofascial pain syndrome (MPS) in cancer patients.Aims1) To estimate the prevalence of MPS in cancer patients; 2) to examine the efficacy of current treatment options for MPS in cancer patients.MethodsNarrative review. PubMed, CINAHL, PEDro, and Google Scholar databases were searched from inception until November 2017, for the keywords: cancer; cancer pain; breast cancer; mastectomy; lumpectomy; myofascial pain; trigger points. Trials of any methodological quality were included. All published material with an emphasis on randomized control trials was analyzed.ResultsMPS is prevalent in cancer patients who suffer from pain, with a prevalence of between 11.9% and 44.8% in those diagnosed either with neck or head or breast cancer. Clinical studies showed conflicting results. Four interventional studies found that specific treatment for MPS may reduce the prevalence of active myofascial trigger points and therefore decrease pain level, sensitivity, and improve range of motion (in shoulder) in cancer patients. Two recent randomized control trials showed that pressure release of trigger points provides no additional beneficial effects to a standard physical therapy program for upper limb pain and function after breast cancer surgery.ConclusionsWe recommend including the evaluation of myofascial pain in routine clinical examination of cancer patients suffering from pain. Future studies are needed to investigate the long- and short-term effect of MPS treatments in cancer patients.     

Treatment of complex regional pain syndrome type 1 in a pediatric patient using the lidocaine patch 5%: a case report

Background

Successful treatment of complex regional pain syndrome type 1 (CRPS-1) requires a coordinated, multidisciplinary approach. Physical rehabilitation is an important component of long-term treatment. Unfortunately, patients with significant allodynia or hyperalgesia characteristic of CRPS-1 often have difficulty progressing through a physical therapy (PT) regimen. In most adults with CRPS-1, the treatment of choice is PO opioids.

Objective

This article presents a case report of the use of the lidocaine patch 5%, a targeted peripheral analgesic, in a pediatric patient and its effects on reducing pain, improving the patient's overall attitude, and facilitating compliance with ongoing PT.

Results

A 10-year-old girl developed CRPS-1 after arthroscopic surgery for a sprained ankle. Attempts at PT were unsuccessful due to inadequate pain relief from various treatment modalities. Therapy with the lidocaine patch 5% was initiated and resulted in significant pain relief, improvements in the patient's attitude, and progress with PT.

Conclusion

This case report of a child with CRPS-1 showed that therapy with lidocaine patch 5% may be efficacious in treating children with pain resulting from CRPS-1, thereby increasing the success of PT.     

Myofascial pain response to topical lidocaine patch therapy: case report

This is a case from a preliminary open trial to assess the efficacy of topically applied lidocaine patches as an alternative to trigger point injections for myofascial pain. We describe one case in this report that had a dramatic response to the lidocaine patch. Her pain relief increased, pain intensity decreased, and functional capacity increased. Her pain intensity and relief was measured by the Brief Pain Inventory-Short Form (BPI-SF). A quality of life measure was also included in the BPI-SF. While this was a dramatic response to this patient, it is only one case from an open-trial. The response to other patients has varied. The true clinical utility cannot be obtained from this one report, but only after the data have been analyzed from this initial trial. If the data are promising, a randomized, double-blind, crossover trial is planned.     

Lidocaine patch treatment in patients with low back pain: results of an open-label, nonrandomized pilot study

This prospective, 6-week, multicenter, open-label, nonrandomized pilot study was designed to assess the effectiveness and safety of a lidocaine patch 5% in patients with low back pain (LBP). Patients with moderate to severe LBP, defined as acute/subacute (< 3 months, n = 21), short-term chronic (3-12 months, n = 33), or long-term chronic (> 12 months, n = 77), were recruited from 5 clinics; participants applied < or = 4 patches (560 cm total) once daily to area of maximal LBP as add-on treatment through week 2, with the option to taper concomitant analgesics during weeks 3-6. Scores on Brief Pain Inventory (BPI) were obtained at weeks 2 and 6. Safety analyses included reports of adverse events (AEs) and skin sensitivity to pinprick/light touch. Significant improvements in average daily pain intensity on the BPI were noted at weeks 2 and 6 (P < or = 0.001). Significant improvements in pain interference with quality of life (QOL) were noted for all BPI measures of QOL at weeks 2 and 6 for the acute/subacute (P < or = 0.007) and long-term chronic LBP groups (P < 0.0001) and for 5 of 7 BPI measures for the short-term chronic LBP group (P < or = 0.042). Fifty-eight percent of patients reported being "satisfied" or "very satisfied" with treatment. The lidocaine patch was well tolerated. Most common AEs were dizziness and rash (n = 5, 3.8%), and most AEs (80%) were mild to moderate in intensity. Significant improvement in pain intensity and QOL in this cohort of LBP patients was noted during treatment with the lidocaine patch 5%. Controlled clinical trials are warranted.     

Enhanced central pain processing of fibromyalgia patients is maintained by muscle afferent input: A randomized, double-blind, placebo-controlled study

Fibromyalgia (FM) syndrome is characterized by pain and widespread hyperalgesia to mechanical, thermal, and electrical stimuli. Despite convincing evidence for central sensitization of nociceptive pain pathways, the role of peripheral tissue impulse input in the initiation and maintenance of FM is unclear. Therefore this randomized, double-blind, placebo-controlled trial of 22 female normal controls (NCs) and 28 female FM subjects tested the effects of trapezius muscle (TrapM) tender point injections with 1% lidocaine on local pain thresholds as well as on remote heat hyperalgesia at the forearm. Prior to muscle injections shoulder pain was standardized by tonic mechanical muscle stimulation, resulting in local pain ratings of 4.0 ± 0.5 VAS units. Tonic muscle stimulation was interrupted for the TrapM injections but was continued afterwards at the same level. NC as well as FM subjects experienced significant increases of TrapM pressure pain thresholds from lidocaine injections but not from placebo injections (p < 0.001). Additionally, heat hyperalgesia of FM participants was significantly reduced at areas remote from the injection site (forearm) by lidocaine but not by placebo (p = 0.02). Neither lidocaine nor saline injections significantly affected clinical FM pain ratings, a result most likely due to the very low dose of lidocaine (50 mg) used in this trial. Conclusion: Lidocaine injections increased local pain thresholds and decreased remote secondary heat hyperalgesia in FM patients, emphasizing the important role of peripheral impulse input in maintaining central sensitization in this chronic pain syndrome; similar to other persistent pain conditions such as irritable bowel syndrome and complex regional pain syndrome.     

Injectable Lidocaine Provides Similar Analgesia Compared to Transdermal Lidocaine/Tetracaine Patch for the Incision and Drainage of Skin Abscesses: A Randomized,Controlled Trial

Background

Local anesthesia used for incision and drainage of abscesses is known to be painful.

Study Objective

We studied the analgesia provided by a lidocaine/tetracaine patch compared to injectable lidocaine during incision and drainage (I&D) of skin abscesses.

Methods

This was a prospective, double-blind, randomized, controlled trial carried out in the Emergency Department (ED) of an adult tertiary referral center. Adult patients with a skin abscess in need of I&D were randomized to one of two groups. One group received a lidocaine/tetracaine patch and injectable normal saline for anesthesia. The second group received a placebo patch and injectable 1% lidocaine. A visual analog pain scale was used to record the patient's pain level prior to treatment, during the procedure, and after I&D.

Results

There were 20 patients enrolled in the study, including 12 randomized to the lidocaine/tetracaine patch and 8 to the injectable lidocaine. Pain scores preprocedure were similar in the two groups. Pain scores during I&D and postprocedure were compared between groups using a paired t-test. Patients receiving injectable lidocaine experienced pain that was similar (50.1 ± 5.9 mm; 95% confidence interval [CI] 45.2–55.1) to those receiving the transdermal lidocaine/tetracaine patch (60.1 mm ± 11.0; 95% CI = 55.2–68.1), p = 0.04, with a power of 80% to detect a difference of 20 mm at p ≤ 0.05; although this was statistically significant, it was not clinically significant. There was also no statistical difference between the two groups in the postprocedure pain scores (p = 0.65).

Conclusion

Local injection of lidocaine provided clinically similar analgesia compared to the lidocaine/tetracaine patch during I&D of skin abscesses in the ED. Pain at presentation and after the procedure was similar in both groups. Emergency physicians should continue to use a local injected anesthetic for I&D of skin abscesses until a less painful alternative is identified.     

Capsaicin 8% Patch in Painful Diabetic Peripheral Neuropathy: A Randomized,Double-Blind,Placebo-Controlled Study

This 12-week study evaluated the efficacy and safety of capsaicin 8% patch versus placebo patch in painful diabetic peripheral neuropathy (PDPN). Patients aged 18 years or older with PDPN were randomized (1:1) to one 30-minute treatment (capsaicin 8% patch or placebo patch) to painful areas of the feet. Overall, 369 patients were randomized (capsaicin 8% patch, n = 186; placebo patch, n = 183). Percentage reduction in average daily pain score from baseline to between weeks 2 through 8 (the primary end point) was statistically significant for capsaicin 8% patch versus placebo (?27.4% vs ?20.9%; P = .025); improvements in pain were observed from week 2 onward. Versus placebo, patients treated with capsaicin 8% patch had a shorter median time to treatment response (19 vs 72 days) and modest improvements in sleep interference scores from baseline to between weeks 2 through 8 (P = .030) and weeks 2 through 12 (P = .020). Apart from application site reactions, treatment-emergent adverse events were similar between groups. No indications of deterioration in sensory perception of sharp, cold, warm, or vibration stimuli were observed. In patients with PDPN, capsaicin 8% patch treatment provided modest pain relief and sleep quality improvements versus a placebo patch, similar in magnitude to other treatments with known efficacy, but without systemic side effects or sensory deterioration.

Diclofenac potassium liquid-filled soft gelatin capsules in the management of patients with postbunionectomy pain: A phase III,multicenter, randomized,double-blind,placebo-controlled study conducted over 5 days

Background: Diclofenac potassium liquid-filled soft gelatin capsule (DPSGC) is a rapidly absorbed formulation of diclofenac potassium developed for the treatment of mild to moderate acute pain.Objective: The present study was conducted to assess the efficacy and safety profile of DPSGC 25 mg in patients with pain after first-metatarsal bunionectomy.Methods: This was a Phase III, multicenter, randomized, double-blind, parallel-group, placebo-controlled study conducted over 5 days. Patients experiencing the requisite level of pain (score ≥4 on an 11-point numeric pain rating scale [NPRS] from 0 = no pain to 10 = worst possible pain) on the day after bunionectomy were randomized to receive DPSGC 25 mg or matching placebo. A second dose was given when patients requested additional medication for pain. Subsequent doses were given every 6 hours over a 48-hour inpatient multiple-dose period and continued over an additional 48-hour outpatient multiple-dose period. Opioid rescue medication was available as needed after the second dose of study medication. The primary efficacy end point was the mean NPRS score over the 48-hour inpatient multiple-dose period. Additional measures included NPRS scores at predefined times over 48 hours, the summed pain intensity difference over 48 hours (SPID48), the time-weighted sum of pain relief scores over the first 8 hours, the mean dosing interval (the time from dosing to the time rescue medication or the next dose of study medication was administered, whichever was less), the proportion of patients requiring rescue medication, and the onset of perceptible and meaningful pain relief (2-stopwatch method). Tolerability was assessed based on physician monitoring and patient reporting of adverse events (AEs) and the results of standard laboratory tests.Results: Of 201 randomized patients (102 DPSGC 25 mg, 99 placebo; 86.6% female; 58.2% white; mean [SD] age, 45.2 [11.5] years; weight range, 49.4–108.0 kg), 198 completed the study. Mean baseline NPRS scores did not differ significantly between the DPSGC and placebo groups (6.9 and 7.3, respectively). DPSGC was associated with significant improvements compared with placebo in mean NPRS score over 48 hours (2.5 vs 5.6, respectively; P < 0.001), mean SPID48 (210.0 vs 90.3; P < 0.001), and overall mean dosing interval (331.5 vs 263.9 min; P < 0.001). Significant differences in NPRS scores between DPSGC 25 mg and placebo were noted at all time points from baseline through 48 hours (P < 0.001). The proportion of patients requiring rescue medication was significantly lower in the DPSGC group compared with the placebo group (39.2% vs 87.9% on day 1; 21.6% vs 64.6% on day 2; both, P < 0.001). Patients receiving DPSGC had a significantly faster onset of meaningful pain relief compared with those receiving placebo (P = 0.008). The most commonly reported AEs were nausea (7.8% vs 18.2%), headache (5.9% vs 9.1%), vomiting (3.9% vs 9.1%), and constipation (3.9% vs 2.0%). The overall incidence of AEs occurring in ≥2% of patients was significantly lower in the DPSGC group than in the placebo group (20.6% vs 44.4%; P < 0.05); no patient receiving DPSGC had a serious AE.Conclusions: DPSGC 25 mg taken every 6 hours was effective in reducing postbunionectomy pain in the patients studied. DPSGC was well tolerated, suggesting that it may be a practicable option for the treatment of mild to moderate acute pain. ClinicalTrials. gov identifier: NCT00366444     

Effects of treatment of peripheral pain generators in fibromyalgia patients

Fibromyalgia syndrome (FS) frequently co‐occurs with regional pain disorders. This study evaluated how these disorders contribute to FS, by assessing effects of local active vs placebo treatment of muscle/joint pain sources on FS symptoms. Female patients with (1) FS+myofascial pain syndromes from trigger points (n=68), or (2) FS+joint pain (n=56) underwent evaluation of myofascial/joint symptoms [number/intensity of pain episodes, pressure pain thresholds at trigger/joint site, paracetamol consumption] and FS symptoms [pain intensity, pressure pain thresholds at tender points, pressure and electrical pain thresholds in skin, subcutis and muscle in a non‐painful site]. Patients of both protocols were randomly assigned to two groups [34 each for (1); 28 each for (2)] to receive active or placebo local TrP or joint treatment [injection/hydroelectrophoresis] on days 1 and 4. Evaluations were repeated on days 4 and 8. After therapy, in active – but not placebo‐treated groups: number and intensity of myofascial/joint episodes and paracetamol consumption decreased and pressure thresholds at trigger/joint increased (p<0.001); FS pain intensity decreased and all thresholds increased progressively in tender points and the non‐painful site (p<0.0001). At day 8, all placebo‐treated patients requested active local therapy (days 8 and 11) vs only three patients under active treatment. At a 3‐week follow‐up, FS pain was still lower than basis in patients not undergoing further therapy and had decreased in those undergoing active therapy from day 8 (p<0.0001). Localized muscle/joint pains impact significantly on FS, probably through increased central sensitization by the peripheral input; their systematic identification and treatment are recommended in fibromyalgia.     

Topical lidocaine patch relieves a variety of neuropathic pain conditions: an open-label study. (Department of Pain Medicine and Palliative Care, Beth Lsrael Medical Center, New York, NY) Clin J Pain 2000;16:205–208.

Our goal was to perform a pilot, open‐label, prospective study to access the effectiveness and tolerability of a topical lidocaine patch (Lidoderm) for the treatment of peripheral neuropathic pain conditions other than postherpetic neuralgia. Sixteen patients with refractory peripheral neruopathic pain conditions who had reported intolerable side effects or inadequate pain relief with antidepressant, anticonvulsant, antiarrhythmic, and opioid medications participated in this study. Diagnoses included postthoracotomy pain, stump neuroma pain, intercostal neuralgia, diabetic polyneuropathy, meralgia paresthetica, complex regional pain syndrome, radiculopathy, and postmastectomy pain. A 6‐item Pain Relief Scale was used. Moderate or better pain relief was reported by 13 of the 16 participants (81%). One patient stopped treatment after 4 days due to lack of relief. The remaining 15 patients had a mean duration of patch use of 6.2 weeks with continued relief. Only 1 patient reported a side effect, a mild skin irritation. Conclude the Lidoderm patch provides clinically meaningful pain relief in most of these refractory neuropathic pain patients without side effects. Controlled trials need to be performed to confirm these preliminary findings. Comment by Tat‐Leang Lee, M.D. This is an interesting study that highlighted a simple, efficacious method for the treatment of resistant neuropathic pain. As this was a pilot study using an open‐label method, and treating a heterogenous group of neuropathic pain conditions, caution should be adopted in the interpretation of the results. What remains unanswered is the reason for the success of the lidocaine patch, particularly when previous studies have documented the failure of EMLA in the treatment of neuropathic pain. Indeed, several patients who participated in this study had used EMLA unsuccessfully before, although no details on its administration was reported. Both the lidocaine patch and EMLA contain 5% lidocaine, which presumably would result in greater penetration by the EMLA cream. Therefore, a placebo‐controlled randomized trial is needed to confirm the findings of this pilot study. Nevertheless, this is a promising treatment that is convenient, lacks systemic effect, easily added‐on to existing treatment, and with only minor side effects, that is worth considering for our patients.     

Efficacy and Side Effects of Diclofenac Patch in Treatment of Patients with Myofascial Pain Syndrome of the Upper Trapezius

Locally administered nonsteroidal anti-inflammatory drugs have been widely used in acute soft-tissue damage and articular musculoskeletal pain. This double-blind, placebo-controlled, randomized study was designed to evaluate the efficacy and safety of a topical diclofenac sodium patch in the relief of pain and inflammation as a result of myofascial pain syndrome (MPS) in the upper trapezius. After sample size calculations indicated that 147 patients would be needed to detect a 25% difference between drug and control, 153 patients with MPS were recruited and randomized to receive either a diclofenac sodium patch or control (menthol) patch. Visual analog scale (VAS), cervical active range of motion, pressure pain threshold of the myofascial trigger point (MTrP), patient global assessment, Neck Disability Index, and the occurrence of adverse events were assessed on Day 0 (baseline), Day 4, and Day 8. Use of the diclofenac sodium patch elicited favorable responses for the VAS, cervical active range of motion, and Neck Disability Index by the end of the treatment course (P < 0.05), and was consistently superior to the control patch at all time intervals. No significant differences were observed for the pressure pain threshold of the MTrP for either patch. Tolerability assessment similarly showed the diclofenac patch to be comparatively superior. When assessed at the end of the study, 20 diclofenac patch patients, but only four control patients, considered the tolerability of treatment to be “very good.” Significant differences in adverse reactions were observed between the diclofenac and control patches, with the control patch more likely to produce overall skin irritation. This study demonstrate that the diclofenac sodium patch was superior to the control patch in terms of reducing pain and improving functional outcomes, and did not result in significant adverse effects.     

Topical lidocaine patch therapy for myofascial pain

An open label study of topical lidocaine 5% patches was conducted for myofascial pain management based on the hypothesis that electrical dysfunction is a component of myofascial pain and therefore sodium channel blockade may be useful in managing myofascial pain. The efficacy of topical lidocaine patch therapy for myofascial pain impact of the therapy on associated quality of life were investigated in the one-month trial. Principal outcome measures were Brief Pain Inventory- Short Form for pain intensity and quality of life score changes. Twenty-seven patients with moderate-severe myofascial pain were enrolled. Eighteen had low back pain. Two patients reported complete pain relief and 3 reported a lot of relief. Mean improvements for average pain intensity (7, 14, and 28 days), general activity (7 and 28 days), mood and sleep (7, 14, and 28 days), walking (14 and 28 days), and ability to work, relationships, and enjoyment of life (28 days) were significant (P < 0.05). These results suggest lidocaine patches may be useful in the management of myofascial pain.     

10% Lidocaine spray as a local anesthetic in blood gas sampling: A randomized,double-blind,placebo-controlled study

AimRadial artery blood gas sampling is a very common procedure undertaken in the emergency department to evaluate respiratory and metabolic parameters. This intervention causes both anxiety and pain for the patient. Therefore, the current study aimed to examine the analgesic efficacy of lidocaine spray compared to a placebo during radial artery blood gas sampling.MethodsThis study was conducted in the emergency department of a tertiary hospital with a randomized, double-blind, placebo-controlled design. A total of 144 patients were randomly divided into two groups: One group (n = 72) received 10% lidocaine spray and the other (n = 72) was the placebo group. The analgesic efficacy of the 10% lidocaine spray was compared with the placebo group using the Visual Analog Scale (VAS).ResultsIn the evaluation of the analgesic efficacy of the 10% lidocaine spray, the VAS score was 1.5 [interquartile range (IQR): 2.0] for the lidocaine group and 5 (IQR: 2.0) for the placebo group. The role of lidocaine spray in reducing pain was statistically significant compared to the placebo (p = 0.000).ConclusionIn blood gas sampling, 10% lidocaine spray has analgesic efficacy. Therefore, we recommend the use of lidocaine spray while performing arterial blood gas sampling in emergency departments.     

Intramuscular and nerve root stimulation vs lidocaine injection to trigger points in myofascial pain syndrome.

OBJECTIVES: To compare the efficacies of an intramuscular stimulation technique and 0.5% lidocaine injection to trigger points in myofascial pain syndrome. PARTICIPANTS: Forty-three people with myofascial pain syndrome of the upper trapezius muscle. INTERVENTIONS: Twenty-two subjects were treated with intramuscular stimulation and another 21 with 0.5% lidocaine injection at all the trigger points on days 0, 7 and 14. RESULTS: Intramuscular stimulation resulted in a significant reduction in Wong-Baker FACES pain scale scores at all visits and was more effective than trigger point injection. Intramuscular stimulation also resulted in significant improvement on the Geriatric Depression Scale - Short Form. Local twitch responses occurred in 97.7% (42/43) of patients. All the passive cervical ranges of motion were significantly increased. Post-treatment soreness was noted in 54.6% of patients in the intramuscular stimulation group and 38.1% in the trigger point injection group, respectively, and gross subcutaneous haemorrhage (> 4 cm2) was seen in only one patient in the trigger point injection group. CONCLUSION: In managing myofascial pain syndrome, after one month intramuscular stimulation resulted in more significant improvements in pain intensity, cervical range of motion and depression scales than did 0.5% lidocaine injection of trigger points. Intramuscular stimulation is therefore recommended for myofascial pain syndrome.