Sustained release of levobupivacaine from temperature-sensitive injectable hydrogel for long-term local anesthesia in postoperative pain management.

Postoperative pain is a major concern for most of the surgical patients, and an inadequate postoperative pain control may cause a series of complications. With an effective pain control and lesser side effects, local anesthetics are preferred for use in postoperative pain management. However, the action duration of current local anesthetics is too short to meet the requirements of postoperative analgesia. In this study, an injectable levobupivacaine (LB)-loaded thermo-sensitive hydrogel system based on biodegradable poly(D,L-lactide)-poly(ethylene glycol)-poly(D,L-lactide) (PLEL) was developed for long-acting local anesthetic, in which the soluble charged cation form of LB (LB HCl) was partly alkalified to the poorly soluble base form (LB base). This hybrid LB loaded PLEL system (hLB/PLEL) is a free flowable liquid at room temperature and changes into a semi-solid hydrogel once injection in response to the physiological temperature. Then, the dissolved LB HCl could release firstly from the hydrogel contributing to a quick work, and the insoluble LB base dissolved and released gradually as the decrease of the pH during the biodegradation of PLEL hydrogel, resulting in a long-term LB release in local. The drug release behavior, pharmacokinetic, and biocompatibility of the thermo-sensitive hLB/PLEL were studied in vitro and in vivo. The anesthetic effects of hLB/PLEL system were evaluated in the rat models of sciatic nerve block, subcutaneous infiltration anesthesia and postoperative pain as well. This hLB/PLEL system generated a significantly prolonged analgesic effect in rat models, which produced approximately 7 times longer duration than 0.75% LB HCl and effectively relieved the spontaneous pain for 3 days. In general, the presented hLB/PLEL system can not only achieve a fast-acting but also sustainably release LB to block the nerve and significantly extend the effect of local analgesia, which means a promising candidate for long-acting postoperative pain management.

Effectiveness Of Local Anaesthetic In Reducing Postoperative Pain At Port Site After Laparoscopic Cholecystectomy.

Background: Laparoscopy has become the highest quality level way to deal with cholecystectomy since its inception 30 years preceding, and is perhaps the most normally performed general surgeries. Pain being a significant issue after laparoscopic cholecystectomy bringing about extended admissions or readmissions. With significant varieties in pain relieving conventions an integrated approach is important to diminish pain. The aim of this study is to assess the effectiveness of Bupivacaine as local anesthetic agent at port sites after laparoscopic cholecystectomy. Method: Study population of 84 patients was divided into control group (receiving no local anesthetic) and study group (receiving Bupivacaine as local anesthetic). Visual analogue scale was used to quantify and compare pain perceived by each group; at fixed intervals of 6, 12 and 24 hours after shifting of the patients back to the ward. Results: Each group comprised 42 patients. At 6 hours post operative pain score in study group, 4.5±0.32 was significantly lower than in control group, 7.6±0.41 (p<0.05). Though pain assessments at 12 and 24 hours didn't reveal any significant differences among the two groups; postoperative requirement of Tramadol was significantly (p<0.05) lower in study group (92±0.064mg) in comparison to control group (158±0.21mg). Conclusion: Use of long-acting local anesthetic injections at port sites after laparoscopic cholecystectomy significantly lowers pain during first 6 hours post operatively and also lowers narcotic analgesics requirements during post operative period.

The Efficacy of Local Anesthesia for Postoperative Pain Control in Breast Augmentation Surgery: A Systematic Review and Network Meta-Analysis of Randomized Controlled Trials.

BACKGROUND: Breast augmentation can cause severe postoperative pain; therefore, some surgeons perform wound infiltration with a local anesthetic solution. This study investigated the postoperative pain relief of local analgesics in breast augmentation surgery. METHODS: We searched three databases for randomized controlled trials evaluating the outcomes of local wound irrigation with local analgesics during or after breast augmentation surgery. The solutions included ropivacaine, bupivacaine, bupivacaine plus ketorolac. The control groups may be saline alone or no irrigation. Network meta-analysis was further employed based on the frequentist approach. Outcomes were reported as weighted mean differences with 95% confidence intervals. RESULTS: Comparisons between the interventions of our included studies revealed that only bupivacaine plus ketorolac (versus placebo) significantly reduced pain at 1 h postoperatively, as indicated by the visual analog scale pain score reduction of 2.22 (- 3.98, - 0.47). Other comparisons showed no significant differences. Moreover, three of the included studies reported postoperative medication use. Two of them reported that postoperative narcotic use was reduced, but the others did not report any such reduction. CONCLUSIONS: Our results showed possibility that local irrigation with bupivacaine plus ketorolac might reduce pain 1 h after surgery. In addition, local anesthesia might reduce postoperative narcotic use. However, due to the small number of included studies, the clinical benefits of local anesthesia in breast augmentation surgery require further confirmation. LEVEL OF EVIDENCE III: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

The Analgesic Effect of Ultrasound-guided Bilateral Pectointercostal Fascial Plane Block on Sternal Wound Pain After Open Heart Surgeries: A Randomized Controlled Study.

OBJECTIVES: We aimed to evaluate the analgesic efficacy of ultrasound-guided bilateral pectointercostal fascial plane block after open heart surgeries. METHODS: Seventy patients aged above 18 years and scheduled for on-pump coronary artery bypass grafting or valve replacement or both through median sternotomy were enrolled in this study. Patients were randomly allocated into 2 groups of 35 (block group or control group). The block group had the block performed through 20 ml of a solution of 0.25% bupivacaine plus epinephrine (5 mcg/mL), and the control group received dry needling. The primary outcome was the 24-hour cumulative morphine consumption. The secondary outcomes were time to the first analgesic request, pain score, quality of oxygenation, intensive care unit stays, and hospital stay. RESULTS: The cumulative morphine consumption in the first 24 hours was significantly lower in the block group, with a mean difference of -3.54 (95% confidence interval=-6.55 to -0.53; P=0.015). In addition, the median estimate time to the first analgesic request was significantly longer in the block group than in the control group. Finally, during the postoperative period (4 to 24 h), mean sternal wound objective pain scores were, on average, 0.58 units higher in the block group. CONCLUSION: pectointercostal fascial block is an effective technique in reducing morphine consumption and controlling poststernotomy pain after cardiac surgeries. Also, it may have a role in better postoperative respiratory outcomes.

Spinal Anesthesia Using Ropivacaine Leads to Earlier Ambulation After Total Hip Arthroplasty.

Spinal anesthesia has grown in popularity for total hip arthroplasty (THA) due to its documented low complications. However, the use of a local anesthetic agent dictates the recovery of neuraxial blockade. Bupivacaine has emerged as the most popular choice, but its relatively long-acting effect limits its use with rapid recovery. Although not well studied, ropivacaine may offer a viable alternative with shorter-acting properties. Primary unilateral THA patients who received either ropivacaine or bupivacaine spinal anesthesia were retrospectively reviewed. These groups were compared for common demographics, such as age, sex, and body mass index. The primary outcomes included postoperative ambulation time and distance, post-anesthesia care unit transition time, and selective complications. Five hundred three patients were included. Of these, 227 received ropivacaine and 276 received bupivacaine. The ropivacaine group showed superior ambulation time and distance, quicker post-anesthesia care unit transition, and equivalent complications compared with the bupivacaine group. Ropivacaine shows a clear advantage over bupivacaine for spinal anesthesia during THA when considering rapid recovery. Its use should be strongly considered, especially in the ambulatory setting. [Orthopedics. 2021;44(3):e343-e346.].

Bupivacaine-eluting soy protein structures for controlled release and localized pain relief: An in vitro and in vivo study.

Burn pain is known to be excruciating, and while burn care has greatly advanced, treatment for burn-related pain is lacking. Current pain relief methods include systemic administration of analgesics, which does not provide high drug concentration at the wound site. In the present study, soy protein was used as the base material for bupivacaine-loaded hybrid wound dressings. The effect of the formulation on the drug release profile was studied using high performance liquid chromatography, and the cytotoxicity was tested on human fibroblasts. A second-degree burn model in rats was used to quantify the efficacy of the wound dressings in vivo, using the Rat Grimace Scale. All tested films exhibited high biocompatibility, and the drug release profiles showed rapid release during the initial 5 hr and a continuous slower release for another 24 hr. Significant pain relief was achieved in the animal trials, proving a decrease of 51-68% in pain levels during days 1-3 post-burn. Hence, the results indicate a safe and controlled bupivacaine release for a period of more than 24 hr, effectively treating pain caused by second-degree burns. The understanding of the formulation-properties effects, together with our in vivo study, enables to advance this field toward tailorable systems with high therapeutic potential.

The eight cervical nerve and its role in tinnitus.

INTRODUCTION: The eight cervical nerve might be a source of input to the auditory system. OBJECTIVES: The object was to assess the efficacy of infiltration of the eight cervical nerve root for treating tinnitus patients and to find indicators for a successful result. DESIGN: Retrospective cohort study. Subjects were 79 tinnitus patients visiting our clinic in a three-year period and who were treated with infiltration of the eight cervical nerve root. RESULTS: Twenty-six percent of the tinnitus patients had a reduction of their tinnitus following an infiltration of the eight cervical nerve root. Most of the successfully treated patients rated the effect of therapy as a moderate reduction of 25% to 50%. Fifty percent of the successful treated patients still had benefit at 6.6 months. In 5% of the patients, their tinnitus was aggravated after the infiltration of the eight cervical nerve roots. Patients with a hearing loss at 500 Hz that exceed the hearing loss at 2 kHZ responded the most to infiltration of the eight cervical nerve. CONCLUSION: Infiltration of the eight cervical nerve root reduced the intensity of tinnitus in 26% of the cohort of 79 tinnitus patients with a moderate to good effect. This therapy for tinnitus patients' needs to be considered, especially in those with a hearing loss at 500 Hz that exceed the hearing loss at 2 kHZ.

Syringe or mask? Loop electrosurgical excision procedure under local or general anesthesia: a randomized trial.

BACKGROUND: Loop electrosurgical excision procedure may be performed under local anesthesia or general anesthesia, and practice patterns differ worldwide. No randomized head-to-head comparison has been published to confirm or refute either practice. OBJECTIVE: This study aimed to compare loop electrosurgical excision procedure under local anesthesia vs general anesthesia regarding patient satisfaction and procedure-related outcomes such as rates of involved margins, complications, pain, and blood loss. STUDY DESIGN: Consecutive women referred to our colposcopy unit were recruited. Loop electrosurgical excision procedure was performed under local anesthesia with 4 intracervical injections of bupivacaine hydrochloride 0.5% or under general anesthesia with fentanyl, propofol, and a laryngeal mask with sevoflurane maintenance. The primary endpoint was patient satisfaction assessed on the day of surgery and 14 days thereafter using a Likert scale (score 0-100) and a questionnaire. Secondary endpoints included rates of involved margins, procedure-related complications, pain, blood loss, and surgeon preference. Results were compared using nonparametric and chi-square tests. RESULTS: Between July 2018 and February 2020, we randomized 208 women, 108 in the local anesthesia arm and 100 in the general anesthesia arm. In the intention-to-treat analysis, patient satisfaction did not differ between the study groups directly after surgery (Likert scale 100 [90-100] vs 100 [90-100]; P=.077) and 14 days thereafter (Likert scale 100 [80-100] vs 100 [90-100]; P=.079). In the per-protocol analysis, women in the local anesthesia arm had significantly smaller cone volumes (1.11 cm3 [0.70-1.83] vs 1.58 cm3 [1.08-2.69], respectively; P<.001), less intraoperative blood loss (Δhemoglobin, 0.2 g/dL [-0.1 to 0.4] vs 0.5 g/dL [0.2-0.9]; P<.001), and higher satisfaction after 14 days (100 [90-100] vs 100 [80-100]; P=.026), whereas surgeon preference favored general anesthesia (90 [79-100] vs 100 [90-100], respectively; P=.001). All other secondary outcomes did not differ between groups (resection margin status R1, 6.6% vs 2.1% [P=.26]; cone fragmentation, 12.1% vs 6.3% [P=.27]; procedure duration, 151.5 seconds [120-219.5] vs 180 seconds [117-241.5] [P=.34]; time to complete hemostasis, 60 seconds [34-97] vs 70 seconds [48.25-122.25] [P=.08]; complication rate, 3.3% vs 1.1% [P=.59]). In a multivariate analysis, parity (P=.03), type of transformation zone (P=.03), and cone volume (P=.02) and not study group assignment, age, body mass index, and degree of dysplasia independently influenced the primary endpoint. CONCLUSION: Loop electrosurgical excision procedure under local anesthesia is equally well tolerated and offers patient-reported and procedure-related benefits over general anesthesia, supporting the preferred practice in some institutions and refuting the preferred practice in others.

Comparative evaluation of epidural bupivacaine alone and bupivacaine combined with magnesium sulfate in providing postoperative analgesia: a meta-analysis of randomized controlled trials.

BACKGROUND: The comparative efficacy of epidural bupivacaine alone and bupivacaine combined with magnesium sulfate in providing postoperative analgesia remains controversial. METHODS: We searched Mediline (OvidSP), EMBASE (OvidSP) and Cochrane Central Register of Controlled Trials (CENTRAL) to identify trials that compared epidural bupivacaine and magnesium sulfate combination (intervention) with bupivacaine alone (control). Grading of Recommendations, Assessment, Development and Evaluations (GRADE) framework was used to assess the quality of evidence. RESULTS: Eleven studies fulfilled our inclusion criteria after screening. We found that epidural bupivacaine combined with magnesium sulfate could prolong the time for first rescue analgesics (SMD 4.96; 95% CI [2.75, 7.17], P < 0.00001, I2 = 98%), reduce the number of patients who need rescue analgesics (RR 0.38; 95% CI [0.20, 0.74], P = 0.004, I2 = 75%) and requirement for rescue analgesics (SMD -2.65; 95% CI [- 4.23, - 1.06], P = 0.001, I2 = 96%). CONCLUSIONS: Magnesium suifate as an adjuvant of epidural bupivacaine improved postoperative analgesia. However, we rated the quality of evidence to be very low because of high heterogeneity, imprecise of results and small sample sizes. Furthermore, further large high-quality trials are still needed to confirm the effects of magnesium sulfate on postoperative analgesia.

Sterility and concentration of liposomal bupivacaine single-use vial when used in a multiple-dose manner.

OBJECTIVE: To evaluate the sterility of bupivacaine liposome injectable suspension (Nocita®) used in a multiple-dose fashion for 5 days. STUDY DESIGN: Triplicate liposomal bupivacaine vials were stored under two conditions, (1) room temperature (24°C) and (2) refrigerated temperature (5°C). A 3-mL aliquot was withdrawn from each vial daily. Samples were inoculated in tryptic soy broth in triplicate and then incubated for 24 hours at 37°C and subcultured every 48 hours onto blood agar and Sabouraud dextrose agar, respectively. Separate 1.5-mL aliquots of liposomal bupivacaine were centrifuged at 3500 g to separate liposome-encapsulated bupivacaine from the solution. Concentration of unencapsulated bupivacaine was analyzed via high-pressure liquid chromatography. Data were analyzed by using mixed effects procedure with multiple comparisons. SAMPLE POPULATION: Ten 20-mL vials of bupivacaine liposome injectable suspension stored under two conditions, (1) room temperature (24°C) and (2) refrigerated temperature (5°C). RESULTS: Five days of repeated withdrawal from the single-use vials yielded no bacterial growth. One control vial, which was opened and punctured once on the last day of the experiment, yielded fungal growth of an Aspergillus spp, likely an environmental contaminant. The concentration of free bupivacaine did not significantly differ until the fifth day of sampling. CONCLUSION: When aseptic technique was used, liposomal bupivacaine remained sterile for 5 days. Concentrations of free bupivacaine were unchanged from baseline for 4 days in both refrigerated and room temperature conditions. CLINICAL SIGNIFICANCE: Single-use liposomal bupivacaine vials can be used extralabel in a multiple-dose fashion for up to 4 days when stored either refrigerated or room temperature when sterile technique is used.

Controlled, non-inferiority trial of bupivacaine liposome injectable suspension.

OBJECTIVES: Recently, a bupivacaine liposome injectable suspension (BLIS) became commercially available in the veterinary market that may provide local analgesia for 72 h. The purpose of this study was to compare a BLIS incisional block with a control protocol in cats after ovariohysterectomy (OHE). The hypothesis was that a BLIS block would provide equivalent pain relief. METHODS: This study was designed as a randomized, double-blind, non-inferiority trial. Students performed an OHE followed by a two-layer incisional and body wall block with either standard bupivacaine (control) or BLIS. Postoperatively, cats in the control group received robenacoxib, whereas the BLIS cats received saline. All cats were evaluated using the feline Glasgow Composite Measure Pain Scale (GCMPS) at multiple time points postoperatively. RESULTS: There were 24 control cats and 23 BLIS cats. One cat from each group required rescue medication. The mean GCMPS scores were low and the groups were equivalent at all time points (P <0.05). This study showed that BLIS was equivalent to the control group up to 42 h and pain scores remained low up to 68 h after surgery. CONCLUSIONS AND RELEVANCE: BLIS incisional block is equivalent to a control pain protocol and reduces the need for continued postoperative drug administration.

The Efficacy of Ultrasound-Guided Paravertebral Block in Laparoscopic Cholecystectomy.

Background and objectives: Despite its wide use in thoracic procedures, to date, few studies have assessed the effectiveness of paravertebral block (PVB) in laparoscopic cholecystectomy (LC) in an adult population. In these studies, PVB was performed bilaterally using nerve stimulator guidance. To the best of our knowledge, the effectiveness of unilateral preoperative and postoperative ultrasound-guided PVB has not been evaluated in patients undergoing elective LC. The aim of this study was to evaluate the efficacy of single-dose unilateral paravertebral block (PVB) in patients undergoing laparoscopic cholecystectomy (LC) under general anesthesia. Materials and Methods: Patients undergoing LC were randomly separated into control, preoperative block, and postoperative block groups. PVB was performed unilaterally using bupivacaine under ultrasound guidance. Postoperative pain within the first 24 h, side effects, intraoperative opioid and postoperative analgesic requirements were noted. Evaluation was made of a total of 90 patients (25 males, 65 females) with a mean age of 45.78 ± 14.0 years (range, 19⁻74 years). Results: Opioid and additional analgesic needs and nausea/vomiting rates were significantly reduced in the preoperative block group compared to the other groups (p < 0.05). Visual Analog Scale (VAS) scores were significantly lower in the preoperative and postoperative block groups compared to the control group (p < 0.05 for all). When the VAS scores were compared between the preoperative and postoperative block groups, a significant difference in favor of the preoperative group was observed in terms of the zero minute-, 1st and 2nd h assessments (p < 0.05 for all). Conclusions: Ultrasound-guided PVB is a useful and safe approach for pain management during and after LC. Preoperative block can also reduce the rate of requirement for intraoperative opioid and postoperative analgesia.

Effect of operative local anesthesia on postoperative pain outcomes of inflatable penile prosthesis: prospective comparison of two medications.

Few studies have examined the roles of dorsal penile nerve block (DPNB) and penile ring block (PRB) in surgery of inflatable penile prosthesis (IPP) placement. We sought to compare the postoperative pain outcomes of two different medications used in DPNB plus PRB. We thus carried out a prospective study of patients with erectile dysfunction who underwent "de novo" IPP placement between January 2013 and June 2013. Patients were divided to one of three groups: 1-DPNB plus PRB with bupivacaine injection; 2-DPNB plus PRB with ropivacaine injection and, 3-Control group without DPNB or PRB injection. Postoperative pain score and pain medication usage were recorded 2 h postoperatively, and every 24 h, for a week. The Visual Analog Scale (VAS) was used as pain scale measurement. A total of 131 patients were included in this study: 40 to bupivacaine, 47 to ropivacaine, and the rest were controls. Two hours postoperatively, mean VAS was significantly different (p < 0.0001) between medicated patients and the control group, however, no significant differences were observed between medication groups. Mean VAS was not significantly different among the groups from post-surgical day 2 thru 7. In conclusion, DPNB plus PRB during IPP provided effective analgesia in the immediate post-operative recovery.

A randomized double-blind placebo-controlled trial on the effect of local analgesia on postoperative gluteal pain in patients undergoing sacrospinous ligament colpopexy.

BACKGROUND: The incidence of temporary gluteal pain after sacrospinous ligament colpopexy ranges from 6.1% to 15.3%. Gluteal pain may occur as a result of injury to S3 to S5 nerve roots that course over the mid-portion of the coccygeus-sacrospinous ligament complex at the time of suspension suture placement. There are no data on the use of injections to prevent postoperative pain from nerve entrapment at the time of suture placement. OBJECTIVE: The purpose of this study was to determine whether intraoperative local analgesia that is administered at the level of the sacrospinous ligament can lessen the gluteal pain felt by patients postoperatively after sacrospinous ligament colpopexy. STUDY DESIGN: In a randomized double-blind placebo-controlled trial, women with vaginal apex prolapse who were undergoing surgical treatment with sacrospinous ligament colpopexy underwent intraoperative injection with either 0.25% bupivacaine or normal saline solution. Subjects completed visual analog pain scales (0-10) and the Activities Assessment Scale and recorded the use of pain medications over a 6-week period. The primary outcome was postoperative gluteal pain. A sample size of 50 subjects (25 in each arm) was planned to test the hypothesis that local analgesia administration will lessen postoperative pain compared with placebo. RESULTS: Between April 2014 and March 2016, 51 women were enrolled in the study, and 46 women underwent sacrospinous ligament colpopexy. On postoperative day 1, 90.2% of all subjects (n=41) reported gluteal pain. At weeks 1 and 2, 63.8% (n=29) and 44.1% (n=20) women reported pain; at weeks 4 and 6, 33.3% (n=15) and 26.9% (n=12) women continued to have some pain. On day 1, the mean score for gluteal pain was 3.7±2.9. By week 1, the score was 1.8±2.6; by week 6, the mean score was 0.1±0.3. There were no differences in pain scores for patients who had undergone injection with 0.25% bupivacaine and those who were injected with normal saline solution. Patients in the placebo group used significantly more nonsteroidal antiinflammatory drugs than the treatment group: adjusted odds ratio, 1.25; 95% confidence interval, 1.04-1.35; P=.01). By 6 weeks, 87.5% of patients had returned to their baseline "light" activity level. There was no difference in time to return to baseline between the groups. CONCLUSION: Intraoperative administration of local analgesia does not reduce patients' perceptions of postoperative gluteal pain after sacrospinous ligament colpopexy; however, it may reduce the need for pain medication after surgery.

Local sustained delivery of bupivacaine HCl from a new castor oil-based nanoemulsion system.

Bupivacaine HCl (1-butyl-2',6'-pipecoloxylidide hydrochloride), an amide local anesthetic compound, is a local anesthetic drug utilized for intraoperative local anesthesia, post-operative analgesia and in the treatment of chronic pain. However, its utility is limited by the relative short duration of analgesia after local administration (approximately 9 h after direct injection) and risk for side effects. This work is aimed to develop a nanoemulsion of bupivacaine HCl with sustained local anesthetics release kinetics for improved pain management, by exhibiting extended analgesic action and providing reduced peak levels in the circulation to minimize side effects. Herein, biodegradable oils were evaluated for use in nanoemulsions to enable sustained release kinetics of bupivacaine HCl. Only with castor oil, a clear and stable nanoemulsion was obtained without the occurrence of phase separation over a period of 3 months. High loading of bupivacaine HCl into the castor oil-based nanoemulsion system was achieved with about 98% entrapment efficiency and the resulting formulation showed high stability under stress conditions (accelerated stability test) regarding changes in visual appearance, drug content, and droplet size. We show herein that the in vitro release and in vivo pharmacokinetic profiles as well as pharmacodynamic outcome (pain relief test) after subcutaneous administration in rats correlate well and clearly demonstrate the prolonged release and extended duration of activity of our novel nanoformulation. In addition, the lower Cmax value achieved in the blood compartment suggests the possibility that the risk for systemic side effects is reduced. We conclude that castor oil-based nanomulsion represents an attractive pain treatment possibility to achieve prolonged local action of bupivacaine HCl.

Central Sensitization Is Modulated Following Trigger Point Anesthetization in Patients with Chronic Pain from Whiplash Trauma. A Double-Blind, Placebo-Controlled, Crossover Study.

Objective: Central sensitization (CS) with low peripheral pain thresholds (PPTs) is a common finding among patients with chronic pain after whiplash (CPWI). While it has been proposed that myofascial myofascial trigger points (MTrPs) may act as modulators of central sensitization, previously reported findings are conflicting and inconclusive. The present study was designed to investigate immediate responsiveness of CS to alterations in nociceptive input. Design: Controlled, double-blind, cross-over. Subjects: Thirty-one patients with chronic pain (trapezius myalgia) and CS after whiplash. Methods: Participants were referred by randomization to group A for injection of a single peripheral pain generator (MTrP or other discrete tender point) with local anesthetic or to group B for sham injection and cross-over. Documentation of PPT (Algometer), maximum jaw opening (caliper), and grip strength (Vigorimeter), as well as subjective overall pain (visual analog scale [VAS]), was made before and after each intervention. Results: Statistical analysis of data (Student's t test, analysis of variance) confirmed that peripheral pain thresholds were significantly higher and maximum jaw opening significantly greater after anesthetizing a focal pain generator in the trapezius, but not after a sham injection. In contrast with the objective variables, subjective generalized pain improved (VAS) after not only an injection of local anesthetic, but also, and to a similar extent, after a sham injection. Conclusions: CS, as expressed by lowered PPT, is a rapidly adjusting physiological response to nociceptive stimuli in some patients with chronic pain after whiplash. PPT are likely modulated by myofascial tender points in selected patients with CS. With reference to the present findings, surgical ablation of MTrPs is discussed as a potential treatment modality for CS.

Comparison of the Efficiency of Ultrasound-Guided Injections of the Rhomboid Major and Trapezius Muscles in Myofascial Pain Syndrome: A Prospective Randomized Controlled Double-blind Study.

OBJECTIVES: We aimed to investigate the effect of ultrasound (US)-guided injections of the rhomboid major (deep) and trapezius (superficial) muscles on pain, disability, and quality of life in patients with myofascial pain syndrome. METHODS: In this prospective randomized controlled double-blind study, 65 patients with a diagnosis of myofascial pain syndrome were randomized into 2 groups. In group 1 (n = 33), US-guided rhomboid major muscle injection was performed, and in group 2 (n = 32), US-guided trapezius muscle injection was performed. The patients were assessed by a visual analog scale for pain, the Pressure Pain Threshold, the Neck Pain and Disability Scale, and Short Form 12. Data were obtained before treatment (week 0), the second week after treatment, and the fourth week after treatment. RESULTS: In both groups, significant improvements were observed for all parameters at both weeks 2 and 4 compared to pretreatment values (P < .05). A comparison of the groups showed significantly superior results in group 1 for all parameters at week 2 (P < .05) and for all parameters but the Physical Component Scale of Short Form 12 at week 4 (P < .05). CONCLUSIONS: We think that US-guided deep injection of the rhomboid major muscle was more effective than superficial injection of the trapezius muscle for pain, disability, and quality of life in patients with myofascial pain syndrome.

Local infiltration analgesia or femoral nerve block for postoperative pain management in patients undergoing total hip arthroplasty. A randomized, double-blind study.

BACKGROUND AND AIMS: Several methods for pain management following total hip arthroplasty (THA) have been described but the best postoperative pain management technique remains uncertain. We compared surgeon applied local infiltration analgesia (LIA) with anaesthesiologist performed femoral nerve block (FNB) using ultrasound. The primary aim was to assess pain intensity 24h after THA. METHODS: In this randomized, double-blind study, 56 patients (ASA I-III) undergoing THA consented to participate. In Group FNB, patients received an ultrasound-guided femoral nerve block using 30ml of ropivacaine 7.5mg/ml (225mg) while Group LIA received a similar volume of saline. Spinal anaesthesia was then performed and bupivacaine heavy, 3-3.5ml injected depending on patient characteristics. During surgery, patients in Group LIA received a mixture of 300mg (150ml) ropivacaine, ketorolac 30mg (1ml) and adrenaline 0.5mg (0.5ml) (total volume 151.5ml) peri-articularly and subcutaneously while Group FNB received 151.5ml of saline peri-articularly in a systematic way by the surgeon. A multi-hole catheter was placed with the tip placed intra-articularly at the end of surgery in both groups. After 23h, the LIA mixture consisting of 20ml ropivacaine (7.5mg/ml), ketorolac 30mg (1ml), adrenaline 0.1mg (1ml) (total volume 22ml) was injected in Group LIA and the same volume of saline in Group FNB. Postoperative pain, analgesic consumption (postoperative and post-discharge), side effects, home discharge, quality of life and hip function were recorded, the latter up to 6 months after surgery. RESULTS: Postoperative pain intensity was significantly lower in Group LIA compared to Group FNB during mobilization at 24h (primary endpoint), mean difference 1.8 NRS units (95% CI 0.7-2.9) (P=0.006), at rest after 4h (P=0.029) and on standing after 24 (P=0.0003) and 48h (P=0.043). Rescue morphine consumption was also significantly lower in Group LIA during 0-24, mean difference 13.5mg (95% CI, 6.1-20.9) (P=0.002) postoperatively. Motor block was greater at 6h (P=0.029) postoperatively in Group FNB. Two patients (one in each group) had persistent post-surgical pain (NRS>3) at 3 months (3.6%) but none at 6 month. No other differences were found between the groups. CONCLUSION: Local infiltration analgesia significantly reduces pain intensity on standing and mobilization, and rescue analgesic consumption compared to femoral nerve block without causing significant side effects. The superior analgesia in the LIA group may result from the secondary injection at 23h postoperatively and needs to be further evaluated in future studies. No differences were found in home discharge, quality of life and hip dysfunction between the groups. IMPLICATION: Local infiltration analgesia is the preferred method for postoperative pain management following THA compared to single-shot femoral nerve block.