Pain Control Research Articles

Feasibility and Analgesic Efficacy of Thoracolumbar Dorsal Ramus Nerve Block Using Multiorifice Pain Catheters for Scoliosis Surgery: A Prospective Cohort Study.

Approximately 38,000 scoliosis surgery correction operations are performed annually in the United States; these operations are associated with considerable postoperative pain which can be difficult to manage. This is largely attributed to an incision spanning multiple vertebral segments with paraspinal muscle dissection and retraction to facilitate the implantation of segmental hardware and rods. Frequently utilized analgesic modalities include intravenous patient-controlled analgesia and epidural analgesia, often in combination. We sought to ascertain the feasibility and analgesic efficacy of continuous thoracolumbar dorsal ramus nerve (TDRN) block using surgically placed multiorifice catheters. Forty-two patients diagnosed with idiopathic scoliosis who underwent a posterior spinal fusion (PSF) were enrolled after consent was obtained. Patients were managed utilizing a standardized Enhanced Recovery After Surgery) protocol including a perioperative opioid-sparing regimen. Data were collected at specified time intervals during the recovery period. These data points included pain scores using the Numeric Rating Scale. Parenteral or both oral and parenteral opioid consumption doses were also collected every 4 hours. Any significant postoperative adverse events were recorded as well. A total of 42 patients had surgically placed TDRN catheters, and 40 patients were included in this study. The patients all reported low to moderate pain scores with low opioid consumption postoperatively, while the TDRN catheter delivery of local anesthetic analgesics did not result in significant complications. A regional technique utilizing TDRN catheters could be a valuable component of the postoperative pain management protocols for PSF surgery, and additional studies are warranted. This study evaluated the feasibility and analgesic efficacy of TDRN catheters for postoperative pain control following multilevel PSF for idiopathic scoliosis. Continuous local anesthetic delivery through TDRN catheters is a feasible and safe technique for postoperative pain control in these patients. Selective blockade of the dorsal rami might have benefits over epidural analgesia or other regional techniques.

Dynamic renal scans as a modality for follow-up of flexible ureteroscopy.

To determine whether dynamic renal scans - DTPA or MAG3 - routinely performed after flexible ureteroscopies (f-URS) could detect the development of an obstruction and thus promote prompt early intervention for kidney preservation. In this retrospective study, with all the data recorded prospectively between April 2010 and October 2023, 250 renal units in 242 patients with upper urinary tract stones (UUTS) who underwent ureterorenoscopy by one surgeon in the same medical center were evaluated. Stone-free rate (SFR) was defined as no residual fragments at all using an intraoperative "triple test". The following characteristics were examined: gender, BMI, age, Hounsfield unit, stone diameter, laterality, renal/ureteral stones, stone-free rate, and auxiliary procedures per renal unit. The Clavien-Dindo classification was used to report complications. Renal units with residual stones were scheduled for a 2nd f-URS. Post- flexible ureteroscopy ureteral obstruction and renal function were detected using renal scan DTPA or MAG-3. The primary outcome was renal/ ureteral obstruction. The mean patient age was 53 years. The mean stone size was 12.3 mm. Stones in renal pelvis, upper, middle and lower calyces were treated in 9.2% (23), 27.6% (69), and 30.8% (77) of cases, respectively; 44% (110) ureteral stones were also treated. The single- and second-session SFRs were 94.8% and 99.7%, respectively. A third auxiliary procedure was needed in one renal unit (0.4%). The mean number of procedures per renal unit was 1.06 (264/250). Ureteral double-J stents were inserted in 53.6% (134) of the cases. In 37 (14.8%) cases, a stent was placed before surgery. Post-operative complications were minor, with readmission and pain control needed in only two patients (0.8%). No avulsion or perforation of the ureters was observed. In six patients with t1/2 between 10-20 minutes, a second renal scan revealed spontaneous improvement and no obstruction in five patients. One patient with large stones and a history of prior ureteroscopy developed a ureteral stricture (0.4%) and needed treatment with laser endoureterotomy. Post-flexible ureteroscopy obstruction due to ureteral stricture is very rare. A routine renal scan post-operatively may be used in potentially high-risk patients.

Analysis of lumbar spine loading during walking in patients with chronic low back pain and healthy controls: An OpenSim-Based study

Low back pain (LBP) is one of the most prevalent and disabling disease worldwide. However, the specific biomechanical changes due to LBP are still controversial. The purpose of this study was to estimate the lumbar and lower limb kinematics, lumbar moments and loads, muscle forces and activation during walking in healthy adults and LBP. A total of 18 healthy controls and 19 patients with chronic LBP were tested for walking at a comfortable speed. The kinematic and dynamic data of the subjects were collected by 3D motion capture system and force plates respectively, and then the motion simulation was performed by OpenSim. The OpenSim musculoskeletal model was used to calculate lumbar, hip, knee and ankle joint angle variations, lumbar moments and loads, muscle forces and activation of eight major lumbar muscles. In our results, significant lower lumbar axial rotation angle, lumbar flexion/extension and axial rotation moments, as well as the muscle forces of the four muscles and muscle activation of two muscles were found in patients with LBP than those of the healthy controls (p < 0.05). This study may help providing theoretical support for the evaluation and rehabilitation treatment intervention of patients with LBP.

SupporTive Care At Home Research (STAHR) for patients with advanced cancer: Protocol for a cluster non-randomized controlled trial.

Advancements in the treatment and management of patients with cancer have extended their survival period. To honor such patients' desire to live in their own homes, home-based supportive care programs have become an important medical practice. This study aims to investigate the effects of a multidimensional and integrated home-based supportive care program on patients with advanced cancer. SupporTive Care At Home Research is a cluster non-randomized controlled trial for patients with advanced cancer. This study tests the effects of the home-based supportive care program we developed versus standard oncology care. The home-based supportive care program is based on a specialized home-based medical team approach that includes (1) initial assessment and education for patients and their family caregivers, (2) home visits by nurses, (3) biweekly regular check-ups/evaluation and management, (4) telephone communication via a daytime access line, and (5) monthly multidisciplinary team meetings. The primary outcome measure is unplanned hospitalization within 6 months following enrollment. Healthcare service use; quality of life; pain and symptom control; emotional status; satisfaction with services; end-of-life care; advance planning; family caregivers' quality of life, care burden, and preparedness for caregiving; and medical expenses will be surveyed. We plan to recruit a total of 396 patients with advanced cancer from six institutions. Patients recruited from three institutions will constitute the intervention group, whereas those recruited from the other three institutions will comprise the control group.

Analgesia for the treatment of acute pancreatitis: a protocol for a systematic review and network meta-analysis

IntroductionGastrointestinal hospitalisations in the USA cause over US$130 billion in expenditures, and acute pancreatitis is a leading cause of these hospitalisations. Adequate pain control is one of the primary treatment...

Deep learning in oral surgery for third molar extraction: empirical evidence and original model

Preemptive analgesia is an analgesic intervention to influence postoperative pain sensation. Control of postoperative pain is a major challenge for any surgeon. Adequate control of postoperative pain continues to be a challenge for modern medicine. The advent of artificial intelligence (AI) in all spheres of life, including medicine, has created the technical ability to process a variety of types and characteristics of data related to many diseases. The application of artificial neural networks in medical science has made it possible to obtain an independent, objective assessment as a consequence of the application of preemptive analgesia. The data analysis by our original model, compared with the routinely used statistical methods, show the presence of a tendency for a positive effect of preemptive analgesia. In order to obtain an efficient self-learning neural network, it is necessary to use large arrays of properly selected data that fulfill the role of input parameters for the neural network. The results obtained from the original model used are comparable to the traditionally used statistical methods. This model objectifies to a certain extent the preemptive analgesia in the surgery of third mandibular molars.

High prevalence of severe pain is associated with low opioid availability in patients with advanced cancer: Combined database study and nationwide questionnaire survey in Japan.

Opioid availability for the palliative care of patients with advanced cancer is increasing globally. However, opioid availability remains extremely low in Japan. We investigated whether pain is appropriately controlled by low-dose opioid prescriptions in patients with advanced cancer in Japan. A web-based nationwide survey for caregivers from 2000 community comprehensive support care centers was performed in Japan to assess details about pain in the 30 days before patients died of end-stage cancer. Separately, the data for opioid prescription doses and medical services in the 90 days before the death of patients with cancer were extracted from a health insurance claim database. Responses from 1034 responders were retrieved and 665 patients were included. In total, 254 patients (38.2%) complained of severe-to-intolerable cancer-related pain. The median cumulative prescription dose of opioids in the 90 days before patient death was 311.0 mg by oral morphine equivalent doses. Multiple regression analyses across prefectures revealed that the proportion of patients with severe-to-intolerable cancer-related pain was negatively associated with the cumulative opioid consumption expressed as morphine-equivalent doses within 90 days before death. The very low availability of opioids for patients with end-stage cancer could result in high rate of severe-to-intolerable cancer-related pain patients. There were several limitations in this study, and the interpretations of the findings should be carefully. However, the increase in the absolute dose of opioids could improve the palliative care framework to the pain control levels of the global standard.

A Comparative Study to Evaluate Postoperative Analgesia with USG Guided Unilateral Adductor Canal by using Combination of Bupivacaine with Dexamethasone or Morphine After Total Knee Replacement

TKR surgery refer to surgical intervention in the knee joint to replace diseased joint and many studies investigated post operative pain control, Adductor canal block is a newer alterative to femoral block after TKR with better multimodal analgesia and better quadriceps muscle strength, Many studies investigated the prolongation of analgesic duration when adjunct is added to a local anesthetic. A prospective randomized ,double blind, parallel- two group trial. A total of 78 ASA 1 and ASA 2 patients undergoing total knee replacement were included in the study. Seventy eight patients undergoing TKR were randomly allocated into two groups and received block as per the study protocol and the main outcome measure was the duration of postoperative analgesia. The result revealed that at equal volumes Bupivacaine 0.5% with 30mcg/kg of morphine has an advantage over Bupivacaine 0.5% when combined with 8mg of dexamethasone. We conclude that adductor canal block with 0.5% Bupivacaine with 30mcg/kg of morphine has better outcome over conventional intravenous paracetamol analgesia

Preoperative opioid use and its association with postoperative complications

ABSTRACT Background The negative impact of opioid use in the U.S. has led providers to seek alternative methods for pain control. More specifically, preoperative opioid usage has been demonstrated to adversely affect patients and clinical outcomes. This study aims to assess the extent of the relationship between preoperative opioid use on postoperative outcomes across surgical disciplines using statewide population databases. Methods The study used the Utah All Payers Claims Database and Utah Population Database to identify a cohort of adult patients who underwent a single surgery between 2013 and 2016 and had continuous insurance enrollment. Preoperative opioid prescription within one year prior to the index surgery was the independent variable, while complications and hospital admissions one year following the index surgery were the primary outcomes. Results Our model of 18,647 patients found that the odds of any complication with preoperative opioid use was 1.28. Depression (OR 1.17) and drug misuse (OR 1.41) were also associated with a higher risk of postoperative complications. Rates of hospital readmission in the preoperative opioid use group compared to the opioid naïve group were increased (19.43% vs. 12.44%, p < .01). Conclusion The data can be used to guide patient-physician conversations and better inform prescribing habits perioperatively.

Assessment of pain control in advanced cancer patients admitted to a palliative care unit

Introduction: Pain in people with cancer is prevalent and should have an individualized therapeutic plan. Objectives: To evaluate pain control in advanced cancer patients in a hospital palliative care unit. Methods: This is a cohort study, with prospective design, and quantitative approach, including advanced cancer patients admitted to a palliative care unit between June 2021 and February 2022 reporting pain. Data was collected from medical records and the Brief Pain Inventory (BPI) was used to assess pain on the first (D1), third (D3) and seventh (D7) day of hospitalization. Results: One hundred and four patients participated in the study. The most prevalent tumors were of the gastrointestinal tract (n=23; 22%), cervix (n=21; 20%) and breast (n=17; 16%). Abdomen was the most reported site of pain (n=34; 33%), with 50% classified as nociceptive pain, 39% neuropathic pain, and 11% mixed. On D1, 43% reported severe pain, 31% moderate, and 12% mild pain. There was an evolutionary drop in the percentage of severe pain (BPI3 70% to 37.1%; BPI4 12.6% to 5.4%; BPI5 42.5% to 13.5%; and BPI9 67.8% to 21.6%) according to the answers to all BPI questions during the period. On D1, D3 and D7, the average equipotent doses of oral morphine were 116 mg, 133 mg and 154 mg and the frequency of use of adjuvant use was 60%, 75%, and 69%, respectively. Conclusions: Pain was properly controlled and was related to the increased use of adjuvants, both for general and neuropathic pain. It was possible to observe that the use of adjuvants was related to better pain control.

The evolution of the FARM Animal Care program: Trends, priority issues and opportunities for veterinarians

The FARM Program’s goal is to assist U.S. dairy farmers, par­ticipating cooperatives and processors in providing assurance to dairy buyers that U.S. dairy farmers care for their animals, workforce and land in a humane and ethical manner. Over 17,000 second-party evaluations and 480 third-party verifica­tions have been conducted on U.S. dairy farms under Version 4 of the animal care program. Though the majority of farms meet FARM standards, lack of a VCPR and herd health plan signed by the veterinarian in the past 12 months, missing/incomplete continuing education records for employees, not meeting the benchmark for broken tails, lack of pain control for disbud­ding, and incomplete drug treatment records are the most com­mon corrective actions. Overall, a high percentage of herds have met animal observation benchmarks (99% knee lesions, 98% body condition, 97% locomotion, 95% hock lesions, 91% hygiene, and 85% broken tails). Veterinarians are positioned as a critical resource in this program; they are not only needed to comply with program standards and when out of compliance, have a specific opportunity to consult, advise, guide and sup­port clients regarding the health and welfare of their herd.

Efficacy of Duloxetine With Arthrocentesis in the Management of TMJ Internal Derangement.

Temporomandibular joint (TMJ) arthrocentesis is one of the most commonly used non-invasive surgical interventions in the treatment of refractory pain and dysfunction associated with internal derangement. Several adjunctive therapies have been used in combination with arthrocentesis in an attempt to increase its efficacy and long-term maintenance. Duloxetine is a selective serotonin and norepinephrine reuptake inhibitor which is used in different chronic pain conditions. This study aimed to assess the efficacy of duloxetine in combination with arthrocentesis compared with arthrocentesis alone. Twenty-eight patients with chronic TMJ pain were included and randomly allocated into 2 groups (control and study groups). The control group included patients who underwent TMJ arthrocentesis only, and the study group included patients who underwent arthrocentesis followed by giving duloxetine (30mg) orally twice daily for 3 months. Pain, maximum mouth opening, and level of anxiety and depression were assessed preoperatively and followed at regular intervals of 1 week, 1 month, 3 months, and 6 months postoperatively. Pain was significantly reduced in both groups at all postoperative intervals and was significantly lower in the study group than the control group at 6 months. Maximum mouth opening increased significantly in both groups, but the difference between them was not significant. Level of anxiety and depression was significantly decreased in both groups, with no statistically significant difference between them. The results of this study indicate that duloxetine in combination with arthrocentesis may provide effective and long-term pain control; however, its use is associated with a higher risk of adverse events.

Analgesia in Pregnant Patients: A Literature Review

Pregnant patients physiologically undergo various changes in their bodies due to hormonal actions. The oral cavity is not exempt from these alterations, and repercussions on oral health are also identified. It is essential to provide safe and appropriate dental care during pregnancy, taking into account the gestational trimester and the patient's overall health. Analgesia in pregnant patients remains a taboo for many professionals, especially for newly graduated dental surgeons. The use of local anesthetics in the office as a pain control method makes the procedure safer and more efficient. Regarding orally administered analgesics, acetaminophen is considered the first choice, with dipyrone as the second option. Aspirin, ibuprofen, and corticosteroids may be an option, but their use should be rationalized and when the benefits outweigh the risks to the maintenance of pregnancy and maternal health. The use of analgesia or reduction of the pain protocol in a pregnant patient in the office can be performed with 2% lidocaine with epinephrine, as it is considered safe. However, certain anesthetics, such as benzocaine and procaine, should be avoided due to risks of methemoglobinemia. Nonetheless, the professional must always weigh the risks and benefits of using analgesic medications for the pregnant patient and the fetus when choosing the medication.

Continuous Superficial Parasternal Intercostal Plane Catheters for Poststernotomy Pain Control: A Case Series.

This case series describes the safety and effectiveness of superficial parasternal intercostal plane catheters for poststernotomy pain control in 4 patients who underwent multivessel coronary artery bypass grafting. Patients had reduced sternal pain and opioid consumption while the catheters ran continuously for 72 hours without complications. Our experience suggests the effectiveness of parasternal blocks can be safely prolonged with catheters, and they can be a useful addition to pain management strategies for this patient population.

A clinical evaluation of low-level laser therapy for pain reduction in early treatment stages: A pilot study

Objectives: This study aimed to clinically evaluate the efficacy of low-level laser therapy (LLLT) in reducing pain associated with orthodontic movement during the early stages of treatment. Material and Methods: A randomized controlled trial was conducted with 20 participants undergoing non-extraction orthodontic treatment. The laser group (LG, n = 10) received LLLT (808 nm, 100 mW) immediately after appliance installation, while the control group (CG, n = 10) received no pain control intervention. Pain levels were assessed using a visual analog scale (VAS) at 6, 24, 48, and 72 h till 7 days with an interval of 24 h. Statistical analyses included Chi-square tests and Mann–Whitney tests. Results: The LG consistently demonstrated significantly lower pain scores during chewing and at rest compared to the CG. After 6 h post-treatment, the median pain score on chewing in the LG was markedly lower than the CG (P &lt; 0.001), a trend observed at each subsequent interval till 7 days. The comparison of spontaneous pain also favored the LG at various time points. Lower median VAS scores for pain on chewing among the LG and CG were zero and two, respectively, with a significant difference. The maximum median VAS scores for pain on chewing among the LG and CG were five and seven, respectively, with a significant difference. Conclusion: This study provides robust evidence supporting the effectiveness of LLLT in reducing orthodontic pain during the early stages of treatment. The sustained and significant reduction in pain scores, coupled with rigorous statistical analyses, emphasizes the potential of LLLT as a valuable adjunctive therapy in orthodontic practice.

Risk Factors Associated with Postoperative Cerebrospinal Fluid Leaks After Intrathecal Drug Delivery System and an External Pump Implantation in Cancer Patients: A Retrospective Study.

To determine risk factors associated with postoperative cerebrospinal fluid leaks (CSFLs) after intrathecal drug delivery system (IDDS) and external pump implantation. The clinical data of 248 patients with advanced cancer who underwent IDDS implantation from January 2021 to December 2022 at the Department of Pain Medicine at the Hunan Cancer Hospital were retrospectively reviewed. Information regarding age, gender, height, weight, body mass index (BMI), tumour type, albumin levels, haemoglobin levels, history of diabetes and pre- and postoperative anti-tumour therapy was collected and analysed. Postoperative CSFLs occurred in 7 of 231 patients (3.30%). Statistical analysis indicated that gender, age, height, weight, BMI, tumour type, albumin levels, haemoglobin levels, history of diabetes, pre- and postoperative chemotherapy, pre- and postoperative radiotherapy, preoperative immunotherapy and postoperative targeted therapy were not independent factors for CSFLs. Preoperative targeted therapy [odds ratio (OR): 16.64; 95% confidence interval (CI): 1.42, 195.56; P = 0.01] and postoperative immunotherapy (OR: 13.38; 95% CI: 1.60, 111.65; P = 0.017) were factors associated with an increased postoperative CSFL rate. Of the two locations where CSFLs can occur, the back (puncture site of catheter, n = 4) and the hypochondriac region (location of infusion port implanted, n = 3), back CSFLs occurred earlier than in the hypochondriac region (18.25 ± 6.45 vs 115 ± 62.02 days, P = 0.032). Based on the data from our study, the timing of preoperative targeted therapy and postoperative immunotherapy should be considered to prevent the occurrence of CSFLs in cancer pain patients who have an IDDS and external pump.

Peripheral nerve blocks for analgesia following cesarean delivery A narrative review

Abstract Spinal and epidural blocks are commonly employed for pain relief during and following cesarean section. Intrathecal morphine (ITM) has been the gold standard for the same for many years. In recent times, many peripheral nerve blocks (PNBs) have been tried for postoperative analgesia following cesarean delivery (PACD). This article has reviewed the common PNBs used for PACD. The role of PNBs along with ITM has been studied and the current best strategy for PACD has also been explored. Currently, Ilio-inguinal nerve and anterior transversus abdominis plane block in conjunction with intrathecal morphine have been found to be the most effective strategy, providing lower rest pain at 6 hours as compared to ITM alone. In patients not receiving intrathecal morphine, recommended PNBs are lateral transversus abdominis plane block, single shot local anesthetic wound infiltration, or continuous wound infiltration with catheter below rectus fascia. PNBs are recommended for PACD. They have an opioid-sparing effect and are devoid of adverse effects associated with central neuraxial blocks such as hypotension, bradycardia, and urine retention. However, caution must be observed with PNBs for possible local anesthetic toxicity due to the large volumes of drug required. Key Messages: Peripheral nerve blocks form an effective component of multi-model analgesic regimens for pain control following cesarean section. Ilio-inguinal nerve and anterior transversus abdominis plane block in conjunction with intrathecal morphine is the most effective strategy. In the absence of intrathecal morphine, lateral transversus abdominis plane block or local anesthetic wound infiltration should be administered.

Ultrasound-guided caudal epidural injection to treat symptoms of lumbar spinal stenosis: a retrospective study.

Lumbar spinal stenosis (LSS) occurs when bony, ligamentous, and synovial elements of the lower axial spine degenerate and overgrow, compressing neural and vascular elements in the spinal canal. Compression can cause static back pain, radicular lower extremity pain, or neurogenic claudication. Radiological and clinical findings are needed to diagnose lumbar stenosis. In this framework, caudal epidural steroid injection (ESI) is a standard treatment. The volume injected and needle positioning are the main issues that could compromise the effectiveness of the epidural injection. However, ultrasound-guided caudal epidural injections have become more common in recent years. Since Klocke and colleagues described the ultra-sound-guided caudal block in 2003, it has grown in popularity. Multiple ethnic studies have reported ultrasound-guided caudal injection success rates of 96.9-100%. Color Doppler ultrasonography can also determine if a drug solution reaches the lumbosacral region. We enrolled 42 patients with lumbar spinal stenosis, persistent lumbosciatalgia, and neurogenic claudicatio unresponsive to painkillers who were not surgical candidates. Each patient receives four weekly injections for four weeks. If the patient responds to treatment but still has pain, monthly injections are needed to reach and maintain the benefit. Treatment will be changed if the patient does not respond after 4 caudal injections. Sterile caudal epidural injections are performed with ultrasound guidance and a spinal needle 21G. Triamcinolone 40 mg, levobupivacaine 10 mg, and physiological solution 10 ml are delivered. Each patient received an average of 4 injective treatments (4±2, Means 4, SD 2). Data analysis shows that the treatment reduced pain significantly before and after therapy, which persisted after 3 months. Caudal epidural injection is one of the most common conservative treatments for chronic low back pain with radiculopathy, and lidocaine alone or with steroids is effective. In this framework, the two main literature issues about caudal epidural injection effectiveness on lumbar pain are correct. Therefore, 10 ml is suitable and effective for treating symptoms without side effects. Pain reduction of over 50% from start to finish and three-month follow-up have shown significant results in pain control and disability improvement. Finally, caudal epidural injection for lumbar spinal stenosis symptoms is effective, safe, and provides long-term pain relief.

ACM BCB 2023: Predicting Postoperative Pain and Opioid Use with Machine Learning Applied to Longitudinal Electronic Health Record and Wearable Data.

Managing acute postoperative pain and minimizing chronic opioid use is crucial for patient recovery and long-term well-being. This study explored using preoperative electronic health records (EHR) and wearable device data for machine-learning models that predict postoperative acute pain and chronic opioid use. The study cohort consisted of ~347 All of Us Research Program participants who underwent one of eight surgical procedures and shared EHR and wearable device data. We developed four machine learning models and used the Shapley additive explanations (SHAP) technique to identify the most relevant predictors of acute pain and chronic opioid use. The stacking ensemble model achieved the highest accuracy in predicting acute pain (0.68) and chronic opioid use (0.89). The area under the curve (AUC) score for severe pain vs. other pain was highest (0.88) when predicting acute post-operative pain. Values of logistic regression, random forest, extreme gradient boosting, and stacking ensemble ranged from 0.74 to 0.90 when predicting postoperative chronic opioid use. Variables from wearable devices played a prominent role in predicting both outcomes. SHAP detection of individual risk factors for severe pain can help healthcare providers tailor pain management plans. Accurate prediction of postoperative chronic opioid use before surgery can help mitigate the risk for the outcomes we studied. Prediction can also reduce the chances of opioid overuse and dependence. Such mitigation can promote safer and more effective pain control for patients during their recovery.

Efficacy of a Lidocaine-Impregnated Elastrator Band for Castration and Tail Docking in Lambs

The primary objective of this study was to demonstrate the non-inferiority between lidocaine-impregnated ligation bands (LLBs) and control bands (CBs) with respect to the efficacy of castration and tail docking. Secondary objectives were to compare castration and tail-docking success, evaluate local site reactions, and compare average daily gain (ADG) between the treatment groups. A total of 238 male lambs were enrolled and randomly assigned to receive LLBs or CBs on their tail and scrotum. Lambs were weighed, had a health assessment, and the band site was observed on −3, 7, 14, 21, 28, 35, and 42 days after the bands were applied. A linear regression model was built to assess average daily gain, whereas a repeated measures model was used to evaluate body weight differences at each of the measured timepoints. Furthermore, logistic regression models were used to evaluate associations with casting outcomes. Few differences were noted between treatment groups with respect to casting success for the scrotum and tail and ADG over the entire experimental period. Non-inferiority calculations demonstrated no differences in tail docking and scrotal casting success, with casting occurring for the majority of animals by d 21 and d 42 for castration and tail docking, respectively. However, lambs receiving LLBs gained more weight from d −3 to 7 (+0.03 kg/d; 95% CI: 0 to 0.07), which may be an indication of effective pain control during the first week following band application. Overall, the use of an LLB does not affect the time to successful casting of the tail and could improve short-term growth when compared to a control band. Further studies are needed to compare LLBs to multimodal methods of pain relief.