Therapeutic effect of epidural dexamethasone palmitate in a rat model of lumbar spinal stenosis.

BACKGROUND: Dexamethasone palmitate (DEP), a prodrug of dexamethasone (DEX), is a synthetic corticosteroid medication distinguished by the inclusion of a fatty acid component known as palmitate. This study introduces DEP as a novel therapeutic option for spinal epidural injection, aiming to provide safer and longer-lasting pain relief as an alternative to for patients with spinal stenosis. METHODS: 40 rats were randomly divided into four groups: those receiving epidural administration of normal saline (NS), and DEP in the lumbar spinal stenosis (LSS) model, and non-model rats receiving epidural NS administration. Paw withdrawal thresholds to mechanical stimulation and motor function (neurogenic intermittent claudication) were observed for up to 21 days. Hematology and blood chemistry analyses were performed 1 week after drug therapy. Tissue samples were collected for steroid pathology examination to evaluate adhesion degree, perineural area inflammation, and chromatolysis in the dorsal root ganglion (DRG), and adrenal gland. RESULTS: The DEX and DEP groups demonstrated significant recovery from mechanical allodynia and motor dysfunction after 2 weeks of drug therapy (p<0.001). However, by the third week, the effect of DEX started to diminish while the effect of DEP persisted. Furthermore, the DEP group exhibited reduced fibrosis and less chromatolysis than the NS group. No steroid overdose or toxin was observed in any group. CONCLUSION: The epidural administration of DEP demonstrated therapeutic efficacy in reducing allodynia and hyperalgesia resulting from chronic DRG compression, thus offering prolonged pain relief. These findings underscore the potential of DEP as a promising treatment alternative for pain associated with LSS, serving as a viable substitute for .

Effect duration of lumbar sympathetic ganglion neurolysis in patients with complex regional pain syndrome: a prospective observational study.

Lumbar sympathetic ganglion neurolysis (LSGN) has been used for long-term pain relief in patients with complex regional pain syndrome (CRPS). However, the actual effect duration of LSGN has not been accurately measured. This prospective observational study measured the effect duration of LSGN in CRPS patients and investigated the relationship between temperature change and pain relief. After performing LSGN, the skin temperatures of both the maximum pain site and the plantar area in the affected and unaffected limbs were measured by infrared thermography, and pain intensity was assessed before and at 2 weeks, 1 month, and 3 months. The median time to return to baseline temperature was calculated using survival analysis. The skin temperature increased significantly at all-time points relative to baseline in both regions (maximum pain site: 1.4 °C ± 1.0 °C, plantar region: 1.28 °C ± 0.8 °C, all P < 0.001). The median time to return to baseline temperature was 12 weeks (95% confidence interval [CI] 7.7-16.3) at the maximum pain site and 12 weeks (95% CI 9.4-14.6) at the plantar area. Pain intensity decreased significantly relative to baseline, at all-time points after LSGN. In conclusion, the median duration of the LSGN is estimated to be 12 weeks.

Analysis of the efficacy of retrodiscal approach percutaneous epidural adhesiolysis with WHIP catheter® in patients with lumbar radiculopathy: A retrospective study.

Percutaneous epidural adhesiolysis (PEA) is an effective treatment for patients with lumbar radiculopathy unresponsive to single steroid injections. Various approaches and instruments have been developed to access these lesions. This study aimed to evaluate the utility of a retrodiscal approach for epidural adhesiolysis using a WHIP catheter®. This retrospective study was conducted at Bundang Seoul National University Hospital, reviewing cases from January to December 2022. Forty-seven patients diagnosed with lumbar radiculopathy, aged 20 to 80 years, who underwent PEA with the WHIP catheter® were included. Outcomes assessed Numeric Rating Scale (NRS) for pain, Patients' Global Impression of Change (PGIC) scores, and the incidence of procedure-related complications. Follow-up evaluations occurred at 1, 3, and 6 months post-procedure. Among 47 patients, 41 completed the study, showing significant pain reduction at all follow-up points: 1 month (N = 41, 1.32 ±â€…1.68, P < .001), 3 months (N = 31, 1.90 ±â€…2.14, P < .001), and 6 months (N = 30, 2.50 ±â€…2.30, P < .001). PGIC scores indicated that 40% of the patients reported substantial improvement at one-month post-procedure. The complications were minimal, with only one case of intradiscal injection and 2 cases of vascular uptake. The retrodiscal approach PEA using the WHIP catheter® demonstrated significant efficacy in pain reduction with minimal safety concerns for patients with lumbar radiculopathy. These findings suggest that this procedure is a viable option for patients who are unresponsive to conservative treatment. However, the retrospective nature of this study and its small sample size necessitate further prospective controlled studies to confirm our results and establish long-term outcomes.

Development of a Deep Learning Model for the Analysis of Dorsal Root Ganglion Chromatolysis in Rat Spinal Stenosis.

Objective: To create a deep learning (DL) model that can accurately detect and classify three distinct types of rat dorsal root ganglion neurons: normal, segmental chromatolysis, and central chromatolysis. The DL model has the potential to improve the efficiency and precision of neuron classification in research related to spinal injuries and diseases. Methods: H&E slide images were divided into an internal training set (80%) and a test set (20%). The training dataset was labeled by two pathologists using pre-defined grades. Using this dataset, a two-component DL model was developed with the first component being a convolutional neural network (CNN) that was trained to detect the region of interest (ROI) and the second component being another CNN used for classification. Results: A total of 240 lumbar dorsal root ganglion (DRG) pathology slide images from rats were analyzed. The internal testing results showed an accuracy of 93.13%, and the external dataset testing demonstrated an accuracy of 93.44%. Conclusion: The DL model demonstrated a level of agreement comparable to that of pathologists in detecting and classifying normal and segmental chromatolysis neurons, although its agreement was slightly lower for central chromatolysis neurons. Significance: DL in improving the accuracy and efficiency of pathological analysis suggests that it may have a role in enhancing medical decision-making.

Erector spinae plane block in laparoscopic colorectal surgery for reducing opioid requirement and facilitating early ambulation: a double-blind, randomized trial.

Various techniques have been formulated to reduce pain and ensure early recovery after surgery, as these are major concerns among surgeons, anesthesiologists, and patients. Erector spinae plane block (ESPB), the injection of local anesthetic into the fascial plane, is a simple and novel analgesia technique widely used due to its minimal risk of complications. ESPB has been tried in various surgeries; however, no study has reported its use in colorectal surgery. This study investigated whether ESPB could promote early recovery following laparoscopic colorectal surgery (LCS) by reducing opioid consumption and pain intensity. After randomization into the ESPB or control groups, an ultrasound-guided ESPB was performed at the thoracic 10th-11th level with 40 mL of 0.25% bupivacaine or normal saline. The ESPB group used less fentanyl during the initial 24 h after surgery (P = 0.004) and experienced less pain (P < 0.05 at all-time points) than the control group. The time to the first ambulation and the length of hospital stay were shorter in the ESPB group than in the control group (P = 0.015 and P = 0.008, respectively). In conclusion, ESPB could promote early recovery by reducing opioid consumption and pain intensity in patients receiving LCS.

Effect of Nonsurgical Spinal Decompression on Intensity of Pain and Herniated Disc Volume in Subacute Lumbar Herniated Disc.

Objective: Nonsurgical spinal decompression therapy (NSDT) is a conservative treatment for the lumbosacral herniated intervertebral disc (L-HIVD). This study aimed to evaluate the clinical effectiveness of the NSDT and change in disc volume through magnetic resonance imaging (MRI) in subacute L-HIVD. Methods: Sixty patients with subacute L-HIVD were randomized into either the decompression group (group D, n = 30) or the nondecompression group (group N, n = 30). In group D, NSDT was performed ten times in eight weeks. In group N, pseudodecompression therapy (no force) was performed with the same protocol. Lower back and lower leg pain intensities and functional improvements were measured by the visual analog scale and the Korean Oswestry Disability Index (K-ODI). The change in the lumbosacral disc herniation index (HI) was evaluated through a follow-up MRI three months after the therapy. Results: The lower leg pain intensity in group D was lower than that in group N at two months (p=0.028). Additionally, there were significantly lower K-ODI scores in group D at two and three months (p=0.023, 0.019) than in group N. The change in HI after the therapy was -27.6 ± 27.5 (%) in group D and -7.1 ± 24.9 (%) in group N, with a significant difference (p=0.017). Approximately 26.9% of patients in group D and no patients in group N showed over 50% reduction in HI (p=0.031). Conclusion: NSDT may be a suitable treatment option for conservative treatment of subacute L-HIVD.

Aspirin Cessation Before Interventional Procedures: Not Blindly Following Guidelines but Making Test-based Decisions.

BACKGROUND: Deciding whether to continue or discontinue aspirin prior to interventional procedures is a major concern for pain physicians. Many guidelines have been published on the discontinuation of aspirin before invasive procedures; however, the recommendations are inconsistent and do not consider individual platelet function. Furthermore, many studies have shown a high prevalence of aspirin resistance  in patients taking this medication. OBJECTIVES: To determine the necessity of discontinuing aspirin prior to interventional pain procedures in relation to individual platelet function. STUDY DESIGN: Multicenter, cross-sectional study. SETTING: University-affiliated hospitals. METHODS: We examined platelet function among patients scheduled for an interventional pain procedure by measuring their closure time using collagen/epinephrine cartridges in a commercial platelet-function analyzer. The patients were categorized into either an aspirin-taking or nonaspirin-taking group (Group A or Group N, respectively). The proportion of patients who showed normal/abnormal platelet function was calculated and compared between the groups. RESULTS: A total of 1,111 patients were included in this study. In Group A, 56.4% (102/181) showed normal platelet function, whereas 43.6% (79/181) showed abnormal platelet function. In Group N, 85.8% (798/930) and 14.2% (132/930) showed normal and abnormal platelet function, respectively. LIMITATION: The proportion of laboratory, not clinical aspirin resistance was evaluated. Factors affecting platelet function were not investigated exhaustively. CONCLUSION: The high prevalence of normal platelet function in patients taking aspirin suggests no necessity of discontinuation before procedures in such patients. Abnormal platelet function can occur even in patients who are not taking aspirin. Therefore, platelet function should be measured and considered on a case-by-case basis prior to interventional procedures, and discontinuation of aspirin should be decided based on these factors.

Determining the Definitive Time Criterion for Postherpetic Neuralgia Using Infrared Thermographic Imaging.

INTRODUCTION: The time criteria used in many studies of postherpetic neuralgia (PHN) are arbitrary and do not have supporting evidence. Therefore, this study sought to determine the definite time criterion for PHN by analyzing the skin temperature to estimate the time point when zoster-induced skin inflammatory reaction ends. METHODS: Infrared thermography was used to measure the difference in skin temperature between the affected and unaffected areas (ΔTemp) in the craniocervical and thoracic regions of patients with herpes zoster (HZ). Because the ΔTemp changes from a positive value to zero when the skin is no longer inflamed, a ΔTemp ≤ 0 was defined as the end of skin inflammation, and this time point was considered the starting point for PHN. This cutoff time point was estimated using receiver operating characteristic (ROC) curve analysis. RESULTS: A total of 503 patients were included in this study. The ROC curve analysis showed that the time point when the ΔTemp was ≤ 0 occurred at 12 weeks after HZ onset (95% confidence interval 11-15 weeks, area under the ROC curve 0.901). Using this time point as the time criterion of PHN, the sensitivity, specificity, and classification accuracy were 0.807, 0.905, and 0.871, respectively. CONCLUSIONS: The transition of skin temperature from warm to cold occurs 12 weeks after HZ onset, which implies the end of local inflammation. Therefore, PHN associated with pathophysiologic change may be defined as 12 weeks after the skin rash. This finding provides a theoretical basis for the timing definition of PHN.

Receiver operating characteristic curve: overview and practical use for clinicians.

Using diagnostic testing to determine the presence or absence of a disease is essential in clinical practice. In many cases, test results are obtained as continuous values and require a process of conversion and interpretation and into a dichotomous form to determine the presence of a disease. The primary method used for this process is the receiver operating characteristic (ROC) curve. The ROC curve is used to assess the overall diagnostic performance of a test and to compare the performance of two or more diagnostic tests. It is also used to select an optimal cut-off value for determining the presence or absence of a disease. Although clinicians who do not have expertise in statistics do not need to understand both the complex mathematical equation and the analytic process of ROC curves, understanding the core concepts of the ROC curve analysis is a prerequisite for the proper use and interpretation of the ROC curve. This review describes the basic concepts for the correct use and interpretation of the ROC curve, including parametric/nonparametric ROC curves, the meaning of the area under the ROC curve (AUC), the partial AUC, methods for selecting the best cut-off value, and the statistical software to use for ROC curve analyses.

The principles of presenting statistical results using figures.

Tables and figures are commonly adopted methods for presenting specific data or statistical analysis results. Figures can be used to display characteristics and distributions of data, allowing for intuitive understanding through visualization and thus making it easier to interpret the statistical results. To maximize the positive aspects of figure presentation and increase the accuracy of the content, in this article, the authors will describe how to choose an appropriate figure type and the necessary components to include. Additionally, this article includes examples of figures that are commonly used in research and their essential components using virtual data.

Radiation-Shielding Devices: The Best Combination for Spine Interventional Procedures.

PURPOSE: Although many studies have examined the efficiency of various protective devices for reducing the dose of radiation exposure to physicians during interventional pain procedures, no study has compared the protective effect of these devices when they are used in combination. The purpose of this prospective experimental study was to determine the best combination of radiation-shielding devices. MATERIALS AND METHODS: Using anthropomorphic phantoms of a physician and patient, we measured the radiation protection efficiency (RPE) of each of the following protection methods and in combination during C-arm-guided simulated lumbar epidural injection: (a) personal protective equipment (PPE), (b) bedside curtain shield (Curtain), (c) x-ray tube filter (Filter), and (d) fluoroscopic collimation method (Collimation). We measured exposure doses using personal electronic dosimeters at the eye, thyroid, and gonad levels for 1 minute. Each experiment was repeated 15 times. RESULTS: The radiation exposure dose and RPE with the best single-, double-, and triple-protection methods were as follows: PPE for the single-protection method (11.82 µSv/min, 80.04%), PPE + Collimation for the double-combination method (4.68 µSv/min, 92.09%), and PPE + Collimation + Curtain for the triple-combination method (3.08 µSv/min, 93.39%). Additionally, PPE + Collimation + Curtain + Filter for the quadruple-combination method resulted in a radiation exposure and RPE of 2.91 µSv/min and 93.61%, respectively, compared with nonprotection. CONCLUSIONS: The best single-, double-, and triple-protection method was PPE, PPE + Collimation, and PPE + Collimation + Curtain, respectively. While preparing protective equipment, we recommend prioritizing equipment in this order.

Comparison of a New Video Intubation Stylet and McGrath® MAC Video Laryngoscope for Intubation in an Airway Manikin with Normal Airway and Cervical Spine Immobilization Scenarios by Novice Personnel: A Randomized Crossover Study.

The use of both a video laryngoscope and a video intubation stylet, compared with the use of a direct laryngoscope, is not only easier to learn but also associated with a higher success rate in performing endotracheal intubation for novice users. However, data comparing the two video devices used by novice personnel are rarely found in literature. Nondelayed intubation is an important condition to determine the prognosis in critically ill patients; hence, exploring intubation performance in various situations is of clinical significance. This study is aimed at comparing a video stylet and a video laryngoscope for intubation in an airway manikin with normal airway and cervical spine immobilization scenarios by novice personnel. We compared the performance of intubation by novices between the Aram Video Stylet and the McGrath® MAC video laryngoscope in an airway manikin. Thirty medical doctors with minimal experience of endotracheal intubation attempted intubation on a manikin five times with each device in each setting (normal airway and cervical spine immobilization scenarios). The order of use of the devices in each scenario was randomized for each participant. In the normal airway scenario, the Aram stylet showed a significantly higher rate of successful intubation than the McGrath® (98.7% vs. 92.0%; odds ratio (95% CI): 6.4 (1.4-29.3); p = 0.006). The intubation time was shorter using the Aram Stylet than that using the McGrath® video laryngoscope (p < 0.001). In the cervical immobilization scenario, successful endotracheal intubation was also more frequent using the Aram stylet than with the McGrath® (96.0% vs. 87.3%; odds ratio (95% CI): 3.5 (1.3-9.0); p = 0.007). The Aram Stylet intubation time was shorter (p < 0.001). In novice personnel, endotracheal intubation appears to be more successful and faster using the Aram Video Stylet than the McGrath® MAC video laryngoscope.

Effect of epidural polydeoxyribonucleotide in a rat model of lumbar foraminal stenosis.

BACKGROUND: We aimed to investigate the effect of epidural polydeoxyribonucleotide (PDRN) on mechanical allodynia and motor dysfunction in a rat model of lumbar foraminal stenosis (LFS). METHODS: This study was conducted in two stages, using male Sprague-Dawley rats. The rats were randomly divided into eight groups. In the first stage, the groups were as follows: vehicle (V), sham (S), and epidural PDRN at 5 (P5), 8 (P8), and 10 (P10) mg/kg; and in the second stage, they were as follows: intraperitoneal PDRN 8 mg/kg, epidural 3,7-dimethyl-1-propargilxanthine (DMPX) (0.1 mg/kg), and DMPX (0.1 mg/kg). The LFS model was established, except for the S group. After an epidural injection of the test solutions, von Frey and treadmill tests were conducted for 3 weeks. Subsequently, histopathologic examinations were conducted in the V, S, P5, and P10 groups. RESULTS: A total of 65 rats were included. The P8 and P10 groups showed significant recovery from mechanical allodynia and motor dysfunction at all time points after drug administration compared to the V group. These effects were abolished by concomitant administration of DMPX. On histopathological examination, no epineurial inflammation or fibrosis was observed in the epidural PDRN groups. CONCLUSIONS: Epidural injection of PDRN significantly improves mechanical allodynia and motor dysfunction in a rat model of LFS, which is mediated by the spinal adenosine A2A receptor. The present data support the need for further research to determine the role of epidural PDRN in spinal stenosis treatment.

Transforaminal Epidural Steroid Injection for Zoster-Related Pain: The Golden Period for the Best Outcome.

BACKGROUND: Zoster-related pain (ZRP) has many negative effects on a patient's quality of life. The transforaminal steroid injection (TFESI), which reduces neural inflammation and pain, has been advocated by pain physicians. Many reports demonstrated that early administration of TFESI showed better efficacy; however, the golden period during which TFESI is most effective remains unclear. OBJECTIVES: This multicentre retrospective cohort study aimed to identify the golden period by which TFESI yields the best outcome in patients with ZRP. STUDY DESIGN: Multicenter, retrospective cohort study. SETTING: University-affiliated hospitals. METHODS: After performing the TFESI in patients with ZRP, the patients were classified into two groups: the effective group (E) and the not effective group (N) based on the changes in the pain intensity 3 months after the TFESI. The receiver operating characteristic (ROC) curve analysis was used to assess the cut-off time point for predicting TFESI effectiveness. Furthermore, a logistic regression analysis was performed to identify patients' factors associated with a successful treatment outcome. RESULT: Of the 302 patients, 186 and 116 patients were classified into the E and N group, respectively. ROC curve analysis showed that the best cut-off time point for TFESI was 12 weeks (95% confidence interval [CI]; 10-14 weeks) after the onset of HZ. The only variable associated with a favorable outcome was a symptom duration of ? 12 weeks compared with > 12 weeks (Odd ratio, 0.107; 95% CI, 0.055-0.205; P < 0.001). Other patient variables were not significantly associated with the effectiveness of TFESI. TFESI was most effective when administered within 12 weeks of the onset of herpes zoster. LIMITATION: This study was not a prospective randomized controlled trial (RCT) and the follow-up period was only 3 months after TFESI. CONCLUSION: TFESI is more effective when administered within 12 weeks of onset of herpes zoster.

Non-Particulate Steroids (Betamethasone Sodium Phosphate, Dexamethasone Sodium Phosphate, and Dexamethasone Palmitate) Combined with Local Anesthetics (Ropivacaine, Levobupivacaine, Bupivacaine, and Lidocaine): A Potentially Unsafe Mixture.

PURPOSE: Particulate steroids used in epidural steroid injections have been suspected as a cause of post-procedural embolic events. Some particulate steroids have been suspended only when the transforaminal approach is used for an epidural block of the spine. In contrast, non-particulate steroids are generally accepted for safety during epidural steroid injections. However, the safety of using a mixture of non-particulate steroids and local anesthetics is unknown. This study analyzed whether mixtures of commonly used non-particulate steroids and local anesthetics form crystals in solution. METHODS: We mixed non-particulate steroids (betamethasone sodium phosphate, dexamethasone sodium phosphate, and dexamethasone palmitate) and local anesthetics (ropivacaine, levobupivacaine, bupivacaine, and lidocaine) at different ratios. We used fluorescence microscopy to observe whether crystals formed in mixed solutions; we also measured the pH of each steroid, local anesthetic, and the mixtures. RESULTS: Ropivacaine or levobupivacaine and betamethasone sodium phosphate produced large crystals (>50 µm). Ropivacaine or levobupivacaine and dexamethasone sodium phosphate produced small crystals (<10 µm). Lidocaine and all non-particulate steroids produced no identifiable crystals; dexamethasone palmitate and all local anesthetics did not form significant particulates. Betamethasone sodium phosphate and dexamethasone sodium phosphate demonstrated basic pH, while all local anesthetics demonstrated acidic pH. Mixtures showed a wide pH range. CONCLUSION: Non-particulate steroids can form crystals upon combination with local anesthetics. Crystal formation may be caused by alkalinization of steroids. The mixing of ropivacaine or levobupivacaine and betamethasone sodium phosphate may require caution during an epidural steroid injection. Lidocaine or bupivacaine is recommended as a local anesthetic. Dexamethasone palmitate is a candidate for a mixture, but additional studies on its safety and effectiveness are needed.

The principles of presenting statistical results: Table.

General medical journals such as the Korean Journal of Anesthesiology (KJA) receive numerous manuscripts every year. However, reviewers have noticed that the tables presented in various manuscripts have great diversity in their appearance, resulting in difficulties in the review and publication process. It might be due to the lack of clear written instructions regarding reporting of statistical results for authors. Therefore, the present article aims to briefly outline reporting methods for several table types, which are commonly used to present statistical results. We hope this article will serve as a guideline for reviewers as well as for authors, who wish to submit a manuscript to the KJA.