Shin Hyung Kim

Influence of Centrally Mediated Symptoms on Postoperative Pain in Osteoarthritis Patients Undergoing Total Knee Arthroplasty: A Prospective Observational Evaluation.

Central sensitization plays an important role in the chronic pain experienced by osteoarthritis (OA) patients. In this prospective observational study, we investigated the influence of the level of preoperative centrally mediated symptoms measured by the Central Sensitization Inventory (CSI) on pain intensity after total knee arthroplasty (TKA) for OA.

Patient-controlled Epidural Analgesia with Ropivacaine and Fentanyl: Experience with 2,276 Surgical Patients

Background Good postoperative pain control is an important part of adequate postoperative care. Patient-controlled epidural analgesia (PCEA) provided better postoperative analgesia compared to other conventional analgesic methods, but several risks have been observed as well. We therefore surveyed the efficacy and safety of PCEA in this retrospective observational study. Methods We analyzed collected data on 2,276 elective surgical patients who received PCEA with ropivacaine and fentanyl. Patients were assessed by a PCA service team in the post-anesthesia care unit (PACU), at 1-6 h, 6-24 h, and 24-48 h postoperatively for adequate pain control. The presence of PCEA-related adverse events was also assessed. Results Numerical pain score (median [interquartile range]) were 3 [1-4], 5 [4-7], 4 [3-5], and 3 [3-5] in the PACU, at 1-6 h, 6-24 h, and 24-48 h postoperatively. Median pain scores in patients underwent major abdominal or thoracic surgery were higher than other surgical procedure in the PACU, at 1-6 h after surgery. Nausea and vomiting (20%) and numbness and motor weakness (15%) were revealed as major PCEA-related adverse events during the postoperative 48 h period. There were 329 patients (14%) for whom PCEA was ceased within 48 h following surgery. Conclusions Our data suggest that the use of PCEA provides proper analgesia in the postoperative 48 h period after a wide variety of surgical procedures and that is associated with few serious complications. However, more careful pain management and sustainable PCEA monitoring considering the type of surgical procedure undergone is needed in patients with PCEA.

Factors Associated with Higher Reported Pain Levels in Patients with Chronic Musculoskeletal Pain: A Cross-Sectional, Correlational Analysis

Background Chronic musculoskeletal pain is highly prevalent, disabling, and costly, and has many negative effects on quality of life. The aim of this study was to investigate factors associated with higher reported pain levels in patients with chronic musculoskeletal pain among demographic, clinical, and psychological factors, and to evaluate whether insomnia is independently associated with pain intensity in this population. Methods A total of 357 patients with chronic musculoskeletal pain (pain duration ≥ six months) satisfied the study inclusion criteria and were included in the analyses. Patient demographics, clinical, and psychological factors were evaluated with hierarchical multivariate logistic analysis to identify factors associated with severe pain (NRS [numeric rating scale] ≥ 7). Hierarchical linear regression analysis also performed to identify factors associated with pain intensity (0 to 10 NRS). Results Multivariate logistic analyses revealed older age (OR [odds ratio] = 1.017, 95% CI [confidence interval] 1.001–1.032, P = 0.034), high anxiety level (OR = 1.162, 95% CI 1.020–1.324, P = 0.024), high pain catastrophizing (OR = 1.043, 95% CI 1.007–1.081, P = 0.018), and severe insomnia (OR = 1.112, 95% CI 1.057–1.170, P<0.001) were significantly associated with severe pain. Hierarchical linear regression analysis showed age (β = 0.106, P = 0.041), pain catastrophizing (β = 0.249, P<0.001), and insomnia (β = 0.286, P<0.001) were significantly associated with pain intensity. The variance in pain intensity explained by the final model was 32.2%. Conclusions Older age, severe insomnia, and high pain catastrophizing were significantly associated with higher reported pain levels. Insomnia was independently associated with pain intensity, even after controlling for various demographic and clinical factors. These factors should be considered when devising pain management strategies for this population.

Factors associated with increased risk for pain catastrophizing in patients with chronic neck pain: A retrospective cross-sectional study.

Abstract Pain catastrophizing is becoming increasingly recognized as a clinically important psychological factor in chronic musculoskeletal pain. In this retrospective cross-sectional study, we have identified factors associated with an increased risk for pain catastrophizing in chronic neck pain (CNP) patients. We obtained data from our medical database on 331 patients who were treated for neck pain as their chief complaint at our clinic. The Pain Catastrophizing Scale (PCS) was used to define a high pain catastrophizing state (PCS score ≥21) in this study. Patient demographics, pain-related factors, and psychological factors were evaluated with logistic regression analysis to identify risk factors of high pain catastrophizing among patients with CNP. A total of 256 patients with CNP satisfied the study inclusion criteria and were included in the analyses. The median PCS score was 16 (range, 0–45), and 86 of 256 patients (33.5%) reported a PCS score ≥21. In multivariate analysis, high pain intensity, clinical insomnia, and a high level of depression/anxiety were strongly associated with high pain catastrophizing in patients with CNP. Depression was the strongest predictor of high pain catastrophizing, with an odds ratio of 7.35 (95% confidence interval 2.23–24.22). High pain catastrophizing was not significantly related to age, gender, comorbidities, or neck pain-related physical symptoms. In conclusion, poor psychological states should be addressed as an important part of pain management in CNP patients who are susceptible to high pain catastrophizing.

Clinical Effectiveness of the Obturator Externus Muscle Injection in Chronic Pelvic Pain Patients

Because of its anatomical location and function, the obturator externus (OE) muscle can be a source of pain; however, this muscle is understudied as a possible target for therapeutic intervention in pain practice. In this retrospective observational study, we evaluated the clinical effectiveness of the OE muscle injection with a local anesthetic in chronic pelvic pain patients with suspected OE muscle problems.

Cadaveric Evaluation of Different Approaches for Quadratus Lumborum Blocks

Background A quadratus lumborum (QL) block is an abdominal truncal block technique that primarily provides analgesia and anaesthesia to the abdominal wall. This cadaveric study was undertaken to compare the dye spread between different needle approaches for ultrasound-guided QL blocks in soft-embalmed cadavers. Methods After randomization, an experienced anesthesiologist performed two lateral, three posterior, and five alternative QL blocks on the left or right sides of five cadavers. The target injection point for the alternative approach was the lumbar interfascial triangle, same as that of conventional posterior QL block, with a different needle trajectory. For each block, 20 ml of dye solution was injected. The lumbar region and abdominal flank were dissected. Results Ten blocks were successfully performed. Regardless of the approach used, the middle thoracolumbar fascia was deeply stained in all blocks, but the anterior layer was less stained. The alternative approach was more associated with spread of injectate to the transversus abdominis and transversalis fascia plane. Despite accurate needle placement, all lateral QL blocks were associated with a certain amount of intramuscular or subcutaneous infiltration. Two posterior QL blocks showed a deeply stained posterior thoracolumbar fascia, and one of them was associated with obvious subcutaneous staining. The subcostal, iliohypogastric, and ilioinguinal nerves were mostly involved, but the thoracic paravertebral space and lumbar plexus were not affected in all blocks. Conclusions The alternative approach for QL blocks was able to achieve a comparable extent when compared to the conventional approach.

Comparing the injectate spread and nerve involvement between different injectate volumes for ultrasound-guided greater occipital nerve block at the C2 level: a cadaveric evaluation

Purpose The spread patterns between different injectate volumes have not yet been investigated in ultrasound-guided greater occipital nerve (GON) block at the C2 level. This cadaveric study was undertaken to compare the spread pattern and nerve involvements of different volumes of dye using this technique. Materials and methods After randomization, ultrasound-guided GON blocks with 1 or 5 mL dye solution were performed at the C2 level on the right or left side of five fresh cadavers. The suboccipital regions were dissected, and nerve involvement was investigated. Results Ten injections were successfully completed. In all cases of 5 mL dye, we observed the deeply stained posterior neck muscles, including the suboccipital triangle space. The suboccipital and third occipital nerves, in addition to GONs, were consistently stained when 5-mL dye was used in all injections (100%). Although all GONs were successfully stained in the 1-mL dye cases, three of five injections (60%) concomitantly stained the third occipital nerves. Conclusion The clinical efficacy of this technique using the 5-mL injectate seems unlikely to arise from the blockade of GON alone. Instead, its efficacy likely arises from the blockade of most nerves originating from the dorsal ramus of the upper cervical spinal nerve at the suboccipital area. Even using 1 mL of injectate may not guarantee blockade of the GON alone.

Predictors of the analgesic efficacy of pulsed radiofrequency treatment in patients with chronic lumbosacral radicular pain: a retrospective observational study

Background Pulsed radiofrequency (RF) targeting the adjacent dorsal root ganglion (DRG) is one treatment option for lumbosacral radicular pain. However, the analgesic efficacy of this procedure is not always guaranteed. The aim of this retrospective study was to identify the predictors of the analgesic efficacy of pulsed DRG RF treatment in patients with chronic lumbosacral radicular pain. Methods Patients who underwent pulsed DRG RF treatment from 2006 to 2017 at our clinic were enrolled. Positive response was defined as a ≥50% reduction in pain score from baseline at day 30. Patient demographics, pain-related factors, and clinical factors were evaluated using logistic regression analysis to identify the predictors of a positive response to the treatment. Results A total of 60 patients satisfied the study protocol requirements. Twenty-eight patients (46.7%) had a positive outcome. Multivariate logistic regression analysis revealed that the absence of comorbid musculoskeletal pain (OR=0.518, 95% CI=0.029–0.858, P=0.033) and positive response to previous epidural steroid injection (OR=3.269, 95% CI=1.046–10.215, P=0.042) were independent predictors of the analgesic efficacy of pulsed DRG RF treatment. Conclusion Comorbid musculoskeletal pain and previous epidural injection response appear to affect the outcome of pulsed DRG RF treatment in patients with chronic lumbosacral radicular pain.

Comparison of Incidences of Intravascular Injection between Medial and Lateral Side Approaches during Traditional S1 Transforaminal Epidural Steroid Injection

Purpose. Intravascular injection rates are higher during traditional S1 transforaminal epidural steroid injection (TFESI) compared with lumbar transforaminal injection. We compared the incidences of intravascular injection between the medial and lateral approaches to the S1 foramen during S1 TFESI. Materials and Methods. A total of 139 patients underwent one or more TFESIs (170 total injections). The patients received S1 TFESI by either medial or lateral side of S1 foramen under fluoroscopic anteroposterior view using digital subtraction method. The intravascular injection rates, epidural spread patterns, and contrast volumes required to reach the superior aspect of the L5-S1 intervertebral disc (SIVD) were compared between groups. Results. Intravascular injection rates during S1 TFESI were significantly lower in the medial approach compared with the lateral approach patients (4.9% versus 38.6%, resp., P < 0.001). The medial approach group had more epidural spread to the L5-S1 SIVD than the lateral group (82.1% versus 58.8%, resp.); lower contrast volume amounts were required to extend the L5-S1 SIVD (1.46 ± 0.48 versus 1.90 ± 0.62, resp.). Conclusion. During S1 TFESI, approaching the needle towards the medial part of the S1 foramen may reduce intravascular injection risk.

The Effect of Skin Pressure on Needle Entry Point Accuracy During Fluoroscopically Guided Lumbar Transforaminal Epidural Injections: A Randomized Clinical Trial.

Objective The aim of this study was to investigate the effect of skin pressure on needle entry point accuracy during fluoroscopically guided lumbar transforaminal epidural injection. Design This study is a prospective randomized clinical trial; 64 patients with a body mass index of 25 kg/m2 or greater were enrolled. For patients in the pressing group, the operator marked the needle entry point on the patient’s back while pressing the patient’s skin with the tip of an indicator. For patients in the nonpressing group, the tip of the indicator was gently positioned on the patient’s skin. The data related to technical performance and radiation exposure during the procedure were compared. Results Sixty patients (nonpressing group, n = 30; pressing group, n = 30) were analyzed. There were more attempts to reposition the needle (n) and increased procedure time (in seconds) in the pressing group (median, 5 vs. 4 [P = 0.019]; 400.0 vs. 358.5 [P = 0.033]). The fluoroscopy time (in seconds) and the kerma-area product (in cGy cm2) were also significantly longer and greater in the pressing group, respectively (median, 63.5 vs. 50.5 [P = 0.038]; 416.3 vs. 318.6 [P = 0.014]). Conclusions This study shows that practitioners should not press the skin with a radiopaque indicator when determining the needle entry point by fluoroscopy during lumbar transforaminal epidural injection.