Billy K. Huh

Topical amitriptyline versus lidocaine in the treatment of neuropathic pain.

Objective Oral amitriptyline, a tricyclic antidepressant, is effective for treating neuropathic pain. We conducted a double-blind, randomized, placebo-controlled crossover study to evaluate the efficacy of topical 5% amitriptyline and 5% lidocaine in treating patients with neuropathic pain. Methods Thirty-five patients with postsurgical neuropathic pain, postherpetic neuralgia, or diabetic neuropathy with allodynia or hyperalgesia were assigned to receive 3 topical creams (5% amitriptyline, 5% lidocaine, or placebo) in random sequence. The primary outcome measure was change in pain intensity (baseline vs. posttreatment average pain) using a 0 to 100 mm Visual Analog Scale. Secondary outcome measures included the McGill Pain Questionnaire, requirement for rescue medication, and patient satisfaction. Primary statistical comparisons were made with paired t tests or signed-rank tests. Results A reduction in pain intensity was observed with topical lidocaine (P<0.05). No significant change in pain intensity was found with topical amitriptyline or placebo. In pairwise comparison of treatments, topical lidocaine and placebo each reduced pain more than topical amitriptyline (P<0.05). Discussion This randomized, placebo-controlled crossover study examining topical 5% amitriptyline and 5% lidocaine in the treatment of neuropathic pain showed that topical lidocaine reduced pain intensity but the clinical improvement is minimal and that topical 5% amitriptyline was not effective.

Self-compassion in patients with persistent musculoskeletal pain: Relationship of self-compassion to adjustment to persistent pain

CONTEXT Self-compassion entails qualities such as kindness and understanding toward oneself in difficult circumstances and may influence adjustment to persistent pain. Self-compassion may be a particularly influential factor in pain adjustment for obese individuals who suffer from persistent pain, as they often experience heightened levels of pain and lower levels of psychological functioning. OBJECTIVES The purpose of the present study was to examine the relationship of self-compassion to pain, psychological functioning, pain coping, and disability among patients who have persistent musculoskeletal pain and who are obese. METHODS Eighty-eight obese patients with persistent pain completed a paper-and-pencil self-report assessment measure before or after their appointment with their anesthesiologist. RESULTS Hierarchical linear regression analyses demonstrated that even after controlling for important demographic variables, self-compassion was a significant predictor of negative affect (β=-0.48, P<0.001), positive affect (β=0.29, P=0.01), pain catastrophizing (β=-0.32, P=0.003), and pain disability (β=-0.24, P<0.05). CONCLUSION The results of this study indicate that self-compassion may be important in explaining the variability in pain adjustment among patients who have persistent musculoskeletal pain and are obese.

Radiation Dose Exposure for Lumbar Spine Epidural Steroid Injections: A Comparison of Conventional Fluoroscopy Data and CT Fluoroscopy Techniques

OBJECTIVE The purpose of this article is to compare the radiation dose of conventional fluoroscopy-guided lumbar epidural steroid injections (ESIs) and CT fluoroscopy (CTF)-guided lumbar ESI using both clinical data and anthropomorphic phantoms. MATERIALS AND METHODS We performed a retrospective review of dose parameters for 14 conventional fluoroscopy ESI procedures performed by one proceduralist and 42 CTF-guided ESIs performed by three proceduralists (14 each). By use of imaging techniques similar to those for our clinical cohorts, a commercially available anthropomorphic male phantom with metal oxide semiconductor field effect transistor detectors was scanned to obtain absorbed organ doses for conventional fluoroscopy-guided and CTF-guided ESIs. Effective dose (ED) was calculated from measured organ doses. RESULTS The mean conventional fluoroscopy time for ESI was 37 seconds, and the mean procedural CTF time was 4.7 seconds. Calculated ED for conventional fluoroscopy was 0.85 mSv compared with 0.45 mSv for CTF. The greatest contribution to the radiation dose from CTF-guided ESI came from the planning lumbar spine CT scan, which had an ED of 2.90 mSv when z-axis ranged from L2 to S1. This resulted in a total ED for CTF-guided ESI (lumbar spine CT scan plus CTF) of 3.35 mSv. CONCLUSION The ED for the CTF-guided ESI was almost half that of conventional fluoroscopy because of the shorter fluoroscopy time. However, the overall radiation dose for CTF-guided ESIs can be up to four times higher when a full diagnostic lumbar CT scan is performed as part of the procedure. Radiation dose reduction for CTF-guided ESI is best achieved by minimizing the dose from the preliminary planning lumbar spine CT scan.

Pain Acceptance, Hope, and Optimism: Relationships to Pain and Adjustment in Patients With Chronic Musculoskeletal Pain

UNLABELLED There is growing interest in the role that positive aspects of psychological adjustment, such as pain acceptance, hope, and optimism, may play in explaining adjustment in persons suffering from persistent pain. This study conducted in obese patients with persistent musculoskeletal pain (N = 89) examined the degree to which pain acceptance and hope explained pain intensity, pain unpleasantness, psychological distress, and pain-related disability, after controlling for the effects of optimism. In correlational analyses, pain acceptance and optimism were associated with psychological distress and pain disability with hope being related to only psychological distress. Pain acceptance, optimism, and hope were not significantly associated with pain. Hierarchical linear regression (HLR) analyses found that pain acceptance remained a significant predictor of psychological distress and pain disability after controlling for optimism, demographic, and medical variables. HLR analyses found that hope was not a significant predictor of psychological distress after controlling for optimism, pain acceptance, and demographic and medical variables. The results of this study are important because they indicate that pain acceptance, hope, and optimism are all related to pain adjustment. They also highlight the importance of controlling for optimism when examining the effects of pain acceptance and hope on pain adjustment. PERSPECTIVE In a sample of obese patients with persistent musculoskeletal pain, pain acceptance was a significant predictor of psychological distress and pain disability even after controlling for optimism, demographic, and medical variables. These results add to the growing literature on the importance of pain acceptance in understanding adjustment to persistent pain.

Retrospective analysis of low-dose methadone and QTc prolongation in chronic pain patients

Background Methadone is a synthetic opioid that is widely used for the treatment of chronic pain. The association between methadone treatment and QT interval prolongation or which can lead to torsades de pointes has been confirmed with larger studies on high dose methadone. The aim of this study was to determine the effect of methadone on the QTc interval in patients, whether the daily dose of methadone should be lower than what has been previously investigated. Methods A total of 130 patients were included, with 90 patients in the methadone group and 40 patients in the control group. For each ECG, heart rate, QT interval and corrected QT (QTc) interval were recorded. The patient demographics, methadone dose and serum level, duration of methadone use and past medical history were collected. Results The QTc interval was significantly longer in the treatment group than in the control group (443 ± 30.0 ms versus 408 ± 28.0 ms, respectively, P < 0.0001) and more patients in the treatment group had a QTc interval greater than 450 ms (36.7% versus 7.5%, respectively, P = 0.0005). The QTc interval was not associated with methadone dose P = 0.9278), serum level (P = 0.2256) or duration of treatment (P = 0.1822). Conclusions This study has shown that methadone use is associated with longer QTc intervals, even among patients with daily doses of less than 80 mg. In this study, no correlation was found between QTc duration and methadone dose, serum levels or duration of use. However, the magnitude of the QTc interval was associated with female gender and the use of antidepressants.

Preincisional dextromethorphan combined with thoracic epidural anesthesia and analgesia improves postoperative pain and bowel function in patients undergoing colonic surgery.

Colonic surgery is associated with severe postoperative pain and postoperative ileus, which contribute to delayed hospital discharge. In previous studies, we demonstrated that IM dextromethorphan (DM) provided preemptive analgesia and improved postoperative pain. The benefit of thoracic epidural anesthesia (TEA) and postoperative epidural analgesia on postoperative pain was well demonstrated. The goal of this study was to investigate the effect of preincisional IM DM combined with intraoperative TEA and postoperative patient-controlled epidural analgesia (PCEA) on pain and bowel function after colonic surgery. Patients were randomized into 3 equal groups to receive: 1) chlorpheniramine maleate (CPM) 20 mg and general anesthesia (CPM-GA); 2) CPM 20 mg and GA combined with TEA (CPM-TEA); or 3) DM 40 mg (containing 20 mg of CPM) and GA combined with TEA (DM-TEA). The CPM, DM, and TEA with lidocaine were administered after GA induction via an IM injection and 30 min before the skin incision. All patients received postoperative PCEA for pain control. Analgesic effects were evaluated for 72 h after surgery using visual analog scale pain scores at rest and moving, time to first PCEA request for pain relief, total PCEA consumption, and the time to first passage of flatus. Statistically significant improvement of postoperative pain and bowel function was observed in the following order: DM-TEA > CPM-TEA > CPM-GA. Compared with the CPM-TEA group, the DM-TEA group averaged 1.6 points lower on first-hour pain scores, 40 min longer to first PCEA request, 15.8 mL less PCEA drug over 72 h, and 14.7 h earlier bowel function (all P < 0.01). We conclude that the combination of preincisional DM (40 mg IM), intraoperative TEA, and postoperative PCEA enhances analgesia and facilitates recovery of bowel function, suggesting possible synergistic interaction with local anesthetics and opioids.

Epidural clonidine for postoperative pain after total knee arthroplasty: a dose-response study.

BACKGROUND: Combinations of epidural clonidine, local anesthetics, and opioids have improved postoperative analgesia after total knee arthroplasty. In this study we sought to determine the optimal epidural bolus dose of clonidine, which provides the best analgesia and fewest side effects. METHODS: Eighty ASA I–III patients, who underwent total knee arthroplasty were randomly assigned to one of four groups of 20 patients each. Identical epidural anesthesia procedures were used for all groups. After surgery, groups C0, C1, C2, and C4 received patient-controlled epidural analgesia (PCEA) with clonidine (0, 1.0, 2.0, or 4.0 &mgr;g/mL, respectively) and morphine (0.1 mg/mL) in 0.2% ropivacaine. The analgesia effect was estimated by PCEA consumption volume and visual analog pain scale at rest and with movement at 1, 2, 4, 12, 24, 48, and 72 h after surgery. Systolic blood pressure, heart rate, sedation, and sensory and motor blockade were also recorded for 72 h after surgery. RESULTS: The PCEA consumption volume for groups C0, C1, C2, and C4 were 71.8 ± 19.5 mL, 49.6 ± 12.3 mL, 48.1 ± 9.3 mL, and 39.4 ± 9.0 mL, respectively. The clonidine groups experienced less postoperative pain (P = 0.002). In the C4 group, four patients had prolonged sensory blockade and one patient had both severe sedation and prolonged sensory motor blockade. No significant statistical difference in analgesic consumption (P = 0.78) and pain intensity (P = 0.66) between groups C1 and C2 were noted. CONCLUSIONS: The optimal amount of epidural clonidine in a solution of morphine and ropivacaine for postoperative pain management is 1.0 &mgr;g/mL.

Kerma Area Product Method for Effective Dose Estimation During Lumbar Epidural Steroid Injection Procedures: Phantom Study

OBJECTIVE The purpose of this study was to derive from the kerma area product the dose conversion coefficient for estimating the effective dose for lumbar epidural steroid injection procedures. MATERIALS AND METHODS A mobile fluoroscopy system was used for fluoroscopic imaging guidance of lumbar epidural steroid injection procedures. For acquisition of organ dose measurements, 20 diagnostic metal oxide semiconductor field effect transistor detectors were placed at each organ in an anthropomorphic phantom of a man, and these detectors were attached to four mobile metal oxide semiconductor field effect transistor wireless bias supplies to obtain the organ dose readings. The kerma area product was recorded from the system console and independently validated with an ion chamber and therapeutic x-ray film. Fluoroscopy was performed on the phantom for 10 minutes for acquisition of the dose rate for each organ, and the average clinical procedure time was multiplied by each organ dose rate for acquisition of individual organ doses. The effective dose was computed by summing the product of each organ dose and the corresponding tissue weighting factor from International Commission on Radiologic Protection publication 60. RESULTS The effective dose was computed as 0.93 mSv for an average lumbar epidural steroid injection procedure (fluoroscopic time, 40.7 seconds). The corresponding kerma area product was 2.80 Gy.cm(2). The dose conversion coefficient was derived as 0.33 mSv/(Gy.cm(2)). CONCLUSION The effective dose for lumbar epidural steroid injection can be easily estimated by multiplying the derived dose conversion coefficient by the console-displayed kerma area product.

Utilization of spinal cord stimulation in patients with failed back surgery syndrome.

Study Design. Retrospective analysis of a population-based insurance claims data set. Objective. To evaluate the use of spinal cord stimulation (SCS) and lumbar reoperation for the treatment of failed back surgery syndrome (FBSS), and examine their associated complications and health care costs. Summary of Background Data. FBSS is a major source of chronic neuropathic pain and affects up to 40% of patients who undergo lumbosacral spine surgery for back pain. Thus far, few economic analyses have been performed comparing the various treatments for FBSS, with these studies involving small sample sizes. In addition, the nationwide practices in the use of SCS for FBSS are unknown. Methods. The MarketScan data set was used to analyze patients with FBSS who underwent SCS or spinal reoperation between 2000 and 2009. Propensity score methods were used to match patients who underwent SCS with those who underwent lumbar reoperation to examine health care resource utilization. Postoperative complications were analyzed with multivariate logistic regression. Health care use was analyzed using negative binomial and general linear models. Results. The study cohort included 16,455 patients with FBSS, with 395 undergoing SCS implantation (2.4%). Complication rates at 90 days were significantly lower for SCS than spinal reoperation (P < 0.0001). Also in the matched cohort, hospital stay (P < 0.0001) and associated charges (P = 0.016) were lower for patients with SCS. However outpatient, emergency room, and medication charges were similar between the 2 groups. Overall cost totaling

Attenuation of neurological injury with early baicalein treatment following subarachnoid hemorrhage in rats

82,586 at 2 years was slightly higher in the lumbar reoperation group than in the SCS group with total cost of