Physicochemical Stability and Compatibility of Mixtures of Ropivacaine with Dexamethasone or Betamethasone for Epidural Steroid Injections: An In Vitro Study.

BACKGROUND: Epidural steroid injections are widely used to treat spinal and radiating pain. However, crystal formation has recently been reported in mixtures of ropivacaine and nonparticulate steroids, commonly used in epidural steroid injections. OBJECTIVES: Our study assessed the physicochemical stability of mixtures of different nonparticulate steroids and ropivacaine and aimed to propose a safe regimen for epidural steroid injections. STUDY DESIGN: An in vitro protocol was used to examine the physicochemical stability of epidural steroid injection mixtures most commonly used at our institution. SETTING: In vitro laboratory study. METHODS: Twelve solutions were prepared by mixing 0.75% or 0.2% ropivacaine with dexamethasone or betamethasone at volume ratios of 1:1, 2:1, and 3:1 in propylene syringes at 24°C. The physical properties of the mixtures were observed with the naked eye and under a microscope, and their pH was measured. The concentration of each drug in the mixture was evaluated using high-performance liquid chromatography. RESULTS: None of the ropivacaine and dexamethasone mixtures showed macroscopic or microscopic crystal formation after 2 hours, and there were no significant changes in pH. The concentrations of the 2 drugs remained stable for up to 2 hours. In contrast, at least 10 mu-m crystals were observed microscopically and macroscopically in all mixtures of ropivacaine and betamethasone; the ropivacaine concentration was reduced by > 10% after one hour. LIMITATIONS: Confirming the stability of drugs in vitro does not ensure that their pharmacokinetics and pharmacodynamics remain unaltered in vivo. CONCLUSION: The combination of ropivacaine and betamethasone should be avoided because of their physicochemical instability. Combinations of ropivacaine and dexamethasone should be administered cautiously because they are more physicochemically stable than combinations of ropivacaine and betamethasone.

Percutaneous Vertebroplasty in a Patient with Chronic Back Pain Caused by Multiple Schmorl's Nodes: A Case Report.

Background and Objectives: Schmorl's nodes (SNs), formed by the herniation of intervertebral discs into adjacent vertebral bodies, are generally asymptomatic and do not require treatment. However, certain types of SNs can cause intractable back pain. Case Presentation: A 63-year-old man presented to our hospital with back pain after a fall 1 month prior. Physical examination revealed back pain that worsened with movement and paraspinal tenderness. Magnetic resonance imaging (MRI) performed immediately after presentation revealed subacute to chronic compression fractures with SNs at the upper endplates of the 11th and 12th thoracic and 1st lumbar vertebrae. Pain (numeric rating scale (NRS), 7-8/10) persisted despite 6 months of conservative treatment and MRI revealed increased signal intensity in T2-weighted images in the regions around the SNs. Based on these findings, an epidural nerve block was performed, and then repeated; however, no significant improvement was observed. Percutaneous vertebroplasty (PVP) was performed at the 11th and 12th thoracic and 1st lumbar vertebrae. Pain levels decreased substantially 1 week after PVP (NRS, 3-4/10). Subsequent treatment with non-steroidal anti-inflammatory drugs (NSAIDs) and steroids for two weeks further reduced pain levels (NRS, 1-2/10), following which steroid use was discontinued and NSAID use became intermittent. At the six-month follow-up, pain levels remained low and the patient reported an improvement in activity levels of 90% or more. Conclusions: This case report demonstrates that PVP safely and effectively improved symptoms in a patient with multiple SNs and intractable back pain. Nevertheless, further research, particularly large-scale randomized prospective studies, is necessary to validate the long-term efficacy and safety of this intervention.

Spinal Cord Injury and Postdural Puncture Headache following Cervical Interlaminar Epidural Steroid Injection: A Case Report.

Background: Cervical interlaminar epidural steroid injection (CIESI) is increasingly used as an interventional treatment for pain originating from the cervical spine. However, serious neurological complications may occur during CIESI because of direct nerve damage following inappropriate needle placement. Case report: A 35-year-old woman presented with posterior neck pain radiating to the left upper arm. Cervical magnetic resonance imaging (MRI) revealed left C6 nerve impingement. CIESI under fluoroscopic guidance was performed at another hospital using the left C5/6 interlaminar approach. Immediately after the procedure, the patient experienced dizziness, decreased blood pressure, motor weakness in the left upper arm, and sensory loss. She visited our emergency department with postdural puncture headache (PDPH) that worsened after the procedure. Post-admission cervical MRI revealed intramedullary T2 high signal intensity and cord swelling from the C4/5 to C6/7 levels; thus, a diagnosis of spinal cord injury was made. The patient's PDPH spontaneously improved after 48 h. However, despite conservative treatment with steroids, the decrease in abduction of the left fifth finger and loss of sensation in the dorsum of the left hand persisted for up to 6 months after the procedure. As noticed in the follow-up MRI performed 6 months post-procedure, the T2 high signal intensity in the left intramedullary region had decreased compared to that observed previously; however, cord swelling persisted. Furthermore, left C7/8 radiculopathy with acute denervation was confirmed by electromyography performed 6 months after the procedure. Conclusions: Fluoroscopy does not guarantee the prevention of spinal cord penetration during CIESI. Moreover, persistent neurological deficits may occur, particularly due to intrathecal perforation or drug administration during CIESI. Therefore, in accordance with the recommendations of the Multisociety Pain Workgroup, we recommend performing CIESI at the C6/7 or C7/T1 levels, where the epidural space is relatively large, rather than at the C5/6 level or higher.

The usefulness of dual channel elastomeric pump for intravenous patient-controlled analgesia in geriatrics: a randomized, double-blind, prospective study.

BACKGROUND: Intravenous patient-controlled analgesia (IV-PCA) is often used in the postoperative period. However, determining an appropriate opioid dose is difficult. A previous study suggested the usefulness of variable-rate feedback infusion. In this study, we used a dual-channel elastomeric infusion pump to provide changes in PCA infusion rate by pain feedback. METHODS: Ninety patients undergoing orthopedic surgery of American Society of Anesthesiologists grade I-III and 65 to 79 years of age participated in the study. All patients were given a dual-chamber PCA. Patients were randomly allocated to a treatment group (Group D; PCA drugs divided into both chambers) or control group (Group C; PCA drugs only in the constant flow chamber with normal saline in the adjustable flow chamber). The primary outcome was the amount of fentanyl consumption via PCA bolus. The secondary outcome variables were pain score, total fentanyl consumption, rescue analgesic use, patient satisfaction, recovery scores, and adverse events including postoperative nausea and vomiting (PONV). RESULTS: Group D showed decreased fentanyl consumption of the PCA bolus, a decrease in rescue analgesic use, and better patient satisfaction compared with group C. The incidence of PONV was much higher in group C. There was no difference in other adverse events. CONCLUSIONS: We showed the usefulness of dual chamber IV-PCA to change the flow rate related to pain feedback without any complications. Our results suggest a noble system that might improve existing IV-PCA equipment. TRIAL REGISTRATION: The study registered at UMIN clinical trial registry (registered date: 05/03/2020, registration number: UMIN000039702 ).

Risk factors for new vertebral compression fracture after kyphoplasty and efficacy of osteoporosis treatment: A STROBE-compliant retrospective study.

Kyphoplasty (KP) has been widely used to treat vertebral compression fractures (VCFs). However, the issue of new VCFs after KP remains controversial. Identification of risk factors for new VCF after KP may help prevent their occurrence in patients. This study aimed to retrospectively determine the major risk factors for new VCF after KP, including those associated with osteoporosis drugs used after kyphoplasty. We reviewed 117 patients who underwent single-level KP. During the follow-up period of 1 year after KP, the demographic data of these patients were compared by dividing them into two groups: those with new fractures (n = 19) and those without new fractures (n = 98). We investigated the age, sex, fracture location, medical history, steroid use history, bone mineral density (BMD), type of osteoporosis treatment, period from fracture to KP, KP method (unilateral or bilateral), bone cement dose, intradiscal cement leakage, preoperative and postoperative compression ratio, kyphotic angle (KA), and lowest vertebral body height in the fractured vertebrae. Based on these data, the factors related to new VCFs after KP were investigated using univariate and multivariate logistic regression analyses. We also investigated whether there were differences in new VCFs according to the type of osteoporosis treatment. During the 1-year follow-up period after KP, the rate of new VCFs was 16.2%. Factors related to new VCFs were BMD, intradiscal cement leakage, KA recovery rate after 1 day, and baseline height in the univariate and multivariate logistic regression analyses. The group treated with zoledronate after KP tended to show a lower frequency of developing new VCFs than the groups treated with alendronate (P = .07), calcium (P = .05), selective estrogen receptor modulator (SERM) (P = .15), and risendronate (P = .02). This study showed that for patients with new VCFs after KP, lower BMD, greater intradiscal cement leakage, greater KA recovery rate, and lower baseline vertebral height were likely risk factors for the development of new VCFs. Additionally, among the drugs used for the treatment of osteoporosis after KP, zoledronate tends to reduce the development of new VCFs compared with other bisphosphonates, SERMs, or calcium.

Microbiological and Physicochemical Stability of Fentanyl, Oxycodone, Hydromorphone, Ketorolac, Ramosetron, and Ondansetron for Intravenous Patient-controlled Analgesia: An In Vitro Study.

BACKGROUND: Postoperative patient-controlled analgesia provides pain relief, encourages early mobilization, and results in a shortened hospital stay. Patient-controlled analgesia involves the mixing of different types of drugs. When using patient-controlled analgesia, it is important to confirm the microbiological and physicochemical stability of each drug in a mixture to guarantee that the drug is delivered to the patient in an unaltered form. OBJECTIVES: To confirm the microbiological and physicochemical stability of various drug mixtures for intravenous patient-controlled analgesia. STUDY DESIGN: An in vitro protocol to examine the microbiological and physicochemical stability of the most commonly used postoperative intravenous patient-controlled analgesia mixtures at our institution. SETTING: In vitro laboratory study. METHODS: Each mixture contained a total of 4 drugs: fentanyl 400 µg, ketorolac 30 mg, either hydromorphone 4 mg or oxycodone 10 mg, and either ramosetron 0.3 mg or ondansetron 10 mg. Each mixture was placed in a portable patient-controlled analgesia system containing 0.9% saline and stored at a constant temperature of 24°C for 96 hours. Physical properties (color, transparency, and sedimentation) were observed with the naked eye and optical microscopy. Sterility testing was performed to assess microbiological contamination in the drug mixture during the 96-hour study period. The pH of each mixture was evaluated for up to 96 hours after mixing. The concentration of each drug was evaluated by high-performance liquid chromatography every 24 hours until 96 hours after mixing. RESULTS: All mixtures appeared visibly transparent, and no sediments were visible under the microscope. Bacterial or fungal growth was not observed in any of the samples after 14 days of incubation. The pH variations in all mixtures were maintained within 0.25 over the 96-hour study period. The concentration of drugs, except ketorolac, ranged from 90-110% of the initial concentration up to 96 hours after mixing. In the mixtures with a pH of 4.21-4.39, the concentration of ketorolac significantly decreased at 24 hours and 48 hours. LIMITATIONS: Confirmation of the stability of drugs in vitro does not automatically ensure that the pharmacokinetics and pharmacodynamics of the drugs are not altered in vivo. CONCLUSION: With the exception of ketorolac, the drugs used in the intravenous patient-controlled analgesia drug mixtures in this study were physicochemically stable up to 96 hours after mixing. The concentration of ketorolac decreased in more acidic mixtures.

Burst Stimulation of the Thoracic Spinal Cord near a Cardiac Pacemaker in an Elderly Patient with Postherpetic Neuralgia: A Case Report.

New developments in spinal cord stimulation (SCS) have improved the treatment of patients with chronic pain. Although the overall safety of modern SCS has been established, there are no published reports regarding safety considerations when implanting a burst-mode spinal cord stimulator in patients with permanent cardiac pacemakers (PCPs). An 80-year-old man with a complete atrioventricular block implanted with a PCP was considered as a candidate for burst-mode SCS due to well-established postherpetic neuralgia (>180 days after rash). Cardiac monitoring during the burst-mode spinal cord stimulator trial and insertion did not indicate any interference. After the insertion of the burst-mode spinal cord stimulator, the patient showed functional improvement and significant pain relief. The safety of traditional tonic-mode SCS in patients with PCP has been previously reported. This is the first case report describing the safe and effective use of burst-mode SCS in a patient with PCP.

Efficacy and Safety of the Controlled-release Pregabalin Tablet (GLA5PR GLARS-NF1) and Immediate-release Pregabalin Capsule for Peripheral Neuropathic Pain: A Multicenter, Randomized, Double-blind, Parallel-group, Active-controlled, Phase III Clinical Trial.

PURPOSE: This study compared the efficacy and safety of controlled-release pregabalin (GLA5PR GLARS-NF1 tablets) with those of an immediate-release pregabalin capsule after 12 weeks' administration to patients with peripheral neuropathic pain. METHODS: In this multicenter, randomized, double-blind, active-controlled, parallel-group, Phase III study, the primary outcome was to confirm that a single treatment with the study drug (after the evening meal) is clinically noninferior to the control drug (BID regimen) at improving the mean Daily Pain Rating Scale score for treating peripheral neuropathic pain. Secondary outcomes were the Daily Sleep Interference Scale, Medical Outcomes Study Sleep Scale, Hospital Anxiety and Depression scale, and frequency of rescue medication use. The safety and tolerability of GLA5PR GLARS-NF1 tablets were also evaluated. The total daily dose of pregabalin is 150-600 mg. FINDINGS: Of the 352 randomized subjects, 261 (n = 130, study group; n = 131, control group) were analyzed. The difference in adjusted mean Daily Pain Rating Scale scores between the groups was -0.11 (95% confidence interval, -0.05 to 0.30), indicating that the study group is noninferior to the control group. There was no statistically significant difference in Daily Sleep Interference Scale, Medical Outcomes Study Sleep Scale, and Hospital Anxiety and Depression scale scores between the groups at treatment termination. Logistic regression analysis revealed no significant difference in the use of rescue medication between the groups (P = 0.217). The overall adverse event profile of the groups was similar, and no serious adverse drug reactions were observed. IMPLICATIONS: GLA5PR GLARS-NF1 tablets can be effectively and safely administered to patients with peripheral neuropathic pain. Furthermore, we found that sleep, anxiety, and depression were improved with pain control. Owing to the once-daily administration, treatment effects can be maximized by improved treatment compliance. ClinicalTrials.gov identifier: NCT03221907.

Comparison of efficacies of unipedicular kyphoplasty and bipedicular kyphoplasty for treatment of single-level osteoporotic vertebral compression fractures: A STROBE-compliant retrospective study.

Kyphoplasty (KP) is an effective method for treating osteoporotic vertebral compression fractures (OVCFs). Although the bipedicular approach is considered the main treatment approach, the unipedicular approach has also been shown to be effective. This study aimed to retrospectively compare the radiological and clinical outcomes of unipedicular and bipedicular KP in the treatment of single-level OVCFs.In total, 96 patients with single-level OVCF who received KP were divided into 2 groups: the unipedicular group, in which 28 patients underwent KP via the unipedicular approach, and the bipedicular group, in which 68 patients underwent KP via the bipedicular approach. Clinical results, radiological findings, and complications were compared between the groups. The clinical results were evaluated for up to 1 year after surgery using a numerical rating scale score. The radiological findings were compared in terms of recovery of the lowest vertebral body height at the same location on radiographs taken both 1 day and 1 year after surgery. The degrees of recovery of the kyphotic angle (KA) were simultaneously compared. The surgical time, amount of cement used, and any postoperative complications were also compared.Both groups showed significant improvements in all clinical and radiological parameters until 1 year after surgery. The unipedicular group required significantly lower amounts of cement than the bipedicular group (unipedicular: 4.4 ±â€Š0.8 mL, bipedicular: 5.6 ±â€Š1.0 mL, P = .00), but there were no significant differences in the clinical and radiological results for up to 1 year after surgery. There were no significant differences in leakage of intradiscal cement, appearance of adjacent vertebral compression fractures within 1 year of surgery, and surgical time.Unipedicular and bipedicular KP significantly reduced the pain experienced by patients with single-level OVCF, restored vertebral height, and corrected the KA, which remained stable for at least 1 year after treatment. Unipedicular KP required lower amounts of cement than bipedicular KP and was as effective as bipedicular KP in terms of radiological and clinical outcomes. The results of this study have level three evidence and grade B recommendation.

Efficacy of electrical stimulation on epidural anesthesia for cesarean section: a randomized controlled trial.

BACKGROUND: Loss of resistance (LOR) technique is a widely used method to identify the epidural space. However, cases of inadequate epidural anesthesia in cesarean section were frequently reported. Also, the success rate of epidural anesthesia with LOR technique varied depending on the proficiency of the practitioner. The purpose of this study was to assess the efficacy and safety of electrical stimulation to identify epidural spaces in cesarean section for novices or clinicians with recent gap in experience. METHODS: Pregnant women scheduled for elective cesarean section were randomly allocated to two groups. Groups were classified based on the methods used for identifying the epidural space: the LOR group (group L) and the LOR with epidural electrical stimulation group (group E). Clinicians with less than 10 epidural cesarean section experiences in the recent year performed epidural anesthesia for cesarean section. In the group E, a RegionalStim® conductive catheter was inserted through the Tuohy needle, and the guidewire passing through the catheter was connected to a peripheral nerve stimulator. The intensity of the stimulation was gradually increased from 0.25 mA to 1.5 mA until paresthesia was elicited and radiated. We assessed the success of epidural anesthesia (complete success, partial success or failure). Other clinical parameters including maternal satisfaction, time required for epidural anesthesia, neonatal Apgar scores, pain scores and adverse events were compared between the two groups. RESULTS: Except for 6 patients who withdrew consent, 54 patients were enrolled in this study (28 for the group L and 26 for the group E). The demographic data showed no difference between the two groups. There was no adverse event resulted from electrical stimulation. The group E showed higher rate of complete success, sensitivity in finding epidural space and maternal satisfaction compared to the group L (21/26 vs. 15/28, p = 0.034, 0.96 vs. 0.68, p = 0.012 and 4.04 vs. 3.39, p = 0.02, respectively). The other clinical parameters showed no differences between the two groups. CONCLUSION: In addition to the conventional LOR technique, identifying epidural spaces using electrical stimulation led to better outcomes without additional risks for novices as well as clinicians with recent gap in experience. TRIAL REGISTRATION: This study was retrospectively registered in the ClinicalTrials.gov Registry (NCT03443466) on February 23, 2018.

Comparison of ropivacaine with ropivacaine and fentanyl in continuous epidural analgesia for postherpetic neuralgia: A STROBE-compliant retrospective study.

Continuous epidural analgesia (CEA) using local anesthetics is frequently used to control herpes zoster pain and prevent postherpetic neuralgia (PHN). However, few studies have been conducted to determine the efficacy of epidural drugs administered as CEA to manage PHN. This retrospective study was designed to evaluate the effectiveness of CEA with ropivacaine alone or with ropivacaine and fentanyl for controlling pain caused by PHN.We reviewed the medical records of 71 patients. We studied 2 groups: epidural ropivacaine (ER; CEA with ropivacaine alone; n = 44) and epidural ropivacaine and fentanyl (Epidural ropivacaine and fentanyl (ERF); CEA with ropivacaine and fentanyl; n = 27). To evaluate pain, a numeric rating scale (NRS) was evaluated at 6 time points: immediately before the procedure (baseline NRS score); 1 hour after the procedure; 14 days after the procedure; and 1, 3, and 6 months after the procedure. Complication rates were recorded during CEA. We also investigated whether additional invasive procedures were needed due to insufficient pain control during the 6-month follow-up period.After adjusting for confounding variables, there were no significant differences in the NRS scores between the 2 groups at any time point. The adjusted odds ratio for additional invasive procedures within 6 months after CEA was 1.03-times higher in the ERF group than in the ER group, but this difference was not statistically significant (95% confidence interval: 0.33-3.23, P = .96). Rates of complication (dysuria, vomiting, nausea, itching sensation, and hypotension) during CEA were higher in the ERF group than in the ER group. However, the differences were not statistically significant.There was no difference in the management of pain in patients with PHN between the groups. Epidural administration of fentanyl with ropivacaine did not improve pain management when compared to ropivacaine alone. Although not statistically significant, the incidence of complications during CEA was higher in the opioid combination group.

Efficacy of continuous epidural infusion with epidural electric stimulation compared to that of conventional continuous epidural infusion for acute herpes zoster management: a retrospective study.

BACKGROUND: Continuous epidural infusions are commonly used in clinical settings to reduce the likelihood of transition to postherpetic neuralgia via pain control. The purpose of this study was to compare the efficacy of conventional continuous epidural infusion to that of continuous epidural infusion in which the catheter is guided by electric stimulation to areas with neurological damage for the treatment of zoster-related pain and prevention of postherpetic neuralgia. METHODS: We analyzed the medical records of 114 patients in this study. The patients were divided into two groups: contrast (conventional continuous epidural infusion) and stimulation (continuous epidural infusion with epidural electric stimulation). In the contrast group, the position of the epidural catheter was confirmed using contrast medium alone, whereas in the stimulation group, the site of herpes zoster infection was identified through electric stimulation using a guidewire in the catheter. Clinical efficacy was assessed using a numerical rating scale (pain score) up to 6 months after the procedures. We compared the percentage of patients who showed complete remission (pain score less than 2 and no further medication) in each group. We also investigated whether the patients required additional interventional treatment due to insufficient pain control during the 6-month follow-up period after each procedure. RESULTS: After adjusting for confounding variables, the pain score was significantly lower in the stimulation group than in the contrast group for 6 months after the procedure. After adjustment, the odds of complete remission were 1.9-times higher in the stimulation group than in the contrast group (95% confidence interval [CI]: 0.81-4.44, P = 0.14). Patients in the contrast group were significantly more likely to require other interventions within 6 months of the procedure than patients in the stimulation group (odds ratio: 3.62, 95% CI: 1.17-11.19, P = 0.03). CONCLUSION: Epidural drug administration to specific spinal segments using electric stimulation catheters may be more helpful than conventional continuous epidural infusion for improving pain and preventing postherpetic neuralgia in the acute phase of herpes zoster.

Comparison of the Analgesic Effect of Ropivacaine with Fentanyl and Ropivacaine Alone in Continuous Epidural Infusion for Acute Herpes Zoster Management: A Retrospective Study.

Background and Objectives: Currently, few studies have reported the effects of opioids during continuous epidural infusion (CEI) to control pain owing to herpes zoster (HZ). This study aimed to retrospectively compare the effectiveness of epidural opioids in the treatment of acute HZ pain. Materials and Methods: We reviewed medical records of 105 patients who were divided into two groups: R group (CEI with ropivacaine) and RF group (CEI with ropivacaine and fentanyl). Clinical efficacy was evaluated using the numeric rating scale (NRS) score for 6 months after the procedures. We compared the percentage of patients with complete remission in each group. We investigated the complication rates during CEI. Results: No significant differences in the NRS scores were observed between the two groups in the 6-month period. The adjusted odds ratio (OR) for patients included in the complete remission was 0.6 times lower in the RF group than in the R group (95% confidence interval: 0.22-1.71, p = 0.35). The OR for complications during CEI was higher in the RF group than in the R group. However, the difference was not statistically significant. Conclusions: No difference was observed in the management of HZ pain and the prevention of postherpetic neuralgia between the two groups. The incidence of complications tended to be higher in the RF group than in the R group.

Comparison of the efficacy of continuous epidural block with epidural electrical stimulation and conventional continuous epidural block for management of zoster-associated pain beyond the acute phase: A retrospective study.

Continuous epidural block (CEB) is a popular clinical method for controlling postherpetic neuralgia (PHN). However, the long-term effects of CEB on PHN have not yet been established. This study aimed to confirm the clinical efficacy of epidural electrical stimulation catheters in CEB to manage PHN.Patients were classified into 2 groups: those with subacute PHN, between 30 and 180 days after the onset of the rash; and those with chronic PHN, over 180 days after the onset of the rash. On the basis of the type of catheter used, the patients were further divided into the following 2 groups: the esopocan group, in which the site of herpes zoster infection was confirmed using a contrast medium alone; and the epistim group, in which an additional method of electrical stimulation through a guide-wire in the catheter was used for detecting the site affected by herpes. Clinical efficacy was assessed with a numerical rating scale immediately 1, 3, and 6 months after the procedure. We also investigated whether additional interventional treatment was necessitated because of insufficient pain control during the 6-month follow-up.We examined 88 patients. In the subacute PHN period, the numerical rating scale score was significantly lower in the epistim group than in the esopocan group until 6 months. In the chronic PHN period, no significant differences in the numerical rating scale scores were observed between the 2 groups until 6 months. In the subacute PHN period, the adjusted odds ratio for other interventional procedures within 6 months in the esopocan group versus the epistim group was 2.59 (95% confidence interval [CI] 0.83-8.09, P = .10), and in the chronic PHN period, it was 1.31 (95% CI 0.11-5.46, P = .79).Epidural drug administration to specific segments using electrical stimulation catheters may be more useful in mitigating zoster-associated pain in subacute PHN.

Electric stimulation-guided epidural analgesia for vaginal delivery: A randomized prospective study.

BACKGROUND: The failure rate of epidural anesthesia using the loss of resistance technique is 13-23%. OBJECTIVES: To investigate the efficacy of epidural electric stimulation-guided epidural analgesia in vaginal delivery. STUDY DESIGN: An open label randomized prospective study. METHODS: Laboring women were randomized to two groups: epidural catheter insertion using only a loss of resistance technique or a loss of resistance technique with confirmation by electric stimulation. Catheters in both groups were initially tested with 3 ml of 1% lidocaine and those with any evidence of motor blockade were considered intrathecal. Sensory blockade and an 11 point numerical rating score for pain were assessed 30 minutes after administration of an epidural bolus of 10 ml of 0.22% ropivacaine with fentanyl. Successful epidural analgesia was defined as a decrease of 2 or more in the pain score and a bilateral L1-T10 sensory blockade. RESULTS: Thirty-one patients were randomized to each group. The first 20 patients in each group were enrolled in a pilot study and were also included in the final analysis. One patient in the electric stimulation group was excluded owing to dural puncture by the Tuohy needle. One patient in each group demonstrated motor blockade after test dose and were considered failures. The number (% (95% confidence interval)) of successful cases were 29 out of 30 (97% (85, 100%)) in the electric stimulation group and 24 out of 31 (77% (61, 89%)) in the loss of resistance group (P = 0.053). However, analysis of only patients with absence of motor blockade revealed that 29 out of 29 (100% (92, 100%)) patients in the electric stimulation group and 24 of 29 (80% (63, 91%)) patients in the loss of resistance group had adequate analgesia (P = 0.024). CONCLUSIONS: Although limited by lack of blinding, small study size and inclusion of pilot study data, this study suggests epidural electric stimulation improves the success rate of subsequent labor analgesia.

Continuous cervical epidural block: Treatment for intractable hiccups.

Intractable hiccups, although rare, may result in severe morbidity, including sleep deprivation, poor food intake, respiratory muscle fatigue, aspiration pneumonia, and death. Despite these potentially fatal complications, the etiology of intractable hiccups and definitive treatment are unknown. This study aimed to evaluate the effectiveness of continuous cervical epidural block in the treatment of intractable hiccups.Records from 28 patients with a history of unsuccessful medical and invasive treatments for hiccups were evaluated. Continuous cervical epidural block was performed with a midline approach at the C7-T1 or T1-T2 intervertebral space with the patient in the prone position. The epidural catheter was advanced through the needle in a cephalad direction to the C3-C5 level. Catheter placement was confirmed using contrast radiography. A 6-mL bolus of 0.25% ropivacaine was injected, and a continuous infusion of 4 mL/h of ropivacaine was administered through the epidural catheter using an infuser containing 0.75% ropivacaine (45 mL ropivacaine and 230 mL normal saline). When the hiccups stopped and did not recur for 48 hours, the catheter was removed.Cumulative complete remission rates were 60.71% after the first cervical epidural block, 92.86% after the second, and 100% after the third. One patient complained of dizziness that subsided. No other adverse effects were reported.Continuous C3-C5 level cervical epidural block has a successful remission rate. We suggest that continuous cervical epidural block is an effective treatment for intractable hiccups.

Effectiveness of continuous epidural analgesia on acute herpes zoster and postherpetic neuralgia: A retrospective study.

Despite early treatment of herpes zoster (HZ), postherpetic neuralgia (PHN) can persist. This study was designed to compare the therapeutic and pain relief effects of continuous epidural analgesia (CEA) on the chronic phase as well as the acute phase of HZ with standard medical treatment.Medical records of 227 patients with moderate to severe zoster-associated pain that had not responded to standard medications were retrospectively reviewed. Patients received standard treatment alone (medical group) or standard treatment plus concurrent CEA (epidural group). The acute and chronic groups were classified according to a 4-week cut-off with regard to time between the onset of the rash and the first treatment. Four groups were studied: Group A (acute/medical group); Group B (acute/epidural group); Group C (chronic/medical group); and Group D (chronic/epidural group). Pain was assessed using the visual analog scale (VAS) and measured every 2 weeks for 6 months. We compared the pain rating at 6 months after the first treatment with the initial pain rating. Response to treatment was defined as a ≥50% reduction in pain severity since the initial visit. Remission was considered complete for patients whose VAS pain score was ≤2 for >3 successive visits and who no longer needed medical support.Patients who received a combination of standard treatment plus CEA (Groups B and D) had significantly higher response to treatment (P = .001) than patients receiving standard treatment alone (Groups A and C). The adjusted odds ratio (OR) for response to treatment in the epidural group versus the medical group was 5.17 (95% confidence interval [CI]: 1.75-15.23) in the acute group and 5.37 (95% CI: 1.62-17.79) in the chronic groups. The adjusted OR for complete remission in the epidural group versus the medical group was 3.05 (95% CI: 1.20-7.73) in the acute group and 4.46 (95% CI: 1.20-16.54) in the chronic group.CEA can effectively relieve pain caused by PHN and acute HZ and increase remission rates. Combining CEA with standard medical treatment may offer a clinical advantage in the management of pain caused by PHN as well as acute HZ.

Failed Percutaneous Vertebroplasty Due to Insufficient Correction of Intravertebral Instability in Kummell's Disease: A Case Report.

Kummell's disease, caused by osteonecrosis of the vertebral body, is a cause of vertebral collapse. In Kummell's disease, intravertebral instability from nonunion between the cement and bone after percutaneous vertebroplasty (PVP) can cause persistent severe pain and dysfunction. A 75-year-old woman presented with severe pain in the lower back, both buttocks, groin, and both posterior thighs for a period of 30 days. Lumbar radiographs and magnetic resonance images showed an acute compression fracture of the first lumbar vertebra with an intravertebral cleft filled with fluid. The patient underwent PVP for the L1 compression fracture; however, this failed to provide sufficient pain relief. The patient was re-evaluated with dynamic radiography, and intravertebral instability and bone cement displacement of the L1 vertebra were detected. Repeat PVP was performed. After the procedure, intravertebral instability was restored and her pain completely subsided. PVP is a good treatment choice for symptomatic Kummell's disease. However, there is no consensus on the best technique of injecting bone cement to achieve optimal results. It is important to inject more bone cement than the volume of the intravertebral cleft to prevent instability caused by nonunion in PVP for Kummell's disease. We report a case of failed PVP because of insufficient correction of intravertebral instability in Kummell's, along with a review of the literature.

Complex Regional Pain Syndrome Caused by Lumbar Herniated Intervertebral Disc Disease.

Most cases of complex regional pain syndrome (CRPS) occur after some inciting injury. There are a few cases of CRPS after an operation for disc disease. CRPS from a mild herniated intervertebral disc (HIVD) without surgical intervention is even rarer than CRPS after an operation for disc disease.A 22-year-old man was transferred to a pain clinic. He had continuously complained about back and right leg pain. He presented with a skin color change in the right lower leg, intermittent resting tremor, stiffness, and swelling in the right leg. He complained of a pulling sensation and numbness in his right buttock, posterior thigh, lateral calf, and ankle. This symptom was in accordance with L4/5 radiculopathy. Magnetic resonance imaging (MRI) also showed L4/5 HIVD that was central to the bilateral subarticular protrusion.He was diagnosed as having CRPS, which fits the revised International Association for the Study of Pain (IASP) criteria. He fulfilled 4 symptom categories (allodynia, temperature asymmetry and skin color change, sweating changes, decreased range of motion and motor dysfunction) and 3 of 4 sign categories (allodynia, temperature asymmetry and skin color changes, decreased range of motion and motor dysfunction). The bone scan and thermography also revealed CRPS.For the past 2 months, we have performed intensive treatments. But, he never became pain-free and walking for 5 minutes led to persistent leg pain. We decided to perform percutaneous nucleoplasty, which can directly decompress a HIVD. On the next day, he achieved dramatic symptom relief. The visual analog scale (VAS) score improved to 3, compared to the VAS score of 9 at the first visit. The skin color change, allodynia, and tremor in the right leg disappeared, and the temperature asymmetry normalized. Motor weakness of the right leg also recovered.We report an unusual case of CRPS that was caused by L4/5 HIVD without a history of trauma or surgery. It has a clear causal relationship between HIVD and CRPS and definitively fits in the newly revised IASP criteria. In conclusion, mild HIVD can cause CRPS without any trauma. And percutaneous nucleoplasty can be considered as a treatment option.