Transforaminal Epidural Block and Erector Spinae Plane Block to Manage Acute Zoster-Associated Pain: A Retrospective Case-Control Study.

Background and Objectives: Achieving adequate pain reduction in the acute phase of herpes zoster is essential for preventing postherpetic neuralgia (PHN). For this purpose, appropriate antiviral medications, oral analgesic medications, and various nerve block methods could be applied. Erector spinae plane block (ESPB) is a simple, novel ultrasound-guided block technique, and its use has increased because the procedure is convenient and relatively safe. Although several cases have reported the zoster-associated pain (ZAP) control effect of ESPB, the efficacy of ESPB has not been compared with that of other types of nerve blocks for managing ZAP. This study aimed to compare the efficacy of ESPB with that of other types of nerve blocks for managing ZAP. Study Design: Retrospective case-control study. Materials and Methods: Medical records of 53 patients with acute thoracic herpes zoster were reviewed. We divided the participants into two groups: patients who received transforaminal epidural injection (TFEI) (n = 32) and those who received ESPB (n = 21). The efficacy of the procedure was assessed by a numerical rating scale (NRS) and by recording patient medication doses before the procedure and at 1 week, 1 month, 2 months, and 3 months after the procedure. Results: The time required for pain intensity to decrease to NRS ≤ 2 was not significantly different between the groups. The rate of medication discontinuation also was not different between the groups. There was no significant difference between the two groups in the proportion of clinically significant PHN (NRS ≥ 3) at any time point. Limitations: The relatively small sample size from a single center and the retrospective nature of the study served as limitations. Conclusions: The clinical effects of ESPB and TFEI were similar in patients with acute thoracic herpes zoster. ESPB could be considered an interventional option for ZAP management.

Abdominal Wall Block Decreases Intraoperative Opioid Con-Sumption by Surgical Pleth Index-Guided Remifentanil Administration in Single-Port Laparoscopic Herniorrhaphy: A Prospective Randomized Controlled Trial.

Abdominal wall blocks (AWBs) can reduce pain during surgery and lessen opioid demand. Since it is difficult to know the exact level of intraoperative pain, it is not known how much the opioid dose should be reduced. In this study, using the surgical pleth index (SPI), which indicates pain index from sympathetic fibers, the amount of remifentanil consumption was investigated. We conducted single-port laparoscopic hernia repair in 64 patients, as follows: the regional block group (R group) was treated with AWB, while the control group (C group) was only subjected to general anesthesia. In both groups, the remifentanil concentration was adjusted to maintain the SPI score between 30 and 40 during surgery. The primary parameter was the amount of remifentanil. A total of 52 patients completed the study (24 in the R group, 28 in the C group). The remifentanil dose during surgery was decreased in the R group (29 ± 21 vs. 56 ± 36 ng/kg/min; p = 0.002). Visual analogue scale score and additional administrated analgesics were also low in the R group. As such, AWB can reduce the remifentanil dose while maintaining the same pain level.

Role of erector spinae plane block in controlling functional abdominal pain: Case reports.

RATIONALE: Functional abdominal pain is an intractable medical condition that often reduces quality of life. Celiac plexus block is a representative intervention for managing intractable abdominal pain. However, celiac plexus block can be technically difficult to perform and carries the risk of potential complications. During erector spinae plane block (ESPB), the injectate can enter the paravertebral space and reach the sympathetic chain. If local anesthetics spread to the sympathetic chain that supplies fibers to the splanchnic nerve, abdominal pain theoretically could be reduced. PATIENT CONCERNS: Three patients suffered from abdominal pain of unknown cause, and no medical abnormalities were found in various examinations. DIAGNOSIS: As a result of collaboration with related medical departments, the abdominal symptoms of the patients were suspected to be functional abdominal pain. INTERVENTIONS: We successfully controlled symptoms by performing ESPB at the lower thoracic level in 3 patients with functional abdominal pain. OUTCOMES: After the procedure, the patients' abdominal pain improved significantly over several months. LESSONS: We suggest that lower thoracic ESPB could be an option for management of functional abdominal pain.

Comparison of Touhy and Quincke needles on intravascular injection rate in lumbar transforaminal epidural block: a randomized prospective trial.

BACKGROUND: Transforaminal epidural steroid injection is widely used in clinical practice to effectively deliver injectate into the ventral epidural space. Complications associated with intravascular injection such as spinal cord infarction and paraplegia can occur during transforaminal epidural steroid injection. To improve the safety of the procedure, avoidance of intravascular injection is crucial, for which appropriate needle selection is important. The primary aim of this study was to compare intravascular injection rates during transforaminal epidural steroid injection between commonly used Quincke and Tuohy needles. METHOD: Two hundred and four transforaminal epidural steroid injection cases were randomly assigned to one of two needle groups (22-gage Quincke needle or 22-gage Tuohy needle). Intravascular injection was evaluated using digital subtraction angiography. Spread of contrast medium to the ventral and medial epidural spaces was evaluated. Procedure time was compared between the two needle types. RESULTS: The overall incidence of intravascular injection was 7.8%. The rate of intravascular injection was significantly lower in the Tuohy needle group than the Quincke needle group (2.9% vs 12.7%, p=0.009). The ventral and medial epidural spread rates of the Tuohy needle group were 92.2% and 95.1%, respectively, significantly higher than those of the Quincke needle group. The procedure time was shorter in the Tuohy needle group than in the Quincke needle group (97.4 (19.3) seconds vs 117.8 (31.9) s; mean difference -20.40 (95% CI -34.35 to -6.45), p=0.005). CONCLUSIONS: In conclusion, Tuohy needles had a lower intravascular injection rate and higher medial and ventral epidural spreading rates than Quincke needles. TRIAL REGISTRATION NUMBER: KCT0002095.

Novel method for modified interlaminar approach using contralateral oblique view: A technical suggestion.

A modified interlaminar (MIL) approach has been proposed for improved accessibility to the target epidural space. However, even with fluoroscopic guidance, uncertainty about the distance between the needle tip and the epidural space can remain. Using the contralateral oblique (CLO) view, determination of the epidural space can be easier with clearer identification of the interlaminar opening. We inserted the needle at the midpoint of the interlaminar opening on the fluoroscopic anteroposterior (AP) view and made the needle oriented toward the pedicle of the target side. Then, CLO view was created by rotating the intensifier approximately 45 degrees to the contralateral side of the target. Through the CLO view, the ventral interlaminar line (VILL) was confirmed and the needle was able to enter the epidural space more easily. The medical records of 29 patients who were conducted MIL approach using CLO view were retrospectively analyzed to evaluate the effectiveness and safety of this procedure. The accessibility to the ventral epidural space was 93.1%. There was no procedure-related complication. Using CLO view, uncertainty can be reduced during the MIL approach, which in turn shortens procedure time and improves safety.

A Prospective, Randomized Cross-Over Trial of T2 Paravertebral Block as a Sympathetic Block in Complex Regional Pain Syndrome.

BACKGROUND: Sympathetic block is commonly performed in clinical practice for management of intractable pain conditions. However, stellate ganglion block (SGB) alone often does not achieve sufficient sympatholysis of the upper extremity. The paravertebral space continues up to the cervical sympathetic chain and includes the stellate ganglion. We compared the sympatholytic and analgesic effect of paravertebral block performed at the T2 level (T2 PVB) with that of SGB in patients with complex regional pain syndrome (CRPS) of the upper extremity. OBJECTIVES: The aim of this study was to compare the sympatholytic property of T2 PVB with that of the conventional SGB in patients with CRPS of the upper extremity. STUDY DESIGN: Prospective, randomized cross-over trial. SETTING: University hospital pain center in Korea. METHODS: Fifteen patients with upper extremity CRPS were randomly assigned to 1 of 2 intervention methods (SGB or T2 PVB). After effects of the first block receded, the patients were crossed over to the second procedure. A difference in temperature increase between the treated side and the opposite side (DeltaT) DeltaT greater than or equal to1.5°C was considered as a successful primary outcome. Rate of successful primary outcome, degree of pain reduction, duration of effect, and patient satisfaction scores were compared between the 2 intervention methods. RESULTS: Rate of successful primary outcome (DeltaT greater than or equal to 1.5°C) was significantly higher in the T2 PVB cases than in the SGB cases (80.0% vs. 20.0%; P = 0.003). Numeric Rating Scale scores after the procedure were significantly lower in the T2 PVB group. Patient satisfaction scores were significantly higher, and the duration of the block was significantly longer in the T2 PVB cases than in the SGB cases. LIMITATIONS: The relatively small sample size from a single center, and the lack of standardization of the injected volume of T2 PVB and SGB were limitations. CONCLUSIONS: T2 PVB showed superior sympatholytic effect than SGB; other clinical outcomes were also better with T2 PVB than with SGB. T2 PVB can be a useful option for producing sympatholytic and analgesic effect in patients with CRPS of the upper extremity. KEY WORDS: Sympathetic block, Complex Regional Pain Syndrome, paravertebral block, stellate ganglion block.

Ultrasound-Guided Block of the Axillary Nerve: A Prospective, Randomized, Single-Blind Study Comparing Interfascial and Perivascular Injections.

BACKGROUND: The ultrasound-guided block of the axillary nerve may be complicated in cases in which the posterior circumflex humeral artery (PCHA) follows an abnormal course. OBJECTIVES: To develop a new technique that does not rely on direct visualization of the PCHA or the axillary nerve, and to compare interfascial injection and conventional perivascular injection for a block of the axillary nerve. STUDY DESIGN: A prospective randomized study. SETTING: An interventional pain-management practice in a university hospital. METHODS: A total of 56 patients received ultrasound-guided block of the axillary nerve with either interfascial injection (IF Group) or perivascular injection with nerve stimulation (PV Group). The primary outcome was procedure duration, defined as the time interval from when the transducer contacted the skin to when the needle was removed from the skin. RESULTS: The mean procedure time was significantly shorter in the IF Group than in the PV Group (64 seconds [SD 28.3] vs. 135 seconds [50.3], difference of -71.4 seconds; 95% confidence interval, -93.2 to -49.5) (P < 0.001). There were no differences in secondary outcomes, including the quality of blocks, between the 2 groups. LIMITATIONS: The practitioner was not blinded to the group to which the patients belonged. CONCLUSIONS: Ultrasound-guided block of the axillary nerve with interfascial injection can be performed without placing the needle near the PCHA. KEY WORDS: Block of axillary nerve, ultrasound-guided block, posterior circumflex humeral artery, interfascial injection.

Response to Transforaminal Epidural Block as a Useful Predictive Factor of Postherpetic Neuralgia.

Despite the high frequency of nerve blocks in the acute phase of herpes zoster, factors associated with intervention, such as response to epidural block, have not been analyzed as predictive factors of postherpetic neuralgia (PHN). To determine the predictive factors of progression to PHN in the presence of interventions, we analyzed the medical records of 145 patients who underwent transforaminal epidural injection (TFEI) in the acute phase of herpes zoster. A total volume of 5 mL (a mixture of 0.5% lidocaine and 5 mg dexamethasone) was injected during TFEI. Corticosteroid was used only for the first TFEI. Clinical data of age, sex, involved dermatome, presence of comorbidity, time from zoster onset to first TFEI, numerical rating scale (NRS) before TFEI, NRS at 1 week and 1, 3, and 6 months after the first TFEI, and number of TFEI were collected and analyzed. Through multivariate logistic regression analysis, pain improvement less than 50% at 1 week after the first TFEI was a strong predictive factor of progression of PHN at all time points. Response to TFEI appears to be a stronger predictive factor of progression to PHN than patient factors of sex, age, degree of initial pain, and presence of co-morbidity.

Clinical effects of pulsed radiofrequency to the thoracic sympathetic ganglion versus the cervical sympathetic chain in patients with upper-extremity complex regional pain syndrome: A retrospective analysis.

Pulsed radiofrequency (PRF) to the thoracic sympathetic ganglion (TSG PRF) or to the cervical sympathetic chain (CSC PRF) can be performed to overcome transient effects of single sympathetic blocks in patients with upper-extremity complex regional pain syndrome (CRPS).We retrospectively compared the clinical effects of TSG PRF and CSC PRF. Seven TSG PRF cases and 10 CSC PRF cases were enrolled in the present analysis. We assessed effectiveness with multiple clinical measurements: a numerical rating scale (NRS) of pain before and 1 week after the procedure, postprocedure temperature, effect duration, and a self-described patient satisfaction score.The temperature was significantly higher in TSG PRF cases than in CSC PRF cases. Pain values (according to the NRS) 1 week after the procedure were significantly lower, and the effect duration was significantly longer, after TSG PRF than after CSC PRF.TSG PRF is a more effective procedure than CSC PRF for managing chronic upper-extremity CRPS.

Correlation of Perfusion Index Change and Analgesic Efficacy in Transforaminal Block for Lumbosacral Radicular Pain.

Transforaminal epidural injection is used to treat radicular pain. However, there is no objective method of assessing pain relief following transforaminal injection. Perfusion index is a metric for monitoring peripheral perfusion status. This study evaluates the correlation between perfusion index change and analgesic efficacy in transforaminal blocks for lumbosacral radicular pain. We retrospectively analyzed data of 100 patients receiving transforaminal block for lumbosacral radicular pain. We assessed perfusion index before treatment and at 5, 15, and 30 min following the block. We defined responders (group R) and non-responders (group N) as those with ≥50% and <50% pain reduction, respectively, 30 min following block. Clinical data and perfusion index of the groups were analyzed. Ninety-two patients were examined, of whom 57 (61.9%) and 35 (38.0%) patients reported ≥50% and <50% pain reduction, respectively. Group R had a significantly higher perfusion index change ratio 5 min following the block (p = 0.029). A perfusion index change ratio of ≥0.27 was observed in group R (sensitivity, 75.4%; specificity, 51.4%; AUC (area under the curve), 0.636; p = 0.032). A perfusion index change ratio of ≥0.27 at 5 min after block is associated with, but does not predict improvement in, pain levels following lumbosacral transforaminal block.

Clinical efficacy of transforaminal epidural injection for management of zoster-associated pain: a retrospective analysis.

OBJECTIVES: Transforaminal epidural injection (TFEI) has superior accessibility to the dorsal root ganglion, which is an essential location of pain signaling in herpes zoster. However, the effectiveness of TFEI for herpes zoster patients has not previously been studied. We retrospectively analyzed the efficacy of TFEI for pain control and prevention of PHN in patients with acute and subacute herpes zoster. METHODS: Medical records of 137 patients who underwent TFEI for zoster-associated pain (ZAP) were reviewed. The participants were divided into two groups: acute TFEI group (TFEI within 30 days after zoster) and subacute TEEI group (TFEI between 30 and 90 days). The efficacy of TFEI was assessed by a numerical rating scale (NRS), doses of medications, and time to relief of ZAP. Incidence of PHN at 1 week to 6 months after TFEI was evaluated. RESULTS: Time to ZAP relief was significantly shorter and the incidence of PHN was significantly lower in the acute TFEI group than in the subacute TFEI group. Rate of medication discontinuation was significantly higher in the acute TFEI group than in the subacute TFEI group. CONCLUSIONS: Early application of TFEI in the acute phase of zoster can be a useful option for ZAP control and prevention of chronic neuropathic pain such as PHN.

Comparison of efficacy of continuous epidural block and pulsed radiofrequency to the dorsal root ganglion for management of pain persisting beyond the acute phase of herpes zoster.

BACKGROUND: There is little evidence regarding the effectiveness of intervention methods in the treatment of zoster-related pain (ZAP) after the acute phase of zoster. Generally, if ZAP remains after more than 180 days from its onset, the likelihood of pain reduction is very low; this condition is considered as a "well established" post-herpetic neuralgia (PHN). Although the clinical efficacy of intrathecal steroid injection and spinal cord stimulation (SCS) for ZAP management has been reported, these interventions are not widely used due to inherent disadvantages. Continuous epidural block is widely used in clinical practice, and the effectiveness of pulsed radiofrequency (PRF) to the dorsal root ganglion (DRG) in the treatment of ZAP already has been reported. OBJECTIVES: The purpose of this study was to compare the clinical efficacy of continuous epidural block and DRG PRF beyond acute phase of zoster, bur before PHN was well established (from 30 days to180 days after zoster onset). STUDY DESIGN: Retrospective comparative study. METHODS: A total of 42 medical records were analyzed. Patients were divided into two groups according to the type of procedure utilized: continuous epidural block (continuous epidural group) and DRG PRF (PRF group). The clinical efficacy of the procedure was evaluated using a numeric rating scale (NRS) and the medication dose before and 1 to 6 months after the procedure. RESULTS: There was a significant decrease in the NRS value with time in both groups. However, this decrease was more significant in the PRF group than in the continuous epidural group. The medication doses decreased significantly in the PRF group over time, but not in the continuous epidural group. The rate of clinically meaningful PHN (NRS≥3) was also lower in the PRF group than in the continuous epidural group. CONCLUSIONS: This study revealed that DRG PRF was more effective than a continuous epidural block in treating ZAP after the acute phase of zoster. A neuromodulation method such as DRG PRF may be a useful option for reducing the progression of neuropathic changes caused by the persistent transmission of a pain signal after the acute phase of zoster.

Guidelines for prescribing opioids for chronic non-cancer pain in Korea.

As the treatment of chronic non-cancer pain gradually increases, clinicians have more opportunities to encounter opioid prescription. However, guidelines for prescribing opioids for chronic non-cancer pain have never been published in Korea. The present guidelines were prepared by reviewing various research data. In cases in which the data were insufficient, recommendations were presented following discussion among experts affiliated with the Opioids Research Group in the Korean Pain Society. The present guidelines may need to be continuously revised and amended as more clinical evidence is acquired.

Ultrasound-guided pulsed radiofrequency treatment of the cervical sympathetic chain for complex regional pain syndrome: A retrospective observational study.

The stellate ganglion is a common target to manage neuropathic pain in the upper extremities. However, the effect duration of a single stellate ganglion block is often temporary. To overcome the short-term effects of a single sympathetic block, pulsed radiofrequency (PRF) can be applied. The aim of the present study was to investigate the efficacy of PRF on the cervical sympathetic chain under ultrasound guidance for complex regional pain syndrome (CRPS).Twelve CRPS patients who underwent PRF on the cervical sympathetic chain were enrolled in this retrospective analysis. Under ultrasound guidance, PRF was performed for 420 seconds at 42°C on the C6- and C7-level sympathetic chain.The pain intensity decreased significantly at 1 week after the procedure. Overall, 91.7% of patients experienced at least moderate improvement. A positive correlation was observed between the extent of pain reduction at 1 week after PRF and the degree of overall benefit (r = 0.605, P = 0.037). This reduction in symptoms was maintained for a mean of 31.41 ±â€Š26.07 days after PRF. There were no complications associated with this procedure.PRF on the cervical sympathetic chain, which can be performed easily and safely under ultrasound guidance, should be considered an option for managing CRPS of the upper extremities.

Efficacy of continuous epidural block in acute herpes zoster: Incidence and predictive factors of postherpetic neuralgia, a retrospective single-center study.

The aim of the present study was to investigate efficacy of continuous epidural block for prevent postherpetic neuralgia (PHN) progression in cases of acute herpes zoster with severe pain and also to identify predictive factors for PHN in such conditions.We retrospectively analyzed the clinical data of patients with herpes zoster who underwent continuous epidural block between March 2013 and October 2015. Time points were set as 1 month, 3 months, and 6 months after zoster onset. PHN was defined as the presence of pain with NRS ≥3 at certain time points.The incidence of developing PHN was 38.1%, 27.0%, and 19.0% 1 month, 3 months, and 6 months after zoster onset, respectively. Age and duration of catheterization were predictive factors for PHN at 1 month. Age, duration of catheterization, and NRS at first visit were identified as predictive factors for PHN at 3 months. Presence of diabetes, duration of catheterization, and NRS during catheterization were significant predictive factors for PHN at 6 months.The incidence of PHN is higher in zoster patients with severe pain that requires continuous epidural block compared to incidence in the general population. Advanced age and severe initial pain intensity were predictive factors of PHN development. Prolonged catheterization resulting from weak response to treatment strongly suggested progression to PHN.

Comparison of the Ventral Epidural Spreading in Modified Interlaminar Approach and Transforaminal Approach: A Randomized, Double-Blind Study.

OBJECTIVE: To evaluate the effectiveness of a modified interlaminar (MIL) approach for accessing ventral epidural space compared with the transforaminal (TF) approach. STUDY DESIGN: Randomized double blinded control trial METHODS: Eighty-four patients with lumbar radicular pain were randomly assigned into two groups in which drug delivery to the ventral epidural space was performed through either the MIL (n = 42) or the TF approach (n = 42). Within each group, subgroups were classified according to the dominant pathology as assessed by magnetic resonance imaging (MRI): bulging disc, herniated nucleus pulposus (HNP), and foraminal stenosis. Degenerative changes such as scoliosis and facet hypertrophy was also evaluated. RESULTS: The overall accessibility to the ventral epidural space was similar between the two groups. In cases with foraminal stenosis, the success rate of ventral epidural spreading was significantly higher in the MIL group compared with the TF group (TF approach = 50.00% vs MIL approach = 100.00%, P = 0.013). Medial spread of contrast was more dominant in the MIL group (P < 0.001). There was no significant difference between the two groups in overall clinical outcome. The total success rate of accessing the ventral epidural space in degenerative bony changes was higher in the MIL group than in the TF group (TF approach = 57.1% vs MIL approach = 84.6%), but the difference was not statistically significant. CONCLUSION: In cases where access to the ventral epidural space by conventional approach is limited, our MIL approach can be considered a suitable alternative, especially in the case of foraminal stenosis.