Epidural Steroid Injection in Korean Pain Physicians: A National Survey

BACKGROUND: Epidural steroid injection (ESI) is one of the most common procedures for patients presenting low back pain and radiculopathy. However, there is no clear consensus on what constitutes appropriate steroid use for ESIs. To investigate optimal steroid injection methods for ESIs, surveys were sent to all academic pain centers and selected private practices in Korea via e-mail. METHODS: Among 173 pain centers which requested the public health insurance reimbursements for their ESIs and were enrolled in the Korean Pain Society, 122 completed questionnaires were returned, for a rate of 70.5%; also returned were surveys from 39 academic programs and 85 private practices with response rates of 83.0% and 65.9%, respectively. RESULTS: More than half (55%) of Korean pain physicians used dexamethasone for ESIs. The minimum interval of subsequent ESIs at the academic institutions (3.1 weeks) and the private practices (2.1 weeks) were statistically different (P = 0.01). CONCLUSIONS: Although there was a wide range of variation, there were no significant differences between the academic institutions and the private practices in terms of the types and single doses of steroids for ESIs, the annual dose of steroids, or the limitations of doses in the event of diabetes, with the exception of the minimum interval before the subsequent ESI.

Radiofrequency thermocoagulation of the thoracic splanchnic nerve in functional abdominal pain syndrome: A case report / 대한마취과학회지

The thoracic splanchnic nerve block has been used in managing abdominal pain, especially for pains arising from abdominal cancers. A 27-year-old male patient who had a constant abdominal pain was referred to our clinic for pain management but had no organic disease. The numeric rating scale (NRS) for pain scored 7/10. We applied a diagnostic thoracic splanchnic nerve block under the diagnosis of functional abdominal pain syndrome. Since the block reduced the pain, we applied a radiofrequency thermocoagulation at the T11 and T12 vertebral level. Thereafter, his symptoms improved markedly with pain decreasing to an NRS score of 2-3/10. Hereby, we report a successful management of functional abdominal pain via radiofrequency thermocoagulation of the thoracic splanchnic nerves.

Definition of lumbar spinal pain

The prevalence of lumbar spinal pain rose significantly over 10 years. With respect to clinical management of lumbar spinal pain, the most important things are to understand the definition of terms related to lumbar spinal pain. Despite the efforts of the International Association for the Study of Pain, misuse and confusion still continue among clinicians about the definition of terms related to lumbar spinal pain; back pain, referred pain, radicular pain, radiculopathy, and sciatica. Failure to distinguish one type of lumbar spinal pain from the others may lead to unnecessary tests, misdiagnosis, and mismanagement such as an unnecessary surgery. This confusion also exists in developing animal models of lumbar spinal pain by basic scientists. Thus, the exact understandings of definition and physiology of terms related to lumbar spinal pain are essential to manage patients and research the lumbar spinal pain properly.

Breakage of a thoracic epidural catheter during its removal: A case report / 대한마취과학회지

The breakage of an epidural catheter is a rare complication during the removal of a thoracic epidural catheter. There are many causes to breakage of an epidural catheter, such as the characteristics of the catheter itself, patient's factors (anatomy, position during insertion and removal of the catheter, and the BMI), and the difficulty of the procedure. Surgical removal is considered if there is a possibility that the retained catheter might cause neurological problems. We experienced a breakage of an epidural catheter during its removal, which led to surgical intervention. To prevent the catheter breakage during its removal, the catheter should be withdrawn without excessive tension. In addition, an understanding of the patient's anatomy is essential.

Determination of Adequate Entry Angle of Lumbar Sympathetic Ganglion Block in Korean

BACKGROUND: The target of lumbar sympathetic ganglion block is the anterolateral surface of the L2, 3 and 4 vertebral bodies, where the lumbar sympathetic ganglion usually lies. In most cases, a block-needle is inserted approximately 5-8 cm lateral to spinous process on the skin and directed to the anterolateral surface of vertebral body obliquely. The purpose of this study is to determine the safe entry angle and entry point in Korean by using the abdominal CT scan images. METHODS: The abdominal CT images of eighty five patients were recruited to this study. The minimal angle aimed at the lumbar sympathetic ganglion that can pass through the lateral aspect of body and maximal angle that avoids puncturing the kidney, ureter or retroperitoneal space were measured. The distance from midline to skin entry point was also measured. RESULTS: There was no significant difference in entry angle among L2, 3, and 4 level. The entry angle was similar in the right and left side, and in males and females. The entry angle of old age group was significantly smaller than that of young age group. The calculated safe entry angle was 30.5 +/- 0.4degrees and entry point was 7.7 +/- 0.2 cm and 6.7 +/- 0.1 cm lateral from midline in males and females respectively. CONCLUSION: These measurements can be used as a reference for lumbar sympathetic ganglion block and radiofrequency lesioning. Prior to performing the lumbar sympathetic ganglion block for cancer patients, the abdominal CT scan should be reviewed to prevent complications.

Comparative Analysis of the Independent Medical Examination Reports and Legal Decisions in Pain Medicine

BACKGROUND: An independent medical examination (IME) is a critical process for awarding reparation for injury. However, conducting an IME in pain medicine is very difficult, not only because pain is a subjective symptom, but also because there are no proper objective methods to demonstrate it. This study was conducted to compare IME reports and the court decisions on the disability status of the patients. METHODS: We analyzed 79 IME reports and 25 corresponding court decisions on the disability status of patients. The diagnoses, causal relationships between the patients' status and the trauma, McBride's degree of disability, the American Medical Association's impairment ratings, the estimated annual cost for future treatment, and the necessity of care-giving were compared and analyzed. RESULTS: The diagnoses in the 79 cases were complex regional pain syndrome (CRPS) type I (58 cases), CRPS type II (7 cases), peripheral neuropathy (5 cases), myofascial pain syndrome (4 cases), herniated intervertebral disc (2 cases), and fibromyalgia (1 case). The types of accidents were road traffic accidents (50 cases), military injuries (14 cases), industrial accidents (11 cases), and others (4 cases). The IME reports and the court decisions stated considerably different McBride's degrees of disability (P = 0.014). However, there was no significant difference in the estimated cost for future treatment between the IME reports and the court decisions (P = 0.912). CONCLUSION: IME reports should be accurate, fair, and based on objective findings. Feedback on IMEs from the court decisions is helpful for reference use.

The Neurological Safety of Epidural Pamidronate in Rats

BACKGROUND: Pamidronate is a potent inhibitor of osteoclast-mediated bone resorption. Recently, the drug has been known to relieve bone pain. We hypothesized that direct epidural administration of pamidronate could have various advantages over oral administration with respect to dosage, side effects, and efficacy. Therefore, we evaluated the neuronal safety of epidurally-administered pamidronate. METHODS: Twenty-seven rats weighing 250-350 g were equally divided into 3 groups. Each group received an epidural administration with either 0.3 ml (3.75 mg) of pamidronate (group P), 0.3 ml of 40% alcohol (group A), or 0.3 ml of normal saline (group N). A Pinch-toe test, motor function evaluation, and histopathologic examination of the spinal cord to detect conditions such as chromatolysis, meningeal inflammation, and neuritis, were performed on the 2nd, 7th, and 21st day following administration of each drug. RESULTS: All rats in group A showed an abnormal response to the pinch-toe test and decreased motor function during the entire evaluation period. Abnormal histopathologic findings, including neuritis and meningeal inflammation were observed only in group A rats. Rats in group P, with the exception of 1, and group N showed no significant sensory/motor dysfunction over a 3-week observation period. No histopathologic changes were observed in groups P and N. CONCLUSIONS: Direct epidural injection of pamidronate (about 12.5 mg/kg) showed no neurotoxic evidence in terms of sensory/motor function evaluation and histopathologic examination.

Fluoroscopy-guided pudendal nerve block and pulsed radiofrequency treatment : A case report / 대한마취과학회지

Pudendal nerve block (PNB) is performed for differential diagnosis and treatment of chronic pelvic and perineal pain. Several block methods, such as transvaginal, transperineal, computerized tomography-, ultrasound- and fluoroscopy-guided approach are currently under practice. Compared to others, a fluoroscopy-guided approach has several advantages, such as its relatively low cost, facility and ease of landmark recognition. We depicted a fluoroscopy-guided PNB technique to selectively block and elaborate a pulsed radiofrequency treatment in a 51-year-old man with chronic pelvic and perineal pain. The patient had undergone a ganglion of impar block with a limited pain relief. Thereafter, a PNB was performed and the pain was relieved significantly for 2 weeks. Further PNB with a pulsed radiofrequency treatment reduced the pain for more than 8 weeks. The pain relief sustained up to the time of this report. The fluoroscopy-guided PNB and pulsed radiofrequency treatment allowed simplicity in manipulation and precision in performing the procedures with a favorable outcome.

Epidemiology of Complex Regional Pain Syndrome: A Retrospective Chart Review of 150 Korean Patients

Complex regional pain syndrome (CRPS) is a chronically painful and disabling disorder. However, no data are available even on the epidemiology of CRPS in Korea. This study was undertaken to retrospectively assess the epidemiologic characteristics of CRPS in 150 consecutive patients at a tertiary chronic pain center from March 2002 to February 2006. Information was obtained regarding patients' demographics, nature of injury, and treatment modalities. Seventy-one percent of patients had CRPS type I. The mean 11-point verbal numerical rating scale score at initial examinations and at the time of study were 8.0 and 5.7, respectively. Thirty-two percent of patients showed no change or increase in pain intensity during follow-up at our pain center. The mean duration of CRPS symptoms prior to our pain center evaluation and prior to the time of study were 27 months and 50 months, respectively. These patients had seen on average 5 different physicians before being referred to our center. This study shows that the majority of CRPS patients were referred to our center after more than 2 yr of symptoms. The clinical implication of such delayed transfer and strategies to avoid this problem are discussed.

Intravascular injection in cervical medial branch block: an evaluation of 361 injections

BACKGROUND: The prevalence of persistent neck pain, secondary to involvement of cervical facet or zygapophysial joints, has been described in controlled studies as varying from 39% to 67%. Cervical medial branch block (MBB) represents a useful interventional pain management procedure indicated in patients with a chronic neck pain of facet joint origin. In the current study, we prospectively evaluated the incidence of, and the factors associated with, intravascular injection during block. In addition, we assessed the efficiencies of generally accepted safety measures, such as pre-injection aspiration and intermittent fluoroscopy to avoid intravascular injections. METHODS: We prospectively examined 361 cervical MBBs in 158 patients performed by 2 physicians. Aspiration test, spot radiography, and contrast injection under real-time fluoroscopic visualization were performed sequentially without repositioning the needle. Incidences of blood flash back and the presence of intravascular contrast spread on spot radiographic images and during real-time fluoroscopy were checked. The factors studied for intravascular injection included patient age and sex and block spinal level. RESULTS: No specific factors were found to affect the incidence of intravascular uptake during block. The overall incidence of intravascular uptake was 3.3% per nerve block (12/361), and 7 of these were predicted by pre-injection aspiration (sensitivity = 58.3%) and 8 by spot radiography (sensitivity = 66.7%). CONCLUSIONS: The aspiration test with or without spot radiography frequently missed the intravascular uptake of contrast during cervical MBBs. We strongly advocate the use of real-time fluoroscopy during contrast injection to increase diagnostic and therapeutic value and to avoid possible complications.

The Effective Steroid Dose of Caudal Epidural Injection with Unilateral Epidural Catheter Position in Patients with Symptomatic Herniated Nucleus Purposus / 대한마취과학회지

BACKGROUND: The epidural steroid injection is commonly used in the management of chronic low back pain and radiating pain. We compared the efficacy of 40, 60, and 80 mg of methylprednisolone acetate in patients with lumbar herniated disc disease treated with caudal epidural block. METHODS: Seventy-two patients with lumbar herniated nucleus purposes on magnetic resonance imaging were included.All patients received fluoroscopically guided caudal epidural injections, with the guidewire-reinforced epidural catheter introduced through a Tuohy needle.After confirming the catheter tip position at the affected nerve root, contrasts were injected until patients felt discomfort in their site of pain.24 patients in each group received 40 mg, 60 mg, 80 mg of methylprednisolone acetate, respectively.We evaluated the improvements by pain relief scale (0-100%) after 2 weeks. RESULTS: There are no significant differences in the pain improvement between three groups (P = 0.537 ). CONCLUSIONS: Sixty and 80 mg methylprednisolone acetate injection during caudal epidural block showed no further benefit compared to 40 mg injection.

Experience of the Pediatric Patients Consulted to Pain Center

BACKGROUND: The aim of this study was to investigate the management of pediatric patients who were referred to the pain center. METHODS: The data was collected based on 32 pediatric patients referred to the pain center from March 2002 to August 2006. The number of patients each year, gender distribution, age, requested departments, clinical causes of consultation, and the pain management before and after the consultation were analyzed retrospectively. RESULTS: 32 pediatric patients (19 males and 13 females), aged 3- 17 years, were enrolled in this study. Fifty-six percent of patients were in adolescence. The major need for the consultation was cancer pain (50.0%), myofascial pain syndrome (10.0%) and central pain (10.0%). Before the consultation, 62.1% of the patients were managed by opioid-based medications of which 26.1% were managed by only partial agonists and 29.6% were managed by only PRN. At the pain center, opioid-based medication was also the main treatment. CONCLUSIONS: The number of pediatric patients referred to the pain center has increased. Under this condition, the pain physician should be concerned about pediatric pain patients and their management.

The Effect of Angle on the Position of the Catheter Tip in Paramedian Approach of Thoracic Epidural Catheterization

BACKGROUND: Thoracic epidural analgesia is the mainstay of postoperative pain control after thoracotomy. Usually the epidural catheter is blindly inserted and secured without confirming the tip position. The purpose of this study was to determine the influence of epidural approach angle on the position of the thoracic epidural catheter tip. METHODS: 129 patients scheduled for thoracotomy were enrolled. Patients were randomized into two groups: narrow angle group and wide angle group. The epidural needle was inserted at the skin of T8-9 level in both groups. In the narrow angle group the epidural space was approached at T7-8, whereas in the wide angle group the epidural space was approached at T6-7. After epidural space confirmation, a B-D nylon multi-hole epidural catheter was threaded 8cm into the epidural space. The epidural catheter tip position was assessed using a small amount of radiocontrast dye under fluoroscopy. RESULTS: The mean (95% confidence interval) position of the catheter tip was the mid-body of T5 (T5-6 - T5 upper body) in the narrow angle group and T3-4 (mid-body of T4-T3 lower body) in the wide angle group (P = 0.037). CONCLUSIONS: When approaching the thoracic epidural space by a wide angle, we can place the epidural catheters at a higher level because of a straighter threading.

Perioperative Pain Management in the Patient with Complex Regional Pain Syndrome: A case report / 대한통증학회지

Complex regional pain syndrome (CRPS) is a syndrome of pain and sudomotor or vasomotor instabilities. The perioperative pain management in CRPS patients is very important, as surgery can aggravate preexisting symptoms, especially when performed around the lesion site. Despite the increasing interest in CRPS research, little is known about the optimal perioperative treatment strategy for CRPS patients. Herein, the case of a female CRPS patient, who underwent elective surgery at the lesion site, is reported. As a preemptive analgesia, the patient was satisfactorily managed with two weeks of patient-controlled epidural analgesia, initiated 2 days prior to surgery. The techniques for the prevention of perioperative pain, including preemptive analgesia, as well as its importance, are discussed.

Spinal Cord Stimulation in Management of Intractable Chronic Pain: A 5-Year Experience / 대한마취과학회지

BACKGROUND: We investigated the effect of spinal cord stimulation on intractable chronic pain retrospectively and report our 5-year experience. METHODS: 49 patients with the medical history of trial spinal cord stimulation have been retrospectively analyzed. They consist of 34 men and 15 women, ranging in age from 22 to 89 years. Causes of intractable chronic pain included postherpetic neuralgia, failed back surgery syndrome, complex regional pain syndrome, chronic back and leg pain, cauda equina syndrome, perineal pain, diabetic polyneuropathy, and spinal cord injury. RESULTS: The pain due to failed back surgery syndrome, complex regional pain syndrome, chronic low back and leg pain, and spinal cord injury was well controlled by using spinal cord stimulation system. After a trial period of stimulation, 20 patients had permanent stimulators implanted. Most of them reported satisfactory pain relief for maximum 60 months and minimum 9 months. Noticeable complications included electrode displacement and hemorrhage. CONCLUSIONS: We may suggest that spinal cord stimulation is an effective and safe therapy for chronic intractable pain.

An Analysis of Paresthesia Areas Evoked by Spinal Cord Stimulation in Relation to the Position of Electrode Tip / 대한통증학회지

BACKGROUND: Spinal cord stimulation is a well-established method for the management of several types of chronic and intractable pain. This form of stimulation elicits a tingling sensation (paresthesia) in the corresponding dermatomes. The goal of this study was to establish a correlation between the spinal levels of the implanted epidural electrodes and the paresthesia elicited due to stimulation of the neural structures. METHODS: Thirty five patients, who received trial spinal cord stimulation, were evaluated. After the insertion of the lead to the selected position, the areas of paresthesia evoked by stimulation were evaluated. RESULTS: Seventy-one percent of cases showed paresthesia in the shoulder area when the tip of the electrode was located between the C2 C4 levels. At the upper extremities, paresthesia was evoked in 86 93% of cases, regardless of the location of the electrode tip within the cervical spinal segments. The most common tip placement of the leads eliciting hand stimulation was at the C5 level. The most common level of electrode tip placement eliciting paresthesia of the anterior and posterior thigh and the foot were at the T7 T12, T10 L1 and T11 L1 vertebral segments, respectively. CONCLUSIONS: Detailed knowledge of the patterns of stimulation induced paresthesia in relation to the spine level of the implanted electrodes has allowed the more consistent and successful placement of epidural electrodes at the desired spine level.

The Effects of Fluoroscopy Guided Interventional Microadhesiolysis and Nerve Stimulation (FIMS) in Lumbar Spinal Stenosis / 대한마취과학회지

BACKGROUND: Intramuscular stimulation (IMS) shows good results in the treatment of chronic pain patients who did not respond to other treatments such as oral analgesics, trigger point injection, nerve block and epidural steroid injection. Fluoroscopy Guided Interventional Musculoskeletal Adhesiolysis and Nerve Stimulation (FIMS) was used to stimulate the correct anatomic point using fluoroscopy. We present the results of FIMS in spinal stenosis. METHODS: 106 patients with ages ranging from 39 to 87 years were enrolled in this study. All the patients were postoperatively evaluated for the clinical outcomes such as numeric rating scale (NRS) for pain at 1 month, reduction in the analgesics dose, and the overall satisfaction rate. The patients considered to have received clinical benefit from FIMS were evaluated for the recurrence of pain by either a follow-up or telephone interview. RESULTS: FIMS reduced the level of pain compared with the pretreatment (P < 0.001). In addition, 61% of patients reported that they were satisfied. There were no procedural related serious complications. Three months after FIMS, there was continuing pain relief in 50% of the patients treated successfully. CONCLUSIONS: FIMS is a safe and effective treatment modality for spinal stenosis.

Pulsed Radiofrequency Treatment in Glossopharyngeal Neuralgia: A report of 2 cases / 대한마취과학회지

Glossopharyngeal neuralgia (GPN) is a pain syndrome characterized by unilateral sharp pain in the sensory distribution of the ninth cranial nerve. The first line of treatment for GPN is medical. However, it usually provides only partial relief. Pulsed radiofrequency has been proposed as safe, nondestructive treatment method. We present two cases of secondary GPN that was managed with pulsed radiofrequency by extraoral approach. The results were satisfactory.

A Case of Balloon Kyphoplasty in High Risk under Cement Leakage: A case report / 대한통증학회지

A vertebral compression fracture can cause chronic back pain, and may also result in progressive kyphosis. The traditional treatments of a vertebral compression fracture include bed rest, analgesics and bracing. Balloon kyphoplasty can restore the vertebral height and allow safe bone cement injection into the cavity made by the balloon, which significantly reduces the risk of cement leakage compared to vertebroplasty. An 82-year-old female patient suffered from severe low back pain. Due to the intractable pain and immobility, which could not be relieved by conventional care, as well as the empty vertebral body associated with communicated fractures of the vertebral surfaces, balloon kyphoplasty, with a thicker bone cement injection than usual with balloon kyphoplasty, was chosen. The preoperative intractable pain and immobility were dramatically relieved soon after the procedure, without any complications.

Effects of Difference in Arterial Oxygen Tension on Ischemia/Reperfusion Injury of Spinal Cord in Rabbits / 대한마취과학회지

BACKGROUND: In the milieu of the postischemic nerve system, oxygen plays an important, but different role on the ischemia/reperfusion injury. Oxygen is needed in newly restored oxidative phosphorylation to reenergize neurons depleted of ATP and membrane potential. Alternatively, oxygen may also be used as substrate for the destructive free radical-mediated processes that seem to be common final pathways in numerous mechanisms of ischemia/reperfusion injury. Several investigators have reported decreasing inspired oxygen concentration was neuroprotective. But, others have demonstrated hyperbaric oxygen was useful for reducing the ischemia/reperfusion injury. Our study aims first to evaluate the effects of difference in arterial oxygen tension on early phase of ischemia/reperfusion injury and to outline practical use of oxygen to reduce ischemic/reperfusion injury. METHODS: A rabbit spinal cord ischemia model of infrarenal aortic occlusion for 17 mins was employed. Rabbits were randomly assigned to three groups. The rabbits in control group (n = 3) did not undergo ischemic insult. The rabbits in group A (n = 5) and B (n = 5) underwent ischemic insult for 17 mins and then breathed oxygen (6 L/min) via facial mask or room air, respectively. We observed neurologic function for 2 days. The sections of the spinal cords were stained with hematoxylin and eosin, and the number of spinal motor neurons in ventral region was counted by light microscopy. RESULTS: All rabbits in control group did not have neurologic dysfunction whereas all rabbits in group A and B had neurologic dysfunction at same degree. Spinal motor neurons in ventral gray matter in group A and B decreased significantly compared with those in control group (P < 0.05). But, difference in number between group A and B was not significant. CONCLUSIONS: The result indicated that the level of arterial oxygen tension within the clinical range had little effect on early phase of ischemia/reperfusion injury.