TWIK-Related Spinal Cord K+ Channel Expression Is Increased in the Spinal Dorsal Horn after Spinal Nerve Ligation

PURPOSE: The TWIK-related spinal cord K+ channel (TRESK) has recently been discovered and plays an important role in nociceptor excitability in the pain pathway. Because there have been no reports on the TRESK expression or its function in the dorsal horn of the spinal cord in neuropathic pain, we analyzed TRESK expression in the spinal dorsal horn in a spinal nerve ligation (SNL) model. MATERIALS AND METHODS: We established a SNL mouse model by using the L5-6 spinal nerves ligation. We used real-time polymerase chain reaction and immunohistochemistry to investigate TRESK expression in the dorsal horn and L5 dorsal rot ganglion (DRG). RESULTS: The SNL group showed significantly higher expression of TRESK in the ipsilateral dorsal horn under pain, but low expression in L5 DRG. Double immunofluorescence staining revealed that immunoreactivity of TRESK was mostly restricted in neuronal cells, and that synapse markers GAD67 and VGlut2 appeared to be associated with TRESK expression. We were unable to find a significant association between TRESK and calcineurin by double immunofluorescence. CONCLUSION: TRESK in spinal cord neurons may contribute to the development of neuropathic pain following injury.

Transient Splenial Lesions in the Splenium of Corpus Callosum in Seven Patients: MR Findings and Clinical Correlations

PURPOSE: The purpose of this study is to correlate the imaging findings and the clinical findings in patients with transient splenial lesions (TSL). MATERIALS AND METHODS: Total of 7 patients (M: F = 4: 3; age range 11 - 38 years, mean age 25.5 years) were studied between November 2006 and April 2011. The MRI findings and clinical findings in all patients were retrospectively reviewed. The location, MR signal intensity, restricted diffusion, enhancement pattern and reversibility from the follow up images were reviewed. Clinical features were reviewed with respect to the presented symptoms, signs, treatment and outcome. RESULTS: The lesions were located in the splenium of corpus callosum in all patients. All lesions showed high signal intensity on diffusion weighted imaging (DWI), and six patients showed restricted diffusion on the apparent diffusion coefficient (ADC) map. ADC map was not available in one patient. All lesions (n = 7) showed high signal intensity on the T2 weighted image (T2WI). Five of the patients (71.4%) with follow up images (range 7 - 34 days) showed complete resolution of focal high signal intensity on DWI, with recovery of ADC values as well as T2WI. After contrast media administration, none of the lesions showed any enhancements. All lesions with various etiologies including TB medication were developed in younger age patients and showed reversibility after the acceptable period of minimum 7 days with conservative treatment. CONCLUSION: All TSL showed nonspecific imaging findings, including restricted diffusion on DWI and ADC map on the initial images. However, reversibility of the lesions and the young age preference can be a characteristic finding of TSL with acceptable period of minimum 7 days. In addition, to keep it in mind that various etiologies including TB medication may cause TSL, is important for radiologists as well as clinicians.

Diffusion MR Imaging of Postoperative Bilateral Acute Ischemic Optic Neuropathy

A 57-year-old woman experienced bilateral acute ischemic optic neuropathy after spine surgery. Routine MR imaging sequence, T2-weighted image, showed subtle high signal intensity on bilateral optic nerves. A contrast-enhanced T1 weighted image showed enhancement along the bilateral optic nerve sheath. Moreover, diffusion-weighted image (DWI) and an apparent diffusion coefficient map showed markedly restricted diffusion on bilateral optic nerves. Although MR findings of T2-weighted and contrast enhanced T1-weighted images may be nonspecific, the DWI finding of cytotoxic edema of bilateral optic nerves will be helpful for the diagnosis of acute ischemic optic neuropathy after spine surgery.

The effect of multimodal approach with combination of antiemetics and total intravenous anesthesia on postoperative nausea and vomiting in very high-risk patients

BACKGROUND: Postoperative nausea and vomiting (PONV) is a long standing problem in both surgical patients and anesthesiologists, and the treatment of this problem is very important.The purpose of this study was to evaluate the effect of multimodal approach with combination of antiemetics and total intravenous anesthesia (TIVA) on PONV in very high risk patients identified by the Korean predictive model. METHODS: Between March 2008 and February 2009, we evaluated 96 patients who were considered to be at very high risk of PONV according to the Korean predictive model.Among the patients, those who received antiemetic combination of dexamethasone and ondansetron were allocated to treatment group (T) and, those who underwent operation without antiemetics were placed in control group (C).All patients were anesthetized using propofol and remifentanil.We evaluated the incidences of PONV in two groups during the first 24 hours after surgery. RESULTS: The overall incidence of PONV was 14 (29.17%) in C group and 4 (8.33%) in T group, respectively (P = 0.027). CONCLUSIONS: The overall incidence of PONV in T group was significantly lower than that of C group.This study shows that multimodal approach with combination of antiemetics and TIVA was effective in preventing PONV in patients with very high risk.

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.

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.

Risk Factors of Pressure Sore in Patients undergoing General Anesthesia / 대한마취과학회지

BACKGROUND: The occurrences of pressure sores have an extensive impact on patients and the medical team. Pressure sores decrease quality of life and productivity, as well as increase the overall cost of treatment. The purpose of this study was to identify the risk factors associated with pressure ulcers among surgical patients. METHODS: Data were collected from 588 patients who underwent general anesthesia. The data included age, gender, weight, height, body mass index, ASA status, surgical position, anesthesia time, pre-and postoperative hemoglobin concentration, serum albumin, NYHA class, co-morbidity, steroid use, body temperature, use of warming water mattress and preoperative hospital admission day. The patient's skin was inspected closely before surgery and again within 24 hours after surgery and the locations and severity of skin breakdowns were assessed. RESULTS: Twenty-five patients (4.3%) developed pressure sores during surgery. The hemoglobin concentration change between the preoperative and postoperative period (> or =2 g/dl), position during surgery, length of stay before operation (> or =4 days), anesthesia time (> or =5 hours) and decrease in body temperature (> or =0.5degrees C) were significantly related to the development of pressure sores (P < 0.05). CONCLUSIONS: Five risk factors for pressure ulcers were confirmed. The anesthesiologist can decrease hemoglobin and modify body temperature; therefore, attention should be given to these risk factors during the operation.

The Examination of Internal Jugular Vein and Carotid Artery in Trendelenburg Position with Head Rotation; A Prospective, Randomized Study / 대한마취과학회지

BACKGROUND: This study evaluated the position and relationship between the right internal jugular vein (IJV) and the surrounding external landmarks using ultrasonography. METHODS: Fifty-four patients undergoing central vein access for cardiac surgery were enrolled in this study. The IJV, carotid artery (CA) and sternocleidomastoid muscle (SCM) at the cricoid cartilage level in 15o trendelenburg position with 30o head rotation were examined using a two dimensional ultrasound transducer of a TEE machine. Images of the vessels and the demographic data of the patients were recorded and analysed. RESULTS: At the level of the cricoid cartilage, the position of the right IJV was medial to middle of the clavicular head of the SCM muscle in 26 cases (48.2%), lateral in 11 cases (20.4%) and just above the middle of clavicular head of the SCM muscle in 17 cases (31.5%). In 43 patients (79.6%), the IJV overlapped the CA anterolaterlly < 5 mm, and these cases were regarded as normal. Ten patients (18.5%) had a medially positioned IJV overlapping the CA more than 5 mm and the IJV was positioned lateral to CA in 1 (2%) patient. The mean ratio of the overlapped diameter and the diameter of the CA was 33.6% and the overlapping ratios were greater than 50% in 10 patients (31.4%). The mean skin-to-vein distance at the angle of 30degrees was 1.82 cm. CONCLUSIONS: In 18.5% of patients positioned in the 15o Trendelenburg position, with their head turned to the left 30degrees, the IJV overlapped the CA medially more than 5 mm, which increased the risk of a carotid puncture using the blind technique.

The Effect of H1-Receptor Antagonist on Hemodynamic Change during Anesthesia / 대한마취과학회지

baseline for safe use of a drug. RESULTS: SVR and PVR failed to show statistically significant changes. Heart rates were increased only at 2 minute after administration of chlorpheniramine maleate. Blood pressures were increased but returned to basal level within 4 minutes. Cardiac output showed statistically significant increase until 8 minutes. However, the changes of hemodynamic values were maintained within 20% of basal levels. CONCLUSIONS: Chlorpheniramine maleate is observed to cause statistically significant hemodynamic change after intravenous administration during anesthesia. But the changes were within 20% of basal levels, and we can safely use chlorpheniramine maleate 8 mg IV in the view of hemodynamic changes.

Effects of Insulin on the Resuscitation by Epinephrine for Bupivacaine-Induced Cardiovascular Depression in Dogs / 대한마취과학회지

BACKGROUND: Because of the difficulty of resuscitation caused by bupivacaine-induced cardiotoxicity, the choice of resuscitation medication is still unclear. We investigated whether insulin can improve outcomes of resuscitation by epinephrine from bupivacaine-induced cardiovascular collapse. METHODS: Twenty-four mongrel dogs were randomly allocated to one of the two groups: an EPI group (n = 12), and an EPI + RI group (n = 12). Sixty minutes after induction of general anesthesia, baseline measurement of hemodynamic parameters and arterial blood gas tension was performed. Bupivacaine infusion was started at a rate of 0.5 mg/kg/min and kept until mean arterial blood pressure fell below 40 mmHg and heart rate 40 beats per minute. At this point, bupivacaine infusion was stopped and resuscitation was started, with epinephrine in EPI group and epinephrine combined with regular insulin in EPI + RI group. RESULTS: Bupivacaine infusion caused significant decreases in mean arterial blood pressure, heart rate, cardiac output, and systemic vascular resistance and increases in mean pulmonary blood pressure, pulmonary capillary wedge pressure, pulmonary vascular resistance, and central venous pressure. The recovery rate of EPI + RI group (8/12) was higher than that of EPI group (2/12). CONCLUSIONS: Combined administration of epinephrine and regular insulin improves outcomes of resuscitation of bupivacaine-induced cardiovascular collapse. Therefore, we believe that prompt administration of insulin should be strongly considered in case of bupivacaine-induced cardiotoxicity.

Caudal Epidural Injection with a Guidewire-Reinforced Epidural Catheter in Patients with Herniated Nucleosus Pulpose / 대한통증학회지

BACKGROUND: The epidural injection technique is a commonly used intervention in the management of chronic spinal pain, which has the advantage of delivering various drugs, such as local anesthetics or steroids, in higher concentrations to the inflamed nerve root. A guidewire-reinforced epidural catheter was introduced through a Tuohy needle during the caudal epidural procedure, with a catheter threaded into the affected nerve roots and the spread-pattern of contrast agents observed under fluoroscopy. METHODS: Sixty-seven patients with low back pain, who showed evidence of a herniated nucleus pulposus 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 and threaded either to the right or left side toward the target nerve roots. After confirming the catheter tip position at the affected nerve root, 2 ml increments of contrast agents (up to 6 ml) were injected, and their corresponding AP fluoroscopic views were obtained. Three radiologists reviewed all the radiographic findings and measured the proportion of the area of contrast spread at the side of target nerve roots. RESULTS: Greater proportion of the area of contrast spread was observed at the side of the target nerve roots (P < 0.0001). At each level of contrast injection (2- , 4- and 6 ml), more than 70% of the spread of contrast dye was observed at the side of the target nerve roots in 85%, 70%, and 55% of cases, respectively. CONCLUSIONS: The combination of a caudal epidural injection and use of a guidewire-reinforced epidural catheter significantly enhances the target specificity, as revealed by the selective spread of contrast dye at the side of target nerves.