• Applied Chemistry for Engineering
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• v.9 no.7
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• pp.1090-1097
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• 1998

Lidocaine compounds have widely been used as local anesthetics. Regarding the molecular mechanism for anesthesia by lidocaine, it is proposed that lidocaine molecules penetrate to the hydrophobic region of cell membrane and expand the membrane volume, producing a change in protein conformation that blocks sodium permeability or lidocaine molecules directly adsorb into lidocaine receptor in the protein channel without expanding the cell membrane. But these proposals have never been proven experimentally. In this study, the expansion of cell membrane by lidocaine compounds was investigated by employing lipid monolayer at the air/water interface as the mimetic system of cell membrane. It was found that oil-soluble lidocaine contracted the area/molecule of lipid in the monolayer of phosphatidyl choline, sphingomyelin, DS-PL95E and lipoid, but expanded the monolayer of phosphatidyl ethanolamine only in a certain range of mixing ratios. On the contrary, water-soluble lidocaine-HCl salt expanded the monolayers of all lipids used in this study.

• The Korean Journal of Pain
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• v.31 no.4
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• pp.261-267
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• 2018

Background: To compare the effects of adding two different doses of dexamethasone on the duration and quality of the fascia iliaca block in patients undergoing proximal femoral fracture surgery. Methods: A total of 60 patients (age 18-70 years) undergoing proximal femoral nailing surgery under spinal anesthesia were given fascia iliaca block after random assignment to one of the two groups: Group H received an injection of levobupivacaine (0.5%) 28 ml with 2 ml (8 mg) dexamethasone, and Group L received an injection of levobupivacaine (0.5%) 28 ml with dexamethasone 1 ml (4 mg) with 1 ml normal saline. Assessment of the duration of analgesia and the total tramadol requirement over 48 hours were noted after a successful block. Results: The duration of analgesia was found to be significantly longer in Group H ($17.02{\pm}0.45h$) than in the Group L patients ($14.29{\pm}0.45h$) with a p-value of 0.000. Postoperative analgesic requirement (amount of tramadol in mg) was significantly higher in Group L (Q2: 200.0; IQR: 100.0, 200.0) as compared to Group H (Q2: 100.0; IQR: 100.0, 200.0) with a p-value of 0.034. No patient showed any sign of neurotoxicity. Conclusions: Dexamethasone, in a dose of 8 mg, is superior to 4 mg when used as an adjuvant with levobupivacaine in the FIB. Though both prolonged analgesia and were effective in reducing oral/intravenous analgesics, 8 mg dexamethasone can be recommended as a more efficacious adjuvant to local anesthetics in the FIB.

• The Korean Journal of Pain
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• v.6 no.2
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• pp.220-223
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• 1993

Administration of local anesthetics or morphine through epidural space has the effect of curbing postoperative increases in endocrine hormone. Other benefits include improving metabolic reaction and eliminating postoperative pain. However, repeated administration of local anesthetics through epidural space causes tachyphylaxis, and the unstable blockade of sensory nerve resulting in insufficient analgesia. Morphine has excellent postoperative analgesic effect, but complications including: itching, nausea, vomiting, urinary retention and respiratory depression may be associated with its administration. Sixty patients that fall into the category of ASA class I and II were randomly selected for the purpose of the experiment. Thirty patients were give 4 mg of morphine and the rest, 4 mg of morphine plus 80 ml of 0.25% bupivacaine administered through epidural space with the Baxter infuser. Analgesic effect was satisfactory in both groups. On the day of operation, the effect was stronger in group I (P<0.05) and on postoperative second day, group II showed better analgesic effect (P < 0.05). Group II had more patients who complained of itching (P < 0.05). Other complications were statistically insignificant. The findings indicate that administration of morphine through epidural space for postoperative pain management is an effective procedure. Baxter infuser was found to be very instrumental in pain control while reducing the chance of complications.

• The Korean Journal of Pain
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• v.20 no.2
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• pp.240-245
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• 2007

It is important to treat cancer-related pain in cancer patients to ensure the life quality of the patient, as well as to improve their life span. It has been estimated that at least 5% of cancer patients have pain refractory to medical treatment. Therefore, the need for epidural or intrathecal analgesia with opioids and local anesthetics is indicated if systemic treatment has failed. Intrathecal catheter placement and implantation of the injection port for administration of opioids and local anesthetics may improve pain relief in patients who are unresponsive to epidural routes. Although intrathecal implantation has several complications, similar infection rates have been reported between intrathecal and epidural administration. In addition, intrathecal administration showed better outcomes, including improved pain control, lowered daily doses, and an improvement in the level of drowsiness experienced when compared to epidural administration. We report here a case in which a terminal cancer patient was treated using an intrathecal catheter and subcutaneous port. The patient had cancer-related pain that could not be controlled by epidural opioid administration. Based on the results presented here, we suggest that intrathecal implantation is a feasible long term pain management method for intractable cancer pain patients.

• The Korean Journal of Pain
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• v.32 no.2
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• pp.105-112
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• 2019

Background: Severe pain always develops after thoracotomy; intrapleural regional analgesia is used as a simple, safe technique to control it. This study was performed to evaluate whether a small dose of naloxone with local anesthetics prolongs sensory blockade. Methods: A prospective, randomized double-blinded controlled study was conducted on 60 patients of American Society of Anesthesiologists statuses I and II, aged 18 to 60 years, scheduled for unilateral thoracotomy surgery. After surgery, patients were randomly divided into two groups: through the intrapleural catheter, group B received 30 ml of 0.5% bupivacaine, while group N received 30 ml of 0.5% bupivacaine with 100 ng of naloxone. Postoperative pain was assessed using the visual analog pain scale (VAS). Time for the first request for rescue analgesia, total amount consumed, and incidence of postoperative complications were also recorded. Results: The VAS score significantly decreased in group N, at 6 h and 8 h after operation (P < 0.001 for both). At 12 h after injection, the VAS score increased significantly in group N (P < 0.001). The time for the first request of rescue analgesia was significantly longer in group N compared to group B (P < 0.001). The total amount of morphine consumed was significantly lower in group N than in the bupivacaine group (P < 0.001). Conclusions: Addition of a small dose of naloxone to bupivacaine in intrapleural regional analgesia significantly prolonged pain relief after thoracotomy and delayed the first request for rescue analgesia, without significant adverse effects.

• The Korean Journal of Pain
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• v.32 no.1
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• pp.30-38
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• 2019

Background: The adductor canal block (ACB) is an effective intervention for postoperative analgesia following total knee arthroplasty (TKA). However, the ideal ACB regimen has not yet been established. We compared the analgesic effects between a continuous ACB group and fentanyl-based intravenous patient-controlled analgesia (IV-PCA) with a single-shot ACB group. Methods: Patients who underwent TKA were randomly allocated to either a continuous ACB group (Group CACB) or IV-PCA with a single-shot ACB group (Group IVACB). Before the surgery, ultrasound guided ACB with 0.5% ropivacaine 20 cc was provided to all patients. Before skin incision, the infusion system (0.2% ropivacaine through an adductor canal catheter in group CACB vs. intravenous fentanyl in group IVACB) was connected. The postoperative pain severity; the side effects of local anesthetics and opioids; administration of rescue analgesics and anti-emetics; and sensorimotor deficits were measured. Results: Postoperative pain severity was significantly higher in the IVACB group at 30 min, 4 h, 24 h, and 48 h after surgery. The averages and standard deviations (SD) of the NRS score of postoperative pain were $0.14{\pm}0.37$, $4.57{\pm}2.37$, $6.00{\pm}1.63$, and $4.28{\pm}1.49$, respectively in the IVACB group. Rescue analgesic requirements and quadriceps muscle strength were not statistically different between the groups throughout the postoperative period. Moreover, rescue antiemetic requirements were higher in group IVACB than group CACB. Conclusions: In this study, the continuous ACB provided superior analgesia and fewer side effects without any significant motor deficit than the IV-PCA with a single-shot ACB.

• Journal of Dental Anesthesia and Pain Medicine
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• v.22 no.1
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• pp.11-18
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• 2022

Background: The vasoconstrictive effect of epinephrine in local anesthetics affects the heart, which leads to hesitation among dentists in injecting local anesthetics into patients with cardiovascular disease. Due to its vasoconstrictive effects, the present study investigated the effects of vasopressin administration on cardiac function in rats. Methods: Experiment 1 aimed to determine the vasopressin concentration that could affect cardiac function. An arterial catheter was inserted into the male Wistar rats. Next, 0.03, 0.3, and 3.0 U/mL arginine vasopressin (AVP) (0.03V, 0.3V, and 3.0V) was injected into the tongue, and the blood pressure was measured. The control group received normal saline only. In Experiment 2, following anesthesia infiltration, a pressure-volume catheter was placed in the left ventricle. Baseline values of end-systolic elastance, end-diastolic volume, end-systolic pressure, stroke work, stroke volume, and end-systolic elastance were recorded. Next, normal saline and 3.0V AVP were injected into the tongue to measure their effect on hemodynamic and cardiac function. Results: After 3.0V administration, systolic blood pressures at 10 and 15 min were higher than those of the control group; they increased at 10 min compared with those at baseline. The diastolic blood pressures at 5-15 min were higher than those of the control group; they increased at 5 and 10 min compared with those at baseline. The preload decreased at 5 and 10 min compared to that at baseline. However, the afterload increased from 5 to 15 min compared with that of the control group; it increased at 10 min compared with that at baseline. Stroke volume decreased at 10 and 15 min compared with that of the control group; it decreased from 5 to 15 min compared with that at baseline. Stroke work decreased from 5 to 15 min compared with that of the control group; it decreased from 5 to 15 min compared with that at baseline. Conclusion: Our results showed that 3.0 U/mL concentration of vasopressin resulted in increased blood pressure, decreased stroke volume and stoke work, decreased preload and increased afterload, without any effect on myocardial contractility.

• The Korean Journal of Pain
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• v.1 no.1
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• pp.9-15
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• 1988

Postherpetic neuralgia, the most feared complication of acute herpes zoster, may agonize the pain clinician because the appropriate management of intractable pain can fail inspite of various and prolonged therapeutic techniques. Of all patients with herpes zoster, approximately 5~10% will develop postherpetic neuralgia. Postherpetic neuralgia is very rare in young patient but very common in patients over 60. In other words, the older, the higher incidence. In our pain clinics, 13 postherpetic neuralgic patients were treated with sympathetic blocks, local infiltration with local anesthetics and steroids, TENS, Laser and various drugs including antiderpressant. The results of management of pain in 13 patents were as follows. 1. Excellent pain control :4(30.8%) 2. Good pain control :3(23.0%) 3. Fair pain control :2(15.4%) 4. No effect :4(30.8%).

• The Korean Journal of Pain
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• v.2 no.2
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• pp.167-173
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• 1989

Inadequate pain relief after upper abdominal surgery increases the incidence of pulmonary complications due to the difficulty in coughing and deep breathing. Kvalheim and Reiestad (1984) introduced intrapleural administration of local anesthetic solutions to produce analgesia following cholecystectomy performed through a subcostal incision, unilateral breast surgery and renal surgery. We studied continuous intrapleural administration of bupivacaine and epinephrine, and its effect in controlling pain after cholecystectomy. In 9 patients, an intermittent dosage technique was used. An intrapleural catheter was inserted and 20 ml of 0.5% bupivacaine and 1:100,000 epinephrine was administered. Results were as following: 1) Mean analgesic duration from the initial intrapleural injection to secondary administration of supplementary bupivacaine was 13.5 hours. 2) No specific changes were noted on vital signs and arterial blood gases. 3) Effective analgesia, produced by intrapleural bupivacaine resulted in significant improvement in tidal volume as measured by spirometry. 4) No signs of systemic toxicity and complications were encountered. 5) Intrapleural administration of a local anesthetics after cholecystectomy provides a satisfactory duration of analgesia.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.42 no.3
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• pp.162-165
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• 2016

We report a case of a morbidly obese man with an aortic aneurysm, in whom dental surgery was performed before elective cardiac surgery. His aortic aneurysm required emergency surgery. However, because of his morbid obesity, elective cardiac surgery was planned. Considering the high risk of infective endocarditis, dental surgery was required. Our patient was at a high risk of aortic rupture caused by hypertension and breathing difficulty in the supine position. Dexmedetomidine (DEX) is an anti-anxiety, sedative, and analgesic medicine that can stabilize circulatory dynamics and minimize blood pressure fluctuations. We administered intravenous DEX for sedation of the patient in Fowler's position. In conclusion, our understanding of the risk factors of DEX enabled us to perform safe invasive oral treatment.