• The Korean Journal of Pain
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• v.18 no.1
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• pp.19-22
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• 2005

Background: Most terminal cancer patients suffered from intractable pain. For the treatment of these patients, opioids, via various routes, are usually administered. Continuous epidural opioid, especially morphine, administration is a good method for the management of intractable cancer pain. Methods: We retrospectively analyzed 347 terminal cancer patients, who had been treated with continuous epidural morphine infusion, between 1999 and 2004. For the epidural infusion, an epidural catheter was inserted, tunneled subcutaneously and exited from the anterior chest or abdomen. Multiday $Infursor^{(R)}$ (Baxter, 0.5 ml/h) was used for the continuous infusion. Results: Of the 347 patients studied, there were 211 males and 136 females. The mean treatment time was 54.7 days, ranging from 5 to 481 days. The mean starting and termination doses of morphine were 32.4 (for 5 days) and 100.0 mg, respectively. The doubling time of the morphine dose was 26.3 days, corresponded to a 3.8 percent increase per day. Incidental catheter removal was the most common side effect, which occurred 130 times in 61 cases. Conclusions: The procedure of epidural catheterization, with subcutaneous tunneling, was simple and inexpensive. Despite the disadvantages, such as incidental catheter removal, it is a useful method for the control of terminal cancer pain.

• The Korean Journal of Pain
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• v.18 no.1
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• pp.10-14
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• 2005

Background: Previous studies have suggested synergistic analgesic drug interactions between NSAIDs and opioids in neuropathic and inflammatory pain models. The aim of this study was to investigate the analgesic drug interaction between intraperitoneal (IP) ketorolac and morphine in radiant thermal stimulation rat. Methods: Initially, we assessed the withdrawal latency time of the hindpaw to radiant thermal stimulation every 15 min for 1 hour and every 30 min for next 1 hour after IP normal saline 5 ml (control group). The latency time was changed into percent maximal possible effect (%MPE). Next, IP dose response curves were established for the %MPE of morphine (0.3, 1, 3, 10 mg/kg) and ketorolac (3, 10, 30 mg/kg) to obtain the $ED_{50}$ for each agent. And we confirmed that the IP morphine effect was induced by opioid receptor through IP morphine followed by IP naloxone. At last, we injected three doses of IP ketorolac (3, 10, 30 mg/kg) mixed with one dose of morphine (2 mg/kg) for fixed dose analysis. Results: IP morphine delayed the paw withdrawal latency time dose dependently, but not ketorolac. $ED_{50}$ of IP morphine was 2.1 mg/kg. And the IP morphine effect was reversed to control level by IP naloxone. IP ketorolac + morphine combination showed no further additional effects on paw withdrawal latency time over morphine only group. Conclusions: IP ketorolac did not produce antinociceptive effect during radiant thermal stimulation. There was neither additional nor synergistic analgesic interaction between IP morphine and ketorolac in thermal stimulation rat.

• The Korean Journal of Physiology and Pharmacology
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• v.20 no.5
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• pp.525-531
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• 2016

The analgesic mechanism of opioids is known to decrease the excitability of substantia gelatinosa (SG) neurons receiving the synaptic inputs from primary nociceptive afferent fiber by increasing inwardly rectifying $K^+$ current. In this study, we examined whether a ${\mu}$-opioid agonist, [D-Ala2,N-Me-Phe4, Gly5-ol]-enkephalin (DAMGO), affects the two-pore domain $K^+$ channel (K2P) current in rat SG neurons using a slice whole-cell patch clamp technique. Also we confirmed which subtypes of K2P channels were associated with DAMGO-induced currents, measuring the expression of K2P channel in whole spinal cord and SG region. DAMGO caused a robust hyperpolarization and outward current in the SG neurons, which developed almost instantaneously and did not show any time-dependent inactivation. Half of the SG neurons exhibited a linear I~V relationship of the DAMGO-induced current, whereas rest of the neurons displayed inward rectification. In SG neurons with a linear I~V relationship of DAMGO-induced current, the reversal potential was close to the $K^+$ equilibrium potentials. The mRNA expression of TWIK (tandem of pore domains in a weak inwardly rectifying $K^+$ channel) related acid-sensitive $K^+$ channel (TASK) 1 and 3 was found in the SG region and a low pH (6.4) significantly blocked the DAMGO-induced $K^+$ current. Taken together, the DAMGO-induced hyperpolarization at resting membrane potential and subsequent decrease in excitability of SG neurons can be carried by the two-pore domain $K^+$ channel (TASK1 and 3) in addition to inwardly rectifying $K^+$ channel.

• Korean Journal of Acupuncture
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• v.26 no.2
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• pp.91-108
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• 2009

Objectives: Single colorectal instillation of trinitrobenzenesulphonic acid (TNBS) causes a dose-dependent increase of visceral motor response (VMR) and severity of inflammation. In this study we compared the effects of electroacupuncture in the different acupoints in the acute colitis induced by TNBS intracolonic injection in rats. Methods: In Male Sprague-Dawley rats, weighing $250{\sim}400g$, a single colorectal administration of TNBS 5mg/kg and 50% ethanol under isoflurane anaesthesia after an overnight fast. Electrodes for electromyography (EMG) recording were stitched into the external oblique musculature under general anesthesia. Acupoints of LI4, ST25, or ST36 were stimulated by electroacupuncture, respectively. The balloon was inserted intra-anally and visceral motor response (VMR) to colorectal distensioin (CRD) was quantified with an EMG recording system. Results: At an observation of the visceral hyperalgesia in the day-time series, the visceromotor response increased significantly 3 days after TNBS intra-rectalcolonic injection in rats. Electroacupuncture on either ST25 or ST36 suppressed the visceromotor response to colorectal distension, but not LI4, at 3 days after TNBS injection. Pretreatment of naltrexone (10 mg/kg, i.p.), opioids antagonist, inhibited the VMR suppress of 10Hz EA to ST36 but not phentolamine (5 mg/kg, i.p.). Pretreatment of either naltrexone or phentolamine inhibited effects of 10Hz EA to ST25. Conclusions: Data show that EA at either ST25 or ST36 potently inhibits hypersensitivity of colorectum after TNBS induced colitis and is differently mediated through the endogenous opioid system and adrenergic system.

• 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.

• Korean Journal of Acupuncture
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• v.38 no.3
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• pp.175-181
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• 2021

A 57-year-old female diagnosed with L5-S1 lumbar intervertebral disc herniation, suffering from severe pain despite taking tapentadol received combined Korean medicine treatment, including acupotomy, acupuncture, pharmacopuncture, and herbal therapies for 53 days. To assess pain, Numeric Rating Scale (NRS) and lumbar range of motion (ROM) were checked daily from the day of admission. Moreover, the Oswestry Disability Index (ODI) and European Quality of Life-5 Dimensions (EQ-5D) were used to evaluate function and quality of life. After combined Korean medicine treatment, reabsorptioin of intervertebral disc was confirmed by radiological examination; pain reduced from NRS 5~7 to NRS 1~2; lumbar ROM in extention increased from 20° to 30°; and function and quality of life improved. The results suggest the possibility that a combined Korean medical treatment, including acupotomy, can be used as an alternative to opioids for pain management of lumbar vertebral disc herniation.

• The Journal of Internal Korean Medicine
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• v.42 no.3
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• pp.279-292
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• 2021

Objectives: Analyze papers on the effect of acupuncture on cancer pain from a macroscopic point of view, suggesting global trends and future research directions to promote acupuncture treatment for cancer pain. Methods: By filtering the papers searched for (acupuncture) AND (cancer pain) in the Web of Science database, 351 papers were selected and analyzed by year, field, journal, institution, author, and keyword. Results: Most papers were published in 2020, and research was active in the field of complementary and alternative medicine. Research on the effects of acupuncture in cancer pain has been active in cancer centers and university hospitals, research has been active in various countries. The most frequently mentioned keywords in the titles and abstracts were acupuncture, pain, and quality of life. The latest top 5 keywords were inhibitor-induced arthralgia, acupuncture therapy, risk factors, opioids, and recovery. Conclusions: Acupuncture treatment has the potential to reduce pain and improve quality of life in cancer patients, and it should be actively studied in the future.

• The Korean Journal of Pain
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• v.34 no.2
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• pp.193-200
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• 2021

Background: Local anesthetic infiltration at the site of a surgical wound is commonly used to control postoperative pain. In this study, we examined the effectiveness of continuous local infiltration at an abdominal surgical site in patients undergoing anterior lumbar interbody fusion (ALIF) surgery. Methods: Sixty-one patients who underwent ALIF surgery were enrolled. For thirtyone of them, a continuous local anesthetics infiltration system was used at the abdominal site. We collected data regarding the patients' sleep quality; satisfaction with pain control after surgery; abilities to perform physical tasks and the additional application of opioids in the postoperative 48 hours. Results: The On-Q system group showed reduced visual analogue scale scores for pain at the surgical site during rest and movement at 0, 12, 24, and 48 hours; and more was satisfied with pain control management at the first postoperative day (7.0 ± 1.2 vs. 6.0 ± 1.4; P = 0.003) and week (8.1 ± 1.6 vs. 7.0 ± 1.8; P = 0.010) than the control group. The number of additional patient-controlled analgesia (PCA) bolus and pethidine injections was lower in the On-Q group (PCA: 3.67 ± 1.35 vs. 4.60 ± 1.88; P = 0.049 and pethidine: 2.09 ± 1.07 vs. 2.73 ± 1.38; P = 0.032). Patients who used the On-Q system performed more diverse activity and achieved earlier ambulation than those in the control group. Conclusions: Continuous wound infiltration with ropivacaine using an On-Q system may be effective for controlling postoperative pain after ALIF surgery.

• Journal of Dental Anesthesia and Pain Medicine
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• v.22 no.2
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• pp.129-143
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• 2022

Background: Patient-controlled analgesia (PCA) has been widely used as an effective medical treatment for pain and for postoperative analgesia. However, improper dose errors in intravenous (IV) administration of narcotic analgesics from a PCA infusion pump can cause patient harm. Furthermore, opioid overdose is considered one of the highest risk factors for patients receiving pain medications. Therefore, accurate delivery of opioid analgesics is a critical function of PCA infusion pumps. Methods: We designed a microbalance method that consisted of a closed acrylic chamber containing a layer and an oil layer with an electronic balance. A commercially available infusion analyzer (IDA-5, Fluke Co., Everett, WA, USA) was used to measure the accuracy of the infusion flow rate from a commercially available smart PCA infusion pump (PS-1000, UNIMEDICS, Co., Ltd., Seoul, Korea) and compared with the results of the microbalance method. We evaluated the uncertainty of the flow rate measurement using the ISO guide (GUM:1995 part3). The battery life, delay time of the occlusion alarm, and bolus function of the PCA pump were also tested. Results: The microbalance method was good in the short-term 2 h measurement, and IDA-5 was good in the long-term 24 h measurement. The two measurement systems can complement each other in the case of the measurement time. Regarding battery performance, PS-1000 lasted approximately 5 days in a 1 ml/hr flow rate condition without recharging the battery. The occlusion pressure alarm delays of PS-1000 satisfied the conventional alarm threshold of occlusion pressure (300-800 mmHg). Average accuracy bolus volume was measured as 63%, 95%, and 98.5% with 0.1 ml, 1 ml, and 2 ml bolus volume presets, respectively. A 1 ml/hr flow rate measurement was evaluated as 2.08% of expanded uncertainty, with a 95% confidence level. Conclusion: PS-1000 showed a flow accuracy to be within the infusion pump standard, which is ± 5% of flow accuracy. Occlusion alarm of PS-1000 was quickly transmitted, resulting in better safety for patients receiving IV infusion of opioids. PS-1000 is sufficient for a portable smart PCA infusion pump.

• Clinical Pain
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• v.20 no.2
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• pp.141-144
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• 2021

There are some cases of myofascial pain syndrome (MPS) with chronic upper back pain that does not respond to dry needling or trigger point injection, well-known treatments for MPS. A 67-year-old female developed a stabbing upper back pain with trigger point at left T7~8 levels 10 years ago. She complained of the pain with Numeral Rating Scale (NRS) 8 points. Myofascial release technique and trigger point injection had no effect. Under ultrasound guidance 20 ml of 1% lidocaine was injected into thoracic paravertebral space. Immediately, the pain was reduced to NRS 4 points. One week later, the second block was performed in the same way as the first, and the pain was reduced to NRS 2 points. The stabbing pain disappeared, and oral opioids were discontinued. Ultrasound guided thoracic paravertebral space block is an effective and safe treatment for refractory MPS with chronic upper back pain.