• The Korean Journal of Pain
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• v.27 no.3
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• pp.200-209
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• 2014

Background: Spinal opioid administration is an excellent option to separate the desirable analgesic effects of opioids from their expected dose-limiting side effects to improve postoperative analgesia. Therefore, physicians must better identify either specific opioids or adequate doses and routes of administration that result in a mainly spinal site of action rather than a cerebral analgesic one. Methods: The purpose of this topical review is to describe current available clinical evidence to determine what opioids reach high enough concentrations to produce spinally selective analgesia when given by epidural or intrathecal routes and also to make recommendations regarding their rational and safety use for the best management of postoperative pain. To this end, a search of Medline/Embase was conducted to identify all articles published up to December 2013 on this topic. Results: Recent advances in spinal opioid bioavailability, based on both animals and humans trials support the theory that spinal opioid bioavailability is inversely proportional to the drug lipid solubility, which is higher in hydrophilic opioids like morphine, diamorphine and hydromorphone than lipophilic ones like alfentanil, fentanyl and sufentanil. Conclusions: Results obtained from meta-analyses of RTCs is considered to be the 'highest' level and support their use. However, it's a fact that meta-analyses based on studies about treatment of postoperative pain should explore clinical surgery heterogeneity to improve patient's outcome. This observation forces physicians to use of a specific procedure surgical-based practical guideline. A vigilance protocol is also needed to achieve a good postoperative analgesia in terms of efficacy and security.

• The Korean Journal of Pain
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• v.19 no.2
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• pp.192-196
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• 2006

Background: Epidural opioids are commonly used for postoperative analgesia. However, the side effects of epidural opioids include respiratory depression, sedation, pruritus, nausea, vomiting and urinary retention. Meperidine, due to its intermediate lipid solubility and local anesthetic properties, permits postoperative analgesia. The aim of this study was to compare meperidine alone to meperidine coupled with bupivacaine, and to determine the effects of epidural meperidine without bupivacaine, when used for epidural analgesia following hepatectomy abdominal surgery. Methods: Patients received thoracic epidural analgesia with meperidine alone (3.5 mg/ml in saline) or with additional bupivacaine (0.15%) for 2 days after surgery. Postoperative pain was assessed using a visual analog scale (VAS) pain score 2 days after the operation, with the incidence and dose supplementation also evaluated. Postoperative side effects were assessed using a 3 grade system. Results: No significant difference was found between the two groups in terms of age and weight, or in the pain scores, side effects, incidence and dose supplementation. Conclusions: 3.5 mg/ml epidural meperidine at a dose of 2 ml/hr provides effective postoperative analgesia.

• The Korean Journal of Pain
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• v.9 no.1
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• pp.69-74
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• 1996

Background: Efficacy of spinal opioids for the treatment of intractable cancer pain has been reported by several authors. The epidural route seems to be a more reliable and effective method of pain control as compared to the intrathecal route which can lead to opioids by portal system. Methods: Medical records were reviewed of 18 patients who had been treated with epidural morphine via an implanted port-A-Cath from Mar. 1991 to Sep. 1994. Results: Patients were treated for a mean of 92 days. There were wide variation of dose requirements. The minimum daily dose ranged from 2 to 10mg, and maximum daily dose from 3 to 30 mg. Verbal rating scale were below moderate until 100th days after posrtal implantation. When 3 patients suffered from aggravated pain associated with vertebral metastasis. Five of 11 patients who were administered medication longer than 50 days reguired increased doses ranging from 3 mg to 25 mg which were higher as compared to initial doses. These patients also experienced pain due to vertebral metastasis. There were no report of epidural scarring, respiratory depression, epidural infections, meningitis, or catheter blockade. Conclusion: Continuous epidural morphine administration via Port-A-Cath is an effective method with minimal complication.

• 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.8 no.2
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• pp.386-389
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• 1995

Combined infusion of local anesthetics and opioids has been a common method for providing postoperative analgesia. Complications that can occur with this method include pruritus, nausea and vomiting, urinary retention, hypotension, and both early and late respiratory depression. Late respiratory depression is a rare but feared complication to epidural opioid therapy. We experienced a case of respiratory arrest during epidural infusion of bupivacaine and morphine.

• The Korean Journal of Pain
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• v.26 no.3
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• pp.265-269
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• 2013

Background: Transforaminal epidural steroid injections are known to reduce inflammation by inhibiting synthesis of various proinflammatory mediators and have been used increasingly. The anti-inflammatory properties of opioids are not as fully understood but apparently involve antagonism sensory neuron excitability and pro-inflammatory neuropeptide release. To date, no studies have addressed the efficacy of transforaminal epidural morphine in patients with radicular pain, and none have directly compared morphine with a tramadol for this indication. The aim of this study was to compare morphine and tramadol analgesia when administered via epidural injection to patients with lumbar radicular pain. Methods: A total of 59 patients were randomly allocated to 1 of 2 treatment groups and followed for 3 months after procedure. Each patient was subjected to C-arm guided transforaminal epidural injection (TFEI) of an affected nerve root. As assigned, patients received either morphine sulfate (2.5 mg/2.5 ml) or tramadol (25 mg/0.5 ml) in combination with 0.2% ropivacaine (1 ml). Using numeric rating scale was subsequently rates at 2 weeks and 3 months following injection for comparison with baseline. Results: Both groups had significantly lower mean pain scores at 2 weeks and at 3 months after treatment, but outcomes did not differ significantly between groups. Conclusions: TFEI of an opioid plus local anesthetic proved effective in treating radicular pain. Although morphine surpassed tramadol in pain relief scores, the difference was not statistically significant.

• The Korean Journal of Pain
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• v.1 no.1
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• pp.87-90
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• 1988

In recent years the use of epidural opiates has increased and although this method of pain relief has shown good results in clinical practice It is still subject to certain drawbacks, the most serious of which appears to be delayed respiratory depression. Since ketamine administered systemically is unlikely to produce respiratory depression it seemed worthwhile to investigate the possibility of exploiting the potent analgesic property to ketamine by its epidural administration. The analgesic effect of ketamine 4 mg, administered epidural space, was evaluated. The duration of pain relief varied from less than 3 hours in 20% to over 24 hours in 30% of the cases. In 62.5% of the cases pain relief exceeded 6 hours. There was no evidence of respiratory depression, and there no postoperative neurologic sequelae. The present results indicated the need for further studies to compare the efficacy and safety of epidural ketamine with the response to epidural opioids for the relief of postoperative pain.

• The Korean Journal of Pain
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• v.11 no.1
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• pp.47-53
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• 1998

Background: Epidural coadministration of opioids and local anesthetics has provided excellent analgesia during postoperative period. However, it is usually associated with the occurance of many side effects which were induced by epidural morphine. Low dose of intravenous naloxone has been known to reduce morphine-induced side effects without reversing analgesia, but the effect of epidural naloxone has not been defined in human study. Therefore we evaluated side effects and analgesia when naloxone was administered via epidural route. Methods: Eighty patients having epiduro-general anesthesia for hysterectomy were randomly assigned to one of four study groups. As a mean of postoperative pain control, all received 2 mg of epidural morphine bolusly at 1 hr before the end of surgery and continuous epidural infusion was started by Two-day Infusor containing morphine 4 mg in 0.125% bupivacaine 100 ml with either none of naloxone(Group 1, n=20), 2 ug/kg/day of naloxone(Group 2, n=20), 3 ug/kg/day of naloxone(Group 3, n=20) or 4 ug/kg/day of naloxone(Group 4, n=20). Study endpoints included visual analog scales(VAS) for pain, severity of nausea, itching, somnolence and respiratory depression. They were assessed at 2, 4, 8, 16, 32, and 48 hr postoperatively. Results: VAS for pain showed significant difference in Group 4 compared with Group 1 at all of the evaluation time. Itching score decreased significantly in Group 3 and 4 after 8 hr postoperatively and nausea score decreased significantly in Group 3 after 4 hr postoperatively. Alertness score decreased significantly in Group 3 and 4 especially in early postoperative period. Conclusion: This study suggests that epidural naloxone reduce morphine-induced side effects in dose-dependent fashion without reversal of the analgesic effect of epidural morphine.

• The Korean Journal of Pain
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• v.7 no.2
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• pp.282-286
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• 1994

The central antihypertensive agent clonidine is an ${\alpha}_2$-adrenergic agonist that possesses pain-relieving properties. It has been administered epidurally in the treatment of cancer pain and for postoperative analgesia. 1) Case 1, 62-year-old woman who suffered from neurogenic pain syndrome due to metastatic squamous cell carcinoma of spinal canal was treated. 2) Case 2, 51-year-old woman undergoing lower abdominal surgery, epidurally administered morphine did not produced postoperative analgesia. In these cases, continuous epidural administeration of clonidine (200ug/day) and 0.3% bupivacaine(12 ml/day) produce high quality pain relief. These results suggest that antinociceptive effect of epidural clonidine is assumed to result from activation of ${\alpha}_2$-adrenergic receptors in the dorsal horn of the spinal cord.

• The Korean Journal of Pain
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• v.12 no.1
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• pp.95-100
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• 1999

Background: About 75% of terminal cancer patients have severe pain. For the treatment of these patients, physicians usually use potent opioid analgesics. But many of the cancer patients were not controlled by IV or IM injection of opioids. In spite of the untreatable nature of the patient's illness, they should be hospitalized only for pain control. In that case, epidural opioid injection is one of the most effective methods in pain management. Methods: We retrospectively analyzed 126 terminal cancer patients who were treated with epidural morphine for pain management from 1993-97. In the routine procedure, an epidural catheter was inserted into the epidural space and tunnelled subcutaneously, exiting out from the anterior chest or abdomen. Morphine was used as the main analgesic and Multiday Infusor$^{(R)}$ (Baxter, 0.5 ml/h) as a continuous infusion system. Results: 1. Mean treatment time was 55 days (range; 3~373). 2. Mean daily epidural start mg dose of morphine was 8 mg (range; 2~20). 3. Mean daily dose at termination was 19 mg (range; 4~60) 4. 94 patients were controlled with continuous infusion but 32 patients needed additional bolus doses of morphine. 5. heter-associated subcutaneous infection occurred in 2 patients (1.6%). Conclusion: Terminal cancer pain management administered by a tunnelled epidural catheter is a simple, inexpensive method with a very small rate of infection.