Epidural Infusion Of Morphine Research Articles

Efficacy of epidural analgesia for intractable cancer pain: Asystematic review.

Epidural analgesia is a common technique for managing perioperative and obstetric pain. Patients with cancer who cannot tolerate opioids or not responding to conventional treatment may benefit from epidural analgesia. Therefore, this systematic review aimed to analyze the efficacy and safety of epidural analgesia in patients with intractable cancer pain. We searched PubMed, Embase, and the Cochrane Central Register of Controlled Trials to identify studies on patients with cancer who received epidural analgesia. We assessed the quality of all included studies using the risk-of-bias tool or Newcastle-Ottawa scale. The primary outcome was pain relief after epidural analgesia, and the secondary outcome was quality of life, analgesic consumption, and adverse events. The studies were grouped based on the medications used for epidural analgesia. A descriptive synthesis was performed following the Synthesis Without Meta-analysis reporting guideline. Our systematic review included nine randomized controlled trials (n = 340) and 15 observational studies (n = 926). Two randomized controlled trials suggested that epidural opioids were not superior to systemic opioids in relieving pain. Epidural opioids combined with local anesthetics or adjuvants, including calcitonin, clonidine, ketamine, neostigmine, methadone, and dexamethasone, offered better analgesic effects. No significant difference in pain relief between an intermittent bolus and a continuous infusion of epidural morphine was observed. Epidural opioids had more analgesic effects on nociceptive pain than neuropathic pain. The methods used to evaluate the quality of life and the corresponding results were heterogeneous among studies. Six observational studies demonstrated that some patients could have decreased opioid consumption after epidural analgesia. Adverse events, including complications and drug-related side effects, were reported in 23 studies. Five serious complications, such as epidural abscess and hematoma, required surgical management. The heterogeneity and methodological limitations of the studies hindered meta-analysis and evidence-level determination. Coadministration of epidural opioids, local anesthetics, and adjuvants may provide better pain relief for intractable cancer pain. However, we must assess the patients to ensure that the benefits outweigh the risks before epidural analgesia. Therefore, further high-quality studies are required.

Pneumocephalus Following an Accidental Dural Puncture, Treated Using Hyperbaric Oxygen Therapy. A Case Report.

IntroductionNeuraxial techniques, including epidural anaesthesia, are often used for perioperative pain control and are generally safe. However, both transient, mild and even severe, life-threatening neurologic complications can occur.Case presentationA seventy-eight-year-old man was admitted to the hospital for a radical nephrectomy plus transurethral resection due to kidney and bladder cancer. During the epidural exploration, an accidental dural puncture was noted. This was followed by the patient complaining of an intense headache. The epidural catheter was placed in a different location, and surgery was performed uneventfully. The patient presented with confusion, agitation, vertical nystagmus, vision loss, and paraparesis about two hours later. The epidural levobupivacaine and morphine infusion were stopped, followed by motor block resolution. A computerized head-tomography scan showed extra-axial multiple air spots involving the frontal and temporal lobes. Emergent hyperbaric oxygen therapy was commenced. After a single session, there was complete resolution of all symptoms and a marked reduction in the number and volume of the extra-axial air visible on the CT scan.ConclusionsAlthough rare, pneumocephalus is a well-recognized complication of a dural puncture. Its rapid recognition in a patient with new-onset neurological symptoms and early treatment with hyperbaric oxygen therapy allows rapid clinical and imaging resolution and an improved prognosis.

Opiate Intoxication Caused by Epidural Infusion of Morphine: A Case Report of a Near Fatal Medication Error

Epidural infusion of local anesthetics with opioids is widely used for pain control during the perioperative-and peripartum-periods. Selection of the opioid, appropriate dosing, and follow-up by the acute pain service are critical in providing safe postoperative epidural analgesia. A 71-year-old man was scheduled for a parastomal hernia repair with midline laparotomy. The parastomal hernia was a complication from a previously performed colectomy for ulcerative colitis. Preoperatively, the patient received a lower thoracic epidural catheter. The epidural infusate (0.2% ropivacaine with 0.5µg/mL sufentanil) was prepared and double-checked by holding area nurses. The fact that the right prescription medication label partially covered a morphine label went unnoticed. The intraoperative phase was characterized by stable parameters. Postoperatively, it was not possible to demonstrate an epidural nerve block. No pain was reported, and the patient could be transferred to the ward. The patient developed coma and delayed respiratory depression after discharge to the surgical ward, requiring intensive care unit admission and naloxone administration. Analysis of the syringe content revealed the presence of morphine (1mg/mL). Color-coded prefilled syringes combined with the use of an epidural specific syringe connector to prevent cross-connections should become standard practice. In addition, delayed respiratory depression should be considered after epidural administration of morphine.

Effects of epidural infusion of morphine combined with small-dose naloxone on gastrointestinal interstitial cells of Cajal in rabbits.

To study the effect of epidural infusion of morphine combined with small-dose naloxone on gastrointestinal interstitial cells of Cajal (ICC) in rabbits. A total of 80 healthy New Zealand rabbits were selected as objects of study, and divided into normal saline control group (Group NS, n=20), morphine group (Group M, n=20), naloxone group (Group N, n=20), and morphine + naloxone group (Group NM, n=20). Rabbits in four the groups received epidural catheterization for continuous drug infusion for 7 d, and epidural analgesia pump was connected. Visual analogue scale (VAS) score, intestinal propulsion rate, c-kit expression, and ICC count were detected and compared among four groups of rabbits. No statistical differences of occurrence rates regarding constipation as well as expressions of c-kit and ICC count in the proximal colon were shown among rabbits in Group NS, Group N, and Group NM during drug administration (p>0.05). However, the occurrence rates of constipation of rabbits in Group M at 3-7 d were statistically higher than those in Group NS, Group N, and Group NM, and the differences were statistically significant (p<0.05). Moreover, the VAS scores in Group NS and Group N were significantly higher than those in Group M and Group NM, while the scores in Group M were also significantly increased compared to that in Group NM (p<0.05). The intestinal propulsion rates, expressions of c-kit and ICC counts of rabbits in Group NS, Group N, and Group NM were statistically higher than that in Group M (p<0.05). Epidural infusions of morphine combined with small-dose naloxone effectively inhibit the gastrointestinal motility of rabbits via the reduction of ICC in the proximal colon of the gastrointestinal tract of rabbits. Moreover, small-dose of naloxone enhances the analgesic effect and reduces the risk of adverse reactions.

Postoperative Pain Management in a Sheep Using Continuous Epidural Morphine

Background: Although ruminants experience pain like other species, diagnosis and treatment may be imprecise and challenging, especially because of lack of recognition and restraint of therapeutic resources. In addition to the restrictions inherent in the species, organic dysfunctions may further restrict the analgesic arsenal, making it necessary to find viable and effective alternative for pain control. The continuous administration of opioids in the epidural space has been highlightedas an analgesic resource in several species. However, until this moment, there are few information on this practice in ruminants. Therefore, the aim of this study was to describe the use of continuous epidural infusion of morphine in a sheep undergoing to urethrostomy with a history of chronic pain and urolithiasis.Case: A 3-year-old Santa Ines sheep, weighting 110 kg, was presented to the Veterinary Hospital of Federal University of Bahia with history of recurrent urolithiasis, lameness, severe pain and continuous use of nonsteroidal anti-inflammatory drug (NSAID). The findings of the physical examination, imaging and laboratory tests revealed possible abomasum inflammation, chronic laminitis, left humerus-radioulnar osteoarthritis and urethral urolithiasis with uremia. A clinical stabilization of the animal was performed, including an interruption of the use of the NSAID and the administration of fluid, urinary acidifier (ammonium chloride), histamine H2 receptor antagonist (ranitidine), cytoprotectant (sucralfate), antibiotic (norfloxacin) and dipyrone. After 3 days, urethrostomy was performed followed by the implantation of an epidural catheter (19G) in the lumbosacral space (L7 - S1) by means of a Tuohy needle (18G), after the surgical procedure. Administration of morphine (0.1 mg kg-1) through the catheter at 24-h intervals, associated with dipyrone (25 mg kg-1) intravenously (IV), every 8 h, over a 5-day period, was the postoperative analgesic protocol chosen. The data of heart rate (HR), respiratory rate (f),rectal temperature (T °C), ruminal movements (RM) and possible behavior related to pain were registered at intervals of four-hours until the fifth day after surgery. After 24 h postoperative, stability of the variables (HR, f, T °C) with increased RM concomitant to the interest for food was verified. On the fifth postoperative day, the animal was hydrated, visibly comfortable and with normal levels of serum creatinine.Discussion: Considering the initial clinical status involving renal insufficiency and significant gastric abnormalities, the use of NSAIDs was immediately disregarded. However, the need to relieved musculoskeletal and postoperative pain, has raised interest in the use of morphine, whose literature refers duration of up to 24 h in other species, with reduced adverse effects compared to systemic administration, due to the considerably lower dose. Dipyrone was incorporated into the protocol forproviding visceral analgesia and minimal effects on the organic functions. During the 5-days of evaluation, the signs of well-being presented by the animal associated to the stability of vital parameters, feeding and satisfactory ruminal activity attested to the viability of the protocol tested. It was concluded that the use of morphine, through the continuous epiduralroute, contributed to the relief of postoperative pain, reestablishment of the organic functions and patient welfare, being suitable as an analgesic alternative to NSAID use in sheep.Keywords: ovine, analgesia, opioid, epidural.

Does Epidural Morphine Loading in Addition to Thoracic Epidural Analgesia Benefit the Postoperative Management of Morbidly Obese Patients Undergoing Open Bariatric Surgery? A Pilot Study

Insufficient data exist regarding postoperative thoracic epidural analgesia for morbidly obese patients undergoing open bariatric surgery. This study evaluated the effectiveness of morphine loading in a postoperative thoracic epidural analgesic regimen of patient-controlled epidural analgesia (PCEA) with levobupivacaine combined with continuously administered epidural morphine in this patient group. In this prospective randomized controlled trial, 48 superobese patients (body mass index of ≥ 50 kg/m(2)) undergoing open bariatric surgery were randomly allocated to three groups of 16 patients each. Postoperatively, all groups received a continuous epidural morphine infusion of 0.2 mg/h with 0.1 % levobupivacaine via PCEA. Group A did not receive intraoperative epidural morphine loading, while groups B and C received an intraoperative 1- and 2-mg morphine bolus, respectively. Levobupivacaine consumption via PCEA (primary outcome), pain scores at rest and on cough, the time to return of bowel function and ambulation, and arterial blood gas levels (secondary outcomes) were recorded. The increase in perioperative morphine administration (groups B and C) led to a significantly prolonged return to normal bowel function and delayed ambulation (P<0.05 to 0.01, respectively), without an improvement in postoperative analgesia or a reduction in local anesthetic consumption. Although the prevalence of obstructive sleep apnea (OSA) was high in all groups, no respiratory depression was observed. Thoracic PCEA with 0.1 % levobupivacaine combined with continuous epidural morphine administration of 0.2 mg/h without morphine loading is an effective postoperative analgesic regimen that provides adequate pain control, early ambulation, and early return of bowel function in superobese patients, particularly those with OSA.

Epidural Infusion of Morphine and Levobupivacaine through a Subcutaneous Port for Cancer Pain Management.

BackgroundTo manage intractable cancer pain, an alternative to systemic analgesics is neuraxial analgesia. In long-term treatment, intrathecal administration could provide a more satisfactory pain relief with lower doses of analgesics and fewer side-effects than that of epidural administration. However, implantable drug delivery systems using intrathecal pumps in Korea are very expensive. Considering cost-effectiveness, we performed epidural analgesia as an alternative to intrathecal analgesia.MethodsWe retrospectively investigated the efficacy, side effects, and complications of epidural morphine and local anesthetic administration through epidural catheters connected to a subcutaneous injection port in 29 Korean terminal cancer patients. Patient demographic data, the duration of epidural administration, preoperative numerical pain rating scales (NRS), side effects and complications related to the epidural catheterization and the drugs, and the numerical pain rating scales on the 1st, 3rd, 7th and 30th postoperative days were determined from the medical records.ResultsThe average score for the numerical pain rating scales for the 29 patients decreased from 7 ± 1.0 at baseline to 3.6 ± 1.4 on postoperative day 1 (P < 0.001). A similar decrease in pain intensity was maintained for 30 days (P < 0.001). Nausea and vomiting were the most frequently reported side effects of the epidural analgesia and two patients (6.9%) experienced paresthesia.ConclusionsEpidural morphine and local anesthetic infusion with a subcutaneous pump seems to have an acceptable risk-benefit ratio and allows a high degree of autonomy to patients with cancer pain.

Perioperative gabapentin for the prevention of persistent pain after thoracotomy: a randomized controlled trial

To evaluate the effect of perioperative gabapentin treatment for the prevention of persistent post-thoracotomy pain and to establish whether gabapentin has a significant therapeutic impact on acute postoperative pain. Consecutive patients with pulmonary malignancies scheduled for anterior thoracotomy were enrolled in this randomized, double-blinded, placebo-controlled trial. Patients were given 1200 mg gabapentin or placebo 2 h before surgery followed by increasing doses during 5 postoperative days: 600 mg for day 1; 900 mg for day 2; and 1200 mg for days 3-5. Effective pain relief was provided with perioperative multimodal analgesia with epidural infusion of bupivacaine and morphine for 72 h, and oral acetaminophen, ibuprofen and morphine. The main outcome was persistent post-thoracotomy pain at 6 months. Secondary outcomes included measures of early postoperative post-thoracotomy pain, morphine requirements, recovery and analgesia-related adverse effects over the first 3 weeks as well as persistent post-thoracotomy pain at 3 months. A total of 104 patients were randomly assigned to the intervention or control group; 86 (83%) patients were available for the 14-day analysis, 76 (73%) for the 3-month analysis and 67 (64%) for the 6-month follow-up. At 6 months postoperatively, 47% of patients treated with gabapentin reported persistent post-thoracotomy pain compared with 49% in the placebo group (P = 0.9). No overall clinically or statistically significant differences were observed between groups receiving placebo and gabapentin, respectively, for the secondary outcome measures and treatment-related adverse events. We found no evidence for the superiority of gabapentin over placebo for the treatment of acute pain following thoracotomy or for the prevention of persistent post-thoracotomy pain.

Síndrome dolorosa pós-laminectomia: estudo descritivo da abordagem terapêutica em 56 pacientes

OBJETIVO: Os autores apresentam os resultados da avaliacao clinica e acompanhamento de 56 pacientes com diagnostico de sindrome dolorosa pos-laminectomia lombar. METODOS: Estudo descritivo, prospectivo realizado no periodo de um ano. Neste estudo foram avaliados 56 pacientes caracterizados com sindrome dolorosa pos-laminectomia lombar em nossa instituicao. As idades variaram de 28 a 76 anos (media de 48,8 ± 13,9 anos). Avaliacao da dor com Escala Visual e Analogica (EVA). RESULTADOS: A dor pos-operatoria foi mais intensa (8,3, media de EVA) que a pre-operatoria (7,2). Sindrome dolorosa miofascial (SDM) foi diagnosticada em 85,7% dos pacientes, anormalidades neuropaticas associadas ou nao a SDM em 73,3%. O tratamento farmacologico associado a medicina fisica proporcionou melhora de mais de 50% da dor em 57,2% dos casos, a infiltracao dos pontos-gatilho miofasciais em 60,1% e a infusao de morfina com lidocaina no compartimento epidural lombar em 69,3% dos casos refratarios. CONCLUSAO: Nos pacientes com sindrome pos-laminectomia, a dor pos-operatoria foi mais intensa que a dor pre-operatoria da hernia de disco. Um componente miofascial foi verificado na maioria dos doentes.

Failed back surgery pain syndrome: therapeutic approach descriptive study in 56 patients

The authors show the clinical evaluation and follow-up results in 56 patients diagnosed with a failed back surgery pain syndrome. Descriptive and prospective study conducted over a one-year period. In this study, 56 patients with a failed back surgery pain syndrome were assessed in our facility. The age ranged from 28 to 76 years (mean, 48.8 ± 13.9 years). The pain was assessed through a Visual Analog Scale (VAS). Postoperative pain was more severe (mean VAS score 8.3) than preoperative pain (7.2). Myofascial pain syndromes (MPS) were diagnosed in 85.7% of patients; neuropathic abnormalities associated or not with MPS were found in 73.3%. Drug therapy associated with physical medicine treatment provided > 50% pain improvement in 57.2% of cases; trigger point injection in 60.1%, and epidural infusion of morphine with lidocaína in 69.3% of refractory cases. In patients with a post-laminectomy syndrome, postoperative pain was more severe than preoperative pain from a herniated disk. A miofascial component was found in most patients.

Cefalea postpunción dural en obstetricia

Postdural puncture headache is the most common major complication following neuraxial anesthesia; this adverse event is particularly frequent in obstetrics. The headache is usually benign and self-limited but if left untreated can lead to more serious complications that may be life-threatening. Many treatments and prophylactic measures have been suggested, but evidence supporting them is scarce in many cases. After accidental dural puncture the only effective preventive measure is to leave the catheter inside the dura; epidural morphine infusion may also help. Once symptoms begin, treatment is conservative for the first 24hours. If this approach fails, the most effective intervention continues to be a blood patch, which should not be delayed beyond 24 to 48hours in order to avoid suffering. If more blood patches are required, other possible causes of headache should be ruled out.

Respiratory Failure Following Delayed Intrathecal Morphine Pump Refill: A Valuable, but Costly Lesson

Background: Spinal analgesia, mediated by opioid receptors, requires only a fraction of the opioid dose that is needed systemically. By infusing a small amount of opioid into the cerebrospinal fluid in close proximity to the receptor sites in the spinal cord, profound analgesia may be achieved while sparing some of the side effects due to systemic opioids. Intraspinal drug delivery (IDD) has been increasingly used in patients with intractable chronic pain, when these patients have developed untoward side effects with systemic opioid usage. The introduction of intrathecal opioids has been considered one of the most important breakthroughs in pain management in the past three decades. A variety of side effects associated with the long-term usage of IDD have been recognized. Among them, respiratory depression is the most feared. Objective: To describe a severe adverse event, i.e., respiratory failure, following delayed intrathecal morphine pump refill. Case Report: A 65-year-old woman with intractable chronic low back pain, due to degenerative disc disease, and was referred to our clinic for an intraspinal drug delivery evaluation, after failing to respond to multidisciplinary pain treatment. Following a psychological evaluation confirming her candidacy, she underwent an outpatient patient-controlled continuous epidural morphine infusion trial. The infusion trial lasted 12 days and was beneficial in controlling her pain. The patient reported more than 90% pain reduction with improved distance for ambulation. She subsequently consented and was scheduled for permanent intrathecal morphine pump implantation. The intrathecal catheter was inserted at right paramedian L3-L4, with catheter tip advanced to L1, confirmed under fluoroscopy. Intrathecal catheter placement was confirmed by positive CSF flow and by myelogram. A non-programmable Codman 3000 constant-flow rate infusion pump was placed in the right mid quandrant between right rib cage and right iliac crest. The intrathecal infusion consisted of preservative free morphine, delivering 1.0 mg / day. Over the following 6 months, the dosage was gradually titrated up to 4 mg/day with satisfactory pain control without significant side effects. However, the patient was not able to return to the clinic for pump refill until 12 days later than the previously scheduled pump-refill date. Her pump was accessed and was noted to be empty. Her intrathecal pump was refilled with preservative free morphine, delivering 4 mg/day (the same daily dose as her previous refill). However, on the night of pump refill, 10 hours after the pump refill, the patient was found to be unresponsive by her family members. 911 was called. Upon arriving, paramedics found her in respiratory failure, with shallow breathing at a rate of 5/min, pulse oxymetry showing oxygen saturation about 55-58%. She was emergently intubated on site and rushed to local hospital ER. The on call physician for our clinic was immediately contacted, and advised the administration of intravenous Naloxone. Her respiratory effort improved dramatically after receiving a total of 0.6 mg IV Naloxone IV over 25 minutes. Her intrathecal pump was immediately accessed by clinic on call physician and the remainder of the medication in the catheter space was aspirated. The pump infusate was immediately diluted with preservative free normal saline, to deliver preservative free morphine at 1mg/day. She was transferred to the intensive care unit and extubated the next morning. She recovered fully without any sequelae. Conclusion: Loss of opioid tolerance due to delayed pump refill may subject patients to the development of severe respiratory depression. Meticulous approach should be employed when refilling pumps in these patients when their pumps are completely empty. To our knowledge, this is the first reported case of this type. Key words: intraspinal drug delivery pump, intrathecal morphine, respiratory depression, opioid tolerance

Continuous epidural infusion of morphine versus single epidural injection of extended-release morphine for postoperative pain control after arthroplasty: a retrospective analysis

This study retrospectively compared the continuous epidural infusion of morphine with a single epidural injection of extended-release morphine for postoperative pain control after arthroplasty. Medical records were reviewed for subjects who had total knee or hip arthroplasty (THA) under spinal anesthesia and received either a continuous epidural infusion of morphine (Group EPID; n = 101) or an extended-release epidural morphine (Group EREM; n = 109) for postoperative pain. Data were collected for three postoperative days (POD) on: pain scores; supplemental opioids; medications for respiratory depression, nausea, and pruritus, and distance ambulated during physical therapy. Pain scores were similar until subjects were transitioned to another analgesic approach on POD 2; after that time, pain scores increased in Group EPID, although they decreased in Group EREM. Supplemental opioids were used more on POD1 in Group EREM than in Group EPID, although time to first opioid and total daily morphine equivalents were similar. Naloxone and antiemetics, not antipruritics, were used more in Group EREM. Distance ambulated after THA was greater in Group EREM than in Group EPID. These results suggest that EREM is associated with better postoperative ambulation and analgesia during the transition to oral or intravenous analgesics, although a higher incidence of side-effects was evident.

Comparison of efficacy of continuous epidural infusion of morphine, fentanyl and combination of morphine and fentanyl with bupivacaine for postoperative analgesia in children

Forty-five children of ASA I & II aged 2-10 years scheduled for elective abdominal, urological and major orthopedic procedures were included in the study. They were divided into three groups of 15 each Group I children received continuous epidural infusion of morphine 6ug/kg/hr with 0.0625% bupivacaine group II patients received an epidural infusion of fentanyl 0.4 ug/kg/hr with 0.0625% bupivacaine, whereas patients in group III received continuous epidural infusion of fentanyl 0.2 ug/kg/hr and morphine 3 ug/kg/hr with 0.0625% bupivacaine.

Continuous epidural infusion of morphine versus single epidural injection of extended-release morphine for postoperative pain control after arthroplasty: a retrospective analysis

Continuous epidural infusion of morphine versus single epidural injection of extended-release morphine for postoperative pain control after arthroplasty: a retrospective analysis

Continuous epidural infusion of morphine versus single epidural injection of extended-release morphine for postoperative pain control after arthroplasty: a retrospective analysis

Continuous epidural infusion of morphine versus single epidural injection of extended-release morphine for postoperative pain control after arthroplasty: a retrospective analysis

An acute pain service improves postoperative pain management for children undergoing selective dorsal rhizotomy

A continuous epidural infusion of morphine is the pain treatment modality for children undergoing selective dorsal rhizotomy (SDR) in our institution. The aim of the study was to evaluate the impact of having an organized acute pain service (APS) on postoperative pain management of these children. We conducted a retrospective cohort study using anesthetic records and the APS database to compare the postoperative pain management of children undergoing SDR before and after the introduction of the APS at the Montreal Children's Hospital in April 2001. Ninety-two consecutive children who had their surgery between January 1997 and July 2006 were included. We collected data regarding postoperative pain, opioid-induced side effects, complications (sedation, desaturations < 92%), and hospital length of stay. Pain scores were documented more frequently after the implementation of the APS (61% vs 48.5%). Sedation scores were documented only after the implementation of the APS. Postoperative desaturation was significantly more frequent in the pre-APS group compared to the APS group (45.5% vs 6.8%, P < 0.001). Despite the fact that the epidural catheter was in place for the same duration for both groups [median of 3 days (3-3 25-75%ile)], the duration of hospitalization was 1 day shorter in the APS group compared to the pre-APS group [median of 5 (5-5 25-75%ile) vs 6 (5-6 25-75%ile) days, P < 0.001]. Although we recognize that it is possible that there were changes in care not related specifically to the introduction of a dedicated APS that occurred in our institution that resulted in improvements in general postoperative care and in length of stay, our study did show that having an organized APS allowed to significantly decrease the incidence of postoperative oxygen desaturation and to decrease the hospital length of stay by 1 day.

Severe Peripheral Edema During an Outpatient Continuous Epidural Morphine Infusion Trial in a Patient with Failed Back Surgery Syndrome

Intraspinal drug delivery therapy has been increasingly used in patients with intractable, nonmalignant pain who fail to respond to conventional treatment or cannot tolerate systemic opioid therapy due to side effects. By infusing small amount of analgesics directly into the cerebrospinal fluid in close proximity to the receptor sites in the spinal cord, one is able to achieve the spinally mediated analgesia, sparing side effects due to systemic opioids. Prior to permanent intraspinal pump implantation, an intraspinal opioid screening trial is required to document the efficacy of intraspinal opioid for analgesia. Although there are a few approaches in conducting such screening trials, a patient controlled continuous epidural morphine infusion trial, performed in an outpatient setting, is widely accepted by many interventional pain specialists. The major advantage of conducting an outpatient trial is that it mimics what patients do in their daily living, therefore minimizing the false positive rate. To report a case of severe peripheral edema observed during an outpatient continuous epidural morphine infusion trial. A 64-year-old female, with a 7-year history of severe low back pain and bilateral leg pain due to failed back surgery syndrome, was referred to our clinic for intraspinal drug delivery therapy after failing to respond to conservative treatment, including a previous history of 3 lumbosacral surgeries. Following a pre-implantation psychological evaluation confirming her candidacy, she underwent an outpatient patient-controlled continuous epidural morphine trial. A tunneled lumbar epidural catheter was placed at L2-L3 with catheter tip advanced to T12 under fluoroscopic guidance. Satisfactory catheter placement was confirmed by epidurogram. The proximal tip of the catheter was then tunneled, subcutaneously and connected to a Microject PCEA pump (Codman, Raynham, MA, USA) and reservoir bag containing preservative-free morphine 0.5 mg/mL. The pump was programmed to deliver a basal rate of 0.5 mL/hr. The bolus dose was 0.2 mL with 60 minute lock-out interval. The patient was instructed how to operate the infusion pump before discharging home. During the following 2 weeks, she reported more than 90% reduction of her low back and leg pain. She only had to use the on-demand bolus doses averaging 2 - 3 times a day. She was able to wean off her oral opioids completely. However, she developed bilateral leg edema and gained over 12 pounds during the 2-week infusion trial, despite wearing elastic stockings and keeping her legs elevated whenever possible. She did not experience any other significant side effects. Her edema finally resolved 2 days after termination of the epidural infusion. Peripheral edema may occur and persist during epidural morphine infusion. This report represents the first case report, to the best of our knowledge, describing severe peripheral edema in an otherwise healthy patient while on epidural morphine administration during an outpatient epidural morphine infusion trial. This case report shows that continuous epidural morphine infusion, even in small dose, may cause peripheral edema in some patients.

Priapism — A Rare Complication Following Continuous Epidural Morphine and Bupivacaine Infusion

Background: Intraspinal drug delivery (IDD) therapy has been increasingly used in patients with intractable, nonmalignant pain who fail to respond to conventional treatment or can not tolerate systemic opioid therapy due to side effects. By infusing a small amount of analgesics directly into the cerebrospinal fluid (CSF) in close proximity to the receptor sites in the spinal cord, one is able to achieve the spinally mediated analgesia, sparing side effects ffrom systemic opioids. Prior to permanent intraspinal pump implantation, an intraspinal opioid screening trial is required to document the efficacy of intraspinal opioid for analgesia. Although there are a few approaches in conducting such screening trials, a patient-controlled continuous epidural morphine infusion trial, performed in an outpatient setting, is widely accepted by many interventional pain specialists. The major advantage of conducting an outpatient functional opioid infusion trial versus an inpatient trial is that it more closely mimics what the patient does in his or her usual activities of daily living, therefore minimizing the false positive rate of the inpatient screening trial. Objective: To describe a rare complication, priapism, observed during an outpatient continuous epidural morphine and bupivacaine infusion trial. Case Report: A 49-year-old male with intractable, chronic low back pain due to diffuse lumbar degenerative disc disease, lumbar spondylosis referred to our clinic for consideration of IDD therapy, after failing to respond to multi-modality pain management including medications, physical therapy with modality, transcutaneous nerve stimulation (TENS), and various interventional procedures. Following a pre-implant psychological evaluation, he was scheduled for the outpatient epidural morphine and bupivacaine infusion trial. A tunneled lumbar epidural a catheter was placed at L3-L4 with the catheter tip advanced to L1 under fluoroscopic guidance. The proximal tip of the catheter was then tunneled, subcutaneously, and connected to a MicrojectTM PCEA pump (Codman, Raynham, MA, USA) and reservoir bag containing preservative-free morphine 0.4 mg/mL and bupivacaine 0.016%. The pump was programmed to deliver a basal rate of 0.5 mL/h. The bolus dose was 0.2 mL with a 60-minute lock out interval. The patient was instructed how to use the pump properly before discharging home. Two hours following the initiation of infusion trial, the patient started to experience penile erection. It was initially painless, but became progressively painful and intensified. The unremitting priapism lasted 8 hours, finally resolving 2 to 3 hours after discontinuing the infusion. The patient recovered fully without any sequelae. Conclusion: Priapism may occur as a rare complication following epidural morphine administration. This report represents the third case report thus far in the literature revealing priapism induced by epidural morphine administration, yet, it is the only report, to our knowledge, describing priapism occurring in a patient undergoing an outpatient epidural morphine and bupivacaine infusion trial. We believe that epidural morphine, rather than bupivacaine, is responsible for causing priapism in this patient, through a yet to be defined spinal mechanism. Key words: Epidural morphine and bupivacaine infusion trial, intraspinal drug delivery pump, priapism

Low-dose Intravenous Ketamine Potentiates Epidural Analgesia after Thoracotomy

Ketamine potentiates intravenous or epidural morphine analgesia. The authors hypothesized that very-low-dose ketamine infusion reduces acute and long-term postthoracotomy pain. Forty-nine patients scheduled to undergo open thoracotomy were randomly assigned to receive one of two anesthesia regimens: continuous epidural infusion of ropivacaine and morphine, along with intravenous infusion of ketamine (0.05 mg . kg(-1) . h(-1) [approximately 3 mg/h], ketamine group, n = 24) or placebo (saline, control group, n = 25). Epidural analgesia was continued for 2 days after surgery, and infusion of ketamine or placebo was continued for 3 days. Pain was assessed at 6, 12, 24, and 48 h after surgery. Patients were asked about their pain, abnormal sensation on the wound, and inconvenience in daily life at 7 days and 1, 3, and 6 months after surgery. The visual analog scale scores for pain at rest and on coughing 24 and 48 h after thoracotomy were lower in the ketamine group than in the control group (pain at rest, 9 +/- 11 vs. 25 +/- 20 and 9 +/- 11 vs. 18 +/- 13; pain on coughing, 26 +/- 16 vs. 50 +/- 17 and 30 +/- 18 vs. 43 +/- 18, mean +/- SD; P = 0.002 and P = 0.01, P < 0.0001 and P = 0.02, respectively). The numerical rating scale scores for baseline pain 1 and 3 months after thoracotomy were significantly lower in the ketamine group (0.5 [0-4] vs. 2 [0-5] and 0 [0-5] vs. 1.5 [0-6], median [range], respectively; P = 0.02). Three months after surgery, a higher number of control patients were taking pain medication (2 vs. 9; P = 0.03). Very-low-dose ketamine (0.05 mg . kg(-1) . h(-1)) potentiated morphine-ropivacaine analgesia and reduced postthoracotomy pain.