Comparison of epidural butamben to celiac plexus neurolytic block for the treatment of the pain of pancreatic cancer.

OBJECTIVE: To compare pain relief in metastatic pancreatic cancer patients between neurolytic celiac plexus block (NCPB) and epidural 5% butamben suspension (EBS), a material-based delivery system of a local anesthetic that produces a long-lasting differential nerve block. DESIGN: Open-label patient-selected parallel groups. SETTING: Urban tertiary care medical center. PATIENTS: Twenty-four adult patients with metastatic pancreatic cancer experiencing pain uncontrolled by systemic opioids who were referred to a multidisciplinary pain clinic for interventional therapy. INTERVENTIONS: Antecrural NCPB-block with ethanol and epidural 5% butamben suspension injections. MEASURES: Subjective global pain relief assessments on a 0-100% scale were made weekly for 4 weeks and then monthly. Change in opioid use postintervention. RESULTS: Eight patients had a single NCPB and three patients had two NCPB. Four of the former and two of the latter had successful pain relief defined to be a more than 75% reduction in pain when compared with pretreatment maintained for more than 4 weeks or until death (if less than 4 weeks). Thirteen patients received EBS in divided doses. Eleven patients received a cumulative EBS dose of 5 grams, one patient received a cumulative EBS dose of 2.5 grams, and one patient received a cumulative EBS dose of 8.75 grams. Nine of the eleven patients and each of the other two patients had successful pain relief. The overall incidence (85% EBS vs. 55% NCPB), the duration of successful pain relief, and the percent reduction in opioid use did not differ between the two groups. There were no serious complications. CONCLUSION: EBS appears to be a safe and effective alternative to NCPB in the treatment of pancreatic cancer pain.

Nerve blocks with 5% butamben suspension for the treatment of chronic pain syndromes.

BACKGROUND AND OBJECTIVES: Butamben is a non-water-soluble local anesthetic that can be prepared as an aqueous suspension for nerve blocks. This report describes the use of 5% butamben suspension for the treatment of chronic pain of cancer and noncancer origin. METHODS: The clinical courses of 75 consecutive patients were analyzed following 5% butamben nerve blocks (35 epidural blocks only, 33 peripheral nerve blocks only, and 7 had both epidural and peripheral nerve blocks). Epidural blocks were performed as a series of four with additional blocks offered if needed. Peripheral nerve blocks were done as a single block with repeat injections if needed. Injection volumes varied between 15 and 25 mL for epidural injections and 5 and 20 mL for peripheral nerve blocks. Successful therapy was defined as a -75% reduction in subjective pain assessments for -4 weeks or until death. Daily opioid requirements were also recorded. RESULTS: Fifty-four of the 75 patients (72%) were successfully treated. This included 48 of 67 cancer patients (71.6%) and 6 of 8 noncancer patients (75%). Median duration of pain relief was 12 weeks (range, 1-96) in the cancer patients and 10 weeks (range, 6-166) in the noncancer patients. Mean reduction in opioid requirements in successfully treated cancer patients was 74+/-5%. Pain on epidural injection occurred in half of the patients and was the most prevalent complication of treatment. Five patients had signs of intravascular injection. There were no serious long-term sequelae. CONCLUSIONS: When used as described in this report, 5% butamben suspension appears to be effective for treatment of chronic pain of both cancer and noncancer origin and has a low incidence of adverse sequelae.

Validation of thermography in the diagnosis of reflex sympathetic dystrophy.

OBJECTIVES: To examine the validity of several thermogram-derived indices of autonomic functioning in the diagnosis of reflex sympathetic dystrophy (RSD). DESIGN: A series of chronic pain patients were classified diagnostically based on thermogram results using discriminant function analysis, and validity measures (e.g., sensitivity, specificity) were used to determine the accuracy of computerized thermographic pixel analysis in discriminating RSD from other pathology. SETTING: The study was conducted at the Rush Pain Center, a multidisciplinary outpatient pain clinic. PATIENTS: A series of 46 chronic pain patients referred for suspected sympathetically mediated pain. INTERVENTIONS: All patients underwent computerized thermographic examination under a baseline condition after acclimating to a climate-controlled room, immediately after a cold challenge was applied to the contralateral uninvolved extremity (4 degrees C for 90 s) and 20 min after the cold challenge. OUTCOME MEASURES: Temperature during the three experimental periods, degree of temperature asymmetry between affected and nonaffected limbs during the three periods, response to cold challenge, and recovery following cold challenge were measured. RESULTS: Temperature asymmetry accurately discriminated between RSD and non-RSD patients, with the most accurate asymmetry measures obtained at baseline. Responses to cold challenge and actual temperature values did not discriminate between RSD and non-RSD pain patients. CONCLUSIONS: Thermography can be a useful component of RSD diagnosis. In situations where sensitivity and specificity are equally important, an asymmetry cutoff of 0.6 degree C appears optimal. If specificity (i.e., accurately ruling out non-RSD cases) is more important, a cutoff of 0.8 degree C or 1.0 degree C may be considered as well.

Management of chronic pain. Part II.

Chronic pain is associated with substantial psychosocial and economic stress coupled with functional loss and various levels of vocational dysfunction. The role of a pain center is to focus on chronic pain in a multidisciplinary, comprehensive manner, providing the patient with the most effective opportunity to manage his or her chronic disease syndrome. This article focuses on methods to manage many types of chronic pain and describes a broad range of pharmacologic and non-pharmacologic interventions and options available to the patient. Part I of this two-part monograph described pharmacotherapeutic interventions and regional nerve blocks. Part II focuses on psychologic assessment and treatment and physical therapy. A multimodal management strategy offers patients the greatest improvement potential for specific chronic pain syndromes. Cognitive and behavioral therapies and physical therapies are described. This combination of therapies may provide patients with the skills and knowledge needed to increase their sense of control over pain. The integration of appropriate pharmacotherapeutic regimens, neural blockades, physical therapy, and psychologic techniques maximizes the patient's effectiveness in dealing with chronic pain. Three case studies are presented in Part II.

Management of chronic pain. Part I.

Chronic pain is associated with substantial psychosocial and economic stress, coupled with functional loss and various levels of vocational dysfunction. The role of a pain center is to focus on chronic pain in a multidisciplinary, comprehensive manner, providing the patient with the most effective opportunity to manage his or her chronic disease syndrome. This article focuses on methods to manage many types of chronic pain and describes a broad range of pharmacologic and nonpharmacologic interventions and options available to the patient. Part I of this two-part monograph describes pharmacotherapeutic interventions and regional nerve blocks. Part II focuses on psychologic assessment and treatment and physical therapy. A multimodal management strategy offers patients the greatest improvement potential for specific chronic pain syndromes. Cognitive and behavioral therapies and physical therapies are described. This combination of therapies may provide patients with the skills and knowledge needed to increase their sense of control over pain. The integration of appropriate pharmacotherapeutic regimens, neural blockades, physical therapy, and psychologic techniques maximizes a patient's effectiveness in dealing with chronic pain. Three case studies are presented in Part II.

Microsurgical denervation of the spermatic cord: a surgical alternative in the treatment of chronic orchialgia.

PURPOSE: We demonstrated effective treatment of chronic orchialgia by microsurgical denervation of the spermatic cord. MATERIALS AND METHODS: Seven men with a history of chronic orchialgia (mean duration 16.6 months) underwent this surgical procedure after conservative treatment failed. A bupivacaine spermatic cord block resulted in temporary pain relief. RESULTS: There was an excellent correlation between the response to preoperative temporary cord nerve block and the surgical result. Six men had complete and permanent pain relief after surgery. One patient with bilateral orchialgia had complete unilateral relief and partial relief on the contralateral side. There was no complaint of postoperative regional hypoesthesia. CONCLUSIONS: Microsurgical denervation of the spermatic cord is an effective testicular sparing surgical alternative for the treatment of chronic orchialgia.

Intrathecal clonidine and tizanidine in conscious dogs: comparison of analgesic and hemodynamic effects.

Intrathecal delivery of alpha(2)-adrenergic agonists produces an analgesic effect. However, hemodynamic side effects limit their clinical usage. To more fully characterize the effects on heart rate and arterial blood pressure of alpha(2)-adrenergic agonists, clonidine and tizanidine were injected intrathecally in conscious dogs. Both compounds produced a potent inhibition of thermal foot-withdrawal latencies at 1000 micrograms, which was blocked by the alpha(2)-adrenergic antagonist yohimbine. Tizanidine (250-500 micrograms) did not change heart rate. Clonidine (500 -2000 micrograms) and tizanidine (1000-2000 micrograms) decreased heart rate. The tizanidine effect was inhibited by yohimbine and the alpha(2)/imidazoline antagonist idazoxan, as well as the parasympathetic blocker glycopyrrolate. No drug completely inhibited the clonidine-induced bradycardia. Clonidine had a biphasic effect on arterial blood pressure, a decrease at 500 micrograms and an increase at 2000 micrograms. Tizanidine decreased arterial blood pressure at all doses. The results indicate that, while the analgesic effects of both drugs are similar, the hemodynamic responses differ. While the decrease in heart rate with tizanidine is consistent with alpha(2)-adrenergic binding and vagal action, the bradycardia induced by clonidine is more complex. In addition, the increased arterial blood pressure with high doses of clonidine, which is suggestive of a peripheral vasoconstrictive effect, does not occur with tizanidine.

Postthoracotomy pain management using continuous epidural analgesia in 1,324 patients.

Continuous epidural analgesia consisting of an opioid with or without a local anesthetic agent is a commonly employed technique for pain relief after thoracotomy. In this study, we prospectively evaluated the use of continuous epidural analgesia in 1,324 patients undergoing elective thoracotomy between 1987 and 1993. Epidural pain management was continued for 1 to 3 postoperative days. Patients experienced excellent pain relief, with mean visual analog pain scores of 2.4, 1.7, and 1.4 on postoperative days 1, 2, and 3, respectively. Side effects occurred most frequently in the first 24 hours postoperatively; the incidence of pruritus was 14.1%; nausea, 11.2%; hypotension, 4.3%; sedation, 3.3%; and numbness, 1.1%. Respiratory depression (< 8 breaths per minute) occurred in 1 patient who received 16 mg of supplemental morphine sulfate over a 2-hour period. The incidence of inadequate analgesia (a visual analog pain score of 7 or more persisting for 1 to 2 hours after an epidurally administered bolus) was 3.8%. The results from this study support the use of standard protocols for dosing guidelines, the treatment of inadequate analgesia, and the management of side effects. Daily evaluation by a team member of the postoperative analgesia services section of the Department of Anesthesiology enhances patient care and minimizes adverse effects.

Comparison of patient-assisted epidural analgesia with continuous-infusion epidural analgesia for postoperative patients.

BACKGROUND AND OBJECTIVES: Patient-assisted epidural analgesia, a mode of epidural analgesic delivery in which self-administered epidural boluses supplement a baseline continuous epidural infusion, was compared to continuous epidural infusion in 62 postsurgical patients. METHODS: Patients were randomly assigned to receive continuous epidural infusion (n = 31) or patient-assisted epidural analgesia (n = 31) consisting of fentanyl 10 mcg/mL and bupivacaine 1 mg/mL for the first 2 days after the operation. Variables examined included the adequacy of analgesia, amount of epidural infusion solution used, use of supplemental opioids, as well as incidence of side effects including nausea, pruritus, sedation, urinary retention, and respiratory depression. RESULTS: Visual analog pain scores on days 1 and 2 after the operation, mean total epidural fentanyl consumption, and use of supplemental opioids were all significantly (P < .05) lower in the patient-assisted epidural group than in the continuous infusion group. There was no significant difference in the incidence of side effects between groups. The effects of age and operation type were not significant. CONCLUSIONS: Patient-assisted epidural analgesia can provide superior pain control as compared to continuous epidural infusions while also reducing opioid dosages. Despite the reduction in total analgesic administered no reduction in side effects was seen with this mode of administration.

Oxygen consumption and mixed venous oxygen saturation monitoring during orthotopic liver transplantation.

Mixed venous oxygen saturation (SvO2) monitoring has been advocated for some critically ill patients. Patients with end-stage hepatic failure have oxygen consumption rates that are lower than normal. Using the Fick equation, oxygen consumption may be calculated if mixed venous and arterial oxygen tensions (and saturations), hemoglobin, and cardiac output are determined simultaneously. This report describes a unique pattern of changes in SvO2 and oxygen consumption in 7 patients undergoing liver transplantation. A previous study correlated plasma carbohydrate (glucose) levels with early hepatic graft survival. After induction, the 7 patients reported here had low oxygen consumption and high SvO2 values. The oxygen consumption rates decreased to the lowest point during the anhepatic phase and rose above baseline by the end of the case. The SvO2 and oxygen consumption data reported here follow the presence of presumed hepatic metabolic activity (increased CO2 and ionized calcium). Further research must be completed to determine whether these measurements indicate early hepatic nonfunction.

Postoperative epidural analgesia.

Epidural analgesia is an important advance in the treatment of postoperative pain. Improved pain relief and decreased patient morbidity have combined to make this technique more desirable than the use of traditional intramuscular narcotics. Optimal patient care and satisfaction, however, can only be achieved with the education and assistance of experienced nursing staff familiar with postoperative epidural analgesia therapy.

Patient-controlled analgesia for postoperative pain.

The use of PCA for the treatment of pain is a valuable and growing practice. The technique for PCA initiation and management has been described. This mode of therapy should be in the therapeutic armamentarium of every clinician managing postoperative pain because PCA provides better analgesia than conventional IM or IV narcotic therapy and is generally associated with fewer side effects.

Intraspinal narcotics for treatment of cancer pain.

Inadequate pain relief remains a problem for many patients with cancer. Narcotic administration by the epidural or subarachnoid route is a relatively recent innovation and is indicated when pain is poorly controlled with high doses of systemic narcotics, or when patients experience limiting narcotic side effects. When given by the epidural or intrathecal route, narcotics have a longer duration of action and a lower dose is effective. These techniques involve personnel trained in catheter insertion and maintenance. Epidural and intrathecal administration of narcotics is an alternative when oral narcotics are ineffective. In this report the term "intraspinal" refers to epidural and/or subarachnoid placement of catheters and drugs.

Comparison of continuous epidural infusion of fentanyl-bupivacaine and morphine-bupivacaine in management of postoperative pain.

The short duration of epidural fentanyl has limited its direct comparison with epidural morphine in previous reports. The following study was performed of continuous postoperative epidural infusions at 5 ml/hr fentanyl 10 micrograms/ml (n = 59) or morphine 0.1 mg/ml (n = 48), both with bupivacaine 0.1%, in patients having cesarean sections. Postoperative evaluations included the frequency and magnitude of clinically evident respiratory depression, the adequacy of analgesia, nausea, pruritus, the ability to ambulate, and other side effects for 24 hours. Analgesia and the number of supplemental narcotic injections needed were similar in both groups. The incidence of nausea and pruritus was significantly less in the patients receiving fentanyl. No patient developed respiratory depression in either group. Patient and staff acceptance of the continuous epidural technique was excellent because there were only minor catheter-related problems associated with its use. It is concluded that continuous epidural fentanyl combined with bupivacaine offers excellent postoperative analgesia with minimal side effects.

Inadvertent subdural injection: a complication of an epidural block.

Twenty-one hundred eighty two consecutive lumbar epidural injections were studied to determine the incidence of inadvertent subdural block retrospectively. A subdural block is defined as an extensive neural block in the absence of subarachnoid puncture, that is out of proportion to the amount of local anesthetic injected. Subdural injection is a complication of epidural block that probably occurs more frequently than previously recognized. An earlier report has estimated the incidence of subdural block to be 0.1%. This study, however, reports an incidence of 0.82% from a sample size of 2182 patients. Cadaveric dissection was also performed, further clarifying the presence and anatomic position of the subdural space.

The incidence of venous air embolism during total hip arthroplasty.

Venous air embolism has been reported to occur during total hip arthroplasty. The incidence of venous air embolism, however, has not been previously studied in a large series using Doppler ultrasound and mass spectrometry. Seventy patients undergoing total hip arthroplasty were monitored for venous air embolism with precordial Doppler ultrasound, central venous catheter, end-tidal N2 and CO2 (mass spectrometry), and arterial blood gases (ABG). Changes in the monitored variables consistent with venous air embolism were noted in 57% by Doppler ultrasound, 9% by mass spectrometry, 4% by central venous catheter and 3% of the cases by ABG. A total of 77 Doppler ultrasound events were detected in 40 of the 70 patients studied. Hemodynamic changes consisting of either hypotension, defined as a greater than or equal to 20% decrease in mean arterial pressure (MAP), or cardiac dysrhythmia occurred during 43% of these events. The Doppler ultrasound was the only monitor that detected all cases of venous air embolism with concomitant hemodynamic changes. Air was aspirated from the central venous catheter during 10% of the detections of venous air embolism by Doppler ultrasound. Venous air embolism in total hip arthroplasty is a common event and may be responsible for hemodynamic changes previously ascribed to the use of methylmethacrylate cement. Routine monitoring with Doppler ultrasound appears warranted. The routine use of central venous catheterization may also be warranted.