BackgroundContinuous passive motion after major knee surgery optimizes the functional prognosis but causes severe pain The authors tested the hypothesis that postoperative analgesic techniques influence surgical outcome and the duration of convalescenceMethodsBefore standardized general anesthesia

Effects of perioperative analgesic technique on the surgical outcome and duration of rehabilitation after major knee surgery.

STUDY DESIGN: A systematic review of randomized controlled trials. OBJECTIVES: To assess the effectiveness of the most common conservative types of treatment for patients with acute and chronic nonspecific low back pain. SUMMARY OF BACKGROUND DATA: Many treatment options for acute and chronic low back pain are available, but little is known about the optimal treatment strategy. METHODS: A rating system was used to assess the strength of the evidence, based on the methodologic quality of the randomized controlled trials, the relevance of the outcome measures, and the consistency of the results. RESULTS: The number of randomized controlled trials identified varied widely with regard to the interventions involved. The scores ranged from 20 to 79 points for acute low back pain and from 19 to 79 points for chronic low back pain on a 100-point scale, indicating the overall poor quality of the trials. Overall, only 28 (35%) randomized controlled trials on acute low back pain and 20 (25%) on chronic low back pain had a methodologic score of 50 or more points, and were considered to be of high quality. Various methodologic flaws were identified. Strong evidence was found for the effectiveness of muscle relaxants and nonsteroidal anti-inflammatory drugs and the ineffectiveness of exercise therapy for acute low back pain; strong evidence also was found for the effectiveness of manipulation, back schools, and exercise therapy for chronic low back pain, especially for short-term effects. CONCLUSIONS: The quality of the design, execution, and reporting of randomized controlled trials should be improved, to establish strong evidence for the effectiveness of the various therapeutic interventions for acute and chronic low back pain.

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Conservative treatment of acute and chronic nonspecific low back pain. A systematic review of randomized controlled trials of the most common interventions.

In this study, we assessed the influence of three analgesic techniques on postoperative knee rehabilitation after total knee arthroplasty (TKA). Forty-five patients scheduled for elective TKA under general anesthesia were randomly divided into three groups. Postoperative analgesia was provided with i.v. patient-controlled analgesia (PCA) with morphine in Group A, continuous 3-in-1 block in Group B, and epidural analgesia in Group C. Immediately after surgery, the three groups started identical physical therapy regimens. Pain scores, supplemental analgesia, side effects, degree of maximal knee flexion, day of first walk, and duration of hospital stay were recorded. Patients in Groups B and C reported significantly lower pain scores than those in Group A. Supplemental analgesia was comparable in the three groups. Compared with Groups A and C, a significantly lower incidence of side effects was noted in Group B. Significantly better knee flexion (until 6 wk after surgery), faster ambulation, and shorter hospital stay were noted in Groups B and C. However, these benefits did not affect outcome at 3 mo. We conclude that, after TKA, continuous 3-in-1 block and epidural analgesia provide better pain relief and faster knee rehabilitation than i.v. PCA with morphine. Because it induces fewer side effects, continuous 3-in-1 block should be considered the technique of choice. Implications: In this study, we determined that, after total knee arthroplasty, loco-regional analgesic techniques (epidural analgesia or continuous 3-in-1 block) provide better pain relief and faster postoperative knee rehabilitation than i.v. patient-controlled analgesia with morphine. Because it causes fewer side effects than epidural analgesia, continuous 3-in-1 block is the technique of choice.

Effects of Intravenous Patient-Controlled Analgesia with Morphine, Continuous Epidural Analgesia, and Continuous Three-in-One Block on Postoperative Pain and Knee Rehabilitation After Unilateral Total Knee Arthroplasty

The purpose of this review was to identify and analyze the controlled clinical trial data for peripheral neuropathic pain (PNP) and complex regional pain syndromes (CRPS). A total of 72 articles were found, which included 92 controlled drug trials using 48 different treatments. The methods of these studies were critically reviewed and the results summarized and compared. The PNP trial literature gave consistent support (two or more trials) for the analgesic effectiveness of tricyclic antidepressants, intravenous and topical lidocaine, intravenous ketamine, carbamazepine and topical aspirin. There was limited support (one trial) for the analgesic effectiveness of oral, topical and epidural clonidine and for subcutaneous ketamine. The trial data were contradictory for mexiletine, phenytoin, topical capsaicin, oral non-steroidal anti-inflammatory medication, and intravenous morphine. Analysis of the trial methods indicated that mexiletine and intravenous morphine were probably effective analgesics for PNP, while non-steroidals were probably ineffective. Codeine, magnesium chloride, propranolol, lorazepam, and intravenous phentolamine all failed to provide analgesia in single trials. There were no long-term data supporting the analgesic effectiveness of any drug and the etiology of the neuropathy did not predict treatment outcome. Review of the controlled trial literature for CRPS identified several potential problems with current clinical practices. The trial data only gave consistent support for analgesia with corticosteroids, which had long-term effectiveness. There was limited support for the analgesic effectiveness of topical dimethylsulfoxyde (DMSO), epidural clonidine and intravenous regional blocks (IVRBs) with bretylium and ketanserin. The trial data were contradictory for intranasal calcitonin and intravenous phentolamine and analysis of the trial methods indicated that both treatments were probably ineffective for most patients. There were consistent trial data indicating that guanethidine and reserpine IVRBs were ineffective, and limited trial data indicating that droperidol and atropine IVRBs were ineffective. No placebo controlled data were available to evaluated sympathetic ganglion blocks (SGBs) with local anesthetics, surgical sympathectomy, or physical therapy. Only the capsaicin trials presented data which allowed for meta-analysis. This meta-analysis demonstrated a significant capsaicin effect with a pooled odds ratio of 2.35 (95% confidence intervals 1.48, 3.22). The methods scores were higher (P<0.01) for the PNP trials (66.2±1.5, n=66) than the CRPS trials (57.6±2.9, n=26). The CRPS trials tended to use less subjects and were less likely to use placebo controls, double-blinding, or perform statistical tests for differences in outcome measures between groups. There was almost no overlap in the controlled trial literature between treatments for PNP and CRPS, and treatments used in both conditions (intravenous phentolamine and epidural clonidine) had similar results.

A critical review of controlled clinical trials for peripheral neuropathic pain and complex regional pain syndromes.

Background: The evidence-based practice guidelines for the management of chronic spinal pain with interventional techniques were developed to provide recommendations to clinicians in the United States. Objective: To develop evidence-based clinical practice guidelines for interventional techniques in the diagnosis and treatment of chronic spinal pain, utilizing all types of evidence and to apply an evidence-based approach, with broad representation by specialists from academic and clinical practices. Design: Study design consisted of formulation of essentials of guidelines and a series of potential evidence linkages representing conclusions and statements about relationships between clinical interventions and outcomes. Methods: The elements of the guideline preparation process included literature searches, literature synthesis, systematic review, consensus evaluation, open forum presentation, and blinded peer review. Methodologic quality evaluation criteria utilized included the Agency for Healthcare Research and Quality (AHRQ) criteria, Quality Assessment of Diagnostic Accuracy Studies (QUADAS) criteria, and Cochrane review criteria. The designation of levels of evidence was from Level I (conclusive), Level II (strong), Level III (moderate), Level IV (limited), to Level V (indeterminate). Results: Among the diagnostic interventions, the accuracy of facet joint nerve blocks is strong in the diagnosis of lumbar and cervical facet joint pain, whereas, it is moderate in the diagnosis of thoracic facet joint pain. The evidence is strong for lumbar discography, whereas, the evidence is limited for cervical and thoracic discography. The evidence for transforaminal epidural injections or selective nerve root blocks in the preoperative evaluation of patients with negative or inconclusive imaging studies is moderate. The evidence for diagnostic sacroiliac joint injections is moderate. The evidence for therapeutic lumbar intraarticular facet injections is moderate for short-term and long-term improvement, whereas, it is limited for cervical facet joint injections. The evidence for lumbar and cervical medial branch blocks is moderate. The evidence for medial branch neurotomy is moderate. The evidence for caudal epidural steroid injections is strong for short-term relief and moderate for long-term relief in managing chronic low back and radicular pain, and limited in managing pain of postlumbar laminectomy syndrome. The evidence for interlaminar epidural steroid injections is strong for short-term relief and limited for long-term relief in managing lumbar radiculopathy, whereas, for cervical radiculopathy the evidence is moderate. The evidence for transforaminal epidural steroid injections is strong for short-term and moderate for long-term improvement in managing lumbar nerve root pain, whereas, it is moderate for cervical nerve root pain and limited in managing pain secondary to lumbar post laminectomy syndrome and spinal stenosis.

Interventional Techniques: Evidence-based Practice Guidelines in the Management of Chronic Spinal Pain

A randomized double-blind study was performed to elucidate the interrelationships among volume, concentration, and dosage of bupivacaine administered intrathecally. Sixty male patients between the ages of 40 and 80 years having transurethral surgery in the lithotomy position were studied using 10-, 15-, and 20-mg doses of glucose-free bupivacaine as either a 0.5 or a 0.75% solution. Success rate, time of onset and duration of anaglesia and motor block, and cardiovascular responses were assessed. It was found that both 15 and 20 mg of either concentration of bupivacaine provide satisfactory spinal anesthesia for transurethral urologic procedures. However, three of 20 patients receiving the 10-mg dose required supplementation with general anesthesia. Comparison of various volumes and concentrations of bupivacaine indicates that total dosage of bupivacaine is more important than volume or concentration. In several patients with sensory block involving cervical dermatomes, there was no significant hypotension or bradycardia, which suggests that cardiac output and venous return were maintained, perhaps because of the use of lithotomy position.

A dose-response study of bupivacaine for spinal anesthesia.

A statistical model was developed: 1) to compare the efficacy of patient-controlled analgesia (PCA) and traditional intramuscular (IM) opioids for pain relief in 40 patients after total knee replacement and, 2) to evaluate pain cycles associated with each technique. Hourly visual analog pain scores were subjected to two-way analysis of variance (ANOVA) and time-series analysis. Hourly verbal analog pain scores were used to determine predominant pain levels. According to ANOVA, PCA was no more effective than were IM opioids. Time-series analyses documented a complete cycle of pain every 5.3 hours in patients receiving IM opioids but no pain cycle with use of PCA. Analysis of PCA verbal analog scores demonstrated self-administration of opioids to "moderate" levels of pain relief with use of PCA, not to complete analgesia. These results suggest that certain patients may not envision complete postoperative analgesia as being possible. Hence, they self-administer opioids for pain relief with PCA according to their expectations. Population characteristics may modify PCA efficacy. These characteristics should be delineated and the use of PCA targeted to appropriate patients.

A statistical model for pain in patient-controlled analgesia and conventional intramuscular opioid regimens.

The differential levels of sensory blockade of pinprick, cold, and touch were monitored throughout the course of spinal anesthesia administered to 50 patients to determine variations in the degree of spread during onset, plateau, and regression, and to establish the effects of epinephrine and the effect of posture during injection. A significant difference was observed between the dermatomal level of sensory loss of touch and the dermatomal level of loss of either pinprick or cold during onset, at 5 min in patients given tetracaine with epinephrine, at time of maximum spread in patients given tetracaine with epinephrine or in the sitting position, and in all groups during regression. Loss of touch began later, never extended as far cephalad, and regressed sooner. The extent of this difference was greatest during regression, when the anesthetic was given to patients in the sitting position, after epinephrine. The level at which the sense of touch was lost seemed to mark the limits of the zone of solid spinal anesthesia; these limits could not be assessed effectively using pinprick. We propose that loss of touch sensation be used to assess whether anesthesia is adequate to avoid tourniquet pain. If there is loss of touch sensation above the L1 dermatome, it is unlikely that tourniquet pain will occur.

Differential spread of blockade of touch, cold, and pinprick during spinal anesthesia.

The intrapleural administration of bupivacaine for pain relief was evaluated in patients with multiple rib fractures. In six patients an intermittent dosage technique was used. An intrapleural catheter was inserted and 20 ml of 0.5% bupivacaine was administered every 8 hours for 2-3 days and every 12 hours for an additional 3-4 days. Adequate pain relief was achieved in all patients in this group. In addition, the mean Paco2 decreased significantly from 59.5 ± 1.5 mm, Hg before local anesthetic therapy to 37.4 ± 2.0 mm Hg after intrapleural administration of bupivacaine. In a second group of three patients, an initial intrapleural injection of 20 ml of 0.5% bupivacaine was followed by continuous infusion of 0.25 or 0.5% bupivacaine at a rate of 5-10 ml/hour. Infusion was continued for 5-10 days and provided excellent pain relief. Peak mean venous blood levels of bupivacaine varied from 1.1-2.38 μg/ml in these patients. The continuous infusion of 0.5% bupivacaine produced unilateral anesthesia to pinprick from T2-T10, whereas the 0.25% bupivacaine solution produced pain relief without a discernible level to pinprick. Intercostal or abdominal muscle paresis was not noted in any of the nine patients. Intrapleural administration of bupivacaine appears to be an effective means of providing pain relief for patients with multiple rib iractures. Further studies appear warranted to determine the optimal use of this new technique in such patients.

Intrapleural Administration of Local Anesthetics for Pain Relief in Patients with Multiple Rib Fractures: Preliminary Report

Epidural morphine injection followed by a steroid has been reported to be effective for the post-laminectomy pain ('failed back') syndrome. This double-blind, parallel study was undertaken to evaluate that mode of therapy. Twenty-two patients who had undergone at least one prior laminectomy, who were still symptomatic, were randomized to receive 50 mg of lidocaine epidurally with: (a) 75 mg triamcinolone diacetate (TR); or (b) 8 mg of preservative-free morphine (MP); or (c) both (TR and MP), at 1 month intervals for 3 consecutive months. The spinal interspace identified with the patients' pain complaint was the site of injection. For each treatment, patients were admitted to the Clinical Research Center for 24 h and their condition continuously monitored with a pulse oximeter and apnea monitor. Five to 7 patients in each group had pain relief for less than 1 month. No patient given morphine had pain relief for more than 1 month. Life-threatening ventilatory depression occurred in the group given triamcinolone and morphine. The use of morphine alone or combined with slow release triamcinolone does not appear to be appropriate for the treatment of the post-laminectomy pain syndrome.

Angelo G. Rocco

Papers

A dose-response study of bupivacaine for spinal anesthesia.

A statistical model for pain in patient-controlled analgesia and conventional intramuscular opioid regimens.

Differential spread of blockade of touch, cold, and pinprick during spinal anesthesia.

Intrapleural Administration of Local Anesthetics for Pain Relief in Patients with Multiple Rib Fractures: Preliminary Report

Epidural steroids, epidural morphine and epidural steroids combined with morphine in the treatment of post-laminectomy syndrome.