A facet-based system for computer-assisted instruction in pain management for elderly patients.

DIANA2, a web-based interactive tutor for pain management (see www.talariainc.com), was more effective than conventional methods of learning (such as reading articles that contain the same type of information) in making the principles of pain management for the elderly more easily accessible to learners. DIANA2 was similarly effective for different types of health care providers (students, nurses, and residents), and the study participants were excited by their experience with a different mode of learning. DIANA is based on interactive facet-based learning principles that guide learners to reflect on their understanding of the situation and to modify and augment their understanding in response to real-time facet-specific feedback.

Long-term transcutaneous electrical nerve stimulation (TENS) use: impact on medication utilization and physical therapy costs.

OBJECTIVE: A study was conducted to assess a variety of treatment outcomes in long-term users of transcutaneous electrical nerve stimulation (TENS) who suffer from chronic pain. Key components of the study examined the effects of long-term TENS therapy on pain-related medications and physical/occupational therapy (PT/OT) use. DESIGN: From a population of 2,(X)3 chronic pain patients (CPPs) who acquired a TENS device (Epix XL, Empi, Inc., St. Paul, MN, U.S.A.) for pain management, a randomly selected sample of 376 patients who used TENS were interviewed by telephone by an independent research firm. The survey assessed a variety of outcome variables including changes in medication use, number of pain-related medications, and use of PT/OT prior to TENS and after a minimum 6 months of TENS treatment. The data were subjected to a paired t test analysis. A cost simulation model was then applied to the medication and PT/OT data. RESULTS: The mean duration of pain, for which TENS was prescribed, was 40 +/- 60 months. As compared with the period prior to TENS use, this long-term TENS user group reported a statistically significant reduction in the following types of pain medications: opiate analgesics, tranquilizers, muscle relaxants, nonsteroidal anti-inflammatory drugs (NSAIDs), and steroids. PT/OT use was also significantly reduced. Cost simulations of pain medications and PT/OT are presented. CONCLUSIONS: Long-term use of TENS is associated with a significant reduction in the utilization of pain medication and PT/OT. In this study population, cost simulations of medication and PT/OT indicate that with long-term TENS use, costs can be reduced up to 55% for medications and up to 69% for PT/OT. The potential for TENS associated improvement, combined with reduced medication-related complications and costs, are important points that clinicians should consider when constructing a treatment plan for chronic pain patients. Finally, cost simulation techniques provide a useful tool for assessing outcomes in pain treatment and research.

Prescription opiate abuse in chronic pain patients: clinical criteria, incidence, and predictors.

OBJECTIVES: Opiates are commonly used to treat patients with chronic nonmalignant pain. There is much controversy over the definition, incidence, and risk factors of prescription opiate abuse in chronic pain treatment. The present study, done at the Seattle VA Medical Center, was designed to create opiate abuse criteria, test inter-rater reliability of the criteria, apply the criteria to a group of chronic pain patients, and correlate the risk of opiate abuse with the results of alcohol and drug testing. DESIGN/OUTCOME MEASURES: A committee of experienced pain providers designed a five-point prescription opiate abuse checklist based on DSM-III-R parameters. The criteria were then applied to patients enrolled in the pain clinic. The reliability of the criteria were determined using two providers who were familiar with every patient in the clinic. Drug, alcohol, and psychosocial testing were correlated with the risk of opiate abuse. RESULTS: A total of 19% (76/403) of all pain clinic patients were using chronic opiates. Thirty-four percent (26/76) met one, and 27.6% (21/76) met three or more of the abuse criteria. The criteria had an inter-rater reliability of > 0.9. There were no differences between chronic opiate users (n = 76) and opiate abusers (n = 21) for a history of drug or alcohol abuse or on psychosocial testing. CONCLUSIONS: Prescription opiate abuse criteria for use in patients with chronic nonmalignant pain were designed. The criteria had good reliability and can be applied during normal clinic interactions. The percentage of chronic opiate users who become opiate abusers in pain treatment is within the range reported by others. Past opiate or alcohol abuse or psychosocial testing on clinic admission failed to predict who would become an opiate abuser. The criteria can be used to identify patients who will subsequently require more intensive treatment or intervention or can be used as an outcome to measure to test the effectiveness of treatment strategies.

Transcutaneous electrical nerve stimulation (TENS) treatment outcome in long-term users.

OBJECTIVE: Previous reviewers of the literature on transcutaneous electrical nerve stimulation (TENS) outcome have concluded the following: (a) there are few long-term TENS follow-up studies, and (b) fewer studies have addressed the effect of long-term TENS use on outcome variables other than pain (e.g., function). DESIGN/SETTING/PARTICIPANTS/OUTCOME MEASURES: From a population of 2,003 chronic pain patients (CPPs) who bought a TENS device for pain management, 506 patients were randomly selected and interviewed by telephone long enough after purchase to allow at least 6 months of TENS use. The interview process used a structured "skip" questionnaire designed to assess the CPPs' perceptions regarding the effectiveness of TENS for a variety of outcome variables. Of the 506 CPPs interviewed, 376 (74.3%) had used their TENS device for 6 months or longer and were defined as long-term users. The responses of this group of CPPs to the telephone questionnaire were then subjected to statistical analysis. RESULTS: Paired t-tests, correlated z-tests, SS Wilks, and chi-square tests demonstrated statistically significant change or improvement (p < 0.05) that paralleled the introduction of TENS use in the following outcome variables: less pain interference with work, home, and social activities; increased activity level and pain management; decreased use of other therapies (e.g., physical therapy, occupational therapy, chiropractic); decreased use of narcotics, tranquilizers, muscle relaxants, nonsteroidal anti-inflammatory drugs and steroids. CONCLUSIONS: The results suggest that TENS is associated with improvement on multiple outcome variables in addition to pain relief for CPPs who are long-term users. Also, for some CPPs, long-term TENS use continues to be effective.

Persistent low-back pain is real. However, diagnostic spinal injections are not helpful in its evaluation.

We endeavored to assess the short-term effects of intrathecal fentanyl and lidocaine in chronic-pain patients by ascertaining whether the opioid fentanyl, by virtue of its lack of sensory and motor paralysis, conferred any diagnostic advantages over lidocaine, a local anesthetic whose effects include sensory and motor paralysis. Neuraxial administration of fentanyl has been touted as an improved diagnostic tool to distinguish between peripheral and central pain, because the absence of sensory and motor effects may avert the patient's presumption of the onset of analgesia based on these cues. Twenty-two patients with persistent low-back pain, whose investigations had determined that they were not surgical candidates, were studied using a counter-balanced, placebo-controlled, and double-blinded crossover design. Each patient received three separate lumbar intrathecal injections of equal volume (1.4 ml): cerebrospinal fluid, fentanyl 25 micrograms, and lidocaine 70 mg. Pain and symptom assessments were performed preinjection (baseline), and at regular intervals up to and including 4 h postinjection. Pain was evaluated by verbal patient response using a numerical pain-rating system of 0 to 10. Duration of analgesia, sensation of warmth, and adverse effects were noted. Statistical analyses were performed using nonparametric tests. Subjects' average age was 56 years, with a median low-back pain duration of 16 years. There were no significant differences in the baseline median-pain scores among injection types. The baseline and best cerebrospinal fluid-pain scores were significantly different, suggesting a placebo effect. The best pain scores for fentanyl and lidocaine were superior to their own baseline levels and to the best cerebrospinal fluid scores.(ABSTRACT TRUNCATED AT 250 WORDS)

The use of oral mexiletine for the treatment of pain after peripheral nerve injury.

Neuropathic pain is often a difficult condition to treat. Clinical and laboratory studies using intravenously administered local anesthetics or antiarrhythmic agents support the use of these drugs for the treatment of neuropathic pain. The availability of the oral antiarrhythmic medication, mexiletine, has made it possible to study the effects of an orally administered medication on chronic neuropathic pain. The study used a double-blind placebo-controlled design to examine 11 subjects in whom treatment with conventional pain medications had been unsuccessful. Subjects had a history of peripheral nerve injury or dysfunction, and all complained of symptoms consistent with neuropathic pain. After baseline pain measurements, mexiletine or placebo was given in gradually increasing doses to a maximum daily dose of 750 mg mexiletine. After 1 month at steady state, the subject received the alternative medication. Mexiletine was found to produce a statistically significant reduction in reported pain when compared to baseline or placebo. Pain scores were rated on a scale from 0 (no pain) to 10 (unbearable pain). Median pain scores prior to mexiletine were 7, after placebo treatment 7, and while receiving mexiletine (750 mg/day) 4. Side effects were mild and well-tolerated. Mexiletine may be effective in reducing neuropathic pain for patients in whom alternative pain medications have been unsatisfactory.

An objective comparison of intrathecal lidocaine versus fentanyl for the treatment of lower extremity spasticity.

The reduction of spasticity after administration of intrathecal fentanyl, 35 micrograms, and intrathecal lidocaine, 50 mg, was compared with preinjection spasticity levels in ten subjects with central nervous system disease or injury. Spasticity was objectively assessed by an electronic instrument that simultaneously measures degrees of extension and force during passive knee extension. Duration of spasticity relief and adverse effects were recorded. Both drugs equally reduced spasticity and increased the range of motion. There were no supraspinal side effects from the fentanyl, whereas three subjects became hypotensive after receiving lidocaine. The reduction of spasticity with intrathecal fentanyl lasted at least 3 h. The authors postulate that fentanyl reduced spasticity by an effect on spinal pathways. Intrathecal fentanyl should be considered as an alternative to lidocaine for diagnostic blocks in patients with spasticity.

The dynamic flexometer: an instrument for the objective evaluation of spasticity.

Anesthesiologists may care for patients who have spasticity in the operating room or pain clinic. A number of therapeutic modalities for treatment of spasticity exist, but there are few simple objective methods for evaluating their effect. We describe one instrument, the Dynamic Flexometer, that measures the force required to move the limb passively through its maximum range of motion. The data presented validate the instrument's reliability. Two clinical cases presented here demonstrate the instrument's utility. This device may be of value to anesthesiologists involved in the care of patients with spasticity.

Intrathecal methadone and morphine for postoperative analgesia: a comparison of the efficacy, duration, and side effects.

A double-blind study of patients selected at random compared the analgesic and adverse effects of intrathecal methadone (1 mg) with those of intrathecal morphine (0.5 and 1 mg). The study was conducted on 30 patients who underwent major orthopedic or urologic surgery. The intrathecal opioid was administered at the end of surgery, and assessments began 1 h thereafter and continued for 20 h. Pain measurements, supplementary analgesia requirements, and adverse effects were recorded. Intrathecal morphine (0.5 and 1 mg) provided effective and prolonged analgesia. Methadone, however, was unable to ensure the same degree of analgesia; consequently, the median pain scores were consistently higher following methadone than morphine (0.5 and 1 mg) (P less than 0.05). The time to the onset of discomfort severe enough to require supplemental morphine was longer after intrathecal morphine than that following methadone (24 and 29 h with morphine 0.5 and 1 mg; 6.5 h with methadone; P less than 0.05). Respiratory depression (increases PaCO2) was not associated with methadone and morphine 0.5 mg but was common following morphine 1 mg (P less than 0.05). Facial pruritus was unique to intrathecal morphine. Urinary retention requiring bladder catheterization was more frequent following morphine than methadone, although this was not statistically significant. Nausea and vomiting were common to all groups. Intrathecal morphine (0.5 and 1 mg) provides superior postoperative analgesia to 1 mg methadone. Various explanations for the observed differences between the drugs are discussed, including the possibility that the dose of methadone used in the subarachnoid space was inadequate and that a larger dose might have produced an effect equal to that of morphine.

Intrathecal fentanyl depresses nociceptive flexion reflexes in patients with chronic pain.

To investigate the selective role of intraspinal opioids on the perception and modulation of pain, seven subjects with chronic hip or back pain and one subject with C-6 quadriplegia received 25 micrograms of intrathecal fentanyl. The effect of lumbar intrathecal fentanyl on reported pain, nociceptive flexor withdrawal reflexes, a monosynaptic motor arc (H-reflex), and supraspinal effects such as miosis, nausea, respiratory depression was evaluated. In five of eight subjects the flexor withdrawal reflex was completely abolished within 15 min. In the others the reflex was significantly depressed from control values. Decreases in reported pain paralleled the decrease in the flexor reflex, H-reflexes remained unchanged, and no supraspinal side effects were observed. It is likely that these selective changes observed were from the isolated effect of fentanyl modulating nociception at the spinal cord level.

A dose-response study of intrathecal morphine: efficacy, duration, optimal dose, and side effects.

We performed a double-blind study of the dose-response relationship of intrathecal morphine (0, 0.3, 1, and 2.5 mg) for postoperative pain relief in 33 subjects who underwent total knee or hip replacement surgery. Assessments commenced 1 hour after the opioid injection, which was given at the end of surgery, and continued for 24 hours. Pain measurements, supplementary analgesia requirements, and adverse effects were recorded. Intrathecal morphine provided effective, long-lasting pain relief. All doses delayed the initial perception of discomfort (T-Pain) and also postponed the onset of severe pain requiring analgetic supplementation (T-Morphine) (1.25 hours control with placebo injections; greater than 20 hours with intrathecal morphine 0.3, 1, and 2.5 mg: P less than 0.05). Although 0.3 mg usually provided good analgesia it was unsatisfactory in three of 10 patients (30%), whereas 1 and 2.5 mg were absolutely reliable. Respiratory depression (increased PaCO2), common after the administration of 1 or 2.5 mg intrathecal morphine, was slow in onset and prolonged. The respiratory depression after 2.5 mg was more profound than after 1 mg, and produced apnea necessitating large-dose naloxone therapy. Pruritus was unique to intrathecal morphine administration, but nausea, vomiting, and urinary retention were common in all the groups. We conclude that no ideal dose of intrathecal morphine exists because, even with small quantities, minor adverse effects are evident. Doses between 0.3 and 1 mg, however, should provide good analgesia free from the major complication, respiratory depression.

Effects of intrathecal fentanyl and lidocaine on somatosensory-evoked potentials, the H-reflex, and clinical responses.

Intravenous narcotics increase the latency of somatosensory-evoked potentials (SSEPS), which are decreased but not abolished by epidural local anesthetics. In addition, intrathecal narcotics decrease spasticity in patients with central nervous system disease. This study of the effects of intrathecal fentanyl on posterior tibial SSEPS and the monosynaptic H-reflex arc found that intrathecal fentanyl had no effect on the latency of SSEPS, indicating the effects of narcotics on SSEPS are likely to exist at a supraspinal level. H-reflexes were not affected, confirming the lack of effect on this spinal motor reflex. In the same group of patients, intrathecal lidocaine administered 1 week later completely abolished SSEPS and H-reflexes. Complete suppression of SSEPS corresponded to full motor blockade, but sensation to pain and temperature was already many dermatomes higher than the S1 level. Return of SSEPS occurred with return of motor but not sensory function, indicating the likelihood that SSEPS are carried at least in part by large A-fibers. The study shows that spinal narcotics neither affect the transmission of SSEPS nor decrease the H-reflex, a spinal motor reflex. In addition, changes in SSEPS after intrathecal lidocaine do not correlate with the level of surgical anesthesia.

Resuscitation of dogs from cold-water submersion using cardiopulmonary bypass.

In cold-water drowning, attempts at restoration of spontaneous circulation (ROSC) by external cardiopulmonary resuscitation (CPR) often fail. We explored the longest period of asphyxial cardiac arrest from cold-water submersion (without inhalation of water) from which ROSC is possible using cardiopulmonary bypass (CPB). In 19 lightly anesthetized dogs the tracheal tube was clamped (simulating laryngospasm) and the dogs were immersed in ice water from 20, 40, 60, 90, or 120 minutes. Cardiac arrest occurred after six to 11 minutes of submersion. At start of resuscitation, rectal temperature ranged from 21 C (after 60 minutes) to 34 C (after 20 minutes of submersion), and cerebral temperature was between 7 C (after 120 minutes) and 27 C (after 20 minutes submersion). Resuscitation attempts were performed according to protocol in 16 dogs, using only CPB by venoarterial pumping with an oxygenator and a heat exchanger. Priming was with 400 to 800 mL Dextran 40 and Ringer's solution 1:1 plus heparin. CPB flows were 10 mL/kg/min, and they increased to achieve normotension and return of rectal temperature to 32 C. After one-half to three hours, of CPB, ROSC was successful in 75%. This percentage included one of three dogs after 90 minutes submersion, but not in the one dog after 120 minutes submersion. Spontaneous breathing and EEG activity returned in 56% at two to 24 hours, after 20 to 90 minutes of submersion. Failure of ROSC attempts apparently were due to clotting in large vessels during arrest and capillary leakage during reperfusion. CPB is effective for ROSC after prolonged hypothermic cardiac arrest, and it should be evaluated in animal outcome studies.