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Anesthesiology 2002 Dec;97(6):1591-6
Laboratory of Pain Physiology, Department of Anesthesiology and Intensive Care Medicine, Herlev University Hospital, Herlev, Denmark.
BACKGROUND: The relative importance of different nociceptive mechanisms for the intensity, duration, and character of postoperative pain is not well established. It has been suggested that sensitization of dorsal horn neurones may contribute to pain in the postoperative period. We hypothesized that wound hyperalgesia in postoperative patients and experimentally heat-induced secondary hyperalgesia share a common mechanism, sensitization of central neurones, and consequently, that the short-acting opioid remifentanil would have comparable effects on hyperalgesia in both conditions. METHODS: In a randomized, controlled, double-blind trial, we assessed mechanical hyperalgesia in skin bordering the surgical wound, and an area of experimentally heat-induced secondary hyperalgesia on the thigh, in 12 patients who underwent abdominal hysterectomy within 5 days prior to the investigation. Observations were made before and during a drug challenge with remifentanil, which has been demonstrated to reduce the area of heat-induced secondary hyperalgesia in volunteers. RESULTS: The area of skin with surgically-induced mechanical hyperalgesia, the area of heat-induced secondary hyperalgesia, and pain during cough, were significantly reduced during remifentanil infusion compared with placebo (P = 0.008, P = 0.006, and P = 0.002, respectively). The relative reduction (% of baseline) of the area of skin with surgically-induced hyperalgesia and heat-induced secondary hyperalgesia during infusion of remifentanil was significantly associated (R2 = 0.72, P = 0.001). CONCLUSIONS: Although remifentanil is not a highly targeted "antihyperalgesic," these results support the hypothesis that both wound hyperalgesia in postoperative patients and experimentally heat-induced secondary hyperalgesia may share common mechanisms, and that central neuronal sensitization may contribute to some aspects of postoperative pain. Antihyperalgesic drugs should be further developed and evaluated in clinical trials of postoperative pain.
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PMID: 12459689, UI: 22346949
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Br J Anaesth 2002 Nov;89(5):782-5
Whipps Cross Hospital, Whipps Cross Road, Leytonstone, London E11 1NR, UK.
We present the cases of three women who, within a 6-month period, suffered post-partum generalized tonic-clonic seizures. All had received an epidural in labour for analgesia and were subsequently diagnosed as suffering from postdural puncture headache. All were treated for that headache with Synacthen and one also received sumatriptan before her seizures. All made satisfactory recoveries and were discharged home. None displayed classical patterns suggestive of pre-eclampsia, meningitis, cortical venous thrombosis or any other pathological process that might explain these events adequately, and the specific precipitating factors were left unidentified.
PMID: 12393783, UI: 22280484
Br J Anaesth 2002 Nov;89(5):778-82
Gloucestershire Royal Hospital, Great Western Road, Gloucester GL1 3NN, UK.
We present three cases of epidural abscess, all in patients in whom an epidural catheter had been inserted for postoperative pain management. In all three cases the infecting organism was Staphylococcus aureus and two patients had diabetes. The diagnosis was made within 3 days of epidural catheter removal in two cases, but in one the abscess did not present until after the patient had been discharged from hospital. We have retrospectively calculated the incidence of epidural abscess in our hospital over the 5-yr period 1993-98 to be 1 in 800 (0.12%). We emphasize the importance of using techniques that minimize the risk of bacterial contamination during both catheter placement and the management of infusion, and seek to raise awareness of this relatively rare but significant condition.
PMID: 12393782, UI: 22280483
Br J Anaesth 2002 Nov;89(5):760-1
Department of Anaesthesiology and Intensive Care Medicine, Philipps-University of Marburg, Baldingerstrasse, D-35033 Marburg, Germany.
BACKGROUND: Several attempts have been made to evaluate patients' concerns with respect to postoperative recovery. To identify aspects of postoperative recovery relevant to patients, several methodological and statistical approaches have been used. One of the first to provide useful information was Fredrick Orkin who used conjoint analysis. This methodology is usually performed by market researchers to learn about the relative importance of product attributes. We used conjoint analysis in the present study. METHODS: A total of 220 patients undergoing preoperative anaesthetic examination before impending surgery under general anaesthesia were asked to rate nine scenarios during immediate postoperative recovery based on four factors (alertness, pain, postoperative nausea and vomiting (PONV), and extra costs) each with three levels. Using conjoint analysis the relative impact of each factor on ranking the scenarios was assessed. RESULTS: The relative importance of the four factors (as a percentage of the preference decision) was PONV (49%), pain (27%), alertness (13%), and additional costs (11%). CONCLUSION: Avoidance of PONV is a major concern for patients before surgery.
PMID: 12393775, UI: 22280476
Br J Anaesth 2002 Nov;89(5):697-701
Department of Anaesthesiology and Critical Care, Centre Hospitalier Universitaire Pitie-Salpetriere, Assistance Publique-Hopitaux de Paris (AP-HP), Universite Pierre et Marie Curie, Paris, France.
BACKGROUND: Postoperative morphine titration frequently induces sedation. The assumption is made that patients sleep when their pain is relieved. Some patients complain of persistent pain when they awake. We studied the time-course of sedation and analgesia to understand the determinants of patients' sleep during morphine titration. METHODS: Seventy-three patients requiring morphine titration in a post-anaesthetic care unit after major surgery, were studied. Fifty-two patients slept (Sleep group) and 21 did not (Awake group). When a patient slept during titration, morphine was discontinued. Visual analogue pain scale (VAS), Ramsay score (RS), and the bispectral index (BIS) were recorded at the beginning of titration (STonset), at sleep onset (STsleep), then 5, 10, 20, and 30 min afterwards (ST4). RESULTS: In the Sleep group, mean (SD) RS increased from 1.7 (0.4) to 2.4 (0.6) (P<0.05 vs STonset) and BIS decreased from 95 (5.0) to 89.8 (10.2) between STonset and STsleep (P<0.05), RS remained stable thereafter. Conversely, RS and BIS remained unaltered in the Awake group. The reduction in VAS was comparable between groups (from 78 (17) to 39 (21), and from 64 (16) to 30.4 (11), respectively). Even though mean (SD) VAS was 39 (21) at ST4 in the Sleep group, 13 patients (25%) maintained a VAS above 50 mm. CONCLUSION: We observed dissociated effects of morphine on the time-course of sedation and analgesia with sedation occurring first, followed by analgesia. Therefore, morphine-induced sedation should not be considered as an indicator of an appropriate correct level of analgesia during i.v. morphine titration.
PMID: 12393765, UI: 22280466
Clin Orthop 2002 Dec;405:306-25
*Division of Orthopaedic Surgery, **Department of Radiology, and dagger Department of Pathology, Children's Hospital of Philadelphia, Philadelphia, PA.
[Medline record in process]
PMID: 12461387, UI: 22349286
JAMA 2002 Dec 4;288(21):2745-6
PMID: 12460100, UI: 22350024
Pain 2002 Dec;100(3):299-301
Pain Relief Unit, Rambam Medical Center, The B. Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, P.O. Box 9602, 31096, Haifa, Israel
This case presents a patient with neuropathic pain in a lower extremity, which appeared subsequent to the removal of a C1 meningioma and which was successfully treated by lower thoracic spinal cord stimulation.
PMID: 12468001, UI: 22356984
Pain 2002 Dec;100(3):291-8
Division of Public Health Services and Research, College of Dentistry, University of Florida, P.O. Box 100404, 32610-0404, Gainesville, FL, USA
The purpose of this study was to examine racial/ethnic-related differences in a four-stage model of the processing of chronic pain. The subjects were 1557 chronic pain patients (White=1084, African American=473) evaluated at a pain management clinic at a large southeastern university medical center. Using an analysis of covariance controlling for pain duration and education, African American patients reported significantly higher levels of pain unpleasantness, emotional response to pain, and pain behavior, but not pain intensity than Whites. Differences were largest for the unpleasantness and emotion measures, particularly depression and fear. The groups differed by approximately 1.0 visual analogue scale unit, a magnitude that may be clinically significant. Racial/ethnic differences in the linear relationship between stages were also tested using structural equation modeling and LISREL-8. The results indicate differences in linear associations between pain measures with African Americans showing a stronger link between emotions and pain behavior than Whites.
PMID: 12468000, UI: 22356983
Pain 2002 Dec;100(3):271-9
California School of Professional Psychology, San Diego, 10455 Pomerado Road, 92131, San Diego, CA, USA
The major objective of this research was to evaluate the predictors of fatigue in patients with fibromyalgia (FM), using cross-sectional and daily assessment methodologies. In the cross-sectional phase of the research involving a sample of 105 FM patients, greater depression and lower sleep quality were concurrently associated with higher fatigue. While pain was correlated with fatigue, it did not independently contribute to fatigue in the regression equation. For a subset of patients from the cross-sectional sample (n=63) who participated in a week of prospective daily assessment of their pain, sleep quality, and fatigue, multiple regression analysis of aggregated (averaged) daily scores revealed that previous day's pain and sleep quality predicted next day's fatigue. Depression from the cross-sectional phase was not related to aggregated daily fatigue scores. A path analytic framework was tested with disaggregated (removing between subjects variability) data in which pain was predicted to contribute to lower sleep quality which, in turn, was predicted to lead to greater fatigue. The results revealed that poor sleep quality fully accounted for the positive relationship between pain and fatigue, thus substantiating the mediational role of sleep quality. The findings are indicative of a dysfunctional, cyclical pattern of heightened pain and non-restful sleep underlying the experience of fatigue in FM.
PMID: 12467998, UI: 22356981
Pain 2002 Dec;100(3):259-69
Istituto di Fisiologia Umana and Istituto di Reumatologia, Universita degli Studi, 53100, Siena, Italy
In this study, we evaluated pain sensitivity in patients with fibromyalgia or other types of chronic, diffuse musculoskeletal pain to establish whether fibromyalgia represents the end of a continuum of dysfunction in the nociceptive system. One hundred and forty five patients and 22 healthy subjects (HS) completed an epidemiological questionnaire to provide information about fatigue, stiffness, sleep, the intensity of pain (VAS 0-100) and its extent both at onset and at present. Algometry was performed at all American College of Rheumatology (ACR) tender points and at ten control points. Patients were divided into five main groups: fibromyalgia (FS) patients, secondary-concomitant fibromyalgia (SCFS) patients, patients with widespread pain (WP) but not reaching the ACR criterion of 11 tender points, patients with diffuse multiregional pain (MP) not reaching the ACR criteria (widespread pain, tender point counts), and patients with multiregional pain associated with at least 11 tender points (MPTE). von Frey monofilaments were used to assess superficial punctate pressure pain thresholds. Heat and cold pain thresholds were determined with a thermal stimulator. Ischemic pain was assessed by the cold pressure test and the submaximal effort tourniquet test. The scores for stiffness and present pain intensity gradually increased concomitantly with the increase in tender point count and pain extent. The pressure pain thresholds for positive tender and positive control points were significantly lower in the SCFS, FS and MPTE groups than in HS, MP and WP groups, the latter three groups displaying similar values. In all groups, there were no differences in pain thresholds between positive tender and positive control points. The heat pain threshold and the pain threshold in the cold pressure test were lower in the FS and SCFS groups than in HS. The cold pressure tolerance was lower in patients with widespread pain than in HS. In the von Frey test, all patient groups except MP had similar values, which were significantly lower than in HS. Finally, all patient groups displayed lower tourniquet tolerance than HS. In each psychophysical test, patients with widespread pain and patients with multiregional pain showed similar thresholds; however, the thresholds in the MP or MPTE groups differed from those in the FS and SCFS groups. In the FS group, pain thresholds and pain tolerance did not differ according to the presence of ongoing pain at the stimulated site and were not correlated to ongoing pain. The results indicate that dysfunction in the nociceptive system is already present in patients with multiregional pain with a low tender point count; it becomes more and more severe as the positive tender point count and pain extent increase and it is maximal in fibromyalgia patients.
PMID: 12467997, UI: 22356980
Pain 2002 Dec;100(3):231-42
Department of Physical Medicine and Rehabilitation, University of Alabama at Birmingham, Birmingham, AL, USA
Two studies were designed to examine important predictors of pain following spinal cord injury (SCI), and the impact of pain on self-reported quality of life (QOL). Pain was defined as 'interference in day-to-day activities secondary to pain'. In order to determine risk factors associated with the development of pain interference, Study 1 examined the predictive validity of multiple demographic, medical, and QOL variables at year 1 post-SCI to self-reported pain interference 2 years post-injury. Results showed that middle age (30-59-year-olds), lower self-reported mental health, and pain interference at 1 year post-SCI were the most important unique predictors of pain interference 2 years post-SCI. In Study 2, participants were separated into four groups; (1) those pain-free at years 1 and 2, (2) those pain-free at year 1 and in pain at year 2, (3) those in pain at year 1 and pain-free at year 2, and (4) those in pain at years 1 and 2. Results showed that only those experiencing a change in pain interference status reported a change in QOL. More specifically, those developing pain interference (group 2) from year 1 to year 2 reported decreased life satisfaction, physical health, and mental health, whereas, those with resolving pain interference from year 1 to year 2 reported an increase in these same domains. Unexpectedly, change in pain interference status was unrelated to change in self-reported handicap. Implications and future directions are discussed.
PMID: 12467994, UI: 22356977
Pain 2002 Dec;100(3):219-229
Purdue Biopharma LP, 201 College Road East, 08540, Princeton, NJ, USA
[Record supplied by publisher]
Inoculation of syngeneic MRMT-1 mammary tumour cells into one tibia of female rats produced tumour growth within the bone associated with a reduction in bone mineral density (BMD) and bone mineral content (BMC), severe radiological signs of bone destruction, together with the development of behavioural mechanical allodynia and hyperalgesia. Histological and radiological examination showed that chronic treatment with the bisphosphonate, zoledronic acid (30&mgr;g/kg, s.c.), for 19 days significantly inhibited tumour proliferation and preserved the cortical and trabecular bone structure. In addition, BMD and BMC were preserved and a dramatic reduction of tartrate resistant acid phosphatase-positive polykaryocytes (osteoclasts) was observed. In behavioural tests, chronic treatment with zoledronic acid but not the significantly less effective bisphosphonate, pamidronate, or the selective COX-2 inhibitor, celebrex, attenuated mechanical allodynia and hyperalgesia in the affected hind paw.Zoledronic acid also attenuated mechanical hyperalgesia associated with chronic peripheral neuropathy and inflammation in the rat. In contrast, pamidronate or clodronate did not have any anti-hyperalgesic effect on mechanical hyperalgesia in the neuropathic and inflammatory pain models.We conclude that zoledronic acid, in addition to, or independent from, its anti-metastatic and bone preserving therapeutic effects, is an anti-nociceptive agent in a rat model of metastatic cancer pain. This unique property of zoledronic acid amongst the bisphosphonate class of compounds could make this drug a preferred choice for the treatment of painful bone metastases in the clinic.
PMID: 12467993
Pain 2002 Dec;100(3):213-7
MGH Pain Center, Department of Anesthesia and Critical Care, Massachusetts General Hospital, Harvard Medical School, 02114, Boston, MA, USA
PMID: 12467992, UI: 22356975
Pain 2002 Dec;100(3):211-2
Department of Psychiatry, Behavioral Sciences, Duke University Medical Center, Durham, NC 27710, USA
PMID: 12467991, UI: 22356974
Pain 2002 Sep;99(1-2):333-40
Pain Research Center, Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA.
Abnormal impulses caused by very slowly inactivating Na channels of peripheral nerve have been proposed to play a critical role in neuropathic pain. Low concentrations of local anesthetics, often effective in treating experimental and clinical neuropathic pain, are also known to potently suppress the long after-depolarizations induced by these persistently open Na channels. However, these drug actions on impulses that have propagated away from such sites are undetermined. In the present study, the focal application of anemone toxin II (ATX, 300 nM), which slows Na-channel inactivation, produced prolonged depolarizing after-potentials and, coincidentally, induced spontaneous bursting impulse activity that propagated away from the site of ATX application in the frog sciatic nerve in vitro. The application of low concentrations of lidocaine (1-10 microM), both at the site of ATX exposure and at a distant site, selectively and reversibly inhibited the spontaneous bursting, while having no effect on the electrically stimulated initial spike of the compound action potential. Inhibition occurred as a shortening of burst episodes rather than a reduction in frequency of impulses within a burst or a reduction of intraburst impulse amplitude. Tetrodotoxin also inhibited the induced spontaneous activity, but only at concentrations that also depressed the compound action potential spike. These findings show that low concentrations of lidocaine can restore normal firing patterns in nerve where hyperexcitability has been caused by delayed Na-channel inactivation, without acting directly at the site where ectopic impulses are generated. Thus, it appears that the pattern of abnormal activity rather than an abnormally gating Na channel per se can be a target for lidocaine's therapeutic action. Copyright 2002 International Association for the Study of Pain
PMID: 12237212, UI: 22222890
Spine 2002 Dec 1;27(23):2734-40
Department of Social Services Research, Norwegian Directorate for Health and Social Welfare, Oslo, Norway. inger.scheel@shdir.no
STUDY DESIGN: A cluster-randomized controlled trial. OBJECTIVE: To evaluate the effects of two strategies to increase the use of active sick leave (ASL) among patients with low back pain (LBP) on improved return to work and quality of life. SUMMARY OF BACKGROUND DATA: Active sick leave is an option provided by the Norwegian National Insurance Administration that enables employees to return to modified duties at the workplace with 100% of normal wages. A proactive implementation strategy increased the use of ASL for LBP patients from 11.5% to 17.7% compared with a passive intervention and a control group ( = 0.006). METHODS: Sixty-five municipalities were randomly assigned to a passive intervention, a proactive intervention, or a control group. The interventions, which were designed to improve the use of ASL, were targeted at patients on sick leave for LBP for more than 16 days (n = 6179), their general practitioners, employers, and local insurance officers. The main outcome measures were the average number of days off work, the proportion of patients returning to work within 1 year, and self-reported quality of life while on sick leave. RESULTS: The median number of days on sick leave was similar in the proactive intervention group (70 days), the passive intervention group (68 days), and the control group (71 days) ( = 0.8). The proportion of patients returning to work before 50 weeks was also similar in the proactive (89%), passive (89.5%), and control groups (89.1%). Response rates for the questionnaires that were sent to patients were low (38%), and no significant differences were observed across the three groups for quality of life or patient satisfaction. CONCLUSIONS: It is not likely that efforts to increase the use of ASL will result in measurable economic benefits or improved health outcomes at the population level. The benefits of ASL for individual patients with LBP are not known.
PMID: 12461401, UI: 22350494