Submitted for publication March 16, 2001.
[Record supplied by publisher]
PMID: 11748415
Anesthesiology 2001 Dec;95(6):1473-1479
Submitted for publication April 6, 2001.
BACKGROUND: The new anticonvulsants, gabapentin and pregabalin, are effective in the treatment of neuropathic pain. The sites and mechanisms of their analgesic action are not fully known. The authors have previously demonstrated that systemic gabapentin suppresses ectopic afferent discharges recorded from injured sciatic nerves in rats. In the current study, they further examined the stereospecific effect of pregabalin on neuropathic pain and afferent ectopic discharges in a rodent model of neuropathic pain. METHODS: Tactile allodynia and thermal hyperalgesia were induced by partial ligation of the left sciatic nerve in rats. Single-unit activity of afferent ectopic discharges was recorded from the sciatic nerve proximal to the site of ligation. RESULTS: Intravenous injection of 10-30 mg/kg pregabalin dose-dependently attenuated tactile allodynia (n = 10) and thermal hyperalgesia (n = 8). The stereoisomer of pregabalin, R-3-isobutylgaba, had no analgesic effect in this dose range. Furthermore, intravenous injection of pregabalin, but not R-3-isobutylgaba, significantly inhibited the ectopic discharges from injured afferents in a dose-dependent manner (from 20.8 +/- 2.4 impulses/s during control to 2.3 +/- 0.7 impulses/s after treatment with 30 mg/kg pregabalin, n = 15). Pregabalin did not affect the conduction velocity of afferent fibers and the response of normal afferent nerves to mechanical stimulation. CONCLUSIONS: These data strongly suggest that the analgesic effect of pregabalin on neuropathic pain is likely mediated, at least in part, by its peripheral inhibitory action on the impulse generation of ectopic discharges caused by nerve injury.
PMID: 11748408
Anesthesiology 2001 Dec;95(6):1356-1361
Submitted for publication December 22, 2000.
BACKGROUND: The visual analog scale is widely used in research studies, but its connection with clinical experience outside the research setting and the best way to administer the VAS forms are not well established. This study defines changes in dosing of intravenous patient-controlled analgesia as a clinically relevant outcome and compares it with VAS measures of postoperative pain. METHODS: Visual analog scale measurements were obtained from 150 patients on the morning after intraabdominal surgery. On the same afternoon, 50 of the patients provided a VAS score on the same form used in the morning, 50 on a new form, and 50 were not asked for a second VAS measurement. RESULTS: Visual analog scale values and changes in value were similar for patients who were given a new VAS form in the afternoon and those who used the form that showed the morning value. The proportions of patients requesting additional analgesia were 4, 43, and 80%, corresponding to afternoon VAS scores of 30 or less, 31-70, and greater than 70, respectively. Change from morning VAS score had no apparent influence on patient-controlled analgesic dosing for patients with afternoon values of 30 or less or greater than 70, but changes in VAS scores of at least 10 did discriminate among patients whose afternoon values were between 31 and 70. CONCLUSIONS: When pain is an outcome measure in research studies, grouping final VAS scores into a small number of categories provides greater clinical relevance for comparisons than using the full spectrum of measured values or changes in value. Seeing an earlier VAS form has no apparent influence on later values.
PMID: 11748392
Ann Intern Med 2001 Dec 18;135(12):1038-1046
Research and Training Institute, Hebrew Rehabilitation Center for Aged, 1200 Centre Street, Boston, MA 02131-1097.
BACKGROUND: Widespread musculoskeletal pain is a poorly understood but common problem in older adults. Little is known about the progression of disability related to this condition. OBJECTIVE: To determine whether widespread musculoskeletal pain increases the risk for worsening disability in older women with disabilities. DESIGN: Prospective cohort study. SETTING: The Women's Health and Aging Study. PARTICIPANTS: 1002 community-dwelling women 65 years of age or older with disability. MEASUREMENTS: Widespread musculoskeletal pain was defined as pain in the upper and lower extremities and axial pain with moderate or severe pain in at least one of the three regions. Worsening disability was defined as progression from no or mild difficulty to severe difficulty or inability to perform activities of daily living (ADLs), walk one-quarter mile, or lift 10 lbs. RESULTS: At baseline, 24% of participants had widespread pain and 25% had no pain or only mild pain in a single site. Women with widespread pain were 2.5 to 3.5 times more likely to have severe difficulty with ADLs, walking, or lifting at baseline compared with women who had no or mild pain. In women without severe difficulty initially, widespread pain nearly doubled the risk for progression to severe difficulty in each of the tasks, after adjustment for age, body mass index, comorbid illness, and other confounders. CONCLUSION: Widespread musculoskeletal pain is frequent among community-dwelling older women with disability and appears to predict the progression of disability. Efforts to better understand the cause of this pain and its treatment might reduce the overall burden of disability.
PMID: 11747382
Cancer 2001 Oct 1;92(7):1919-1925
Memorial Sloan-Kettering Cancer Center, Pain and Palliative Care Service, New York, New York.
BACKGROUND: Patients often are rotated from other opioids to methadone when side effects occur before satisfactory analgesia is achieved. Various strategies have been proposed to estimate safe and effective starting doses of methadone when rotating from morphine and hydromorphone; however, there are no guidelines for estimating safe and effective starting doses of methadone when rotating from fentanyl. METHODS: The authors prospectively observed 18 consecutive patients experiencing chronic pain from cancer who underwent opioid rotation from intravenous patient-controlled analgesia (PCA) with fentanyl to intravenous PCA with methadone. Patients were switched from fentanyl to methadone because of uncontrolled pain associated with sedation or confusion. A conversion ratio of 25 &mgr;g/hour of fentanyl to 0.1 mg/hour of methadone was used to calculate the initial dose of methadone in all patients. RESULTS: Mean pain scores decreased from 8.1 to 4.8 on Day 1 after the switch and to 3.22 on Day 4 after the switch. Mean sedation scores were 1.5 before the switch and 0.44 and 0.16 on Days 1 and 4, respectively. Among the 6 patients who experienced confusion while on fentanyl before the switch, 5 improved within 2 days of the switch. None of the patients experienced toxicity from methadone. CONCLUSIONS: On the basis of this preliminary study, the authors suggest that when switching from intravenous fentanyl to methadone a conversion ratio of 25 &mgr;g/hour of fentanyl to 0.1 mg/hour of methadone may be safe and effective. Copyright 2001 American Cancer Society.
PMID: 11745266
J Pediatr 2001 Dec;139(6):838-843
Division of Gastroenterology, Departments of Pediatrics and Medicine, University of Pittsburgh School of Medicine, Pennsylvania.
OBJECTIVE: Our purpose was to evaluate visceral sensitivity and psychologic profiles in children with functional gastrointestinal disorders.Study design: We measured visceral perception in the stomach and in the rectum by using an electronic barostat. Psychologic questionnaires were completed. Ten children with recurrent abdominal pain (RAP)(8 female, mean age 11.3 +/- 0.8 years), 10 children with irritable bowel syndrome (IBS) (8 female, mean age 13.0 +/- 0.9 years), and 15 control children (8 female, mean age 12.7 +/- 1.2 years) completed the study. RESULTS: Thresholds for visceral perception in the rectum were decreased in patients with IBS (P <.001 vs control patients) and in patients with RAP (P <.05 vs control patients). Children with IBS had lower thresholds than children with RAP (P <.01). In contrast, thresholds for perception were decreased in the stomach of children with RAP (P <.005 vs control patients) but not in children with IBS. There were elevated anxiety scores in 45% of patients. Duration of symptoms was associated with higher scores of anxiety (P <.001) and depression (P <.02). CONCLUSIONS: Hyperalgesia was demonstrated in children with RAP and IBS; sites of hyperalgesia appear to be associated with different symptom phenotypes; anxiety was common, and there was an association between the duration of symptoms and increased scores for both anxiety and depression.
PMID: 11743510
J Pediatr 2001 Dec;139(6):785-789
State University of New York-Downstate Medical Center/Kings County Hospital Center, Brooklyn, NY.
OBJECTIVE: The Stroke Prevention Trial (STOP) demonstrated that chronic transfusion is highly effective in reducing the risk of stroke in children with sickle-cell disease and an abnormal transcranial Doppler ultrasonography examination result. Our objective was to determine whether chronic transfusion therapy reduces the incidence of pain and acute chest syndrome. METHODS: During STOP, 130 children with sickle-cell anemia or sickle beta(0)-thalassemia and abnormal transcranial Doppler ultrasonography examination result were randomly assigned to chronic transfusion (n = 63) or observation (n = 67). In addition to monitoring for stroke, nonneurologic sickle-cell complications were identified and recorded. RESULTS: Mean age at STOP study entry was 8.3 +/- 3.3 years, and mean follow-up was 19.6 +/- 6.5 months. Hospitalization rates (based on intent-to-treat analysis) for acute chest syndrome were 4.8 and 15.3 per 100 patient-years (P =.0027) and for pain were 16.2 and 27.6 per 100 patient-years (P =.13) in the chronic transfusion and observed groups, respectively. If analyzed according to treatment actually received, the difference in pain rate becomes significant (9.7 vs 27.1 events per 100 patient-years, P =.014), and transfusion remains protective from acute chest syndrome (2.2 vs 15.7 events per 100 patient-years, P =.0001). CONCLUSIONS: Compliance with aggressive chronic transfusion reduces the frequency of acute chest syndrome and pain episodes.
PMID: 11743502
the above reports in Macintosh PC UNIX Text HTML format documents on this page through Loansome Doc