The journal of pain : official journal of the American Pain Society
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This study evaluated the ability of end-of-day (EOD) ratings to accurately reflect momentary (EMA) ratings on 10 widely used pain and fatigue items. Rheumatology patients (n = 105) completed >or=5 randomly scheduled EMA assessments of each item per day as well as EOD ratings. Correlations were high between EOD and EMA ratings of the 5 pain items (r = .90 to .92) and somewhat lower for the 5 fatigue/energy items (r = .71 to .86). To examine the ability of EOD ratings to represent 1 week of EMA ratings, 7 EOD ratings were averaged and correlated with EMA (r >or= .95 for pain items, r = .88 to .95 for fatigue/energy items). Further, averaging only 3 to 5 EOD ratings achieved very high correlations with 1 week of EMA ratings. Within-subject correlations of EOD with mean daily EMA across 7 days confirmed patients' ability to provide daily ratings that accurately reflect their day-to-day variation in symptom levels. These EOD results were compared to traditional recall ratings collected in the same protocol. It was concluded (1) that EOD ratings were a better representation of EMA than were recall ratings, and (2) that EOD ratings across a reporting period can replace EMA for studies targeting average levels of pain or fatigue. ⋯ This study in chronic pain patients demonstrated that end-of-day ratings of pain are highly accurate representations of average levels of pain experience across a day; ratings of fatigue were somewhat less accurate, though still at a level that would be valid.
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This observational study aimed to determine whether pain sensitivity in patients with noncancer chronic pain, taking either methadone or morphine, is similar to patients maintained on methadone for dependence therapy, compared with a control group. Nociceptive thresholds were measured on a single occasion with von Frey hairs, electrical stimulation, and cold pressor tests. In all subjects receiving methadone or morphine, nociceptive testing occurred just before a scheduled dose. Cold pressor tolerance values in patients with noncancer, chronic pain, treated with morphine and methadone, were 18.1 +/- 2.6 seconds (mean +/- SEM) and 19.7 +/- 2.3 seconds, respectively; in methadone-maintained subjects it was 18.9 +/- 1.9 seconds, with all values being significantly (P < .05) lower than opioid-naïve subjects (30.7 +/- 3.9 seconds). These results indicate that patients with chronic pain managed with opioids and methadone-maintained subjects are hyperalgesic when assessed by the cold pressor test but not by the electrical stimulation test. None of the groups exhibited allodynia as measured using the von Frey hairs. These results add to the growing body of evidence that chronic opioid exposure increases sensitivity to some types of pain. They also demonstrate that in humans, this hyperalgesia is not associated with allodynia. ⋯ This article presents an observational study whereby the pain sensitivity of patients with chronic pain managed with opioids and opioid-maintained patients were compared with opioid-naïve patients. The results suggest that opioid use may contribute to an increase in the sensitivity to certain pain experimental stimuli.
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There is evidence that pain patients demonstrate attentional biases toward some pain-related stimuli (eg, sensory words) and not others (eg, affective words). However, whether individuals in chronic pain caused by rheumatoid arthritis (RA) also demonstrate this bias has not been investigated. Further, within the pain literature, whether these biases reflect hypervigilance or difficulty disengaging from stimuli remains contentious. The present study aimed to determine (a) whether RA patients demonstrate an attentional bias to sensory pain words; and (b) whether this bias is a result of hypervigilance or failure to disengage from the stimuli. RA patients showed a bias toward sensory words and away from threat-related words. The effect for sensory words resulted from slowed performance on incongruent trials (ie, difficulty disengaging), whereas the bias away from threat words resulted from faster responses on incongruent trials (ie, avoidance of threat). The pattern of attention biases in RA patients is very similar to those found in patients with chronic pain. At least in RA, attentional biases appear to be related to a failure to disengage from pain-related words rather than hypervigilance. ⋯ There is continued debate about whether these biases are caused by hypervigilance toward pain stimuli or difficulty disengaging from pain stimuli. This study shows that in a group of RA patients, attentional biases toward pain are caused by difficulty disengaging rather than hypervigilance.
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The purpose of this study was to evaluate the impact of smoking status after a diagnosis of lung cancer on reported pain levels. We conducted a telephone survey of patients with lung cancer identified from 4 participating sites between September 2004 and July 2006. Patients were asked to rate their usual pain level over the past week on a 0 to 10 rating scale on which 0 was "no pain" and 10 "pain as bad as you can imagine." We operationally defined persistent smokers as patients who reported continuing to smoke after their lung cancer diagnosis. A logistic regression analysis was used to test the hypothesis that persistent smokers report higher usual pain levels than nonsmokers. Overall, 893 patients completed the survey. The majority (76%) was found to have advanced cancer (stages IIIb and IV). The mean age was 63 years (SD = 10). Seventeen percent of the patients studied were categorized as persistent smokers. The mean pain score for the study sample was 3.1 (SD = 2.7) and 41% reported moderate (4 to 6) or severe pain (7 to 10). A greater proportion of persistent smokers reported moderate or severe pain than nonsmokers or former smokers (P < .001). Logistic regression analysis revealed that smoking status was associated with the usual pain even after adjusting for age, perceived health status, and other lung cancer symptoms such as dyspnea, fatigue, and trouble eating. In conclusion, patients who continue to smoke after a diagnosis of lung cancer report higher levels of usual pain than nonsmokers or former smokers. More research is needed to understand the mechanisms that relate nicotine intake to pain and disease progression in late-stage lung cancer. ⋯ This article examines the relationship between pain and persistent smoking in patients with lung cancer. Although more research is needed to understand the mechanisms that relate nicotine intake to pain and disease progression, physicians can promote smoking cessation in patients with lung cancer to improve health and quality of life.
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Randomized Controlled Trial
Diclofenac potassium attenuates dysmenorrhea and restores exercise performance in women with primary dysmenorrhea.
We assessed the efficacy of diclofenac potassium, a nonsteroidal anti-inflammatory drug, in alleviating menstrual pain and restoring exercise performance to that measured in the late-follicular phase of the menstrual cycle. Twelve healthy young women with a history of primary dysmenorrhea completed, in a random order, laboratory exercise-testing sessions when they were in the late-follicular (no menstruation, no pain) phase of the menstrual cycle and when they were experiencing dysmenorrhea and receiving, in a double-blinded fashion, either 100 mg of diclofenac potassium or placebo. We assessed the women's leg strength (1-repetition maximum test), aerobic capacity (treadmill walking test), and ability to perform a functional test (task-specific test). Compared with placebo, diclofenac potassium significantly decreased dysmenorrhea on the day of administration (Visual Analog Scale, P < .001 at all times). When receiving placebo for menstrual pain, the women's performance in the tests was decreased significantly, compared with when they were receiving diclofenac potassium for menstrual pain (P < .05) and compared with when they were in the late-follicular phase of the menstrual cycle (P < .05 for treadmill test, P < .01 for task-specific test and 1-repetition maximum test). Administration of diclofenac potassium for menstrual pain restored exercise performance to a level not different from that achieved in the late-follicular phase of the cycle. ⋯ In women with primary dysmenorrhea, menstrual pain, if untreated, decreases laboratory-assessed exercise performance. A recommended daily dose of a readily available nonsteroidal anti-inflammatory drug, diclofenac potassium, is effective in relieving menstrual pain and restoring physical performance to levels achieved when the women were in the late-follicular (no menstruation, no pain) phase of the menstrual cycle.