Poor Sleep Predicts Increased Pain Perception Among Adults With Mild Cognitive Impairment.

BACKGROUND: Older adults with mild cognitive impairment are at an increased risk for dementia of the Alzheimer's type. These older adults also report poorer sleep and more pain than their cognitively intact adult counterparts. Poor sleep and pain are both symptoms associated with an increased risk for dementia in later life. Symptom science research in the direction of how poor sleep affects pain among older adults, especially those with mild cognitive impairment, is needed for the development of targeted sleep interventions to reduce pain and potentially delay/reduce the risk for Alzheimer's disease in this population. OBJECTIVE: The aim of the study was to examine a predictive model of the relationship between poor sleep and pain perception among community-dwelling older adults with mild cognitive impairment. METHODS: A longitudinal prospective design with 58 continuous matched sleep-pain observations of 15 older adults with mild cognitive impairment for up to 6 months was used. Multilevel, mixed-modeling, statistical techniques were used to examine the effects of prior-week sleep on subsequent pain perception. Pain perception (pain intensity, pain interference, and pain behavior) is measured by the Patient-Reported Outcomes Measurement Information System during monthly in-person visits. The ActiGraph GT3X+ was used to measure sleep (total sleep time, sleep efficiency, awakenings after sleep onset) objectively and continuously for up to 6 months, along with other covariates (e.g., physical activity). RESULTS: Increased awakenings after sleep onset in the prior week is associated with increased pain intensity, pain interference, and pain behavior. There was a trend toward sleep efficiency, and increased pain intensity and sleep efficiency predicted increased pain interference and pain behavior. There was no relationship between prior-week total sleep time and subsequent pain perception. DISCUSSION: In this study, poor sleep in the prior week increased pain intensity, pain interference, and pain behavior. Interventions designed to decrease awakening after sleep onset and increase sleep efficiency specifically may effectively reduce pain in this population. Given that these symptoms are prevalent among older adults with mild cognitive impairment, sleep and pain interventions may also ameliorate some of the risk for Alzheimer's disease in this population.

Transition From Acute to Chronic Pain in Lower Extremity Fracture Patients: A Pain Phenotyping Protocol.

BACKGROUND: Traumatic injury is a major source of chronic pain, particularly for individuals with traumatic fracture of the fibula and/or tibia (lower extremity fracture [LEFx]). Although several factors (e.g., older age, being female, high pain intensity at time of initial injury) have been identified as risk factors for chronic pain associated with LEFx. Comprehensive biopsychosical models to predict the odds of transitioning from acute to chronic pain after LEFx are needed to better understand the underlying processes, predict risk for chronic pain, and develop personalized therapies for individuals at higher risk for developing chronic pain. OBJECTIVE: The aim of the study was to outline the study design that will be used to examine the physiological, psychological, and genetic/genomic variables-models that predict the transition from acute to chronic pain after LEFx. METHOD: This prospective descriptive cohort study will enroll 240 participants with a fibula and/or tibia fracture and 40 controls with no LEFx. Data will be collected during an in-hospital baseline visit, five in-person clinic visits (6 weeks, 12 weeks, 24 weeks, 52 weeks, and 24 months), and seven online between-visit surveys (2 weeks, 4 weeks, 8 weeks, 10 weeks, 16 weeks, 20 weeks, and 18 months) from participants with LEFx and at concordant intervals from controls. Measures will consist of 19 questionnaires characterizing pain and psychological status, neurophysiological testing for peripheral sensory nerve function, and peripheral blood samples collections for RNA sequencing. Illumina standard protocols will be used to sequence RNA, and read counts will be used to measure gene expression. ANALYSIS: Direct-entry, multiple logistic regression will be used to produce odds ratios expressing the relative risk on each explanatory variable when controlling for other predictors/covariates in the model. CONCLUSION: This study is one of the first to longitudinally characterize the biopsychosocial variables associated with a clinically relevant problem of the transition from acute to chronic posttraumatic fracture pain in individuals with LEFx. Results from this study will be used to construct predictive risk models of physiological, psychological, and genetic/genomic variables associated with increased risk for transitioning from acute to chronic pain status after LEFx. This work will lead to a better understanding of the trajectory of pain and relevant variables over time; initiate a better understanding of variables associated with risk for transitioning from acute to chronic pain; and, in the future, could provide a foundation for the identification of novel therapeutic targets to improve the outcomes of individuals with LEFx.

Change in Pain Score after Administration of Analgesics for Lower Extremity Fracture Pain during Hospitalization.

BACKGROUND: Effective acute pain management following injury is critical to improve short-and long-term patient outcomes. Analgesics can effectively reduce pain intensity, yet half of injury patients report moderate to severe pain during hospitalization. PURPOSE: The primary aim of this study was to identify the analgesic, different analgesic combinations, or analgesic and adjuvant analgesic combination that generated the largest percent change from pre- to post-analgesic pain score. DESIGN: This was a descriptive retrospective cohort study of 129 adults admitted with lower extremity fractures to a trauma center. METHODS: Name, dose, and frequency of analgesics and adjuvant analgesics administered from admission to discharge were collected from medical records. Percent change was calculated from pain scores documented on the 0-10 numeric rating scale. RESULTS: The analgesic with largest percent change from pre- to post-administration pain score was hydromorphone 2 mg IV (53%) for the emergency department and morphine 4 mg IV (54%) for the in-patient unit. All analgesics administered in the emergency department and ∼50% administered on the in-patient unit produced a minimal (15%) decrease in pain score. CONCLUSIONS: This study revealed that few analgesics administered in the emergency department and the in-patient unit to patients with lower extremity fractures provide adequate pain relief. In the emergency department, all analgesics administered resulted in at least minimal improvement of pain. On the in-patient unit 13 analgesic doses resulted at least minimal improvement in pain while nine doses did not even reach 20% change in pain. Findings from this study can be used guide the treatment of fracture pain in the hospital.

Analgesics Administered for Pain During Hospitalization Following Lower Extremity Fracture: A Review of the Literature.

Effective treatment of acute pain during hospitalization following lower extremity fracture is critical to improve short-term patient outcomes including wound healing, stress response, hospital length of stay, and cost as well as minimizing long-term negative patient outcomes such as delayed return to work, disability, and chronic pain. As many patients report moderate to severe pain during hospitalization, identifying the analgesics that most effectively reduces pain is a priority to improve patient outcomes. The purpose of this review was to examine published studies describing patient response to analgesics administered orally (PO) or intravenously (IV) in the immediate hospitalization following lower extremity fracture. PubMed was queried for articles published through May 2017 that included information on type of study, population, fracture site, pain measurement tool, analgesic, and result. Of 514 articles found, eight met the inclusion criteria. Analgesics administered PO or IV were fentanyl, hydromorphone, morphine, remifentanil, diclofenac, ibuprofen, ketorolac, and etoricoxib. Five of the studies focused on comparisons between one or more analgesics and three studies compared an IV analgesic to a regional anesthetic agent. Two studies compared different nonsteroidal anti-inflammatory drugs (NSAIDs). Bupivacaine, lignocaine, and levobupivacaine administered as regional nerve blocks were superior to controlling pain compared with IV fentanyl and IV hydromorphone. IV morphine provided faster and better pain relief compared with IV ibuprofen. Based on the limited data available, regional nerve blocks provided superior pain relief compared with opioids, and opioids provided superior pain relief compared with NSAIDs. Different NSAIDs provided similar pain relief.

Acute Pain Characteristics in Patients with and without Chronic Pain following Lower Extremity Injury.

Many patients with injuries to lower extremities report chronic pain. High pain intensity at time of admission for injury is a risk factor for chronic pain, but it is not clear whether specific acute pain patterns following injury influence the development of chronic pain. To examine the relationship between the pain trajectory, the mean pain score, and the frequency of pain documentation during the immediate hospitalization following injury, with the report of chronic pain. This was a descriptive, retrospective cohort study of adults admitted with lower extremity fractures to an academic urban trauma center. Participants, 6-45 months postinjury, rated their current pain, worst pain, and average pain over the last 3 months. Pain scores from hospitalization associated with the injury were obtained through a retrospective chart review. The pain trajectory, mean pain score, and frequency of pain documentation was compared between patients with and without chronic pain. A total of 129 patients were enrolled in this study and 78% reported chronic pain at the site of injury. The mean pain score (5.1 vs. 4.2) and first pain score (5.6 vs. 3.4) were higher for patients with chronic pain compared to patients with no chronic pain. Consistent with other studies, high pain intensity at time of injury was associated with chronic pain. The findings contribute valuable information about acute pain characteristics associated with chronic pain and provide insight into the importance of early and adequate acute pain treatment.

Characteristics of Patients with Lower Extremity Trauma with Improved and Not Improved Pain During Hospitalization: A Pilot Study.

Up to 62% of patients report chronic pain at the injury site 6-12 months after blunt trauma, with pain from lower extremity fractures exceeding that from other sites. High pain intensity at time of injury is a risk factor for chronic pain, but it is not clear what patient characteristics influence the pain intensity level during the immediate hospitalization following injury. The purpose of this pilot study was to determine the feasibility of collecting pain scores from medical records to calculate pain trajectories and to determine whether it is possible to examine patient characteristics by classifying them into those whose pain improved and those whose pain did not improve. This descriptive study retrospectively reviewed medical records of 18 randomly chosen patients admitted to an academic trauma center. Patient characteristics and pain scores were collected form electronic and handwritten medical records. The pain trajectories calculated from routinely collected pain scores during the inpatient stay showed that for 44% of patients the pain improved during the hospitalization, for 39% the pain remained the same, and for 17% the pain worsened. The variables age, smoking, weight, abbreviated injury scores, length of hospital stay, mean pain score, and opioid equianalgesic dose differed based on pain trajectory. While patient characteristics differed based on pain trajectory, any significant effects seen from individual tests should be considered tentative, given the number of analyses conducted on this data set. However, feasibility and significance of conducting a larger study has been established.

Evaluation of dynamic weight bearing for measuring nonevoked inflammatory hyperalgesia in mice.

BACKGROUND: Animal models in pain research have suggested that inclusion of both evoked and nonevoked behavioral measures is needed to better reflect the human pain experience. Individuals with chronic pain are known to experience spontaneous pain, in addition to pain after exposure to an external stimulus. Recently, the dynamic weight bearing (DWB) apparatus was developed to assess for nonevoked hyperalgesia by capturing weight bearing and surface distribution in the paws of mice after acute inflammation. OBJECTIVES: The aim of this study was to evaluate the DWB test as a measure of nonevoked hyperalgesia. METHODS: The experimental group received an intraplantar injection in the left hind paw of the inflammatory agent--complete Freund's adjuvant (CFA)--whereas the vehicle control group received a saline injection and the naive control group had no treatment. Calipers and a plethysmometer were used to verify inflammation and the hot-plate test was used as a measure for stimulus-evoked hyperalgesia. Data were collected at baseline; 3 hours; and 1, 3, and 7 days after injection. RESULTS: Mice injected with CFA showed a statistically significant higher mean paw thickness and volume displacement compared with the vehicle and naive control groups. In the hot-plate testing, CFA-treated mice showed lower response temperature at 7 days compared with the other groups. On the DWB test, CFA-treated mice showed a reduction in the ipsilateral paw load and surface area compared with the contralateral paw load at Days 1, 3, and 7. DISCUSSION: Mice with inflammation showed alterations in weight bearing as well as increased thermal hyperalgesia in comparison with control groups. These findings support the use of the DWB test as a tool for measuring nonevoked inflammatory hyperalgesia in a mouse model.

Prior Night Sleep Affects Next-Day Pain Interference Among Community-Dwelling Older Adults With Lower Extremity Chronic Pain.

Emergent work suggests that sleep is a robust biobehavioral predictor of pain; however, it remains unclear how sleep is prospectively linked to pain on a day-to-day basis among older adults. The current prospective study examined how sleep duration (total sleep time), quality (sleep efficiency, wake after sleep onset), and late and irregular sleep timing influenced next-day pain perception among community-dwelling older adults (N = 10; 65 matched observations) with lower extremity chronic pain over 1 week. Multilevel modeling estimated the association between sleep (Actigraph GT9X Link) and pain perception (Brief Pain Inventory Short Form). Increased wake after sleep onset (B = 0.19, p = 0.04), sleep variability (B = 0.02, p = 0.01), and later midsleep time (B = 0.40, p < 0.05) were associated with increased pain interference the following day. Findings support the idea that timely sleep interventions may reduce the effect of poor sleep on next-day pain in older adults. [Research in Gerontological Nursing, 14(4), 173-179.].

Quantitative Sensory Testing Across Chronic Pain Conditions and Use in Special Populations.

Chronic pain imposes a significant burden to the healthcare system and adversely affects patients' quality of life. Traditional subjective assessments, however, do not adequately capture the complex phenomenon of pain, which is influenced by a multitude of factors including environmental, developmental, genetic, and psychological. Quantitative sensory testing (QST), established as a protocol to examine thermal and mechanical sensory function, offers insight on potential mechanisms contributing to an individual's experience of pain, by assessing their perceived response to standardized delivery of stimuli. Although the use of QST as a research methodology has been described in the literature in reference to specific pain populations, this manuscript details application of QST across a variety of chronic pain conditions. Specific conditions include lower extremity chronic pain, knee osteoarthritis, chronic low back pain, temporomandibular joint disorder, and irritable bowel syndrome. Furthermore, we describe the use of QST in placebo/nocebo research, and discuss the use of QST in vulnerable populations such as those with dementia. We illustrate how the evaluation of peripheral sensory nerve function holds clinical promise in targeting interventions, and how using QST can enhance patient education regarding prognostic outcomes with particular treatments. Incorporation of QST methodology in research investigations may facilitate the identification of common mechanisms underlying chronic pain conditions, guide the development of non-pharmacological behavioral interventions to reduce pain and pain-related morbidity, and enhance our efforts toward reducing the burden of chronic pain.

Quantitative Sensory Testing and Current Perception Threshold Testing in Patients With Chronic Pain Following Lower Extremity Fracture.

BACKGROUND: Chronic pain is a significant problem for patients with lower extremity injuries. While pain hypersensitivity has been identified in many chronic pain conditions, it is not known whether patients with chronic pain following lower extremity fracture report pain hypersensitivity in the injured leg. PURPOSE: To quantify and compare peripheral somatosensory function and sensory nerve activation thresholds in persons with chronic pain following lower extremity fractures with a cohort of persons with no history of lower extremity fractures. METHOD: This was a cross-sectional study where quantitative sensory testing and current perception threshold testing were conducted on the injured and noninjured legs of cases and both legs of controls. RESULTS: A total of 14 cases and 28 controls participated in the study. Mean time since injury at the time of testing for cases was 22.3 (standard deviation = 12.1) months. The warmth detection threshold ( p = .024) and nerve activation thresholds at 2,000 Hz ( p < .001) and 250 Hz ( p = .002), respectively, were significantly higher in cases compared to controls. CONCLUSION: This study suggests that patients with chronic pain following lower extremity fractures may experience hypoesthesia in the injured leg, which contrasts with the finding of hyperesthesia previously observed in other chronic pain conditions but is in accord with patients with nerve injuries and surgeries. This is the first study to examine peripheral sensory nerve function at the site of injury in patients with chronic pain following lower extremity fractures using quantitative sensory testing and current perception threshold testing.