The Influence of Sleep Disturbance on Chronic Pain.

PURPOSE OF REVIEW: The purpose of this review is to present an overview of common sleep disturbance pathologies and their impact on chronic pain, while examining various factors that are implicit in the relationship between sleep disturbance and chronic pain, including neurobiochemistry, anatomy, and systemic mediators, and reviewing recent and landmark literature. RECENT FINDINGS: Earlier literature reviews and studies have introduced the bidirectional relationship between sleep disturbance and chronic pain; that is, impaired sleep may worsen chronic pain, and chronic pain causes sleep disturbance. However, more recent reviews and studies seem to show a more associative, rather than causative relationship. There have been recent studies that attempt to determine mechanisms that link sleep disturbance and chronic pain; the results of these studies were more varied, ultimately concluding that there may be a separate, yet-to-be discovered mechanism that shows the causative relationship between sleep disturbance and pain. There are several neurotransmitters that are involved in the mediation of chronic pain and sleep disturbance as separate entities, and some studies have shown that there may be mechanisms that govern both chronic pain and sleep disturbance as a single unit. Other neuroendocrine substances also serve to mediate chronic pain and sleep disturbance. All these substances are found to be associated with various sleep disorders and are also associated with chronic pain symptoms as well. Inflammation plays a role in chronic pain and sleep disturbance, with an increase in inflammatory substances and mediators associated with an increase or worsening in chronic pain symptoms and sleep disorders. The HPA axis plays a role in chronic pain and sleep disorders, influencing pain and sleep pathways through stress response, inflammation, and maintenance of homeostasis. There are several variables that influence both chronic pain and sleep disturbance, and more research into these variables may further our understanding into the complex pathways governing the influence of sleep disturbance on pain, and ultimately to improve treatment for this issue.

The Anesthesiologist's Armamentarium: From Recreation to Medication and Back.

For millennia, mankind has sought a means of altering consciousness, often aided by naturally occurring elements. Psychotropic substances have been an integral part of spiritual, medicinal, and recreational aspects of life. The origin of anesthesiology stems directly from the use of recreational drugs; early inhaled anesthetics were first used as a means of entertainment. Hence, it is no surprise that many medications in the anesthesiologist's armamentarium are diverted for recreational use. In the 172 years following the first successful public demonstration of ether anesthesia, many drugs with abuse potential have been introduced to the practice of anesthesia. Although anesthesiologists are aware of the abuse potential of these drugs, how these drugs are obtained and used for recreational purposes is worthy of discussion. There are articles describing the historical and recreational use of specific drug classes. However, to the best of our knowledge, this is the first comprehensive review focusing on the breadth of drugs used by anesthesiologists.

Risk Factors for Tibial Component Oversizing in Total Knee Arthroplasty among African Americans.

Incidences and risk factors for tibial component oversizing in total knee arthroplasty (TKA) have been well described, predominantly in Caucasian samples. Component oversizing has been linked to variations in proximal tibial shape and morphology, which has been found to be objectively different in African Americans compared with Caucasians. These anthropometric differences may affect the conformity of modern TKA systems to the anatomy of African Americans undergoing TKA. We sought to investigate the incidence and risk factors for tibial baseplate oversizing in an exclusively African American population undergoing TKA with a symmetric tibial baseplate. We reviewed the records of self-reported African American patients who had undergone a primary TKA at a single academic institution between 2005 and 2016. The primary outcome was incidence of tibial baseplate oversizing in the coronal and sagittal planes as determined by a single set of appropriately rotated postoperative orthogonal radiographs. Logistic regression models identified trends in oversizing within the population based on age, sex, body mass index (BMI), and TKA model. Among all 525 knees being evaluated, the occurrences of medial and lateral overhang were 14.2 and 15.2%, respectively. Increase in age was associated with lower risk of medial tibial overhang (odds ratio = 0.97 for each 1-year increase in age). Simple linear regression models described a linear relationship between BMI and overhang, with every one-unit increase in BMI, medial tibial overhang is 0.031 mm higher and posterior tibial overhang is 0.062 mm higher. Mediolateral oversizing was approximately twice more likely in females than males. Among TKA models used, the Stryker Triathlon had the least risk for mediolateral oversizing and the P.F.C. SIGMA demonstrated the least propensity for anteroposterior oversizing. To conclude, incidence of mediolateral tibial oversizing in this population was common. Previously identified variables affecting proximal tibial morphology, including age, body morphotype, and gender, may be equally applicable to the conformity of tibial baseplates in this population. Surgeons must pay particular attention to avoid mediolateral tibial oversizing in this population, especially in obese and older patients.