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Supplemental Digital Content is available in the text., OBJECTIVES: Clinical trials evaluating the safety and effectiveness of sedative medication use in critically ill adults undergoing mechanical ventilation differ considerably in their methodological approach. This heterogeneity impedes the ability to compare results across studies. The Sedation Consortium on Endpoints and Procedures for Treatment, Education, and Research Recommendations convened a meeting of multidisciplinary experts to develop recommendations for key methodologic elements of sedation trials in the ICU to help guide academic and industry clinical investigators. DESIGN: A 2-day in-person meeting was held in Washington, DC, on March 28–29, 2019, followed by a three-round, online modified Delphi consensus process. PARTICIPANTS: Thirty-six participants from academia, industry, and the Food and Drug Administration with expertise in relevant content areas, including two former ICU patients attended the in-person meeting, and the majority completed an online follow-up survey and participated in the modified Delphi process. MEASUREMENTS AND MAIN RESULTS: The final recommendations were iteratively refined based on the survey results, participants’ reactions to those results, summaries written by panel moderators, and a review of the meeting transcripts made from audio recordings. Fifteen recommendations were developed for study design and conduct, subject enrollment, outcomes, and measurement instruments. Consensus recommendations included obtaining input from ICU survivors and/or their families, ensuring adequate training for personnel using validated instruments for assessments of sedation, pain, and delirium in the ICU environment, and the need for methodological standardization. CONCLUSIONS: These recommendations are intended to assist researchers in the design, conduct, selection of endpoints, and reporting of clinical trials involving sedative medications and/or sedation protocols for adult ICU patients who require mechanical ventilation. These recommendations should be viewed as a starting point to improve clinical trials and help reduce methodological heterogeneity in future clinical trials.

Background Unintentional dural puncture with an epidural needle complicates approximately 1% of epidural anaesthetics and causes an acute headache in 60–80% of these patients. Several retrospective studies suggest an increased risk of chronic headache. We assessed the relationship between unintentional dural puncture and chronic disabling headache, defined as one or more functionally limiting headaches within a 2-week interval ending 2, 6, and 12 months postpartum. Methods In this prospective observational study, parturients who experienced unintentional dural puncture were matched 1:4 with control patients. Patients completed questionnaires regarding characteristics of headache and back pain pre-pregnancy, during pregnancy, immediately postpartum, and at 2, 6, and 12 months postpartum. The primary outcome was prevalence of disabling headache in the past 2 weeks, assessed at 2 months postpartum. Secondary outcomes included prevalence and characteristics of headache and back pain at these time points. Results We enrolled 99 patients. At 2 and 6 months postpartum, the prevalence of disabling headache was greater among patients with unintentional dural puncture than matched controls (2 months, 74% vs 38%, relative risk 1.9, 95% confidence interval 1.2–2.9, P=0.009; 6 months, 56% vs 25%, relative risk 2.1, 95% confidence interval 1.1–4.0, P=0.033). There was no difference in the prevalence of back pain at any time point. Conclusions Our prospective trial confirms retrospective studies that chronic headache is more prevalent among women who experienced unintentional dural puncture compared with controls who received uncomplicated neuraxial anaesthesia. This finding has implications for the. patient consent process and recommendations for long-term follow-up of patients who experience unintentional dural puncture.

Background A gender-based compensation gap among physicians is well documented. Even after adjusting for age, experience, work hours, productivity, and academic rank, the gender gap remained and widened over the course of a physician's career. This study aimed to examine if a significant gender pay gap still existed for anesthesiologists in the United States. Methods In 2018, we surveyed 28,812 physician members of the American Society of Anesthesiologists to assess the association of compensation with gender and to identify possible causes of wage disparities. Gender was the primary variable examined in the model, and compensation by gender was the primary outcome. Compensation was defined as the amount reported as direct compensation on a W-2, 1099, or K-1, plus all voluntary salary reductions (eg, 401[k], health insurance). The survey directed respondents to include salary, bonuses, incentive payments, research stipends, honoraria, and distribution of profits to employees. Respondents had the option of providing a point estimate of their compensation or selecting a range in $50,000 increments. Potential confounding variables that could affect compensation were identified based on a scoping literature review and the consensus expertise of the authors. We fitted a generalized ordinal logistic regression with 7 ranges of compensation. For the sensitivity analyses, we used linear regressions of log-transformed compensation based on respondent point estimates and imputed values. Results The final analytic sample consisted of 2081 observations (response rate, 7.2%). This sample represented a higher percentage of women and younger physicians compared to the demographic makeup of anesthesiologists in the United States. The adjusted odds ratio associated with gender equal to woman was an estimated 0.44 (95% confidence interval, 0.37-0.53), indicating that for a given compensation range, women had a 56% lower odds than men of being in a higher compensation range. Sensitivity analyses found the relative percentage difference in compensation for women compared to men ranged from -8.3 to -8.9. In the sensitivity analysis based on the subset of respondents (n = 1036) who provided a point estimate of compensation, the relative percentage difference (-8.3%; 95% confidence interval, -4.7 to -11.7) reflected a $32,617 lower compensation for women than men, holding other covariates at their means. Conclusions Compensation for anesthesiologists showed a significant pay gap that was associated with gender even after adjusting for potential confounding factors, including age, hours worked, geographic practice region, practice type, position, and job selection criteria.

Experimental and clinical acute pain research in relation to biological sex and genetics started in the 1980s. Research methods became more powerful and sensitive with the advancement in affordable gene sequencing methods and high-throughput genetic assays. Decades of research has identified several potential pharmaceutical targets, providing insights into future research direction, and understanding of acute pain and opioid analgesic effects in the clinical setting. However, there is insufficient evidence to make generalized recommendations for using genetic tests for clinical practice of acute pain management.

Objective. Evidence to date, while sparse, suggests that patients taking long-term opioids require special considerations and protections to prevent potential iatrogenic harms from opioid de-prescribing, such as increased pain or suffering. Following this study protocol, the EMPOWER study seeks to address multiple unmet needs of patients with chronic pain who desire to reduce long-term opioid therapy, and provide the clinical evidence on effective methodology. Methods. EMPOWER applies patient-centered methods for voluntary prescription opioid reduction conducted within a comprehensive, multi-state, 3-arm randomized controlled comparative effectiveness study of three study arms (1) group cognitive behavioral therapy for chronic pain; (2) group chronic pain self-management; and (3) usual care (taper only). Specialized electronic data capture systems collect patient reported symptoms and satisfaction data weekly and monthly during the taper, with real-time clinical alerts and electronic feedback loops informing, documenting, and steering needed care actions. Conclusion. The EMPOWER study seeks to provide granular evidence on patient response to voluntary opioid tapering, and will provide evidence to inform clinical systems changes, clinical care, patient satisfaction, and patient outcomes for opioid reduction.

Objective This narrative literature review examines the long-term impact of postdural puncture headache (PDPH) in postpartum women following an unintended dural puncture (UDP) with a large bore needle commonly used for epidural catheter placement. It seeks to bridge the knowledge gap for the neurologist as to the mounting body of obstetric anesthesia literature on the development of chronic headache after PDPH with this unique needle. Background Headache is the most common complication of dural puncture, and the risk is greatest in the parturient population. Preexisting risk factors for this population include youth and sex, and after UDP with a large bore needle, almost 70%-80% report a headache. Additionally, there appears to be a significant cohort who experience long-term, persistent headache after UDP. Methods We performed a narrative review of literature using PubMed, searching terms that included long-term follow-up after UDP with a large bore needle in the postpartum population. Results In women who had UDP with a large bore needle used for epidural catheter placement at delivery, the rate of chronic debilitating headache is around 30% in the months following delivery and may persist for up to a year or longer. Conclusion Based on the existing literature, we have mounting evidence that UDP with the large bore needle used to place an epidural catheter should be understood as a high-risk inciting event for the development of long-term headaches not simply a high risk of acute PDPH. Additionally, consideration should be given to stratifying the etiology of PDPH, based on needle type, and recognizing the entity of chronic PDPH, thus allowing for improvements in research and diagnosis.

Objectives: Since the uprising in 2011, there have been limited health-care data from inside Syria regarding women’s health. This study aimed to provide an updated account of women’s health, including pregnancy, perinatal care, childbirth, and other conditions to identify obstacles and challenges to health-care delivery in Northwestern Syria. Methods: This is a prospective data registry study, using a medical electronic records system that builds on the International Classification of Diseases, Tenth Revision (ICD-10) codes. We collected data from one medical center in Northwestern Syria during 2017. We conducted a survey to understand patients’ knowledge of and barriers limiting antenatal care (ANC). Results: We studied 7213 patients’ health status and surveyed 134 regarding ANC. Prenatal care, delivery, and miscarriage treatment represented the most common (70%) reasons for women’s health-care visits, followed by menstrual disorders (17%). From 2057 delivery records, 70% delivered vaginally and 30% required cesarean delivery. Our findings showed that 1169 (24%) of the pregnant women (4936) in 2017 were adolescents, of them 22 (0.44%) were 14 years old. Regarding ANC visits, 85% of respondents did not have a single ANC visit in the first trimester, 82% had no visits in the second trimester, and 44% had no visits in the third trimester. Thirty-one percent had no ANC visit throughout the entire pregnancy. Only 13% had postnatal care (PNC) visits. Women who live in the refugee camp are 2.7 times less likely to meet the World Health Organization (WHO) criteria for focused ANC (FANC = 4 visits) compared to those who reside in town (P < 0.001), with only 14% having met the FANC. The major barrier to ANC is related to transportation (34%), followed by factors related to the study center (29%) and knowledge and education (19%). We estimated the number of obstetrics-gynecology doctors per 1000 populations to be 0.02. Conclusions: We found a huge deficiency in ANC and PNC visits, a high adolescent birth rate, and a higher cesarean-to-vaginal delivery ratio than what is recommended by the WHO. We also found a severe shortage in the number of obstetrician-gynecologists serving this population.

Patient-centred care and factors associated with patient satisfaction with anaesthesia have been widely studied. However, the most important considerations in the setting of obstetric anaesthesia are uncertain. Identification of, and addressing, factors that contribute to patient dissatisfaction may improve quality of care. We sought to identify factors associated with 100% satisfaction with obstetric anaesthesia care. At total of 4297 women treated by anaesthetists provided satisfaction data 24 h after vaginal and 48 h after caesarean delivery. As 78% of women were 100% satisfied, we studied factors associated with the dichotomous variable, 100% satisfied vs.100% satisfied. We evaluated patient characteristics and peripartum factors using multivariable sequential logistic regression. The following factors were strongly associated with maternal dissatisfaction after vaginal delivery: pain intensity during the first stage of labour; pain intensity during the second stage of labour; postpartum pain intensity; delay 15 min in providing epidural analgesia and postpartum headache (all p 0.0001). Pruritus (p = 0.005) also contributed to dissatisfaction after vaginal delivery, whereas non-Hispanic ethnicity was negatively associated with dissatisfaction (p = 0.01). After caesarean delivery, the intensity of postpartum pain (p 0.0001), headache (p = 0.001) and pruritus (p = 0.001) were linked to dissatisfaction. Hispanic ethnicity also had a negative relationship with dissatisfaction after caesarean delivery (p = 0.005). Thus, inadequate or delayed analgesia and treatment-related side-effects are associated with maternal dissatisfaction with obstetric anaesthesia care. Development of protocols to facilitate identification of ineffective analgesia and provide an appropriate balance between efficacy and side-effects, are important goals to optimise maternal satisfaction.

BackgroundThe phase III research evaluating migraine prophylaxis therapy (PREEMPT) protocol was developed in low-risk migraine patients. We studied longitudinal response to treatment in a sequential retrospective observational cohort to evaluate predictors of effectiveness in patients with multiple overlapping pain syndromes treated in a quaternary pain management clinic.MethodsWe evaluated indicators of individual response in 402 consecutive chronic migraine patients who provided demographic information and used the Collaborative Health Outcomes Information Registry.ResultsThe patients were middle aged 47 (38–56) median (IQR) years old and 83% women. They reported multiple complex pain problems with 11 (6–18) regions represented on a pain body map. Evaluated with National Institutes of Health Patient-Reported Outcomes Measurement Information System measures, they reported higher scores for sleep impairment and disturbance, anxiety, depression, fatigue, pain behavior, pain interference and worse function and satisfaction with social roles compared with the general US population; pConclusionsOur findings point to the importance of identifying and addressing pain interference and depression early in chronic migraine management and, more broadly, highlights the importance of multidisciplinary evaluation and treatment in chronic migraine.

Objective This study aims to assess the feasibility of digital perioperative behavioral pain medicine intervention in breast cancer surgery and evaluate its impact on pain catastrophizing, pain, and opioid cessation after surgery. Design and Setting A randomized controlled clinical trial was conducted at Stanford University (Palo Alto, CA, USA) comparing a digital behavioral pain medicine intervention (“My Surgical Success” [MSS]) with digital general health education (HE). Participants A convenience sample of 127 participants were randomized to treatment group. The analytic sample was 68 patients (N = 36 MSS, N = 32 HE). Main Outcomes The primary outcome was feasibility and acceptability of a digital behavioral pain medicine intervention (80% threshold for acceptability items). Secondary outcomes were pain catastrophizing, past seven-day average pain intensity, and time to opioid cessation after surgery for patients who initiated opioid use. Results The attrition rate for MSS intervention (44%) was notably higher than for HE controls (18%), but it was lower than typical attrition rates for e-health interventions (60–80%). Despite greater attrition for MSS, feasibility was demonstrated for the 56% of MSS engagers, and the 80% threshold for acceptability was met. We observed a floor effect for baseline pain catastrophizing, and no significant group differences were found for postsurgical pain catastrophizing or pain intensity. MSS was associated with 86% increased odds of opioid cessation within the 12-week study period relative to HE controls (hazard ratio = 1.86, 95% confidence interval = 1.12–3.10, P = 0.016). Conclusions Fifty-six percent of patients assigned to MSS engaged with the online platform and reported high satisfaction. MSS was associated with significantly accelerated opioid cessation after surgery (five-day difference) with no difference in pain report relative to controls. Perioperative digital behavioral pain medicine may be a low-cost, accessible adjunct that could promote opioid cessation after breast cancer surgery.

Chorioamnionitis is associated with an increased risk of cesarean delivery and uterine atony. We hypothesized that the onset of maternal fever is temporally associated with decreased uterine contractility.Retrospective cohort.Academic center.Term participants who developed a fever in the setting of an intrauterine pressure catheter.Montevideo units (MVUs) and oxytocin dose at time 0 (first oral temperature ≥38°C) and in the five 1--hour blocks preceding and following T0.Montevideo units relative to the onset of fever. Results were adjusted for oxytocin dose and parity in a mixed-effects model.One hundred participants were included. Uterine contractility was maintained for 2 hours after the onset of maternal fever but thereafter significantly and steadily declined by an average of 6.9 ± 3.2 MVU/h ( P = .03), despite the absence of a parallel decline in oxytocin exposure. Multiparas and nulliparas showed a similar pattern of waning uterine contractility. Patients who delivered vaginally maintained contractility, while those who delivered via cesarean had diminishing contractility ( P = .01). The postpartum hemorrhage (PPH) rate (postpartum bleeding requiring treatment) was 32%.A decline in myometrial contractility occurs 2 hours following the onset of maternal fever. Increased risk of cesarean delivery appears to be directly associated with waning uterine contractility and decreased uterine responsiveness to oxytocin. Clinically, close attention should be given to maintaining adequate uterine contractions following a diagnosis of suspected chorioamnionitis. The likelihood of successful vaginal delivery may decrease over time, and the risk of PPH is clinically significant.

Patients with chronic pain experience stigma within the healthcare system. This stigma is compounded for those taking long-term prescription opioids. Often, public messaging and organizational policies have telegraphed that opioid treatment is a problem to be solved by focusing only on medication reduction efforts. Lack of data has contributed to misperceptions and poor opioid policies. In part, data collection remains poor because patients feel fractured from systems of care and are often not interested in engaging with opioid reduction mandates and research. Similarly, clinicians may fail to engage with opioid stewardship and research due to complexities that exceed their training or capacities. The EMPOWER study applies a coproduction model that engages researchers, patients, clinicians, managers, and other health system users. Key stakeholders shaped the design of the study to best ensure acceptability and engagement of the “end users”—patients who enroll in the study and the clinicians who implement the opioid tapers. Targeting the needs of any stakeholder group in isolation is suboptimal. Accordingly, we detail the EMPOWER patient-centered opioid tapering clinical research framework and specific strategies to address stakeholder concerns. We also discuss how this framework may be applied to enhance engagement in healthcare research broadly.

Background Severe acute post-cesarean delivery (CD) pain has been associated with an increased risk for persistent pain and postpartum depression. Identification of women at increased risk for pain can be used to optimize post-cesarean analgesia. The impact of labor prior to CD (intrapartum CD) on acute post-operative pain and opioid use is unclear. We hypothesized that intrapartum CD, which has been associated with both increased inflammation and affective distress related to an unexpected surgical procedure, would result in higher postoperative pain scores and increased opioid intake. Methods This is a secondary analysis of a prospective cohort study examining opioid use up to 2 weeks following CD. Women undergoing CD at six academic medical centers in the United States 9/2014-3/2016 were contacted by phone two weeks following discharge. Participants completed a structured interview that included questions about postoperative pain scores and opioid utilization. They were asked to retrospectively estimate their maximal pain score on an 11-point numeric rating scale at multiple time points, including day of surgery, during hospitalization, immediately after discharge, 1st week, and 2nd week following discharge. Pain scores over time were assessed utilizing a generalized linear mixed-effects model with the patient identifier being a random effect, adjusting for an a priori defined set of confounders. A multivariate negative binomial model was utilized to assess the association between intrapartum CD and opioid utilization after discharge, also adjusting for the same confounders. In the context of non-random prescription distribution, this model was constructed with an offset for the number of tablets dispensed. Results A total of 720 women were enrolled, 392 with and 328 without labor prior to CD. Patients with intrapartum CD were younger, less likely to undergo repeat CD or additional surgical procedures, and more likely to experience a complication of CD. Women with intrapartum CD consumed more opioid tablets following discharge than women without labor (median 20, IQR 10–30 versus 17, IQR 6–30; p = 0.005). This association persisted after adjustment for confounders (incidence rate ratio 1.16, 95% CI 1.05–1.29; p = 0.004). Pain scores on the day of surgery were higher in women with intrapartum CD (difference 0.91, 95% CI 0.52–1.30; adj. p = Conclusion Intrapartum CD is associated with worse pain on the day of surgery but not other time points. Opioid requirements following discharge were modestly increased following intrapartum CD.

Background We performed a systematic review using Consensus Based Standards for the Selection of Health Measurement Instruments (COSMIN) guidelines to identify the best available patient-reported outcome measure (PROM) of postpartum pain. Methods This review follows COSMIN guidelines. We searched four databases with no date limiters, for previously identified validated PROMs used to assess postpartum pain. PROMs evaluating more than one author-defined domain of postpartum pain were assessed. We sought studies evaluating psychometric properties. An overall rating was then assigned based upon COSMIN analysis, and the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach was used to assess the level of evidence for psychometric properties of included PROMs. These assessments were used to make recommendations and identify the best PROM to assess postpartum pain. Results We identified 19 studies using seven PROMs (involving 3511 women), which evaluated postpartum pain. All included studies evaluated ≥1 psychometric property of the included PROMs. An adequate number of pain domains was assessed by the Brief Pain Inventory (BPI), Short Form-BPI (SF-BPI), and McGill Pain Questionnaire (MPQ). The SF-BPI was the only PROM to demonstrate adequate content validity and at least a low-level of evidence for sufficient internal consistency, resulting in a Class A recommendation (the best performing instrument, recommended for use). Conclusion SF-BPI is the best currently available PROM to assess postpartum pain. However, it fails to assess several important domains and only just met the criteria for a Class A recommendation. Future studies are warranted to develop, evaluate, and implement a new PROM designed to specifically assess postpartum pain.

Study findings reveal continued opioid reduction and enduring pain stability for a substantial fraction of patients, 2 to 3 years after a patient-centered voluntary opioid tapering program., Objective: We previously reported promising results for a 4-month patient-centered voluntary opioid tapering study. Key questions remain about the durability of effects and possible risks after opioid reduction. We provide the longest follow-up data to date for prospective opioid tapering: 2- to 3-year follow-up for pain intensity and daily opioid use in a subset of patients from our original 4-month opioid tapering study. Methods: Twenty-three patients (44% of original sample) responded to contact attempts through telephone and reported their average pain intensity and current opioid use. Opioid doses were converted to morphine equivalent daily dose (MEDD). Data were analyzed within a repeated-measures model where time (baseline, 4 months, and 2–3 years) was the within-subject factor. Results: Among reachable patients, the effect of time on change in MEDD from baseline to 4 months to 2 to 3 years was significant. Since baseline, 20 (95%) of the current sample reduced MEDD, and 15 (71%) further reduced MEDD at 2- to 3-year follow-up. There was no effect of time on change in pain intensity from baseline to 4 months to 2 to 3 years. Since baseline, 11 (52%) of the current sample reported pain reduction, and 12 (57%) reported reduced pain from the 4-month follow-up to the 2- to 3-year follow-up. Five (24%) reported increased pain intensity. Conclusion: Study findings reveal continued MEDD reduction and enduring pain stability 2 to 3 years after a patient-centered voluntary opioid tapering program for a substantial fraction of patients. Notably, we were not able to verify current opioid use through medical records and were limited by self-report.

Background Nicotine and nicotinic acetylcholine receptors (nAChRs) have been explored for the past three decades as targets for pain control. The aim of this review is to introduce readers particularly to α7 nAChRs in a perspective of pain and its modulation. Methods Developments for α7 nAChR modulators and recent animal studies related to pain are reviewed. Results Accumulating evidences suggest that selective ligands for α7 nAChRs hold promise in the treatment of chronic pain conditions as they lack many of side effects associated with other nicotinic receptor types. Conclusion This review provides the reader recent insights on α7 nAChRs from structure and function to the latest findings on the pharmacology and therapeutic targeting of these receptors for the treatment of pain and inflammation.

Item does not contain fulltext OBJECTIVE: To update and expand the 2013 Clinical Practice Guidelines for the Management of Pain, Agitation, and Delirium in Adult Patients in the ICU. DESIGN: Thirty-two international experts, four methodologists, and four critical illness survivors met virtually at least monthly. All section groups gathered face-to-face at annual Society of Critical Care Medicine congresses; virtual connections included those unable to attend. A formal conflict of interest policy was developed a priori and enforced throughout the process. Teleconferences and electronic discussions among subgroups and whole panel were part of the guidelines' development. A general content review was completed face-to-face by all panel members in January 2017. METHODS: Content experts, methodologists, and ICU survivors were represented in each of the five sections of the guidelines: Pain, Agitation/sedation, Delirium, Immobility (mobilization/rehabilitation), and Sleep (disruption). Each section created Population, Intervention, Comparison, and Outcome, and nonactionable, descriptive questions based on perceived clinical relevance. The guideline group then voted their ranking, and patients prioritized their importance. For each Population, Intervention, Comparison, and Outcome question, sections searched the best available evidence, determined its quality, and formulated recommendations as "strong," "conditional," or "good" practice statements based on Grading of Recommendations Assessment, Development and Evaluation principles. In addition, evidence gaps and clinical caveats were explicitly identified. RESULTS: The Pain, Agitation/Sedation, Delirium, Immobility (mobilization/rehabilitation), and Sleep (disruption) panel issued 37 recommendations (three strong and 34 conditional), two good practice statements, and 32 ungraded, nonactionable statements. Three questions from the patient-centered prioritized question list remained without recommendation. CONCLUSIONS: We found substantial agreement among a large, interdisciplinary cohort of international experts regarding evidence supporting recommendations, and the remaining literature gaps in the assessment, prevention, and treatment of Pain, Agitation/sedation, Delirium, Immobility (mobilization/rehabilitation), and Sleep (disruption) in critically ill adults. Highlighting this evidence and the research needs will improve Pain, Agitation/sedation, Delirium, Immobility (mobilization/rehabilitation), and Sleep (disruption) management and provide the foundation for improved outcomes and science in this vulnerable population.

Summary A systematic literature search was performed to identify studies that reported risk factors for persistent pain after childbirth. Many studies have sought to identify risk factors for post-delivery pain in different populations, using different methodologies and different outcome variables. Studies of several different but interrelated post-partum pain syndromes have been conducted. Factors strongly and specifically associated with persistent incisional scar pain after Caesarean delivery include a coexisting persistent pain problem in another part of the body and severe acute postoperative pain. For persistent vaginal and perineal pain, operative vaginal delivery and the magnitude of perineal trauma have been consistently linked. History of pregnancy-related and pre-pregnancy back pain and heavier body weight are robust risk factors for persistent back pain after pregnancy. Unfortunately, limitations, particularly small samples and lack of a priori sample size calculation designed to detect specific effect sizes for risk of persistent pain outcomes, preclude definitive conclusions about many other predictors and the strength of outcome associations. In future studies, assessments of specific phenotypes using a rigorous analysis with appropriate predetermined sample sizes and validated instruments are needed to allow elucidation of stronger and reliable associations. Interventional studies targeting the most robustly associated, modifiable risk factors, such as acute post-partum pain, may lead to solutions for the prevention and treatment of these common problems that impact a large population.

Background The majority of parturients in the United States first return for evaluation by their obstetric practitioner 6 weeks after delivery. As such, there is little granular data on the pain experience, analgesic requirements, and functional recovery during the postpartum period. This prospective observational study was performed to evaluate these factors to provide expectations for patients. Methods A total of 213 nulliparous women were enrolled and assessed daily until they completed 3 outcomes: (1) pain resolution; (2) opioid cessation; and (3) self-assessed functional recovery from delivery. The primary endpoint, pain- and opioid-free functional recovery, was the time required to reach all three of the endpoints. Pain burden was assessed as the area under the curve created by plotting the daily numerical pain rating scale against the days required to attain pain resolution. Times to attain study endpoints after cesarean delivery and vaginal delivery were compared using survival analysis. Results After vaginal delivery, days required for pain and opioid-free functional recovery (median [interquartile range (IQR)]) were 19 [11 to 26], for opioid cessation 0 [0 to 2], termination of all analgesic (including nonsteroidal antiinflammatories and acetaminophen) 11 [5 to 17], and pain resolution 14 [7 to 24]. Achievement of these endpoints after cesarean delivery required 27 [19 to 40], 9 [5 to 12], 16 [11 to 24], and 21 [14 to 27] days, respectively. Conclusions There is clinically significant variability between healthy nulliparous parturients in the pain experience, opioid use, and functional recovery after childbirth following vaginal and cesarean delivery. Recovery to predelivery function is similar after vaginal and cesarean delivery, and approximately half of the variance was explained by pain burden.

To define the amount of opioid analgesics prescribed and consumed after discharge after cesarean delivery.We conducted a survey at six academic medical centers in the United States from September 2014 to March 2016. Women who had undergone a cesarean delivery were contacted by phone 2 weeks after discharge and participated in a structured interview about the opioid prescription they received on discharge and their oral opioid intake while at home.A total of 720 women were enrolled; of these, 615 (85.4%) filled an opioid prescription. The median number of dispensed opioid tablets was 40 (interquartile range 30-40), the median number consumed was 20 (interquartile range 8-30), and leftover was 15 (interquartile range 3-26). Of those with leftover opioids, 95.3% had not disposed of the excess medication at the time of the interview. There was an association between a larger number of tablets dispensed and the number consumed independent of patient characteristics. The amount of opioids dispensed did not correlate with patient satisfaction, pain control, or the need to refill the opioid prescription.The amount of opioid prescribed after cesarean delivery generally exceeds the amount consumed by a significant margin, leading to substantial amounts of leftover opioid medication. Lower opioid prescription correlates with lower consumption without a concomitant increase in pain scores or satisfaction.

Routine pain assessment and the procurement of effective analgesics are of paramount importance to critical care patients. Constant evaluation underpins the important balance between pain relief and the pharmacological side effects of administered agents. The significance of these issues was highlighted during the production of the most recent Society of Critical Medicine’s (SCCM) Pain, Agitation, Delirium, Immobility, and Sleep (PADIS) Guidelines [1]. Patients who partnered as authors and contributors in the SCCM PADIS effort ranked this dimension of clinical care as essential to their well-being, leading to its prioritization for these guidelines [2].

The availability of labor analgesia is highly variable in the People's Republic of China. There are widespread misconceptions, by both parturients and health care providers, that labor epidural analgesia is harmful to mother and baby. Meanwhile, China has one of the highest cesarean delivery rates in the world, exceeding 50%. The goal of the nongovernmental No Pain Labor & Delivery (NPLD) is to facilitate sustainable increases in vaginal delivery rates by increasing access to safe neuraxial labor analgesia, thereby decreasing the cesarean delivery rate. NPLD was launched in 2008 with the stated goal of improving labor outcome in China by increasing the absolute labor epidural analgesia rate by 10%. NPLD established 10 training centers over a 10-year period. We hypothesized that increased availability of labor analgesia would result in reduced requests for cesarean delivery and better labor outcomes for mother and baby. Multidisciplinary teams of Western clinicians and support staff traveled to China for 8 to 10 days once a year. The approach involved establishing 24/7 obstetric anesthesia coverage in Chinese hospitals through education and modeling multidisciplinary approaches, including problem-based learning discussions, bedside teaching, daily debriefings, simulation training drills, and weekend conferences. As of November 2015, NPLD has engaged with 31 hospitals. At 24 of these sites, 24/7 obstetric anesthesia coverage has been established and labor epidural analgesia rates have exceeded 50%. Lower rates of cesarean delivery, episiotomy, postpartum blood transfusion, and better neonatal outcomes were documented in 3 impact studies comprising approximately 55,000 deliveries. Changes in practice guidelines, medical policy, and billing codes have been implemented in conjunction with the modernization of perinatal practice that has occurred concurrently in China since the first NPLD trip in 2008.

BackgroundDisagreement among many underpowered studies has led to an equivocal understanding of the efficacy of the 5-HT3 antagonist ondansetron in preventing the consequences of sympathectomy after subarachnoid anesthesia. The authors assessed the efficacy of ondansetron with respect to the overall quality and statistical power of the meta-analyses.MethodsThe authors used a standard and a newer method of meta-analysis, trial sequential analysis (TSA), to estimate adjusted CIs based on how much information has been accrued. They also used random-effects meta-analyses techniques, small trial bias assessment, selection models, sensitivity analyses, and the Grading of Recommendations on Assessment, Development, and Evaluation system. These results from the aforementioned techniques were compared, and importance of consideration of these factors was discussed.ResultsFourteen randomized placebo-controlled trials (1,045 subjects) were identified and analyzed. By using conventional meta-analyses, the authors determined that ondansetron was associated with reduction in the incidence of hypotension (relative risk = 0.62 [95% CI, 0.46 to 0.83], P = 0.001; TSA-adjusted CI, 0.34 to 1.12; I2 = 60%, P = 0.002) and bradycardia (relative risk = 0.44 [95% CI, 0.26 to 0.73], P = 0.001; TSA-adjusted CI, 0.05 to 3.85; I2 = 0%, P = 0.84). However, the authors found indications of bias among these trials. TSAs demonstrated that the meta-analysis lacked adequate information size and did not achieve statistical significance when adjusted for sparse data and repetitive testing. The Grading of Recommendations on Assessment, Development, and Evaluation system showed that the results had low to very low quality of evidence.ConclusionsThe analyses fail to confirm evidence that ondansetron reduces the incidence of hypotension and bradycardia after subarachnoid anesthesia due to the risk of bias and information sizes less than the required. As results from meta-analysis are given significant weight, it is important to carefully evaluate the quality of the evidence that is input.

OBJECTIVES: To describe novel guideline development strategies created and implemented as part of the Society of Critical Care Medicine's 2018 clinical practice guidelines for pain, agitation (sedation), delirium, immobility (rehabilitation/mobility), and sleep (disruption) in critically ill adults. DESIGN: We involved critical illness survivors from start to finish, used and expanded upon Grading of Recommendations, Assessment, Development and Evaluation methodology for making recommendations, identified evidence gaps, and developed communication strategies to mitigate challenges. SETTING/SUBJECTS: Thirty-two experts from five countries, across five topic-specific sections; four methodologists, two medical librarians, four critical illness survivors, and two Society of Critical Care Medicine support staff. INTERVENTIONS: Unique approaches included the following: 1) critical illness survivor involvement to help ensure patient-centered questions and recommendations; 2) qualitative and semiquantitative approaches for developing descriptive statements; 3) operationalizing a three-step approach to generating final recommendations; and 4) systematic identification of evidence gaps. MEASUREMENTS AND MAIN RESULTS: Critical illness survivors contributed to prioritizing topics, questions, and outcomes, evidence interpretation, recommendation formulation, and article review to ensure that their values and preferences were considered in the guidelines. Qualitative and semiquantitative approaches supported formulating descriptive statements using comprehensive literature reviews, summaries, and large-group discussion. Experts (including the methodologists and guideline chairs) developed and refined guideline recommendations through monthly topic-specific section conference calls. Recommendations were precirculated to all members, presented to, and vetted by, most members at a live meeting. Final electronic voting provided links to all forest plots, evidence summaries, and "evidence to decision" frameworks. Written comments during voting captured dissenting views and were integrated into evidence to decision frameworks and the guideline article. Evidence gaps, reflecting clinical uncertainty in the literature, were identified during the evidence to decision process, live meeting, and voting and formally incorporated into all written recommendation rationales. Frequent scheduled "check-ins" mitigated communication gaps. CONCLUSIONS: Our multifaceted, interdisciplinary approach and novel methodologic strategies can help inform the development of future critical care clinical practice guidelines.

Background Consensus panels regularly recommend aerobic exercise for its health‐promoting properties, due in part to presumed anti‐inflammatory effects, but many studies show no such effect, possibly related to study differences in participants, interventions, inflammatory markers, and statistical approaches. This variability makes an unequivocal determination of the anti‐inflammatory effects of aerobic training elusive. Methods and Results We conducted a randomized controlled trial of 12 weeks of aerobic exercise training or a wait list control condition followed by 4 weeks of sedentary deconditioning on lipopolysaccharide (0, 0.1, and 1.0 ng/mL)‐inducible tumor necrosis factor‐α (TNF‐α) and interleukin‐6 (IL‐6), and on toll‐like receptor 4 in 119 healthy, sedentary young adults. Aerobic capacity by cardiopulmonary exercise testing was measured at study entry (T1) and after training (T2) and deconditioning (T3). Despite a 15% increase in maximal oxygen consumption, there were no changes in inflammatory markers. Additional analyses revealed a differential longitudinal aerobic exercise training effect by lipopolysaccharide level in inducible TNF ‐α ( P =0.08) and IL‐6 ( P =0.011), showing T1 to T2 increases rather than decreases in inducible (lipopolysaccharide 0.1, 1.0 versus 0.0 ng/mL) TNF‐ α (51% increase, P =0.041) and IL‐6 (42% increase, P =0.11), and significant T2 to T3 decreases in inducible TNF‐ α (54% decrease, P =0.007) and IL‐6 (55% decrease, P TNF‐ α or IL‐6. Conclusions The failure to support the primary hypotheses and the unexpected post hoc findings of an exercise‐training–induced proinflammatory response raise questions about whether and under what conditions exercise training has anti‐inflammatory effects. Clinical Trial Registration URL : http://www.clinicaltrials.gov . Unique identifier: NCT 01335737.

Author(s): Devlin, John W; Skrobik, Yoanna; Gelinas, Celine; Needham, Dale M; Slooter, Arjen JC; Pandharipande, Pratik P; Watson, Paula L; Weinhouse, Gerald L; Nunnally, Mark E; Rochwerg, Bram; Balas, Michele C; van den Boogaard, Mark; Bosma, Karen J; Brummel, Nathaniel E; Chanques, Gerald; Denehy, Linda; Drouot, Xavier; Fraser, Gilles L; Harris, Jocelyn E; Joffe, Aaron M; Kho, Michelle E; Kress, John P; Lanphere, Julie A; McKinley, Sharon; Neufeld, Karin J; Pisani, Margaret A; Payen, Jean-Francois; Pun, Brenda T; Puntillo, Kathleen A; Riker, Richard R; Robinson, Bryce RH; Shehabi, Yahya; Szumita, Paul M; Winkelman, Chris; Centofanti, John E; Price, Carrie; Nikayin, Sina; Misak, Cheryl J; Flood, Pamela D; Kiedrowski, Ken; Alhazzani, Waleed

Objective The aim of this study is to determine the relationship between heart rate and/or blood pressure variability, measured at 28 weeks' gestation, and the incidence of pregnancy-induced hypertension or preeclampsia. Study Design Secondary analysis of data from a prospectively enrolled cohort of 385 active military women in whom spectral analysis of continuous heart rate and variability was measured at 28 weeks' gestation. The primary outcome was the predictive value of spectral analysis of heart rate and blood pressure for hypertensive diseases of pregnancy. Results High-frequency heart rate variability was reduced and low-frequency variability of systolic and diastolic blood pressure increased in women who would develop pregnancy-induced hypertension but not preeclampsia. Low-frequency variability of diastolic blood pressure remained a significant predictor of pregnancy-induced hypertension but not preeclampsia after adjustment for age, weight, and blood pressure in a multivariate model. Conclusion Early identification of pregnancy-induced hypertension can facilitate treatment to avoid maternal morbidity. Understanding the physiological underpinnings of the two very different diseases may lead to improved treatment and prevention. If proven effective in a broader population, the ability to differentiate pregnancy-induced hypertension from preeclampsia may reduce unnecessary iatrogenic interventions or inappropriate preterm delivery.

This chapter reviews the pharmacology of the intravenously administered opioids in the practice of geriatric anesthesiology. These drugs include morphine, meperidine, hydromorphone, fentanyl, sufentanil, and methadone. It is important that anesthesiologists understand the differences in pharmacology of opioids in elderly patients, in order to choose the appropriate drug and titrate precisely to achieve the desired analgesic effects while minimizing the risks of opioid toxicity. The key points for this chapter are as follows: (1) Elderly patients need about half the dose as younger patients, (2) The primary reason is pharmacodynamics (the elderly brain is more sensitive to opioids), (3) The pharmacokinetic changes with age are modest, (4) Studies in elderly animals show reduced numbers of μ receptors with increased age. That does not explain the reduction in dose, as decreased receptor density should decrease sensitivity to opioids. The enhancement in drug effect seen in the clinic is more likely attributable to changes in cyclonucleotide coupling and other downstream changes that occur in aging, and (5) Mepiridine should be used with caution in elderly patients due to its effects on myocardium, pharmacokinetics related to its metabolites, and its delirogenic properties.

The physiology that underlies pain perception is complex and clearly influenced by both genetic and environmental factors. This issue of Anesthesia & Analgesia includes 2 articles that identify relationships between single nucleotide polymorphisms (SNPs) in the gene for Catechol-O-methyltransfer

Objective To develop a model that uses cervical effacement, fetal station, and parity to predict progress during the first stage of labor. Study Design This was a secondary analysis of a cohort of 1,128 parturients delivering after 34 weeks. Timed cervical exams from each patient were fit with a biexponential model. Methods for consideration of fetal station, cervical effacement and parity were developed and validated. Results The biexponential model fit the data in an unbiased manner with a median absolute prediction error of 1.1 cm. Although nulliparous women had slower active labor, they did not differ from multiparous women in their rate of latent labor or the cervical dilation at which they transitioned to active labor. In addition, nulliparous women began laboring with a more effaced cervix (45 vs. 31%) and lower fetal station (–2.8 vs. –3.2). Conclusion We validated a biexponential model for labor progress using a large mixed parity cohort. We demonstrated that parity and initial fetal station add important clinical information that can be used to make a labor model more accurate. As such, parity and fetal station can be utilized in such structural models to predict normal labor progress and potentially identify abnormalities in labor progress.

Background Prediction models to identify parturients who experience protracted pain, prolonged opioid use, and delayed self-assessed functional recovery are currently inadequate. Methods For this study, 213 nulliparous women who planned vaginal delivery were enrolled and assessed daily until they completed three outcomes: (1) pain resolution; (2) opioid cessation; and (3) self-assessed functional recovery to predelivery level. The primary composite endpoint, ‘pain and opioid-free functional recovery' was the time required to reach all three endpoints. The subjects were divided into two categories (the worst (longest time) 20% and remaining 80%) for reaching the primary composite endpoint, and each individual component. Prediction models for prolonged recovery were constructed using multivariate logistic regression with demographic, obstetric, psychological, and health-related quality of life characteristics as candidate predictors. Results Labour induction (vs spontaneous labour onset) predicted the worst 20% for the primary composite endpoint in the final multivariate model. Labour induction and higher postpartum day 1 numerical rating score for pain were predictors for being in the worst 20% for both functional recovery and pain burden. Labour type, delivery type, Patient-Reported Outcomes Measurement Information System (PROMIS) anxiety score, RAND 36 Item Health Survey 1.0 (SF-36) physical health composite score, and postpartum breastfeeding success were predictive of delayed opioid cessation. Conclusions Labour induction and elevated numerical rating score for pain are predictive of poor recovery after childbirth. Further research is necessary to determine whether modification would benefit mothers at risk for poor recovery.

Background Activation of nicotinic receptors with nicotine has been shown to reduce post-surgical pain in clinical and preclinical studies. Choline is a selective agonist at α7-type nicotinic receptors that does not have addictive or sympathetic activating properties. It is anti-nociceptive in animal studies. We conducted a double-blind randomized trial of oral choline supplementation with lecithin to aid in the treatment of pain after gynaecological surgery. Methods Sixty women having open gynaecological surgery were randomly assigned to receive 20 g of lecithin before surgery or placebo. Plasma choline concentration and tumour necrosis factor (TNF) were measured. Pain report was the primary outcome measure. Results We achieved a small but statistically significant increase in choline after surgery with oral supplementation. Plasma TNF was not decreased and pain report was not different between groups at rest or with movement. There were no adverse effects of treatment. Conclusions Oral supplementation with lecithin during the perioperative period resulted in very slow absorption and thus only a small increase in plasma choline was achieved. This concentration was inadequate to reduce TNF as has been shown in other studies. The absence of an anti-inflammatory effect was likely related to our failure to demonstrate efficacy in pain reduction.

BACKGROUND Disagreement among many underpowered studies has led to an equivocal understanding of the efficacy of the 5-HT3 antagonist ondansetron in preventing the consequences of sympathectomy after subarachnoid anesthesia. The authors assessed the efficacy of ondansetron with respect to the overall quality and statistical power of the meta-analyses. METHODS The authors used a standard and a newer method of meta-analysis, trial sequential analysis (TSA), to estimate adjusted CIs based on how much information has been accrued. They also used random-effects meta-analyses techniques, small trial bias assessment, selection models, sensitivity analyses, and the Grading of Recommendations on Assessment, Development, and Evaluation system. These results from the aforementioned techniques were compared, and importance of consideration of these factors was discussed. RESULTS Fourteen randomized placebo-controlled trials (1,045 subjects) were identified and analyzed. By using conventional meta-analyses, the authors determined that ondansetron was associated with reduction in the incidence of hypotension (relative risk = 0.62 [95% CI, 0.46 to 0.83], P = 0.001; TSA-adjusted CI, 0.34 to 1.12; I = 60%, P = 0.002) and bradycardia (relative risk = 0.44 [95% CI, 0.26 to 0.73], P = 0.001; TSA-adjusted CI, 0.05 to 3.85; I = 0%, P = 0.84). However, the authors found indications of bias among these trials. TSAs demonstrated that the meta-analysis lacked adequate information size and did not achieve statistical significance when adjusted for sparse data and repetitive testing. The Grading of Recommendations on Assessment, Development, and Evaluation system showed that the results had low to very low quality of evidence. CONCLUSIONS The analyses fail to confirm evidence that ondansetron reduces the incidence of hypotension and bradycardia after subarachnoid anesthesia due to the risk of bias and information sizes less than the required. As results from meta-analysis are given significant weight, it is important to carefully evaluate the quality of the evidence that is input.

Purpose To determine the efficacy of preoperatively administered nicotine nasal spray (3 mg) for analgesia after third molar (TM) surgery. Materials and Methods A single-center, prospective, randomized, double-blind, crossover trial was conducted. The study population consisted of 20 nonsmoking patients referred to the Department of Oral and Maxillofacial Surgery of Columbia University College of Dental Medicine for extraction of all 4 TMs. Each patient received nicotine nasal spray or placebo spray before TM surgery. At a subsequent visit the contralateral TMs were removed with prior administration of the alternate treatment. For an hour postoperatively, subjects reported information on pain and nausea, and hemodynamic variables were recorded at 15-minute intervals. Telephone follow-up was recorded for 5 days postoperatively, where patients reported information on pain, nausea, and use of hydrocodone/acetaminophen as rescue analgesia. Results Nicotine treatment was associated with a highly significant decrease in pain reported during the 5 days after TM surgery. There was no difference in the amount of hydrocodone/acetaminophen used or amount of nausea reported. There was a small but significant increase in heart rate after nicotine treatment compared with placebo during the first hour after surgery. There was no difference in blood pressure between groups. Conclusion Pain is well controlled by hydrocodone/acetaminophen in most patients after TM surgery. However, there is significant variability in pain reported. Nicotinic agonists represent a new class of analgesic that can be considered for patients who are expected to have significant opioid-resistant pain after TM surgery. Caution should be used with patients in whom a small increase in heart rate would be deleterious.

The majority of pregnant women will be treated with a medication other than a vitamin supplement during their pregnancy. Almost half of these medications will be category C or D according to the former US Food and Drug Administration classification system, indicating a lack of human studies with animal studies suggesting adverse fetal effects (category C) or evidence of risk in humans (category D). Changes in maternal physiology alter drug bioavailability, distribution, clearance, and thus the drug half-life in often unpredictable ways. For many drugs, good pharmacokinetic and pharmacodynamic data in pregnancy and parturition are lacking. For other drugs, recent studies demonstrate major pharmacokinetic or pharmacodynamic changes that require dose adjustment in pregnancy, but current dosing guidelines do not reflect these data. In this review, we address the principles that underlie changes in pharmacology and physiology in pregnancy and provide information on drugs that anesthesiologists commonly encounter in treating pregnant patients.

Choline is a dietary supplement that activates alpha7 nicotinic receptors. alpha7 nicotinic activation reduces cytokine production by macrophages and has antinociceptive activity in inflammatory pain models. We hypothesized that systemic administration of choline would reduce the inflammatory response from macrophages and have antinociceptive efficacy in a murine model of postoperative pain.We studied the response of wild-type and alpha7 nicotinic knockout mice to heat and punctate pressure after a model surgical procedure. We investigated the effect of genotype and choline treatment on alpha-bungarotoxin binding to, and their production of tumour necrosis factor (TNF) from, macrophages.Choline provided moderate antinociception. The ED(50) for choline inhibition of heat-induced allodynia was 1.7 mg kg(-1) h(-1). The ED(50) for punctate pressure threshold was 4.7 mg kg(-1) h(-1) choline. alpha7 nicotinic knockout mice had no change in hypersensitivity to heat or pressure and were significantly different from littermate controls when treated with choline 5 mg kg(-1) h(-1) (P0.05, 0.01). Choline 100 mM reduced binding of alpha-bungarotoxin to macrophages by 72% and decreased their release of TNF by up to 51 (sd 11)%. There was no difference by genotype in the inhibition of TNF release by choline.Systemic choline is a moderately effective analgesic via activation of alpha7 nicotinic acetylcholine receptors. The antinocicepive effect may not be mediated by a reduction of TNF pathway cytokine release from macrophages. Although choline at millimolar concentrations clearly inhibits the release of TNF, this effect is not alpha7 subunit-dependent and occurs at concentrations likely higher than reached systemically in vivo.

Nicotine, the prototypical broad spectrum agonist at central nicotinic receptors, has analgesic action after surgery. Various subtype-specific nicotinic agonists have antinociceptive effects in animal models, but the response is highly dependent on the model tested. In an effort to determine what nicotinic subtypes might be targeted in future clinical studies, we tested agonists selective for alpha 4 beta 2 and alpha 7 containing nicotinic receptors in a mouse model of postoperative pain.After paw incision, mice were tested for heat latency and pressure threshold before and after treatment with a dose range of ligands selective for alpha 4 beta 2 and alpha 7 containing nicotinic receptors. To demonstrate that nicotine reduced nociceptive input in this model, the lumbar spinal cords of a subgroup of these mice were stained for the phosphorylated form if CREB.Nicotine and metanicotine (alpha 4 beta 2 selective) were fully effective as an analgesic in heat and pressure testing. The alpha 7 partial agonist GTS-21 significantly increased the heat latency after surgery, but did not alter pressure threshold. The alpha 7 selective antagonist methyllicaconitine decreased the efficacy of nicotine to increase heat latency but did not affect pressure threshold. The number of cells in the superficial dorsal horn with nuclei that stained for pCREB was double on the surgical side and the ratio was reduced by nicotine in a dose-dependent manner.Our findings suggest that nicotine reduced nociceptive input to the superficial and deep dorsal horn. It also provides support for alpha 4 beta 2 and alpha 7 nicotinic-mediated antinociceptive actions.

Background Nicotine has been shown to be antinociceptive in the postoperative period in animal studies. Human studies with nasal nicotine sprays have had mixed results, possibly due to variability in pharmacokinetics and potential patient variables such as exposure to nicotine in tobacco smokers. In this pilot study, we examined the analgesic effect of a transdermal nicotine patch applied before surgery in nonsmokers. Methods We conducted a randomized, double-blind, prospective placebo-controlled trial of 40 subjects, undergoing general surgery that required postoperative patient-controlled analgesia and an overnight hospital admission. Immediately before surgery, a transdermal nicotine patch containing 0, 5, 10, or 15 mg was applied. The primary outcome variable was pain report using a numerical rating scale (NRS) in the first hour after surgery and over the next 5 days. Secondary outcomes were pain medication use, hemodynamic values, nausea, and sedation. Results Patients treated with nicotine reported lower pain scores when compared with those treated with placebo during the first hour after surgery (P = 0.003, average NRS decrease = 1.4, 95% CI = 0.3-2.6) and for 5 days after surgery (P = 0.03, average NRS decrease = 1.0, 95% CI = 0.1-1.9). There was no increased benefit of nicotine with doses larger than 5 mg. There was a trend suggesting decreased pain medicine use, increased nausea, decreased tachycardia, and slightly decreased systolic blood pressure in the nicotine groups, but these values did not reach significance. Conclusions Transdermal nicotine, 5-15 mg, reduced postoperative pain scores but failed to decrease the need for opioid analgesics or opioid-related side effects after general surgical procedures.

BACKGROUND Volatile anesthetics inhibit nicotinic acetylcholine receptors at subanesthetic concentrations. In both animal and human studies, similar concentrations of volatile anesthetics have been associated with increased sensitivity to pain. Nicotinic analgesia is thought to involve the enhanced release of norepinephrine. These studies are intended as a "proof of concept" that alteration of the nicotinic facilitation of norepinephrine release is a potential mechanism for isoflurane-induced pronociception. METHODS We conducted our study using a murine lumbar spinal cord slice model. We evoked norepinephrine release with nicotine in the presence and absence of isoflurane. To identify the type of nicotinic receptor involved, we studied the effect of receptor and subtype-specific ligands and genetically engineered mice, which lacked the gene expression for the nicotinic beta2 subunit. The amount of [(3)H]-norepinephrine released was measured under the different conditions. RESULTS Nicotine-facilitated norepinephrine release was significantly and maximally inhibited by isoflurane at concentrations that enhance pain sensitivity in vivo (0.38%). Facilitation of norepinephrine release was mimicked by the alpha 7 selective agonist choline and inhibited in the presence of alpha-bungarotoxin, an alpha 7-nicotinic selective antagonist. Facilitation of norepinephrine release was not different in animals lacking beta2 subunits compared with matched controls. CONCLUSIONS Nicotinic facilitation of norepinephrine release in the spinal cord is inhibited by isoflurane at low clinically relevant concentrations. Because the net effect of noradrenergic tone in the spinal cord is inhibitory, the removal of this mechanism might be responsible for the enhanced pain sensitivity seen at these concentrations of isoflurane.

BACKGROUND: Inhaled anesthetics have been postulated to act at multiple receptors, with modest action at each site summing to produce immobility to noxious stimulation. Recent experimental results affirm prior findings that inhaled anesthetics interact additively. Synergy implies multiple sites of action by definition. In this essay, we explore the converse: does additivity imply a single site of action? METHODS: The interaction of one versus two ligands competing for the same binding site at a receptor was explored using the law of mass action. Circuits were then constructed to investigate how the potency of drugs and the steepness of the concentration versus response relationship is amplified by the arrangement of suppressors into serial circuits, and enhancers into parallel circuits. Assemblies of suppressor and enhancer circuits into signal processing units were then explored to investigate the constraints signal processing units impose on additive interactions. Lastly, the relationship between synergy, additivity, and fractional receptor occupancy was explored to understand the constraints imposed by additivity. RESULTS: Drugs that compete for a single receptor, and that similarly affect the receptor, must be additive in their effects. Receptors that bind suppressors in serial circuits, or enhancers in parallel circuits, increase the apparent potency of the drugs and the steepness of the concentration versus response relationship. When assemblies of suppressor and enhancer circuits are arranged into signal processing units, the interactions may be additive or synergistic. The primary determinant is the relationship between the concentration of drug associated with the effect of interest and the concentration associated with 50% receptor occupancy, kd. Effects mediated by very low concentrations are more likely to be additive. Similarly, inhaled anesthetics that act at separate sites are unlikely to exhibit additive interactions if anesthetic drug effect occurs at concentrations at or above 50% receptor occupancy. However, if anesthetic drug effect occurs at very low levels of receptor occupancy, then additivity is expected even among anesthetics acting on different receptors. CONCLUSIONS: Additivity among drugs acting on different receptors is only likely if the concentrations responsible for the drug effect of interest are well below the concentration associated with 50% receptor occupancy. (Anesth Analg 2008;107:507‐24)

BACKGROUND:Preclinical studies have suggested that some volatile anesthetics induce a hyperalgesic state that may be secondary to nicotinic inhibition. A previous trial of treatment with nicotine nasal spray demonstrated postoperative analgesia in women anesthetized with isoflurane. To determine whe

Aerobic exercise reduces coronary heart disease risk, but the mechanisms of this protection are not fully understood. Atherosclerosis is an inflammatory disease mediated by monocyte-derived macrophages, which accumulate in arterial plaques and become activated to release factors, including cytokines, that cause damage. Here we studied the effects of aerobic training on monocyte production of tumor necrosis factor (TNF) in whole blood ex vivo. Healthy young sedentary adults ( n = 61, age 20–45 yr) were randomized to a moderate- (M) or a high- (H) intensity 12-wk training program. Whole blood was extracted before and after training, and then it was stimulated by addition of lipopolysaccharide (LPS); inducible TNF was measured in the plasma. Data were analyzed according to intention to treat principles using a random-effect model to determine the impact of training group on maximal aerobic capacity and LPS-stimulated TNF after correcting for covariates. Analyses revealed improvement in aerobic capacity in both the H (9%) and the M (7%) groups. However, aerobic training led to significant ( P < 0.001) decreases in TNF release only in the H group. These data suggest that in healthy young adults, a 12-wk high-intensity aerobic training program downregulates blood monocyte production of stimulated cytokine release.