Prolonged Perioperative Use of Pregabalin and Ketamine to Prevent Persistent Pain after Cardiac Surgery.

BACKGROUND: Persistent postsurgical pain is common and affects quality of life. The hypothesis was that use of pregabalin and ketamine would prevent persistent pain after cardiac surgery. METHODS: This randomized, double-blind, placebo-controlled trial was undertaken at two cardiac surgery centers in the United Kingdom. Adults without chronic pain and undergoing any elective cardiac surgery patients via sternotomy were randomly assigned to receive either usual care, pregabalin (150 mg preoperatively and twice daily for 14 postoperative days) alone, or pregabalin in combination with a 48-h postoperative infusion of intravenous ketamine at 0.1 mg · kg · h. The primary endpoints were prevalence of clinically significant pain at 3 and 6 months after surgery, defined as a pain score on the numeric rating scale of 4 or higher (out of 10) after a functional assessment of three maximal coughs. The secondary outcomes included acute pain, opioid use, and safety measures, as well as long-term neuropathic pain, analgesic requirement, and quality of life. RESULTS: In total, 150 patients were randomized, with 17 withdrawals from treatment and 2 losses to follow-up but with data analyzed for all participants on an intention-to-treat basis. The prevalence of pain was lower at 3 postoperative months for pregabalin alone (6% [3 of 50]) and in combination with ketamine (2% [1 of 50]) compared to the control group (34% [17 of 50]; odds ratio = 0.126 [0.022 to 0.5], P = 0.0008; and 0.041 [0.0009 to 0.28], P < 0.0001, respectively) and at 6 months for pregabalin alone (6% [3 of 50]) and in combination with ketamine 0% (0 of 5) compared to the control group (28% [14 of 50]; odds ratio = 0.167 [0.029 to 0.7], P = 0.006; and 0.000 [0 to 0.24], P < 0.0001). Diplopia was more common in both active arms. CONCLUSIONS: Preoperative administration of 150 mg of pregabalin and postoperative continuation twice daily for 14 days significantly lowered the prevalence of persistent pain after cardiac surgery.

Persistent Postsurgical Pain Following Thoracotomy: A Comparison of Thoracic Epidural and Paravertebral Blockade as Preventive Analgesia.

OBJECTIVE: Persistent postsurgical pain (PPP) is common following thoracotomy. Thoracic epidural (TEB) and paravertebral blockade (PVB) are both established forms of perioperative analgesia for thoracotomy. There is currently a lack of data on their influence on PPP; this study aims to evaluate both techniques on PPP. DESIGN: Observational study, prospectively collected data. METHODS: Adults who underwent thoracotomy had either TEB or PVB for analgesia and were prospectively interviewed at six months. A numerical rating scale, the short form of the Leeds Assessment of Neuropathic Symptoms and Signs, and the EuroQol-5 dimension (EQ-5D) index were used to assess pain, neuropathic pain, and quality of life. RESULTS: Eighty-two patients who underwent a thoracotomy were recruited (TEB N = 36, PVB N = 46). Pain scores had a median (interquartile range [IQR]) of 1 (0 to 4.5) and 1.5 (0 to 4, P = 0.89), presence of PPP was 58.3% (95% confidence interval [CI] = 40.0-74.5%) and 60.9% (95% CI = 45.4-74.9%, P = 0.81), and presence of neuropathic pain was 30.6% (95% CI = 16.3-48.1%) and 28.2% (95% CI = 16.0-43.5%, P = 0.85). Reported quality of life was 0.71 (0.14-0.85) and 0.80 (0.19-0.91, P = 0.21). Patients who had PPP reported worse quality of life measures compared with those who were pain free, with a median (IQR) EQ-5D index of 0.69 (-0.15 to 0.85) and 0.85 (0.72 to 1, P = 0.0007); quality of life was worst when there was a neuropathic component (median = 0.39, IQR = -0.24 to 0.75). CONCLUSIONS: There was no statistical difference in the development of persistent postsurgical pain between patients who received a TEB or a PVB; however, patients who developed PPP had a significantly lower quality of life, which was worse with a neuropathic component.

Characterizing the Somatosensory Profile of Patients With Failed Back Surgery Syndrome With Unilateral Lumbar Radiculopathy Undergoing Spinal Cord Stimulation: A Single Center Prospective Pilot Study.

OBJECTIVES: Currently little objective evidence exists regarding the phenotype or somato-sensory profile of patients with Failed Back Surgery Syndrome (FBSS). The aim of this study is to characterize the somato-sensory profile of the patients with FBSS undergoing spinal cord stimulation (SCS). METHODS: A combined quantitative sensory test and questionnaire approach was used to characterize the somatosensory profiles of patients undergoing SCS. RESULTS: Baseline somatosensory profiles were obtained from 23 patients and full three-month data was obtained from 19 patients. At baseline, there was a high prevalence (>50% prevalence of moderate to severe sensation) of burning, tingling, electric shock, numbness, and pressure pain sensitivity. None of the sensory symptoms were present at significant levels at three months following SCS. At baseline, 65% of patients had an inefficient conditioned pain modulation (CPM). Three months post-SCS, 95% of patients had an efficient CPM. All the patients who had an inefficient CPM at baseline had a successful implant at three months and their CPM became efficient in all but one patient. Only 50% of the patients with an efficient CPM at baseline, had a successful implant at three months post-SCS. CONCLUSION: Although very low numbers, we could demonstrate the somatosensory profiles of patients with FBSS undergoing SCS. Early indication may associate an efficient CPM profile having a higher chance of an unsuccessful implant at three months.

Nano/micro fluorhydroxyapatite crystal pastes in the treatment of dentin hypersensitivity: an in vitro study.

OBJECTIVES: Dentin hypersensitivity (DH) is a prevalent problem. This study aimed to formulate a paste using fluorhydroxyapatite (FA) crystals dispersed in different carriers to treat DH. The ability to occlude patent dentinal tubules and to release ions was investigated. MATERIALS AND METHODS: Twenty percent FA/sodium alginate, 40% FA/poly(hydroxyethyl methacylate(HEMA)), and 40% FA/poly(DMA-co-MEA) were applied to etched dentin samples and examined with scanning electron microscopy (SEM) to determine the degree of tubule occlusion. Fluoride electrode was used to measure F release and spectroscopy to evaluate Ca and PO4 release. The cytotoxicity of the synthesized poly(DMA-co-MEA) gel was tested. Kruskall-Wallis test was used to test the differences in ion release between the groups. RESULTS: FA/poly(DMA-co-MEA) paste obstructed up to 80% of the dentinal tubules, while the coverage was up to 70% for FA/poly(HEMA) and less than 50% for FA/sodium alginate. Fluoride and Ca release was the highest for FA/P(HEMA), 7.2 ± 0.7 and 139.8 ± 32.5 ppm, respectively. The highest concentration of PO4 was 46.2 ± 16.4 ppm for FA/Sodium alginate. No statistical significance was found. CONCLUSIONS: FA/Poly(DMA-co-MEA) and FA/poly(HEMA) pastes may offer immediate short-term relief of DH because of their ability to occlude the tubules and adhere to wet dentin surfaces. The release of the F, Ca, and PO4 ions may offer long-term relief by forming a mineral barrier both within the dentinal tubules and on the dentin surface. CLINICAL SIGNIFICANCE: The tested materials may offer a long-term treatment for DH.

Co-crystal of tramadol-celecoxib (CTC) for acute moderate-to-severe pain.

OBJECTIVE: This narrative review aims to provide a clinical perspective on the potential role of co-crystal of tramadol-celecoxib (CTC) in the management of acute moderate-to-severe pain by synthesizing the available preclinical and clinical data, with emphasis on phase 3 trials. METHODS: A non-systematic literature review was performed using a targeted PubMed search for articles published between January 1, 2000, and May 2, 2023; all publication types were permitted, and selected articles were limited to those published in English. Search results were manually reviewed to identify references based on their preclinical and clinical relevance to CTC and management of acute moderate-to-severe pain. RESULTS: The crystalline structure of CTC alters the physicochemical properties of tramadol and celecoxib, modifying their pharmacokinetics. If taken in a free combination, tramadol reduces absorption of celecoxib. Conversely, administration of CTC slows tramadol absorption and lowers its maximum plasma concentration, while increasing celecoxib plasma concentration through its enhanced release. In clinical studies across models of acute moderate-to-severe pain, CTC demonstrated an early onset of analgesia, with improved efficacy and lower rescue medication use, compared with either agent alone. CTC's safety profile was in line with that expected for the individual components; no additive effects were observed. CTC exhibited tramadol-sparing effects, with efficacy seen at lower daily/cumulative opioid doses vs. tramadol alone. CONCLUSIONS: Results from phase 3 trials suggest that the modified physicochemical properties of tramadol and celecoxib in CTC translate into an improved clinical benefit-risk profile, including fewer opioid-related adverse effects due to lower overall opioid dosing.

Efficacy of Co-Crystal of Tramadol-Celecoxib (CTC) in Patients with Acute Moderate-to-Severe Pain: A Pooled Analysis of Data from Two Phase 3 Randomized Clinical Trials.

BACKGROUND AND OBJECTIVES: New acute pain medications are needed that provide effective analgesia while minimizing side effects and opioid exposure. Clinical trials of co-crystal of tramadol-celecoxib (CTC) have demonstrated an improved benefit/risk profile versus tramadol or celecoxib alone. We pooled data from two phase 3 clinical trials to evaluate the efficacy of CTC 200 mg twice daily (BID) in acute moderate-to-severe pain. METHODS: Efficacy data were pooled from STARDOM1 [acute pain following oral surgery (NCT02982161)] and ESTEVE-SUSA-301 [acute pain following bunionectomy (NCT03108482)]. The primary efficacy outcome was sum of pain intensity difference from 0 to 48 h (SPID0-48). RESULTS: A total of 344 patients received CTC 200 mg BID, 342 received tramadol 50 or 100 mg four times a day, 181 received celecoxib 100 mg BID, and 172 received placebo. The least-squares mean difference in SPID0-48 was -21.8 (p = 0.002) for CTC versus tramadol and -72.8 (p < 0.001) for CTC versus placebo. A similar pattern of SPID0-48 was observed with CTC versus comparator whether patients had moderate or severe pain at baseline. Reduction in pain intensity was faster and reached mild intensity earlier with CTC versus comparators. Patients were significantly (p ≤ 0.005) less likely to receive rescue medication within 4 or 48 h with CTC compared with tramadol or placebo. CONCLUSIONS: This pooled analysis reinforces the efficacy profile of CTC versus tramadol and, given that CTC permits lower daily tramadol dosing and thereby reduces unnecessary opioid use, this highlights its improved benefit/risk profile and its potential for the management of moderate-to-severe pain.

Oculomics: A Crusade Against the Four Horsemen of Chronic Disease.

Chronic, non-communicable diseases present a major barrier to living a long and healthy life. In many cases, early diagnosis can facilitate prevention, monitoring, and treatment efforts, improving patient outcomes. There is therefore a critical need to make screening techniques as accessible, unintimidating, and cost-effective as possible. The association between ocular biomarkers and systemic health and disease (oculomics) presents an attractive opportunity for detection of systemic diseases, as ophthalmic techniques are often relatively low-cost, fast, and non-invasive. In this review, we highlight the key associations between structural biomarkers in the eye and the four globally leading causes of morbidity and mortality: cardiovascular disease, cancer, neurodegenerative disease, and metabolic disease. We observe that neurodegenerative disease is a particularly promising target for oculomics, with biomarkers detected in multiple ocular structures. Cardiovascular disease biomarkers are present in the choroid, retinal vasculature, and retinal nerve fiber layer, and metabolic disease biomarkers are present in the eyelid, tear fluid, lens, and retinal vasculature. In contrast, only the tear fluid emerged as a promising ocular target for the detection of cancer. The retina is a rich source of oculomics data, the analysis of which has been enhanced by artificial intelligence-based tools. Although not all biomarkers are disease-specific, limiting their current diagnostic utility, future oculomics research will likely benefit from combining data from various structures to improve specificity, as well as active design, development, and optimization of instruments that target specific disease signatures, thus facilitating differential diagnoses.

Long-term diseases can stop people living long and healthy lives. In many cases, early diagnosis can help to prevent, monitor, and treat disease, which can improve patients' health. In order to diagnose disease, we need tools that are easy for patients to access, painless, and low-cost. The eye may provide the solution. In this review, we discuss the link between changes in the eye and four types of long-term disease that, together, kill most of the population: (1) Cardiovascular disease (affecting the heart and/or blood). (2) Cancer (abnormal growth of cells). (3) Neurodegenerative disease (affecting the brain and/or nervous system). (4) Metabolic disease (problems storing, accessing, and using the body's fuel). We show that neurodegenerative disease leaves tell-tale signs in lots of different parts of the eye. Signs of cardiovascular and metabolic disease biomarkers are mostly found in the back of the eye, and signs of cancer can be found in the tear fluid. Although signs of disease can be seen in the eye, not all of them will tell us what the disease is. We believe that future research will help us to understand more about long-term disease and how to detect it if we combine information from different structures within the eye and develop new tools to target these specific structures.

Co-crystal of Tramadol-Celecoxib Versus Tramadol or Placebo for Acute Moderate-to-Severe Pain After Oral Surgery: Randomized, Double-Blind, Phase 3 Trial (STARDOM1).

INTRODUCTION: Co-crystal of tramadol-celecoxib (CTC) is the first analgesic co-crystal for acute pain. This completed phase 3 multicenter, double-blind trial assessed the efficacy and safety/tolerability of CTC in comparison with that of tramadol in the setting of moderate-to-severe pain up to 72 h after elective third molar extraction requiring bone removal. METHODS: Adults (n = 726) were assigned randomly to five groups (2:2:2:2:1): orally administered twice-daily CTC 100 mg (44 mg rac-tramadol hydrochloride/56 mg celecoxib; n = 164), 150 mg (66/84 mg; n = 160) or 200 mg (88/112 mg; n = 160); tramadol 100 mg four times daily (n = 159); or placebo four times daily (n = 83). Participants in CTC groups also received twice-daily placebo. The full analysis set included all participants who underwent randomization. The primary endpoint was the sum of pain intensity differences over 0 to 4 h (SPID0-4; visual analog scale). Key secondary endpoints included 4-h 50% responder and rescue medication use rates. Safety endpoints included adverse events (AEs), laboratory measures, and Opioid-Related Symptom Distress Scale (OR-SDS) score. RESULTS: All CTC doses were superior to placebo (P < 0.001) for primary and key secondary endpoints. All were superior to tramadol for SPID0-4 (analysis of covariance least squares mean differences [95% confidence interval]: - 37.1 [- 56.5, - 17.6], - 40.2 [- 59.7, - 20.6], and - 41.7 [- 61.2, - 22.2] for 100, 150, and 200 mg CTC, respectively; P < 0.001) and 4-h 50% responder rate. Four-hour 50% responder rates were 32.9% (CTC 100 mg), 33.8% (CTC 150 mg), 40.6% (CTC 200 mg), 20.1% (tramadol), and 7.2% (placebo). Rescue medication use was lower in the 100-mg (P = 0.013) and 200-mg (P = 0.003) CTC groups versus tramadol group. AE incidence and OR-SDS scores were highest for tramadol alone. CONCLUSIONS: CTC demonstrated superior pain relief compared with tramadol or placebo, as well as an improved benefit/risk profile versus tramadol. TRIAL REGISTRATION: ClinicalTrials.gov identifier, NCT02982161; EudraCT number, 2016-000592-24.

Physical and chemical characterization of the surface layers formed on dentin following treatment with an experimental anhydrous stannous fluoride dentifrice.

PURPOSE: To characterize, in vitro, the mode of action of stannous fluoride containing formulations in occluding dentin tubules, by means of high resolution microscopy techniques. METHODS: Focused ion beam scanning electron microscopy (FIB SEM) was used to site-specifically prepare cross sections for SEM and TEM imaging and analysis of dentin samples treated with either a stannous fluoride dispersion in glycerol or an experimental stannous fluoride dentifrice. RESULTS: An experimental stannous fluoride dentifrice formed a protective layer over the dentin surface and occluded dentin tubules. Additional supporting data derived from a stannous fluoride dispersion in glycerol suggest that stannous fluoride is a key component of this occluding system. Multiple SEM images obtained from sequential FIB cross-sections were reconstructed into 3-dimensional tomograms that showed a formed layer and tubule occlusion. Sections thinned by FIB techniques were observed by transmission electron microscopy (TEM) and related methods and showed that the coating, which was up to 3 microm-thick, consisted of a tin containing precipitate. Chemical analysis by energy dispersive x-ray spectroscopy (EDS) mapping that used scanning TEM (STEM) methods showed interdiffusion of tin up to 200 nm into the dentin structure.

The impact of early postoperative pain on health-related quality of life.

OBJECTIVES: To examine how the severity of postoperative pain affects patient's health-related quality of life (HRQoL) at 1 week following surgery and to compare two generic validated HRQoL instruments. METHODS: Patients undergoing general or orthopaedic surgery at the Royal London Hospital were randomly sampled. The following patient outcome data were collected EQ-5D (EuroQoL) pre-operatively and the Revised American Pain Society Patient Outcome Questionnaire (APS-POQ-R) at 24 hours postoperation; and EQ-5D, Short-Form-12 (SF-12) and APS-POQ-R at 7 days postoperation. The degree of association between pain and HRQoL was assessed using Pearson's correlation coefficient and multivariate generalized linear regression models. RESULTS: Of the 228 patients included, 166 patients provided data at 7 days. Sixteen percent reported severe pain ≥ 50% of the day at 7 days. The severity of pain on both the APS-POQ-R pain severity and interference and affective impairment domains at 7 days was highly correlated with a decrease in HRQoL as assessed by the SF-12 Physical Component Score (PCS), SF-12 Mental Component Score (MCS), and EQ-5D scores (r = -0.34 to -0.61, P < 0.0001). Multivariate regression analyses showed that irrespective of confounding factors (eg, age, gender, and pre-operative HRQoL) patients with severe postoperative pain experience important reductions in both physical and mental well-being domains of their HRQoL. CONCLUSIONS: A proportion of patients continue to experience severe pain at 7 days postoperatively, even after minor surgery. HRQoL is strongly associated with the level of pain and provides additional data on the impact of postsurgery pain on patient's function and well-being. Additional studies are needed to elucidate the interaction between pain severity and HRQoL during the peri-operative period.

Bacterial mechanosensing of surface stiffness promotes signaling and growth leading to biofilm formation by Pseudomonas aeruginosa.

The attachment of bacteria onto a surface, consequent signaling, and the accumulation and growth of the surface-bound bacterial population are key initial steps in the formation of pathogenic biofilms. While recent reports have hinted that the stiffness of a surface may affect the accumulation of bacteria on that surface, the processes that underlie bacterial perception of and response to surface stiffness are unknown. Furthermore, whether, and how, the surface stiffness impacts biofilm development, after initial accumulation, is not known. We use thin and thick hydrogels to create stiff and soft composite materials, respectively, with the same surface chemistry. Using quantitative microscopy, we find that the accumulation, motility, and growth of the opportunistic human pathogen Pseudomonas aeruginosa respond to surface stiffness, and that these are linked through cyclic-di-GMP signaling that depends on surface stiffness. The mechanical cue stemming from surface stiffness is elucidated using finite-element modeling combined with experiments - adhesion to stiffer surfaces results in greater changes in mechanical stress and strain in the bacterial envelope than does adhesion to softer surfaces with identical surface chemistry. The cell-surface-exposed protein PilY1 acts as a mechanosensor, that upon surface engagement, results in higher cyclic-di-GMP levels, lower motility, and greater accumulation on stiffer surfaces. PilY1 impacts the biofilm lag phase, which is extended for bacteria attaching to stiffer surfaces. This study shows clear evidence that bacteria actively respond to different stiffness of surfaces where they adhere via perceiving varied mechanical stress and strain upon surface engagement.

The accumulation and growth of Pseudomonas aeruginosa on surfaces is modulated by surface mechanics via cyclic-di-GMP signaling.

Attachment of bacteria onto a surface, consequent signaling, and accumulation and growth of the surface-bound bacterial population are key initial steps in the formation of pathogenic biofilms. While recent reports have hinted that surface mechanics may affect the accumulation of bacteria on that surface, the processes that underlie bacterial perception of surface mechanics and modulation of accumulation in response to surface mechanics remain largely unknown. We use thin and thick hydrogels coated on glass to create composite materials with different mechanics (higher elasticity for thin composites; lower elasticity for thick composites) but with the same surface adhesivity and chemistry. The mechanical cue stemming from surface mechanics is elucidated using experiments with the opportunistic human pathogen Pseudomonas aeruginosa combined with finite-element modeling. Adhesion to thin composites results in greater changes in mechanical stress and strain in the bacterial envelope than does adhesion to thick composites with identical surface chemistry. Using quantitative microscopy, we find that adhesion to thin composites also results in higher cyclic-di-GMP levels, which in turn result in lower motility and less detachment, and thus greater accumulation of bacteria on the surface than does adhesion to thick composites. Mechanics-dependent c-di-GMP production is mediated by the cell-surface-exposed protein PilY1. The biofilm lag phase, which is longer for bacterial populations on thin composites than on thick composites, is also mediated by PilY1. This study shows clear evidence that bacteria actively regulate differential accumulation on surfaces of different stiffnesses via perceiving varied mechanical stress and strain upon surface engagement.

Patterning of crystalline organic materials by electro-hydrodynamic lithography.

The control of semi-crystalline polymers in thin films and in micrometer-sized patterns is attractive for (opto-)electronic applications. Electro-hydrodynamic lithography (EHL) enables the structure formation of organic crystalline materials on the micrometer length scale while at the same time exerting control over crystal orientation. This gives rise to well-defined micro-patterned arrays of uniaxially aligned polymer crystals. This study explores the interplay of EHL structure formation with crystal alignment and studies the mechanisms that give rise to crystal orientation in EHL-generated structures.

Self-assembly of LiMo3Se3 nanowire networks from nanoscale building-blocks in solution.

LiMo(3)Se(3) is a highly anisotropic solid comprised of a regular pattern of quasi-1-D wire-like structures. Solutions of LiMo(3)Se(3) deposited on substrates and TEM grids reveal the presence of two-dimensional network morphologies. High resolution STEM imaging reveals that the junctions within these networks are not formed by discrete overlying LiMo(3)Se(3) fibers or wires. Rather the junctions are continuous in that the wires are seamlessly interwoven from one bundle to the next. We investigated network formation by dynamic light scattering and AFM and demonstrate that the networks are not pre-existent in solution but rather form via self-assembly of nanoscale building blocks that is driven by solvent evaporation.

Efficacy and safety of co-crystal of tramadol-celecoxib (CTC) in acute moderate-to-severe pain after abdominal hysterectomy: A randomized, double-blind, phase 3 trial (STARDOM2).

BACKGROUND: STARDOM2 is a randomized, double-blind, phase 3 trial evaluating the efficacy and safety of co-crystal of tramadol-celecoxib (CTC)-a first-in-class analgesic co-crystal comprising racemic tramadol hydrochloride and celecoxib in a supramolecular network that modifies their pharmacokinetic properties-for the management of acute postoperative pain (NCT03062644; EudraCT:2016-000593-38). METHODS: Patients with moderate-to-severe pain following abdominal hysterectomy were randomized 2:2:2:2:2:1 to oral CTC 100 mg (rac-tramadol hydrochloride 44 mg/celecoxib 56 mg) twice daily (BID); CTC 150 mg (66/84 mg) BID; CTC 200 mg (88/112 mg) BID; immediate-release tramadol 100 mg four times daily (QID); celecoxib 100 mg BID; or placebo, for 5 days. The primary endpoint was the sum of pain intensity differences over 0-4 h (SPID0-4 ). Key secondary endpoints were rescue medication use within 4 h, 50% response rate at 4 h, and safety/tolerability. RESULTS: Of 1355 patients enrolled, 1138 were randomized (full analysis set) and 1136 treated (safety analysis set). In the prespecified gatekeeping analysis of SPID0-4 , CTC 200 mg was not superior to tramadol but showed non-inferior efficacy (p < 0.001) that was sustained throughout the 120-h period, despite a 5-day cumulative tramadol administration of 880 mg with CTC 200 mg BID versus 2000 mg with tramadol 100 mg QID. Treatment-emergent adverse events (TEAEs) and severe TEAEs were less common with CTC 200 mg versus tramadol. Treatment-related TEAEs were 14.4% with CTC 200 mg and 23.6% with tramadol. CONCLUSIONS: Although the study did not meet its primary endpoint, CTC 200 mg showed a clinically relevant improvement in overall benefit/risk profile versus tramadol alone, with considerably lower cumulative opioid exposure. SIGNIFICANCE: In the randomized, double-blind, phase 3 STARDOM2 trial-in acute moderate-to-severe pain after abdominal hysterectomy-the novel co-crystal of tramadol-celecoxib (CTC) 200 mg BID was superior to placebo and non-inferior to tramadol 100 mg QID. Although superiority to tramadol was not reached, CTC 200 mg BID exposed patients to lower cumulative opioid (tramadol) doses than tramadol (100 mg QID) alone, with fewer treatment-emergent adverse events. CTC 200 mg thus has a clinically relevant improved benefit/risk profile compared with tramadol alone.

An in vivo investigation of photoplethysmographic signals and preliminary pulse oximetry estimation from the bowel using a new fiberoptic sensor.

BACKGROUND: The continuous monitoring of splanchnic organ oxygen saturation could make the early detection of inadequate tissue oxygenation feasible, reducing the risk of hypoperfusion, severe ischemia, multiple organ failure, and, ultimately, death. Current methods for assessing splanchnic perfusion have not been widely accepted for use in the clinical care environment. In an attempt to overcome the limitations of the current techniques, a new fiberoptic photoplethysmographic (PPG)/pulse oximetry sensor was developed as a means of assessing splanchnic organ perfusion during surgery in humans. METHODS: A new fiberoptic splanchnic pulse oximeter and an optically identical fiberoptic finger pulse oximeter have been developed. Simultaneous PPG signals and preliminary estimates of arterial oxygen saturation from the bowel (small and large) and finger were obtained in 17 patients (3 men and 14 women) undergoing open laparotomy. RESULTS: Good quality PPG signals were obtained from the small and large bowel and from the finger in all patients (lower 95% confidence limit for the proportion was 0.64). Comparisons of blood oxygen saturation values acquired when using the splanchnic and the finger fiberoptic sensors and a commercial finger pulse oximeter indicated that there was no statistically significant difference between them (all P>0.454). A Bland and Altman plot of the difference between blood oxygen saturation values from the bowel fiberoptic pulse oximeter and the fiberoptic finger pulse oximeter against their mean showed that the limits of agreement between the 2 pulse oximeters were -3.8% and 4.2% for small bowel measurements, and -3.4% and 4.3% for large bowel measurements. The 95% prediction interval for the difference between the 2 devices was between -4.2% and 4.7%. CONCLUSION: This study demonstrated that good quality PPG signals can be obtained from the bowel using a new fiberoptic sensor. Further evaluation is required to determine whether fiberoptic pulse oximetry of the bowel may provide a suitable method for monitoring splanchnic perfusion.

Central sensitisation in chronic fatigue syndrome and fibromyalgia; a case control study.

INTRODUCTION: Chronic fatigue syndrome (CFS) and fibromyalgia (FM) are both complex conditions that are challenging to treat. This may be related to an incomplete understanding of their pathophysiology, itself obfuscated by their heterogeneity. The symptomatic overlap between them and their common comorbidity suggests a shared vulnerability, which might be explained by central sensitisation. METHODS: 19 CFS cases, 19 FM cases and 20 age and sex matched healthy controls (HC) were recruited primarily from secondary care clinics in London. Those with other pain disorders, psychiatric diagnoses and those taking centrally acting or opiate medications were excluded. Participants were asked to abstain from alcohol and over the counter analgaesia 48 h prior to assessment by static and dynamic quantitative sensory tests, including measures of temporal summation (TS) and conditioned pain modulation (CPM). RESULTS: CS, as defined by the presence of both enhanced TS and inefficient CPM, was present in 16 (84%) CFS cases, 18 (95%) FM cases, and none of the HC (p < 0.001). Pressure pain thresholds were lower in CFS (Median222kPaIQR 146-311; p = 0.04) and FM cases (Median 189 kPa; IQR 129-272; p = 0.003) compared to HC (Median 311 kPa; IQR 245-377). FM cases differed from HC in cold-induced (FM = 22.6 °C (15.3-27.7) vs HC = 14.2 °C (9.0-20.5); p = 0.01) and heat-induced (FM = 38.0 °C (35.2-44.0) vs HC = 45.3 °C (40.1-46.8); p = 0.03) pain thresholds, where CFS cases did not. CONCLUSION: Central sensitisation may be a common endophenotype in chronic fatigue syndrome and fibromyalgia. Further research should address whether central sensitisation is a cause or effect of these disorders.

Subcutaneous tanezumab for osteoarthritis: Is the early improvement in pain and function meaningful and sustained?

BACKGROUND: To evaluate if early improvements in pain and function with subcutaneous tanezumab are meaningful and sustained over 24 weeks. METHODS: Patients with moderate-to-severe osteoarthritis (hip or knee) in Europe and Japan were randomized to placebo, tanezumab 2.5 mg or tanezumab 5 mg (baseline, Week 8 and Week 16). Outcomes included: average daily index joint pain score, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) subscales, rescue medication use, WOMAC responders (within-patient ≥30% reduction in WOMAC Pain or Physical Function), Outcome Measures in Rheumatology-Osteoarthritis Research Society International (OMERACT-OARSI) responders (within-patient) and Patient-reported Treatment Impact Assessment-Modified questionnaire. RESULTS: Patients received placebo (n = 282), tanezumab 2.5 mg (n = 283) or tanezumab 5 mg (n = 284). Changes from baseline in average daily index joint pain (within the first week) and WOMAC subscales (Week 2 through Week 24) were greater for each tanezumab group versus placebo (least squares [LS] mean, unadjusted p ≤ .05). Rescue medication use (days/week) was lower for each tanezumab group versus placebo from Week 2 through Week 12 (LS mean, unadjusted p ≤ .05) but not at Week 16 or 24. A higher proportion of each tanezumab group than placebo achieved ≥30% reduction from baseline in WOMAC Pain or Physical Function, or OMERACT-OARSI response (Week 2 through Week 24, unadjusted p ≤ .05), or were satisfied with treatment at Week 24 (unadjusted p ≤ .05). CONCLUSIONS: Subcutaneous tanezumab, compared with placebo, reduced pain within the first week, and pain and function were improved throughout 24 weeks. The proportions of responders and patients satisfied were higher with tanezumab than placebo. ClinicalTrials.gov:NCT02709486. SIGNIFICANCE: This exploratory analysis of data from a placebo-controlled, Phase 3 study of patients with moderate-to-severe osteoarthritis of the hip or knee for whom standard analgesics were not effective or could not be taken, found that onset of efficacy of subcutaneous tanezumab was within the first week, and efficacy was maintained through the 24-week treatment period. Tanezumab was effective in those patients with the most radiologically severe osteoarthritis.

Current knowledge of buprenorphine and its unique pharmacological profile.

Despite the increasing clinical use of transdermal buprenorphine, questions have persisted about the possibility of a ceiling effect for analgesia, its combination with other µ-opioid agonists, and the reversibility of side effects. In October 2008, a consensus group of experts met to review recent research into the pharmacology and clinical use of buprenorphine. The objective was to achieve consensus on the conclusions to be drawn from this work. It was agreed that buprenorphine clearly behaves as a full µ-opioid agonist for analgesia in clinical practice, with no ceiling effect, but that there is a ceiling effect for respiratory depression, reducing the likelihood of this potentially fatal adverse event. This is entirely consistent with receptor theory. In addition, the effects of buprenorphine can be completely reversed by naloxone. No problems are encountered when switching to and from buprenorphine and other opioids, or in combining them. Buprenorphine exhibits a pronounced antihyperalgesic effect that might indicate potential advantages in the treatment of neuropathic pain. Other beneficial properties are the compound's favorable safety profile, particularly in elderly patients and those with renal impairment, and its lack of effect on sex hormones and the immune system. The expert group agreed that these properties, as well as proven efficacy in severe pain and favorable tolerability, mean that buprenorphine can be considered a safe and effective option for treating chronic cancer and noncancer pain.