Trajectories of pain and opioid use up to one year after surgery: analysis of a European registry.

BACKGROUND: Long-term opioid use after surgery is a crucial healthcare problem in North America. Data from European hospitals are scarce and differentiation of chronic pain has rarely been considered. METHODS: In a mixed surgical cohort of the PAIN OUT registry, opioid use and chronic pain were evaluated before surgery, and 6 and 12 months after surgery (M6/M12). Subgroups with or without opioid medication and pre-existing chronic pain were analysed. M12-chronic pain was categorised as chronic postsurgical pain (CPSP) meeting the ICD-11 definition, chronic pain related to surgery not meeting the ICD-11 definition, and chronic pain unrelated to surgery. Primary endpoint was the rate of M12 opioid users. Variables associated with M12 opioid use and patient-reported outcomes were evaluated. RESULTS: Of 2326 patients, 5.5% were preoperative opioid users; 4.4% and 3.5% took opioids at M6 and M12 (P<0.001). Chronic pain before operation and at M6/M12 was reported by 41.2%, 41.8%, and 34.7% of patients, respectively (P<0.001). The rate of M12 opioid users was highest in group unrelated (22.3%; related 8.3%, CPSP 1.5%; P<0.001). New opioid users were 1.1% (unrelated 7.1%, related 2.3%, CPSP 0.7%; P<0.001). M12 opioid users reported more pain, pain-related physical and affective interference, and needed more opioids than non-users. The predominant variable associated with M12 opioids was preoperative opioid use (estimated odds ratio [95% confidence interval]: 28.3 [14.1-56.7], P<0.001). CONCLUSIONS: Opioid use was low in patients with CPSP, and more problematic in patients with chronic pain unrelated to surgery. A detailed assessment of chronic pain unrelated or related to surgery or CPSP is necessary. CLINICAL TRIAL REGISTRATION: NCT02083835.

Pain After Outpatient Surgical Procedures.

BACKGROUND: Approximately 8.1 million outpatient surgical procedures were performed in Germany in 2021. Little is known about the quality of postoperative pain treatment in the outpatient sector. METHODS: The AQS1 project comprises a combined survey of patients and staff in the framework of quality control for ambulatory surgery. The primary endpoint of this study was the prevalence of relevant incisional pain (≥ 4/10 on the numerical rating scale) up to postoperative day 3. Secondary endpoints included prognostic variables for pain and pain-associated outcomes, based on the AQS1 patient questionnaire. Moreover, mixed regression models were used to analyze potential prognostic variables and associations of pain with other outcomes (study registration number DRKS00028052). RESULTS: Data from 330 008 patients were evaluated (from 1 July 2001 to 31 December 2021). The overall prevalence of relevant incisional pain up to postoperative day 3 was 22.5%, with major differences between different types of procedure (3.2%-51.2%). Pain was most common after hemorrhoid surgery (51.2%) and the laparoscopic lysis of large and small bowel adhesions (45.4%). The main associations of relevant pain were with younger age (odds ratio [OR] 1.87, 95% confidence interval [1.82; 1.91]), early postoperative pain (1.34, [1.30; 1.39]), inadequate provision of analgesics (2.90, [2.71; 3.09]), and surgical wound infections (2.60, [2.43; 2.78]). Patients with pain reported lower overall satisfaction with the procedure and a longer inability to work. CONCLUSION: These data have not been tested for representativeness. They can serve as a point of departure for the optimization of individualized perioperative pain therapy and for the planning of prospective studies.

Cost-effectiveness of the Perioperative Pain Management Bundle a registry-based study.

Introduction: The Perioperative Pain Management Bundle was introduced in 10 Serbian PAIN OUT network hospitals to improve the quality of postoperative pain management. The Bundle consists of 4 elements: informing patients about postoperative pain treatment options; administering a full daily dose of 1-2 non-opioid analgesics; administering regional blocks and/or surgical wound infiltration; and assessing pain after surgery. In this study, we aimed to assess the cost-effectiveness of the Bundle during the initial 24 h after surgery. Materials and methods: The assessment of cost-effectiveness was carried out by comparing patients before and after Bundle implementation and by comparing patients who received all Bundle elements to those with no Bundle element. Costs of postoperative pain management included costs of the analgesic medications, costs of labor for administering these medications, and related disposable materials. A multidimensional Pain Composite Score (PCS), the effectiveness measurement, was obtained by averaging variables from the International Pain Outcomes questionnaire evaluating pain intensity, interference of pain with activities and emotions, and side effects of analgesic medications. The incremental cost-effectiveness ratio (ICER) was calculated as the incremental change in costs divided by the incremental change in PCS and plotted on the cost-effectiveness plane along with the economic preference analysis. Results: The ICER value calculated when comparing patients before and after Bundle implementation was 181.89 RSD (1.55 EUR) with plotted ICERs located in the northeast and southeast quadrants of the cost-effectiveness plane. However, when comparing patients with no Bundle elements and those with all four Bundle elements, the calculated ICER was -800.63 RSD (-6.82 EUR) with plotted ICERs located in the southeast quadrant of the cost-effectiveness plane. ICER values differ across surgical disciplines. Conclusion: The proposed perioperative pain management Bundle is cost-effective. The cost-effectiveness varies depending on the number of implemented Bundle elements and fluctuates across surgical disciplines.

The Perioperative Pain Management Bundle is Feasible: Findings From the PAIN OUT Registry.

OBJECTIVES: The quality of postoperative pain management is often poor. A "bundle," a small set of evidence-based interventions, is associated with improved outcomes in different settings. We assessed whether staff caring for surgical patients could implement a "Perioperative Pain Management Bundle" and whether this would be associated with improved multidimensional pain-related patient-reported outcomes (PROs). METHODS: "PAIN OUT," a perioperative pain registry, offers tools for auditing pain-related PROs and obtaining information about perioperative pain management during the first 24 hours after surgery. Staff from 10 hospitals in Serbia used this methodology to collect data at baseline. They then implemented the "Perioperative Pain Management Bundle" into the clinical routine and collected another round of data. The bundle consists of 4 treatment elements: (1) a full daily dose of 1 to 2 nonopioid analgesics (eg, paracetamol and/or nonsteroidal anti-inflammatory drugs), (2) at least 1 type of local/regional anesthesia, (3) pain assessment by staff, and (4) offering patients information about pain management. The primary endpoint was a multidimensional pain composite score (PCS), evaluating pain intensity, interference, and side effects that was compared between patients who received the full bundle versus not. RESULTS: Implementation of the complete bundle was associated with a significant reduction in the PCS ( P < 0.001, small-medium effect size [ES]). When each treatment element was evaluated independently, nonopioid analgesics were associated with a higher PCS (ie, poorer outcome, and negligible ES), and the other elements were associated with a lower PCS (all negligible small ES). Individual PROs were consistently better in patients receiving the full bundle compared with 0 to 3 elements. The PCS was not associated with the surgical discipline. DISCUSSION: We report findings from using a bundle approach for perioperative pain management in patients undergoing mixed surgical procedures. Future work will seek strategies to improve the effect.

Infliximab in the treatment of patients with severe COVID-19 (INFLIXCOVID): protocol for a randomised, controlled, multicentre, open-label phase II clinical study.

BACKGROUND: Despite the intense global research endeavour to improve the treatment of patients with COVID-19, the current therapy remains insufficient, resulting in persisting high mortality. Severe cases are characterised by a systemic inflammatory reaction driven by the release of pro-inflammatory cytokines such as IL-6 and tumour-necrosis-factor alpha (TNF-α). TNF-α-blocking therapies have proved beneficial in patients with chronic inflammatory diseases and could therefore pose a new treatment option in COVID-19. Hitherto, no results from randomised controlled trials assessing the effectiveness and safety of infliximab-a monoclonal antibody targeting TNF-α-in the treatment of COVID-19 have been published. METHODS: In this phase-2 clinical trial, patients with COVID-19 and clinical and laboratory signs of hyperinflammation will be randomised to receive either one dose of infliximab (5 mg/kg body weight) in addition to the standard of care or the standard of care alone. The primary endpoint is the difference in 28-day mortality. Further assessments concern the safety of infliximab therapy in COVID-19 and the influence of infliximab on morbidity and the course of the disease. For the supplementary scientific programme, blood and urine samples are collected to assess concomitant molecular changes. The Ethics Committee of the Friedrich Schiller University Jena (2021-2236-AMG-ff) and the Paul-Ehrlich-Institute (4513/01) approved the study. DISCUSSION: The results of this study could influence the therapy of patients with COVID-19 and affect the course of the disease worldwide, as infliximab is globally available and approved by several international drug agencies. TRIAL REGISTRATION: The trial was registered at clinicaltrials.gov ( NCT04922827 , 11 June 2021) and at EudraCT ( 2021-002098-25 , 19 May 2021).

Body composition, mitochondrial oxygen metabolism and metabolome of patients with obesity before and after bariatric surgery (COMMITMENT): protocol for a monocentric prospective cohort study.

INTRODUCTION: Obesity, defined as a body mass index ≥30 kg/m2, is one of the most prevalent health conditions worldwide. It is part of the metabolic syndrome, which encompasses arterial hypertension, dyslipoproteinaemia and diabetes. Obesity is viewed as a systemic disease with pathophysiological mechanisms on the molecular level. Dysfunction of the mitochondrion and systemic low-grade inflammation are among the proposed causes for the metabolic changes. In severe cases of obesity, laparoscopic sleeve gastrectomy, a bariatric operation, can achieve the desired weight loss and has been associated with clinical outcome improvement. Hitherto, the influence of patients' body composition on mitochondrial function and concomitant metabolic changes has not been fully understood. This study aims to quantify the patient's body composition before and after laparoscopic sleeve gastrectomy and to correlate these findings with changes in mitochondrial oxygen metabolism, metabolome and immune status. METHODS AND ANALYSIS: In this prospective monocentric cohort study, patients undergoing laparoscopic sleeve gastrectomy (n=30) at Jena University Hospital (Germany) will be assessed before surgery and at four time points during a 1-year follow-up. Body composition will be measured by bioimpedance analysis. Non-invasive assessment of mitochondrial oxygen metabolism using protoporphyrin IX-triplet state lifetime technique (PPIX-TSLT) and blood sampling for, among other, metabolomic and immunological analysis, will be performed. The primary outcome is the difference in relative fat mass between the preoperative time point and 6 months postoperatively. Further outcomes comprise longitudinal changes of PPIX-TSLT and metabolic and immunological variables. Outcomes will be assessed using paired t-tests, Wilcoxon signed-rank tests and regression analyses. ETHICS AND DISSEMINATION: The study was approved by the Ethics Committee of Friedrich Schiller University Jena (2018-1192-BO). Written informed consent will be obtained from all patients prior to enrolment in the study. The results will be published in peer-reviewed journals and presented at appropriate conferences. TRIAL REGISTRATION NUMBER: DRKS00015891.

Towards Better Perioperative Pain Management in Mexico: A Study in a Network of Hospitals Using Quality Improvement Methods from PAIN OUT.

OBJECTIVE: This was a pre-post study in a network of hospitals in Mexico-City, Mexico. Participants developed and implemented Quality Improvement (QI) interventions addressing perioperative pain management. METHODS: PAIN OUT, an international QI and research network, provided tools for web-based auditing and feedback of pain management and patient-reported outcomes (PROs) in the clinical routine. Ward- and patient-level factors were evaluated with multi-level models. Change in proportion of patients reporting worst pain ≥6/10 between project phases was the primary outcome. RESULTS: Participants created locally adapted resources for teaching and pain management, available to providers in the form of a website and a special issue of a national anesthesia journal. They offered teaching to anesthesiologists, surgeons, including residents, and nurses. Information was offered to patients and families. A total of 2658 patients were audited in 9 hospitals, between July 2016 and December 2018. Participants reported that the project made them aware of the importance of: training in pain management; auditing one's own patients to learn about PROs and that QI requires collaboration between multi-disciplinary teams. Participants reported being unaware that their patients experienced severe pain and lacked information about pain treatment options. Worst pain decreased significantly between the two project phases, as did PROs related to pain interfering with movement, taking a deep breath/coughing or sleep. The opportunity of patients receiving information about their pain treatment options increased from 44% to 77%. CONCLUSIONS: Patients benefited from improved care and pain-related PROs. Clinicians appreciated gaining increased expertise in perioperative pain management and methods of QI.

Desire to Receive More Pain Treatment - A Relevant Patient-Reported Outcome Measure to Assess Quality of Post-Operative Pain Management? Results From 79,996 Patients Enrolled in the Pain Registry QUIPS from 2016 to 2019.

Acute postoperative pain is frequently evaluated by pain intensity scores. However, interpretation of the results is difficult and thresholds requiring treatment are not well defined. Additional patient-reported outcome measures (PROMs) might be helpful to better understand individual pain experience and quality of pain management after surgery. We used data from the QUIPS pain registry for a cross-sectional study in order to investigate associations between the desire to receive more pain treatment (D2RMPT) with pain intensity ratings and other PROMs. Responses from 79,996 patients were analyzed, of whom 10.7% reported D2RMPT. A generalized estimating equation Poisson model showed that women had a lower risk ratio (RR) to answer this question with "yes" (RR: .92, P < .001). Factors that increased the risk most were "maximal pain intensity ≥ 6/10 on a numerical rating scale" (RR: 2.48, P < .001) and "any pain interference" (RR: 2.48, P < .001). The largest reduction in risk was observed if patients were "allowed to participate in pain treatment decisions" (RR: .41, P < .001) and if they felt that they "received sufficient treatment information" (RR: .58, P < .001). Our results indicate that the (easily assessed) question D2RMPT gives additional information to other PROMs like pain intensity. The small proportion of patients with D2RMPT (even for high pain scores) opens the discussion about clinicians' understanding of over- und under-treatment and questions the exclusive use of pain intensity as quality indicator. Future studies need to investigate whether asking about D2RMPT in clinical routine can improve postoperative pain outcome. PERSPECTIVE: This article presents characteristics of the patient-reported outcome measure "Desire to receive more pain treatment." This measure could be used to apply pain treatment in a more individualized way and lead to improved treatment strategies and quality.

A Pilot Study on the Association of Mitochondrial Oxygen Metabolism and Gas Exchange During Cardiopulmonary Exercise Testing: Is There a Mitochondrial Threshold?

Background: Mitochondria are the key players in aerobic energy generation via oxidative phosphorylation. Consequently, mitochondrial function has implications on physical performance in health and disease ranging from high performance sports to critical illness. The protoporphyrin IX-triplet state lifetime technique (PpIX-TSLT) allows in vivo measurements of mitochondrial oxygen tension (mitoPO2). Hitherto, few data exist on the relation of mitochondrial oxygen metabolism and ergospirometry-derived variables during physical performance. This study investigates the association of mitochondrial oxygen metabolism with gas exchange and blood gas analysis variables assessed during cardiopulmonary exercise testing (CPET) in aerobic and anaerobic metabolic phases. Methods: Seventeen volunteers underwent an exhaustive CPET (graded multistage protocol, 50 W/5 min increase), of which 14 were included in the analysis. At baseline and for every load level PpIX-TSLT-derived mitoPO2 measurements were performed every 10 s with 1 intermediate dynamic measurement to obtain mitochondrial oxygen consumption and delivery (mito V . O2, mito D . O2). In addition, variables of gas exchange and capillary blood gas analyses were obtained to determine ventilatory and lactate thresholds (VT, LT). Metabolic phases were defined in relation to VT1 and VT2 (aerobic:

Improving perioperative pain management: a preintervention and postintervention study in 7 developing countries.

INTRODUCTION: The burden of untreated postoperative pain is high. OBJECTIVE: This study assessed feasibility of using quality improvement (QI) tools to improve management of perioperative pain in hospitals in multiple developing countries. METHODS: The International Pain Registry and Developing Countries working groups, from the International Association for the Study of Pain (IASP), sponsored the project and PAIN OUT, a QI and research network, coordinated it, and provided the research tools. The IASP published a call about the project on its website. Principal investigators (PIs) were responsible for implementing a preintervention and postintervention study in 1 to 2 surgical wards in their hospitals, and they were free to choose the QI intervention. Trained surveyors used standardized and validated web-based tools for collecting findings about perioperative pain management and patient reported outcomes (PROs). Four processes and PROs, independent of surgery type, assessed effectiveness of the interventions. RESULTS: Forty-three providers responded to the call; 13 applications were selected; and PIs from 8 hospitals, in 14 wards, in 7 countries, completed the study. Interventions focused on teaching providers about pain management. Processes improved in 35% and PROs in 37.5% of wards. CONCLUSIONS: The project proved useful on multiple levels. It offered PIs a framework and tools to perform QI work and findings to present to colleagues and administration. Management practices and PROs improved on some wards. Interpretation of change proved complex, site-dependent, and related to multiple factors. PAIN OUT gained experience coordinating a multicentre, international QI project. The IASP promoted research, education, and QI work.