The burden of pre-operative anaemia and postoperative outcomes in 15 166 surgical patients from a public hospital in Brazil: A retrospective cohort study.

Background: Preoperative anaemia is associated with poor postoperative outcomes; however, few studies have reported its prevalence in developing countries and its association with significant postoperative outcomes.

Objective: We aimed to identify the prevalence of anaemia and its association with postoperative outcomes in a major public hospital in Brazil.

Design: Retrospective cohort study.

Development and validation of the Ex-Care BR model: a multicentre initiative for identifying Brazilian surgical patients at risk of 30-day in-hospital mortality.

Background: Surgical risk stratification is crucial for enhancing perioperative assistance and allocating resources efficiently. However, existing models may not capture the complexity of surgical care in Brazil. Using data from various healthcare settings nationwide, we developed a new risk model for 30-day in-hospital mortality (the Ex-Care BR model).

Troponin elevation as a marker of short deterioration and one-year death in a high-risk surgical patient cohort in a low and middle income country setting: a postoperative approach to increase surveillance.

Purpose: Myocardial injury after noncardiac surgery is common and mostly asymptomatic. The ideal target population that will benefit from routine troponin measurements in low and middle income countries (LMICs) is unclear. This study aims to evaluate the clinical outcomes of a cohort of high-risk surgical patients according to high-sensitivity troponin T (hsTnT) in an LMIC setting.

Latin American surgical outcomes study: study protocol for a multicentre international observational cohort study of patient outcomes after surgery in Latin American countries.

Background: Reported data suggest that 4.2 million deaths will occur within 30 days of surgery worldwide each year, half of which are in low- and middle-income countries. Postoperative complications are a leading cause of long-term morbidity and mortality.

Developing and validating a machine learning ensemble model to predict postoperative delirium in a cohort of high-risk surgical patients: A secondary cohort analysis.

Background: Postoperative delirium (POD) has a negative impact on prognosis, length of stay and the burden of care. Although its prediction and identification may improve postoperative care, this need is largely unmet in the Brazilian public health system.

Objective: To develop and validate a machine-learning prediction model and estimate the incidence of delirium.

The need for data describing the surgical population in Latin America.

Latin American countries have a huge diversity in sociocultural factors, ethnicity, geography, and political systems. Provision of healthcare varies widely in Latin America, and it is unclear how these disparities relate to outcomes for individual patients undergoing surgery. The Latin American Surgical Outcome Study (LASOS), with its pragmatic design, will provide a snapshot of surgical activity throughout Latin America and identify the next steps needed to improve postoperative outcomes.

Measuring emotional preoperative stress by an app approach and its applicability to predict postoperative pain.

Background: The Brief Measure of Emotional Preoperative Stress (B-MEPS) was developed to evaluate the preoperative individual vulnerability to emotional stress. To obtain a refined version of B-MEPS suitable for an app approach, this study aimed: (i) to identify items with more discriminant properties; (ii) to classify the level of preoperative emotional stress based on cut-off points; (iii) to assess concurrent validity through correlation with the Central Sensitization Inventory (CSI) score; (iv) to confirm whether the refined version of B-MEPS is an adequate predictive measure for identification of patients prone to intense postoperative pain.

Methods: We include 1016 patients who had undergone surgical procedures in a teaching hospital.

The impact of the incorporation of a feasible postoperative mortality model at the Post-Anaesthestic Care Unit (PACU) on postoperative clinical deterioration: A pragmatic trial with 5,353 patients.

Background: Practical use of risk predictive tools and the assessment of their impact on outcome reduction is still a challenge. This pragmatic study of quality improvement (QI) describes the preoperative adoption of a customised postoperative death probability model (SAMPE model) and the evaluation of the impact of a Postoperative Anaesthetic Care Unit (PACU) pathway on the clinical deterioration of high-risk surgical patients.

Methods: A prospective cohort of 2,533 surgical patients compared with 2,820 historical controls after the adoption of a quality improvement (QI) intervention.

Development of a recovery-room discharge checklist (SAMPE checklist) for safe handover and its comparison with Aldrete and White scoring systems.

Background: The postoperative care transition from the postanesthetic recovery room (PACU) to the common ward or even home discharge represents a critical step of the surgical patients' handover. Although some systems have been proposed to measure the ability to discharge after an anesthetic-surgical procedure effectively, there is no consensus defining which variables should necessarily be evaluated by these instruments. The instruments routinely used do not evaluate important domains for discharge and are laborious to fill, which compromises the professionals' adhesion.

Validation of the Brazilian version of the child pain catastrophizing scale and its relationship with a marker of central sensitization.

Objectives: The Pain Catastrophizing Scale-Child version (PCS-C) allows to identify children who are prone to catastrophic thinking. We aimed to adapt the Brazilian version of PCS-C (BPCS-C) to examine scale psychometric properties and factorial structure in children with and without chronic pain. Also, we assessed its correlation with salivary levels of Brain-Derived Neurotrophic factor (BDNF).

Few and feasible preoperative variables can identify high-risk surgical patients: derivation and validation of the Ex-Care risk model.

Background: The development of feasible preoperative risk tools is desirable, especially for low-middle income countries with limited resources and complex surgical settings. This study aimed to derive and validate a preoperative risk model (Ex-Care model) for postoperative mortality and compare its performance with current risk tools.

Methods: A multivariable logistic regression model predicting in-hospital mortality was developed using a large Brazilian surgical cohort.

The Brief Measure of Emotional Preoperative Stress (B-MEPS) as a new predictive tool for postoperative pain: A prospective observational cohort study.

Background: Preoperative patients' vulnerabilities such as physical, social, and psychological are implicated in postoperative pain variability. Nevertheless, it is a challenge to analyze a patient's psychological profile in the preoperative period in a practical and consistent way. Thus, we sought to identify if high preoperative emotional stress, evaluated by the Brief Measure of Emotional Preoperative Stress (B-MEPS) scale is associated with higher postoperative pain levels and poor rehabilitation in patients submitted to intermediate or major surgery.

BDNF and serum S100B levels according the spectrum of structural pathology in chronic pain patients.

Central sensitivity syndrome (CSS) consists of adaptive pathophysiological changes associated with neuroplasticity in some chronic pain disorders. It could be grouped in two main conceptual conditions: one includes those chronic pain patients without overt structural pathology such as fibromyalgia, and the other subgroup includes conditions with recognizable structural abnormalities, both somatic (osteoarthritis) and visceral (endometriosis). In order to understand the role of neuromodulators in CCS we aim to determine whether brain-derived neurotrophic factor (BDNF) and S100B are associated to specific chronic pain disorders.

Perioperative mortality related to anesthesia within 48 h and up to 30 days following surgery: A retrospective cohort study of 11,562 anesthetic procedures.

Study Objective: Studying postoperative in-hospital mortality is crucial to the understanding of the perioperative process failures and to the implementation of strategies to improve patient outcomes. We intend to classify the causes of perioperative deaths up to 30 days after procedures requiring anesthesia and to evaluate the risk factors for early (48 h) or late (30 day) mortality.

Design: Retrospective cohort study.

Effects of Transcranial Direct Current Stimulation Block Remifentanil-Induced Hyperalgesia: A Randomized, Double-Blind Clinical Trial.

Remifentanil-induced hyperalgesia (r-IH) involves an imbalance in the inhibitory and excitatory systems. As the transcranial Direct Current Stimulation (tDCS) modulates the thalamocortical synapses in a top-down manner, we hypothesized that the active (a)-t-DCS would be more effective than sham(s)-tDCS to prevent r-IH. We used an experimental paradigm to induce temporal summation of pain utilizing a repetitive cold test (rCOLDT) assessed by the Numerical Pain Score (NPS 0-10) and we evaluated the function of the descending pain modulatory system (DPMS) by the change on the NPS (0-10) during the conditioned pain modulation (CPM)-task (primary outcomes).

Higher Cortical Facilitation and Serum BDNF Are Associated with Increased Sensitivity to Heat Pain and Reduced Endogenous Pain Inhibition in Healthy Males.

Background: Although the brain-derived neurotrophic factor (BDNF) has been intensively investigated in animal models of chronic pain, its role in human pain processing is less understood.

Objective: To study the neurophysiology of BDNF modulation on acute experimental pain, we performed a cross-sectional study.

Methods: We recruited 20 healthy male volunteers (19-40 years old) and assessed their serum BDNF levels, quantitative sensory testing, and cortical excitability parameters using transcranial magnetic stimulation.

Preoperative transcranial direct current stimulation: Exploration of a novel strategy to enhance neuroplasticity before surgery to control postoperative pain. A randomized sham-controlled study.

Background: An imbalance in the excitatory/inhibitory systems in the pain networks may explain the persistent chronic pain after hallux valgus surgery. Thus, to contra-regulate this dysfunction, the use of transcranial direct current stimulation (tDCS) becomes attractive.

Objective: We tested the hypothesis that two preoperative active(a)-tDCS sessions compared with sham(s)-tDCS could improve the postoperative pain [as indexed by Visual Analogue Scale (VAS) at rest and during walking (primary outcomes)].

Derivation and validation of a preoperative risk model for postoperative mortality (SAMPE model): An approach to care stratification.

Ascertaining which patients are at highest risk of poor postoperative outcomes could improve care and enhance safety. This study aimed to construct and validate a propensity index for 30-day postoperative mortality. A retrospective cohort study was conducted at Hospital de Clínicas de Porto Alegre, Brazil, over a period of 3 years.

Combined neuromodulatory interventions in acute experimental pain: assessment of melatonin and non-invasive brain stimulation.

Transcranial direct current stimulation (tDCS) and melatonin can effectively treat pain. Given their potentially complementary mechanisms of action, their combination could have a synergistic effect. Thus, we tested the hypothesis that compared to the control condition and melatonin alone, tDCS combined with melatonin would have a greater effect on pain modulatory effect, as assessed by quantitative sensory testing (QST) and by the pain level during the Conditioned Pain Modulation (CPM)-task.