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). METHODS: A retrospective cohort study was conducted in 10 hospitals from different geographic regions in Brazil. Data were analysed using multilevel logistic regression models. Model performance was assessed using the area under the receiver operating characteristic curve (AUROC), Brier score, and calibration plots. Derivation and validation cohorts were randomly assigned. RESULTS: A total of 107,372 patients were included, and 30-day in-hospital mortality was 2.1% (n=2261). The final risk model comprised four predictors related to the patient and surgery (age, ASA physical status classification, surgical urgency, and surgical size), and the random effect related to hospitals. The model showed excellent discrimination (AUROC=0.93, 95% confidence interval [CI], 0.93-0.94), calibration, and overall performance (Brier score=0.017) in the derivation cohort (n=75,094). Similar results were observed in the validation cohort (n=32,278) (AUROC=0.93, 95% CI, 0.92-0.93). CONCLUSIONS: The Ex-Care BR is the first model to consider regional and organisational peculiarities of the Brazilian surgical scene, in addition to patient and surgical factors. It is particularly useful for identifying high-risk surgical patients in situations demanding efficient allocation of limited resources. However, a thorough exploration of mortality variations among hospitals is essential for a comprehensive understanding of risk. CLINICAL TRIAL REGISTRATION: NCT05796024.

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. METHODS: We conducted a prospective cohort study of 442 high-risk patients undergoing noncardiac surgery at a Brazilian hospital between February 2019 and March 2020. High-sensitivity troponin T levels were measured preoperatively, 24 hr, and 48 hr after surgery and stratified into three groups: normal (< 20 ng·L-1); minor elevation (20-65 ng·L-1); and major elevation (> 65 ng·L-1). We performed survival analysis to determine the association between myocardial injury and one-year mortality. We described medical interventions and evaluated unplanned intensive care unit (ICU) admission and complications using multivariable models. RESULTS: Postoperative myocardial injury occurred in 45% of patients. Overall, 30-day mortality was 8%. Thirty-day and one-year mortality were higher in patients with hsTnT ≥ 20 ng·L-1. One-year mortality was 18% in the unaltered troponin group vs 31% and 41% for minor and major elevation groups, respectively. Multivariable analysis of one-year survival showed a hazard ratio (HR) of 1.94 (95% confidence interval [CI], 1.22 to 3.09) for the minor elevation group and a HR of 2.73 (95% CI, 1.67 to 4.45) for the troponin > 65 ng·L-1 group. Patients with altered troponin had more unplanned ICU admissions (13% vs 5%) and more complications (78% vs 48%). CONCLUSION: This study supports evidence that hsTnT is an important prognostic marker and a strong predictor of all-cause mortality after surgery. Troponin measurement in high-risk surgical patients could potentially be used as tool to scale-up care in LMIC settings. STUDY REGISTRATION: ClinicalTrials.gov (NCT04187664); first submitted 5 December 2019.

RéSUMé: OBJECTIF: Les lésions myocardiques après une chirurgie non cardiaque sont courantes et la plupart du temps asymptomatiques. Nous ne connaissons pas la population cible idéale qui bénéficierait de mesures régulières de la troponine dans les pays à revenu faible et intermédiaire (PRFI). Cette étude vise à évaluer les issues cliniques d'une cohorte de patient·es de chirurgie à haut risque grâce à la troponine T à haute sensibilité (hsTnT) dans un contexte de PRFI. MéTHODE: Nous avons mené une étude de cohorte prospective auprès de 442 patient·es à haut risque bénéficiant d'une chirurgie non cardiaque dans un hôpital brésilien entre février 2019 et mars 2020. Les taux de troponine T à haute sensibilité ont été mesurés avant l'opération, 24 heures et 48 heures après la chirurgie, et stratifiés en trois groupes : normaux (< 20 ng·L−1), élévation mineure (20­65 ng·L−1) et élévation majeure (> 65 ng·L−1). Nous avons réalisé une analyse de survie pour déterminer l'association entre les lésions myocardiques et la mortalité à un an. Nous avons décrit les interventions médicales et évalué les admissions non planifiées à l'unité de soins intensifs (USI) ainsi que les complications à l'aide de modèles multivariables. RéSULTATS: Une lésion myocardique postopératoire est survenue chez 45 % des patient·es. La mortalité globale à 30 jours était de 8 %. La mortalité à trente jours et à un an était plus élevée chez les patient·es avec une hsTnT ≥ 20 ng·L−1. La mortalité à un an était de 18 % dans le groupe troponine inchangée vs 31 % et 41 % pour les groupes à élévation mineure et majeure de la troponine, respectivement. L'analyse multivariée de la survie à un an a montré un rapport de risque (RR) de 1,94 (intervalle de confiance [IC] à 95 %, 1,22 à 3,09) pour le groupe d'élévation mineure et un RR de 2,73 (IC 95 %, 1,67 à 4,45) pour le groupe avec une troponine > 65 ng·L−1. Les admissions non planifiées à l'USI étaient plus fréquentes chez les patient·es présentant une troponine altérée (13 % vs 5 %), tout comme les complications (78 % vs 48 %). CONCLUSION: Cette étude soutient les données probantes selon lesquelles la hsTnT est un marqueur pronostique important et un prédicteur fort de la mortalité toutes causes confondues après la chirurgie. La mesure de la troponine chez la patientèle chirurgicale à risque élevé pourrait potentiellement être utilisée comme outil pour intensifier les soins dans les PRFI. ENREGISTREMENT DE L'éTUDE: ClinicalTrials.gov (NCT04187664); soumis pour la première fois le 5 décembre 2019.

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. Patient and perioperative predictors were considered. Its performance was compared with the Charlson comorbidity index (CCI), Revised Cardiac Risk Index (RCRI), and the Surgical Outcome Risk Tool (SORT). RESULTS: The derivation cohort included 16 618 patients. In-hospital death occurred in 465 patients (2.8%). Age, with adjusted splines, degree of procedure (major vs non-major), ASA physical status, and urgency were entered in a final model. It showed high discrimination with an area under the receiver operating characteristic curve (AUROC) of 0.926 (95% confidence interval [CI], 0.91-0.93). It had superior accuracy to the RCRI (AUROC, 0.90 vs 0.76; P<0.01) and similar to the CCI (0.90 vs 0.82; P=0.06) and SORT models (0.90 vs 0.92; P=0.2) in the temporal validation cohort of 1173 patients. Calibration was adequate in both development (Hosmer-Lemeshow, 9.26; P=0.41) and temporal validation cohorts (Hosmer-Lemeshow 5.29; P=0.71). CONCLUSIONS: The Ex-Care risk model proved very efficient at identifying high-risk surgical patients. Although multicentre studies are needed, it should have particular value in low resource settings to better inform perioperative health policy and clinical decision-making.

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

Background: 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). We tested whether a-tDCS would be more effective than s-tDCS to improve pain perception assessed by the heat pain threshold (HPT) and the reaction time during the ice-water pain test (IPT) (secondary outcomes). Methods: This double-blinded, factorial randomized trial included 48 healthy males, ages ranging 19-40 years. They were randomized into four equal groups: a-tDCS/saline, s-tDCS/saline, a-tDCS/remifentanil and s-tDCS/remifentanil. tDCS was applied over the primary motor cortex, during 20 min at 2 mA, which was introduced 10 min after starting remifentanil infusion at 0.06 µg⋅kg-1⋅min-1 or saline. Results: An ANCOVA mixed model revealed that during the rCOLDT, there was a significant main effect on the NPS scores (F = 3.81; P = 0.01). The s-tDCS/remifentanil group presented larger pain scores during rCOLDT, [mean (SD) 5.49 (1.04)] and a-tDCS/remifentanil group had relative lower pain scores [4.15 (1.62)]; showing its blocking effect on r-IH. a-tDCS/saline and s-tDCS/saline groups showed lowest pain scores during rCOLDT, [3.11 (1.2)] and [3.15 (1.62)], respectively. The effect of sedation induced by remifentanil during the rCOLDT was not significant (F = 0.76; P = 0.38). Remifentanil groups showed positive scores in the NPS (0-10) during the CPM-task, that is, it produced a disengagement of the DPMS. Also, s-tDCS/Remifentanil compared to a-tDCS showed lower HPT and larger reaction-time during the IPT. Conclusion: These findings suggest that effects of a-tDCS prevent the summation response induced by r-IH during rCOLDT and the a-tDCS blocked the disengagement of DPMS. Thereby, tDCS could be considered as a new approach to contra-regulate paradoxical mechanisms involved in the r-IH. Clinical trials identification: NCT02432677. URL:https://clinicaltrials.gov/.