Neuron-specific enolase at admission as a predictor for stroke volume, severity and outcome in ischemic stroke patients: a prognostic biomarker review.

An ideal blood biomarker for stroke should provide reliable results, enable fast diagnosis, and be readily accessible for practical use. Neuron-specific enolase (NSE), an enzyme released after neuronal damage, has been studied as a marker for brain injury, including cerebral infarction. However, different methodologies and limited sample sizes have restricted the applicability of any potential findings. This work aims to determine whether NSE levels at Emergency Department (ED) admission correlate with stroke severity, infarcted brain volume, functional outcome, and/or death rates. A systematic literature review was performed using PubMed, Embase, and Scopus databases. Each reviewer independently assessed all published studies identified as potentially relevant. All relevant original observational studies (cohort, case-control, and cross-sectional studies) were included. Eleven studies (1398 patients) met the inclusion criteria. Among these, six studies reported a significant correlation between NSE levels and stroke severity, while only one found no association. Four studies indicated a positive relationship between infarcted brain volume assessed by imaging and NSE levels, in contrast to the findings of only one study. Four studies identified an association related to functional outcome and death rates, while three others did not reach statistical significance in their findings. These data highlight that NSE levels at ED admissions proved to be a promising tool for predicting the outcome of ischemic stroke patients in most studies. However, they presented high discrepancies and low robustness. Therefore, further research is necessary to establish and define the role of NSE in clinical practice.

The Physician Surprise Question in the Emergency Department: prospective cohort study.

OBJECTIVES: This study aims to test the ability of the surprise question (SQ), when asked to emergency physicians (EPs), to predict in-hospital mortality among adults admitted to an emergency room (ER). METHODS: This prospective cohort study at an academic medical centre included consecutive patients 18 years or older who received care in the ER and were subsequently admitted to the hospital from 20 April 2018 to 20 October 2018. EPs were required to answer the SQ for all patients who were being admitted to hospital. The primary outcome was in-hospital mortality. RESULTS: The cohort included 725 adults (mean (SD) age, 60 (17) years, 51% men) from 58 128 emergency department (ED) visits. The mortality rates were 20.6% for 30-day all-cause in-hospital mortality and 23.6% for in-hospital mortality. The diagnostic test characteristics of the SQ have a sensitivity of 53.7% and specificity of 87.1%, and a relative risk of 4.02 (95% CI 3.15 to 5.13), p<0.01). The positive and negative predictive values were 57% and 86%, respectively; the positive likelihood ratio was 4.1 and negative likelihood ratio was 0.53; and the accuracy was 79.2%. CONCLUSIONS: We found that asking the SQ to EPs may be a useful tool to identify patients in the ED with a high risk of in-hospital mortality.

Association Between Gut Microbiota and Delirium in Acutely Ill Older Adults.

Our aim was to investigate the association between gut microbiota and delirium occurrence in acutely ill older adults. We included 133 participants 65+ years consecutively admitted to the emergency department of a tertiary university hospital, between September 2019 and March 2020. We excluded candidates with ≥24-hour antibiotic utilization on admission, recent prebiotic or probiotic utilization, artificial nutrition, acute gastrointestinal disorders, severe traumatic brain injury, recent hospitalization, institutionalization, expected discharge ≤48 hours, or admission for end-of-life care. A trained research team followed a standardized interview protocol to collect sociodemographic, clinical, and laboratory data on admission and throughout the hospital stay. Our exposure measures were gut microbiota alpha and beta diversities, taxa relative abundance, and core microbiome. Our primary outcome was delirium, assessed twice daily using the Confusion Assessment Method. Delirium was detected in 38 participants (29%). We analyzed 257 swab samples. After adjusting for potential confounders, we observed that a greater alpha diversity (higher abundance and richness of microorganisms) was associated with a lower risk of delirium, as measured by the Shannon (odds ratio [OR] = 0.77; 95% confidence interval [CI] = 0.60-0.99; p = .042) and Pielou indexes (OR = 0.69; 95% CI = 0.51-0.87; p = .005). Bacterial taxa associated with pro-inflammatory pathways (Enterobacteriaceae) and modulation of relevant neurotransmitters (Serratia: dopamine; Bacteroides, Parabacteroides: GABA) were more common in participants with delirium. Gut microbiota diversity and composition were significantly different in acutely ill hospitalized older adults who experienced delirium. Our work is an original proof-of-concept investigation that lays a foundation for future biomarker studies and potential therapeutic targets for delirium prevention and treatment.

Brain injury biomarkers do not predict delirium in acutely ill older patients: a prospective cohort study.

Delirium is a common, serious, and often preventable neuropsychiatric emergency mostly characterized by a disturbance in attention and awareness. Systemic insult and inflammation causing blood-brain-barrier (BBB) damage and glial and neuronal activation leading to more inflammation and cell death is the most accepted theory behind delirium's pathophysiology. This study aims to evaluate the relationship between brain injury biomarkers on admission and delirium in acutely ill older patients. We performed a prospective cohort study which analyzed plasma S100B levels at admission in elderly patients. Our primary outcome was delirium diagnosis. Secondary outcomes were association between S100B, NSE and Tau protein and delirium diagnosis and patients' outcomes (admissions to intensive care, length of hospital stay, and in-hospital mortality). We analyzed 194 patients, and 46 (24%) developed delirium, 25 on admission and 21 during hospital stay. Median of S100B at admission in patients who developed delirium was 0.16 and median was 0.16 in patients who didn't develop delirium (p: 0.69). Levels S100B on admission did not predict delirium in acutely ill elderly patients.Trial registration: The study was approved by the local institutional review board (CAPPESq, no. 77169716.2.0000.0068, October 11, 2017) and registered in Brazilian Clinical Trials Registry (ReBEC, no. RBR-233bct).

Distinct Outcomes in COVID-19 Patients with Positive or Negative RT-PCR Test.

Identification of the SARS-CoV-2 virus by RT-PCR from a nasopharyngeal swab sample is a common test for diagnosing COVID-19. However, some patients present clinical, laboratorial, and radiological evidence of COVID-19 infection with negative RT-PCR result(s). Thus, we assessed whether positive results were associated with intubation and mortality. This study was conducted in a Brazilian tertiary hospital from March to August of 2020. All patients had clinical, laboratory, and radiological diagnosis of COVID-19. They were divided into two groups: positive (+) RT-PCR group, with 2292 participants, and negative (-) RT-PCR group, with 706 participants. Patients with negative RT-PCR testing and an alternative most probable diagnosis were excluded from the study. The RT-PCR(+) group presented increased risk of intensive care unit (ICU) admission, mechanical ventilation, length of hospital stay, and 28-day mortality, when compared to the RT-PCR(-) group. A positive SARS-CoV-2 RT-PCR result was independently associated with intubation and 28 day in-hospital mortality. Accordingly, we concluded that patients with a COVID-19 diagnosis based on clinical data, despite a negative RT-PCR test from nasopharyngeal samples, presented more favorable outcomes than patients with positive RT-PCR test(s).

Timing to Intubation COVID-19 Patients: Can We Put It Off until Tomorrow?

BACKGROUND: The decision to intubate COVID-19 patients receiving non-invasive respiratory support is challenging, requiring a fine balance between early intubation and risks of invasive mechanical ventilation versus the adverse effects of delaying intubation. This present study analyzes the association between intubation day and mortality in COVID-19 patients. METHODS: We performed a unicentric retrospective cohort study considering all COVID-19 patients consecutively admitted between March 2020 and August 2020 requiring invasive mechanical ventilation. The primary outcome was all-cause mortality within 28 days after intubation, and a Cox model was used to evaluate the effect of time from onset of symptoms to intubation in mortality. RESULTS: A total of 592 (20%) patients of 3020 admitted with COVID-19 were intubated during study period, and 310 patients who were intubated deceased 28 days after intubation. Each additional day between the onset of symptoms and intubation was significantly associated with higher in-hospital death (adjusted hazard ratio, 1.018; 95% CI, 1.005-1.03). CONCLUSION: Among patients infected with SARS-CoV-2 who were intubated and mechanically ventilated, delaying intubation in the course of symptoms may be associated with higher mortality. TRIAL REGISTRATION: The study protocol was approved by the local Ethics Committee (opinion number 3.990.817; CAAE: 30417520.0.0000.0068).

Endothelial injury in COVID-19 and septic patients.

Systemic inflammatory response, as observed in sepsis and severe COVID-19, may lead to endothelial damage. Therefore, we aim to compare the extent of endothelial injury and its relationship to inflammation in both diseases. We included patients diagnosed with sepsis (SEPSIS group, n = 21), mild COVID-19 (MILD group, n = 31), and severe COVID-19 (SEVERE group, n = 24). Clinical and routine laboratory data were obtained, circulating cytokines (INF-γ, TNF-α, and IL-10) and endothelial injury markers (E-Selectin, Tissue Factor (TF) and von Willebrand factor (vWF)) were measured. Compared to the SEPSIS group, patients with severe COVID-19 present similar clinical and laboratory data, except for lower circulating IL-10 and E-Selectin levels. Compared to the MILD group, patients in the SEVERE group showed higher levels of TNF-α, IL-10, and TF. There was no clear relationship between cytokines and endothelial injury markers among the three studied groups; however, in SEVERE COVID-19 patients, there is a positive relationship between INF-γ with TF and a negative relationship between IL-10 and vWF. In conclusion, COVID-19 and septic patients have a similar pattern of cytokines and endothelial dysfunction markers. These findings highlight the importance of endothelium dysfunction in COVID-19 and suggest that endothelium should be better evaluated as a therapeutic target for the disease.

Applicability of the GLIM criteria for the diagnosis of malnutrition in older adults in the emergency ward: A pilot validation study.

BACKGROUND & AIMS: Acutely ill older adults are at higher risk of malnutrition. This study aimed to explore the applicability and accuracy of the GLIM criteria to diagnose malnutrition in acutely ill older adults in the emergency ward (EW). METHODS: We performed a retrospective secondary analysis, of an ongoing cohort study, in 165 participants over 65 years of age admitted to the EW of a Brazilian university hospital. Nutrition assessment included anthropometry, the Simplified Nutritional Assessment Questionnaire (SNAQ), the Malnutrition Screening Tool (MST), and the Mini-Nutritional Assessment (MNA). We diagnosed malnutrition using GLIM criteria, defined by the parallel presence of at least one phenotypic [nonvolitional weight loss (WL), low BMI, low muscle mass (MM)] and one etiologic criterion [reduced food intake or assimilation (RFI), disease burden/inflammation]. We used the receiver operating characteristic (ROC) curves and Cox and logistic regression for data analyses. RESULTS: GLIM criteria, following the MNA-SF screening, classified 50.3% of participants as malnourished, 29.1% of them in a severe stage. Validation of the diagnosis using MNA-FF as a reference showed good accuracy (AUC = 0.84), and moderate sensitivity (76%) and specificity (75.1%). All phenotypic criteria combined with RFI showed the best metrics. Malnutrition showed a trend for an increased risk of transference to intensive care unit (OR = 2.08, 95% CI 0.99, 4.35), and severe malnutrition for in-hospital mortality (HR = 4.23, 95% CI 1.2, 14.9). CONCLUSION: GLIM criteria, following MNA-SF screening, appear to be a feasible approach to diagnose malnutrition in acutely ill older adults in the EW. Nonvolitional WL combined with RFI or acute inflammation were the best components identified and are easily accessible, allowing their potential use in clinical practice.

Lower peripheral blood Toll-like receptor 3 expression is associated with an unfavorable outcome in severe COVID-19 patients.

The role of innate immunity in COVID-19 is not completely understood. Therefore, this study explored the impact of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection on the expression of Pattern Recognition Receptors (PRRs) in peripheral blood cells and their correlated cytokines. Seventy-nine patients with severe COVID-19 on admission, according to World Health Organization (WHO) classification, were divided into two groups: patients who needed mechanical ventilation and/or deceased (SEVERE, n = 50) and patients who used supplementary oxygen but not mechanical ventilation and survived (MILD, n = 29); a control group (CONTROL, n = 17) was also enrolled. In the peripheral blood, gene expression (mRNA) of Toll-like receptors (TLRs) 3, 4, 7, 8, and 9, retinoic-acid inducible gene I (RIGI), NOD-like receptor family pyrin domain containing 3 (NLRP3), interferon alpha (IFN-α), interferon beta (IFN-ß), interferon gamma (IFN-γ), interferon lambda (IFN-λ), pro-interleukin(IL)-1ß (pro-IL-1ß), and IL-18 was determined on admission, between 5-9 days, and between 10-15 days. Circulating cytokines in plasma were also measured. When compared to the COVID-19 MILD group, the COVID-19 SEVERE group had lower expression of TLR3 and overexpression of TLR4.

Community-acquired pneumonia severity assessment tools in patients hospitalized with COVID-19: a validation and clinical applicability study.

OBJECTIVE: To externally validate community-acquired pneumonia (CAP) tools on patients hospitalized with coronavirus disease 2019 (COVID-19) pneumonia from two distinct countries, and compare their performance with recently developed COVID-19 mortality risk stratification tools. METHODS: We evaluated 11 risk stratification scores in a binational retrospective cohort of patients hospitalized with COVID-19 pneumonia in São Paulo and Barcelona: Pneumonia Severity Index (PSI), CURB, CURB-65, qSOFA, Infectious Disease Society of America and American Thoracic Society Minor Criteria, REA-ICU, SCAP, SMART-COP, CALL, COVID GRAM and 4C. The primary and secondary outcomes were 30-day in-hospital mortality and 7-day intensive care unit (ICU) admission, respectively. We compared their predictive performance using the area under the receiver operating characteristics curve (AUC), sensitivity, specificity, likelihood ratios, calibration plots and decision curve analysis. RESULTS: Of 1363 patients, the mean (SD) age was 61 (16) years. The 30-day in-hospital mortality rate was 24.6% (228/925) in São Paulo and 21.0% (92/438) in Barcelona. For in-hospital mortality, we found higher AUCs for PSI (0.79, 95% CI 0.77-0.82), 4C (0.78, 95% CI 0.75-0.81), COVID GRAM (0.77, 95% CI 0.75-0.80) and CURB-65 (0.74, 95% CI 0.72-0.77). Results were similar for both countries. For the 1%-20% threshold range in decision curve analysis, PSI would avoid a higher number of unnecessary interventions, followed by the 4C score. All scores had poor performance (AUC <0.65) for 7-day ICU admission. CONCLUSIONS: Recent clinical COVID-19 assessment scores had comparable performance to standard pneumonia prognostic tools. Because it is expected that new scores outperform older ones during development, external validation studies are needed before recommending their use.

Lung ultrasound score predicts outcomes in COVID-19 patients admitted to the emergency department.

BACKGROUND: During the COVID-19 pandemic, creating tools to assess disease severity is one of the most important aspects of reducing the burden on emergency departments. Lung ultrasound has a high accuracy for the diagnosis of pulmonary diseases; however, there are few prospective studies demonstrating that lung ultrasound can predict outcomes in COVID-19 patients. We hypothesized that lung ultrasound score (LUS) at hospital admission could predict outcomes of COVID-19 patients. This is a prospective cohort study conducted from 14 March through 6 May 2020 in the emergency department (ED) of an urban, academic, level I trauma center. Patients aged 18 years and older and admitted to the ED with confirmed COVID-19 were considered eligible. Emergency physicians performed lung ultrasounds and calculated LUS, which was tested for correlation with outcomes. This protocol was approved by the local Ethics Committee number 3.990.817 (CAAE: 30417520.0.0000.0068). RESULTS: The primary endpoint was death from any cause. The secondary endpoints were ICU admission and endotracheal intubation for respiratory failure. Among 180 patients with confirmed COVID-19 who were enrolled (mean age, 60 years; 105 male), the average LUS was 18.7 ± 6.8. LUS correlated with findings from chest CT and could predict the estimated extent of parenchymal involvement (mean LUS with < 50% involvement on chest CT, 15 ± 6.7 vs. 21 ± 6.0 with > 50% involvement, p < 0.001), death (AUC 0.72, OR 1.13, 95% CI 1.07 to 1.21; p < 0.001), endotracheal intubation (AUC 0.76, OR 1.17, 95% CI 1.09 to 1.26; p < 0.001), and ICU admission (AUC: 0.71, OR 1.14, 95% CI 1.07 to 1.21; p < 0.001). CONCLUSIONS: In COVID-19 patients admitted in ED, LUS was a good predictor of death, ICU admission, and endotracheal intubation.

Double-blind, Randomized, Placebo-controlled Trial With N-acetylcysteine for Treatment of Severe Acute Respiratory Syndrome Caused by Coronavirus Disease 2019 (COVID-19).

BACKGROUND: A local increase in angiotensin 2 after inactivation of angiotensin-converting enzyme 2 by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may induce a redox imbalance in alveolar epithelium cells, causing apoptosis, increased inflammation and, consequently, impaired gas exchange. We hypothesized that N-acetylcysteine (NAC) administration could restore this redox homeostasis and suppress unfavorable evolution in patients with coronavirus disease 2019 (COVID-19). METHODS: This was a double-blind, randomized, placebo-controlled, single-center trial conducted at the Emergency Department of Hospital das Clínicas, São Paulo, Brazil, to determine whether NAC in high doses can avoid respiratory failure in patients with COVID-19. We enrolled 135 patients with severe COVID-19 (confirmed or suspected), with an oxyhemoglobin saturation <94% or respiratory rate >24 breaths/minute. Patients were randomized to receive NAC 21 g (~300 mg/kg) for 20 hours or dextrose 5%. The primary endpoint was the need for mechanical ventilation. Secondary endpoints were time of mechanical ventilation, admission to the intensive care unit (ICU), time in ICU, and mortality. RESULTS: Baseline characteristics were similar between the 2 groups, with no significant differences in age, sex, comorbidities, medicines taken, and disease severity. Also, groups were similar in laboratory tests and chest computed tomography scan findings. Sixteen patients (23.9%) in the placebo group received endotracheal intubation and mechanical ventilation, compared with 14 patients (20.6%) in the NAC group (P = .675). No difference was observed in secondary endpoints. CONCLUSIONS: Administration of NAC in high doses did not affect the evolution of severe COVID-19. CLINICAL TRIALS REGISTRATION: Brazilian Registry of Clinical Trials (REBEC): U1111-1250-356 (http://www.ensaiosclinicos.gov.br/rg/RBR-8969zg/).

First-attempt intubation success and complications in patients with COVID-19 undergoing emergency intubation.

Objectives: To evaluate the first-attempt success rates and complications of endotracheal intubation of coronavirus disease 2019 (COVID-19) patients by emergency physicians. Methods: This prospective observational study was conducted from March 24, 2020 through May 28, 2020 at the emergency department (ED) of an urban, academic trauma center. We enrolled patients consecutively admitted to the ED with suspected or confirmed COVID-19 submitted to endotracheal intubation. No patients were excluded. The primary outcome was first-attempt intubation success, defined as successful endotracheal tube placement with the first device passed (endotracheal tube) during the first laryngoscope insertion confirmed with capnography. Secondary outcomes included the following complications: hypotension, hypoxemia, aspiration, and esophageal intubation. Results: A total of 112 patients with confirmed or suspected COVID-19 were enrolled. Median age was 61 years and 61 patients (54%) were men. The primary outcome, first-attempt intubation success, was achieved in 82% of patients. Among the 20 patients who were not intubated on the first attempt, 75% were intubated on the second attempt and 20% on the third attempt; cricothyrotomy was performed in 1 patient. Forty-eight (42%) patients were hypotensive and required norepinephrine immediately post-intubation. Fifty-eight (52%) experienced peri-intubation hypoxemia, and 2 patients (2%) had cardiac arrest. There were no cases of failed intubation resulting in death up to 24 hours after the procedure. Conclusion: Emergency physicians achieve high success rates when intubating COVID19 patients, although complications are frequent. However, these findings should be considered provisional until their generalizability is assessed in their institutions and setting.

Euglycemic Diabetic Ketoacidosis in Pregnancy.

The clinical presentation of diabetic ketoacidosis in pregnancy (DKP) is similar to that observed in nonpregnant women, although reports suggest the presenting blood glucose level may not be as high. It is hypothesized that lower, maternal fasting glucose levels are a result of both the fetus and the placenta consuming glucose. We report the case of a 38-year-old woman gravida 2, para 0, abortion 1 with type 1 diabetes who had euglycemic diabetic ketoacidosis and review the literature on DKP, with a focus on diagnosis, treatment, and monitoring of the mother and fetus.

Pregnancy-induced hypertension syndrome and cardiovascular risk / Síndrome hipertensiva gestacional e risco cardiovascular

Objective: to analyze the changes in life expectancy (LE) and disability-free life expectancy (DFLE) in São Paulo's elderly population to assess the occurrence of compression or expansion of morbidity, between 2000 and 2010. Methods: cross-sectional and population survey, based on official data for the city of São Paulo, Brazil, and data obtained from the Health, Well-Being and Aging Survey (SABE). Functional disability was defined as difficulty in performing at least one basic activity of daily living. The Sullivan method was used to calculate LE and DFLE for the years 2000 to 2010. Results: from 2000 to 2010, there was an increase in disabled life expectancy (DLE) in all age groups and both sexes. The proportion of years of life free of disability, at 60 years of age, decreased from 57.94% to 46.23% in women, and from 75.34% to 63.65% in men. At 75 years of age, this ratio decreased from 47.55% to 34.54% in women, and from 61.31% to 56.01% in men. Conclusion: the expansion of morbidity is an ongoing process in the elderly population of the municipality of São Paulo, in the period 2000-2010. These results can contribute to the development of preventive strategies and planning of adequate health services to future generations of seniors. .

Objetivo: caracterizar o perfil de risco cardiovascular em longo prazo de mulheres com história de síndrome hipertensiva da gestação (SHG) e compará-lo ao de mulheres com histórico de gestação normotensa. Métodos: este é um estudo de coorte retrospectivo que incluiu 60 mulheres que deram à luz na MEAC-UFC entre os anos de 1992 e 2002 (seguimento médio de 15,2 anos). O grupo de exposição (GE) foi composto por 30 mulheres em qualquer categoria de SHG, e o grupo de não exposição (GNE) compreendeu 30 mulheres sem história de patologia obstétrica. Foram avaliados os dados antropométricos e laboratoriais associados ao risco cardiovascular e calculados o escore Framingham (variáveis dependentes). Para variáveis quantitativas, foram usados o teste t de Student e o teste de Mann-Whitney. Para variáveis qualitativas, aplicou-se o teste exato de Fisher. Considerou-se a significância estatística como p<0,05. Resultados: GE apresentou valores mais altos de IMC (p=0,03, OR=1,13, IC 1,00-1,3), PAS (p=0,03, OR=1,03, IC 1,00-1,06), LDL-C (p=0,02, OR=1,02, IC 1,00-1,04) e glicose de jejum (p=0,02, OR=1,03, IC 1,00-1,07), além de valores mais altos no escore de Framingham (p=0,03, OR=1,09, IC 1,00-1,19). As mulheres em GE usaram medicamentos anti-hipertensivos com mais frequência (p=0,03, OR=5,2, IC 1,3-21,2). Conclusão: foi encontrado um perfil de risco cardiovascular desfavorável nas pacientes com história de SHG em comparação com as mulheres sem esse histórico. .

Anesthetics, cerebral protection and preconditioning.

BACKGROUND AND OBJECTIVES: Several studies demonstrate that cerebral preconditioning is a protective mechanism against a stressful situation. Preconditioning determinants are described, as well as the neuroprotection provided by anesthetic and non-anesthetics agents. CONTENT: Review based on the main articles addressing the pathophysiology of ischemia-reperfusion and neuronal injury and pharmacological and non-pharmacological factors (inflammation, glycemia, and temperature) related to the change in response to ischemia-reperfusion, in addition to neuroprotection induced by anesthetic use. CONCLUSIONS: The brain has the ability to protect itself against ischemia when stimulated. The elucidation of this mechanism enables the application of preconditioning inducing substances (some anesthetics), other drugs, and non-pharmacological measures, such as hypothermia, aimed at inducing tolerance to ischemic lesions.

Anestésicos, precondicionamento e proteção cerebral / Anesthetics, cerebral protection and preconditioning / Anestésicos, pre-condicionamiento y protección cerebral

JUSTIFICATIVA E OBJETIVOS: Diversos estudos têm demonstrado o precondicionamento cerebral como mecanismo protetor diante de uma situação de estresse. Fatores determinantes são descritos, bem como a neuroproteção proporcionada por agentes anestésicos e não anestésicos. CONTEÚDO: Fez-se revisão baseada nos principais artigos da literatura que englobam a fisiopatologia da isquemia-reperfusão e lesão neuronal e os fatores não farmacológicos (inflamação, glicemia e temperatura) e farmacológicos relacionados com a mudança da resposta à isquemia-reperfusão, além da neuroproteção induzida pelo uso dos anestésicos. CONCLUSÕES: O cérebro tem a capacidade de se proteger contra a isquemia quando estimulado. A elucidação desse mecanismo possibilita a aplicação de substâncias indutoras do precondicionamento, como alguns anestésicos, outros fármacos e medidas não farmacológicas, como a hipotermia, com o objetivo de induzir tolerância a lesões isquêmicas.

BACKGROUND AND OBJECTIVES: Several studies demonstrate that cerebral preconditioning is a protective mechanism against a stressful situation. Preconditioning determinants are described, as well as the neuroprotection provided by anesthetic and non-anesthetics agents. CONTENT: Review based on the main articles addressing the pathophysiology of ischemia-reperfusion and neuronal injury and pharmacological and non-pharmacological factors (inflammation, glycemia, and temperature) related to the change in response to ischemia-reperfusion, in addition to neuroprotection induced by anesthetic use. CONCLUSIONS: The brain has the ability to protect itself against ischemia when stimulated. The elucidation of this mechanism enables the application of preconditioning inducing substances (some anesthetics), other drugs, and non-pharmacological measures, such as hypothermia, aimed at inducing tolerance to ischemic lesions.

JUSTIFICATIVA Y OBJETIVOS: Diversos estudios han demostrado el pre-condicionamiento cerebral como un mecanismo protector frente a una situación de estrés. Están descritos algunos factores determinantes del PC, como también la neuroprotección proporcionada por los agentes anestésicos y no anestésicos. CONTENIDO: Se hizo la revisión con base en los principales artículos de la literatura que engloban la fisiopatología de la isquemia-reperfusión y la lesión neuronal, y los factores no farmacológicos (inflamación, glucemia y temperatura), y farmacológicos relacionados con el cambio de la respuesta a la isquemia-reperfusión, además de la neuroprotección inducida por el uso de los anestésicos. CONCLUSIONES: El cerebro tiene la capacidad de protegerse contra la isquemia cuando se le estimula. La elucidación de ese mecanismo posibilita la aplicación de sustancias inductoras del precondicionamiento cerebral, como algunos anestésicos, otros fármacos y medidas no farmacológicas, como la hipotermia, con el fin de inducir la tolerancia a las lesiones isquémicas.

Anesthetics, cerebral protection and preconditioning.

BACKGROUND AND OBJECTIVES: Several studies demonstrate that cerebral preconditioning is a protective mechanism against a stressful situation. Preconditioning determinants are described, as well as the neuroprotection provided by anesthetic and non-anesthetics agents. CONTENT: Review based on the main articles addressing the pathophysiology of ischemia-reperfusion and neuronal injury and pharmacological and non-pharmacological factors (inflammation, glycemia, and temperature) related to the change in response to ischemia-reperfusion, in addition to neuroprotection induced by anesthetic use. CONCLUSIONS: The brain has the ability to protect itself against ischemia when stimulated. The elucidation of this mechanism enables the application of preconditioning inducing substances (some anesthetics), other drugs, and non-pharmacological measures, such as hypothermia, aimed at inducing tolerance to ischemic lesions.