Comparação da proporção entre pressão venosa central menos arterial de dióxido de carbono e conteúdo de oxigênio arterial menos venoso central e níveis de lactato como preditores de mortalidade em pacientes críticos: uma revisão sistemática e metanálise / Comparison of central venous minus arterial carbon dioxide pressure to arterial minus central venous oxygen content ratio and lactate levels as predictors of mortality in critically ill patients: a systematic review and meta-analysis

RESUMO Objetivo: A proporção entre pressão venosa central menos arterial de dióxido de carbono e conteúdo de oxigênio arterial menos venoso central (Pcv-aCO2/Ca-cvO2) é frequentemente usada como substituta para a oxigenação tecidual. O objetivo deste estudo foi identificar e sintetizar a literatura e a qualidade das evidências que suportam a Pcv-aCO2/Ca-cvO2 como um preditor de mortalidade em comparação com o lactato em pacientes críticos. Métodos: Pesquisamos vários bancos de dados procurando estudos que tivessem medido a Pcv-aCO2/Ca-cvO2 em pacientes críticos. Pesquisadores independentes realizaram a triagem dos artigos e a extração de dados. Uma metanálise de efeitos aleatórios foi realizada. Diferenças médias padronizadas agrupadas foram usadas para comparar a capacidade prognóstica da Pcv-aCO2/Ca-cvO2 e do lactato. Resultados: Inicialmente, obtivemos 172 estudos; 17 foram incluídos para descrição qualitativa, e dez foram incluídos para síntese quantitativa. A média de Pcv-aCO2/Ca-cvO2 foi maior nos não sobreviventes do que nos sobreviventes (diferença média padronizada agrupada de 0,75; IC95% 0,34 - 1,17; I2 = 83%), assim como os níveis de lactato (diferença média padronizada agrupada = 0,94; IC95% 0,34 - 1,54; I2 = 92%). Ambos os testes foram preditores estatisticamente significativos de mortalidade, embora com sobreposição de IC95% entre eles. Conclusão: Evidências de qualidade moderada mostraram pouca ou nenhuma diferença na capacidade da Pcv-aCO2/Ca-cvO2, em comparação com o lactato, em predizer mortalidade. No entanto, nossas conclusões são limitadas pela considerável heterogeneidade entre os estudos. Registro no PROSPERO:CRD42019130387

ABSTRACT Objective: The central venousarterial carbon dioxide pressure to arterial-central venous oxygen content ratio (Pcv-aCO2/Ca-cvO2) is frequently used as a surrogate for tissue oxygenation. We aimed to identify and synthesize literature and quality of evidence supporting Pcv-aCO2/Ca-cvO2 as a predictor of mortality in critically ill patients compared with lactate. Methods: We searched several databases for studies measuring Pcv-aCO2/Ca-cvO2 in critically ill patients. Independent investigators performed the article screening and data extraction. A random-effects metaanalysis was performed. Pooled standardized mean differences (SMD) were used to compare the prognostic ability of Pcv-aCO2/Ca-cvO2 and lactate. Results: We initially retrieved 172 studies; 17 were included for qualitative description, and 10 were included for quantitative synthesis. The mean Pcv-aCO2/Ca-cvO2 was higher in nonsurvivors than in survivors (pooled SMD = 0.75; 95%CI 0.34 - 1.17; I2 = 83%), as was the case with lactate levels (pooled SMD = 0.94; 95%CI 0.34 - 1.54; I2 = 92%). Both tests were statistically significant predictors of mortality, albeit with overlapping 95%CIs between them. Conclusion: Moderate-quality evidence showed little or no difference in the ability of Pcv-aCO2/Ca-cvO2, compared with lactate, to predict mortality. Nevertheless, our conclusions are limited by the considerable heterogeneity among the studies. PROSPERO registration:CRD42019130387

Dióxido de cloro y derivados del cloro para prevenir o tratar la COVID-19: revisión sistemática / Chlorine dioxide and chlorine derivatives for the prevention or treatment of COVID-19: a systematic review

RESUMEN Objetivos: Realizar una revisión sistemática acerca de la efectividad y seguridad del uso de dióxido de cloro y derivados del cloro, en la prevención o el tratamiento de la COVID-19. Materiales y métodos: Se siguieron las pautas internacionales de elaboración de revisiones sistemáticas de PRISMA y el Manual Cochrane para revisiones sistemáticas de intervenciones. La estrategia de búsqueda la desarrolló un bibliotecario y la revisaron dos de los autores. Se complementó la búsqueda electrónica con una búsqueda manual. Se incluyeron ensayos clínicos aleatorizados, estudios cuasiexperimentales, estudios de cohorte, estudios de casos y controles, estudios de corte transversal y reportes de casos; y se excluyeron estudios in vitro o realizados en animales. Dos revisores, de forma independiente, seleccionaron los estudios según los criterios de elegibilidad definidos, usando el aplicativo web Rayyan, en caso de discordancia se hizo partícipe a un tercer revisor. El protocolo de la revisión sistemática se registró en PROSPERO (CRD42020200641). Resultados: No se identificó ningún estudio publicado ni en proceso de publicación que haya evaluado el uso del dióxido de cloro o derivados del cloro, administrado por vía inhalatoria, oral o parenteral en humanos, como agente preventivo o terapéutico de la COVID-19 o en infecciones por otros coronavirus. Solo se identificó el registro de un único estudio catalogado como observacional que hasta ahora no tiene resultados. Conclusiones: A la fecha, no existe evidencia científica que apoye el uso del dióxido de cloro o derivados del cloro para prevenir o tratar la COVID-19.

ABSTRACT Objectives: To systematically review the effectiveness and safety of chlorine dioxide solution and chlorine derivatives used in the prevention or treatment of COVID-19. Methods: This review adheres to the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) and follows the guidelines provided in the Cochrane Handbook for Systematic Reviews of Interventions. A librarian developed and executed the search strategy; it was further reviewed by two of the authors and complemented by manual search. Randomized clinical trials, quasi-experimental studies, cohort studies, case-control studies, cross-sectional studies, and case reports were included; in vitro or animal studies were excluded. Abstract and full-text screening according to pre-defined eligibility criteria were performed by two reviewers independently using web application Rayyan QCRI. Disagreements on study selection were resolved by a third reviewer. The systematic review protocol was registered in PROSPERO (CRD42020200641). Results: Neither published nor pre-print studies evaluating the use of chlorine dioxide or derivatives on SARS-CoV-2 infection were identified. The only finding was an unpublished observational study registry which has no results released yet. Conclusions: To date, there are no scientific evidence to uphold the use of chlorine dioxide or derivatives as preventive or therapeutic agents against COVID-19.

Worldwide original research production on maternal near-miss: A 10-year bibliometric study

Abstract Objective To evaluate the global productivity regarding original articles on maternal near-miss (MNM). Methods We conducted a bibliometric analysis of original articles published from 2008 to November 2019 in the journals indexed in the Scopus database. The averages of the number of articles by author, of the number of authors by article, of the number of citations by article, and the total number of documents with one or more authors were obtained. An analysis of the co-citation of authors and a co-occurrence analysis of the terms included in the titles and abstracts were performed and were presented as network visualization maps. Results A total of 326 original articles were analyzed. There was an increase in the number of articles (p < 0.001; average annual growth rate = 12.54%;). A total of 1,399 authors, an average number of articles per author of 4.29, with an index of authors per document of 0.23, and an index of co-authors per document of 8.16 were identified. A total of 85 countries contributed with original articles on MNM. Among the top ten countries regarding the contribution of articles, five were low and middle-income countries (LMICs). Brazil had the highest volume of production (31.1%;), followed by the US (11.5%;). Terms related to countries and the measurement of the rates and cases of MNM and the associated factors were found in recent years in the analysis of the co-occurrence of terms. Conclusion There was an increase in the production of original articles on MNM, with a significant participation of authors and institutions from LMICs, which reveals a growing interest in the use of MNM indicators to improve the quality of maternal health care.

Proteína C ultrasensible como factor independiente de riesgo en población con y sin antecedentes cardiovasculares / High sensitivity C protein as an independent risk factor in people with and without history of cardiovascular disease

Entre los nuevos biomarcadores del riesgo de eventos cardiovasculares (ECV), la proteína C reactiva detectada mediante técnicas de alta sensibilidad (PCRus) ha sido uno de los más evaluados. En esta revisión se exploró la evidencia existente sobre la utilidad de la PCRus como factor independiente del riesgo de eventos en sujetos sin antecedentes cardiovasculares, y como marcador pronóstico en sujetos con enfermedad cardiovascular crónica o aguda. Se realizó un overview (revisión de revisiones) con búsqueda en las principales bases bibliográficas suplementada por buscadores genéricos de Internet. En una primera etapa se detectaron revisiones sistemáticas, guías de práctica clínica, evaluaciones de tecnologías sanitarias y políticas de cobertura, y en una segunda etapa se identificaron estudios primarios publicados posteriormente a las fechas de búsqueda de las revisiones sistemáticas. Fueron recuperadas 774 citas, de las cuales se incluyeron 36 publicaciones que evaluaron el papel de la PCRus en poblaciones sanas o con antecedentes coronarios. Se encontró evidencia de alta calidad señalando a la PCRus, tanto como factor de riesgo en población general, como pronóstico en aquellos con ECV en todas las poblaciones evaluadas. Su mayor utilidad residió en sujetos sin historia de ECV y riesgo intermedio de eventos a 10 años, en donde la adición de la PCRus a modelos clásicos de estimación del riesgo de eventos mejora la estratificación del riesgo. No se identificó, en cambio, consenso sobre su utilidad clínica como marcador pronóstico en sujetos con enfermedad coronaria crónica o aguda.

Among the new cardiovascular event (CVE) risk biomarkers, C-reactive protein detected using high sensitive techniques (hs-CRP) has been one of the most commonly evaluated. In this review, the available evidence on the usefulness of hs-CRP was explored as an independent risk event factor in subjects with no cardiovascular history and as prognosis in case of chronic or acute cardiovascular condition. An overview (revision of revisions) was carried out searching in the main bibliographic databases and in other general Internet search engines. During the first stage, systematic reviews, clinical practice guidelines, health technology assessments and coverage policies were found and, during the second stage primary studies published after the systematic review search dates were added. Seven hundred and seventy four quotes were found, including 36 papers assessing the role of hs-CRP in healthy populations or with cardiovascular history. High quality evidence was found pointing out hs-CRP, both as risk factor in the general population and as prognostic factor in those with CVE, in all the populations assessed. It was most useful in subjects with a history of CVE and intermediate risk of events at 10 years; where adding hs-CRP to the classical models for event risk estimation improves risk staging. There was no consensus on its clinical usefulness as a prognostic marker in subjects with chronic or acute disease.