Extracorporeal membrane oxygenation: a literature review. / Oxigenação por membrana extracorpórea: revisão da literatura.

Extracorporeal membrane oxygenation is a modality of extracorporeal life support that allows for temporary support in pulmonary and/or cardiac failure refractory to conventional therapy. Since the first descriptions of extracorporeal membrane oxygenation, significant improvements have occurred in the device and the management of patients and, consequently, in the outcomes of critically ill patients during extracorporeal membrane oxygenation. Many important studies about the use of extracorporeal membrane oxygenation in patients with acute respiratory distress syndrome refractory to conventional clinical support, under in-hospital cardiac arrest and with cardiogenic refractory shock have been published in recent years. The objective of this literature review is to present the theoretical and practical aspects of extracorporeal membrane oxygenation support for respiratory and/or cardiac functions in critically ill patients.

A oxigenação por membrana extracorpórea é uma modalidade de suporte de vida extracorpóreo que possibilita suporte temporário à falência da função pulmonar e/ou cardíaca, refratária ao tratamento clínico convencional. Desde as primeiras descrições da oxigenação por membrana extracorpórea, melhorias significativas ocorreram no dispositivo, no manejo do paciente e, consequentemente, nos desfechos dos pacientes em oxigenação por membrana extracorpórea. Diversos estudos importantes sobre a utilização de oxigenação por membrana extracorpórea em pacientes com síndrome do desconforto respiratório agudo refratária ao suporte clínico convencional, em parada cardíaca intra-hospitalar e choque cardiogênico refratário foram publicados nos últimos anos. Dessa forma, o objetivo desta revisão é apresentar conceitos teóricos e práticos sobre a utilização da oxigenação por membrana extracorpórea em situações de falência pulmonar e/ou cardíaca refratária ao manejo clínico convencional em pacientes críticos.

Oxigenação por membrana extracorpórea: revisão da literatura / Extracorporeal membrane oxygenation: a literature review

RESUMO A oxigenação por membrana extracorpórea é uma modalidade de suporte de vida extracorpóreo que possibilita suporte temporário à falência da função pulmonar e/ou cardíaca, refratária ao tratamento clínico convencional. Desde as primeiras descrições da oxigenação por membrana extracorpórea, melhorias significativas ocorreram no dispositivo, no manejo do paciente e, consequentemente, nos desfechos dos pacientes em oxigenação por membrana extracorpórea. Diversos estudos importantes sobre a utilização de oxigenação por membrana extracorpórea em pacientes com síndrome do desconforto respiratório agudo refratária ao suporte clínico convencional, em parada cardíaca intra-hospitalar e choque cardiogênico refratário foram publicados nos últimos anos. Dessa forma, o objetivo desta revisão é apresentar conceitos teóricos e práticos sobre a utilização da oxigenação por membrana extracorpórea em situações de falência pulmonar e/ou cardíaca refratária ao manejo clínico convencional em pacientes críticos.

ABSTRACT Extracorporeal membrane oxygenation is a modality of extracorporeal life support that allows for temporary support in pulmonary and/or cardiac failure refractory to conventional therapy. Since the first descriptions of extracorporeal membrane oxygenation, significant improvements have occurred in the device and the management of patients and, consequently, in the outcomes of critically ill patients during extracorporeal membrane oxygenation. Many important studies about the use of extracorporeal membrane oxygenation in patients with acute respiratory distress syndrome refractory to conventional clinical support, under in-hospital cardiac arrest and with cardiogenic refractory shock have been published in recent years. The objective of this literature review is to present the theoretical and practical aspects of extracorporeal membrane oxygenation support for respiratory and/or cardiac functions in critically ill patients.

Early versus delayed initiation of renal replacement therapy for acute kidney injury: an updated systematic review, meta-analysis, meta-regression and trial sequential analysis of randomized controlled trials. / Início precoce em comparação ao início tardio da terapia de substituição renal para lesão renal aguda: revisão sistemática atualizada, metanálise, metarregressão e análise sequencial de ensaios clínicos randomizados e controlados.

OBJECTIVE: To evaluate whether early initiation of renal replacement therapy is associated with lower mortality in patients with acute kidney injury compared to delayed initiation. METHODS: We performed a systematic review and meta-analysis of randomized controlled trials comparing early versus delayed initiation of renal replacement therapy in patients with acute kidney injury without the life-threatening acute kidney injury-related symptoms of fluid overload or metabolic disorders. Two investigators extracted the data from the selected studies. The Cochrane Risk of Bias Tool was used to assess the quality of the studies, and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to test the overall quality of the evidence. RESULTS: Six randomized controlled trials (1,292 patients) were included. There was no statistically significant difference between early and delayed initiation of renal replacement therapy regarding the primary outcome (OR 0.82; 95%CI, 0.48 - 1.42; p = 0.488), but there was an increased risk of catheter-related bloodstream infection when renal replacement therapy was initiated early (OR 1.77; 95%CI, 1.01 - 3.11; p = 0.047). The quality of evidence generated by our meta-analysis for the primary outcome was considered low due to the risk of bias of the included studies and the heterogeneity among them. CONCLUSION: Early initiation of renal replacement therapy is not associated with improved survival. However, the quality of the current evidence is low, and the criteria used for -early- and -delayed- initiation of renal replacement therapy are too heterogeneous among studies.

OBJETIVO: Avaliar se, em comparação ao início tardio, o início precoce da terapia de substituição renal se associa com menor mortalidade em pacientes com lesão renal aguda. MÉTODOS: Conduzimos uma revisão sistemática e metanálise de ensaios clínicos randomizados e controlados, que compararam terapia de substituição renal com início precoce àquela com início tardio em pacientes com lesão renal aguda, sem sintomas relacionados à insuficiência renal aguda que oferecessem risco à vida, como sobrecarga hídrica ou distúrbios metabólicos. Dois investigadores extraíram os dados a partir de estudos selecionados. Utilizaram-se a ferramenta Cochrane Risk of Bias, para avaliar a qualidade dos estudos, e a abordagem Grading of Recommendations Assessment, Development and Evaluation (GRADE), para testar a qualidade geral da evidência. RESULTADOS: Incluíram-se seis estudos clínicos randomizados e controlados (1.292 pacientes). Não houve diferença estatisticamente significante entre o início precoce e tardio da terapia de substituição renal, no que se referiu ao desfecho primário (OR 0,82; IC95% 0,48 - 1,42; p = 0,488). Foi maior o risco de infecção da corrente sanguínea relacionada ao cateter quando a terapia de substituição renal foi iniciada precocemente (OR 1,77; IC95% 1,01 - 3,11; p = 0,047). A qualidade da evidência gerada por nossa metanálise para o desfecho primário foi considerada baixa, em razão do risco de viés dos estudos incluídos e da heterogeneidade entre eles. CONCLUSÃO: O início precoce da terapia de substituição renal não se associou com melhora da sobrevivência. Entretanto, a qualidade da evidência atual é baixa, e os critérios utilizados para início precoce e tardio da terapia de substituição renal foram demasiadamente heterogêneos entre os estudos.

Início precoce em comparação ao início tardio da terapia de substituição renal para lesão renal aguda: revisão sistemática atualizada, metanálise, metarregressão e análise sequencial de ensaios clínicos randomizados e controlados / Early versus delayed initiation of renal replacement therapy for acute kidney injury: an updated systematic review, meta-analysis, meta-regression and trial sequential analysis of randomized controlled trials

RESUMO Objetivo: Avaliar se, em comparação ao início tardio, o início precoce da terapia de substituição renal se associa com menor mortalidade em pacientes com lesão renal aguda. Métodos: Conduzimos uma revisão sistemática e metanálise de ensaios clínicos randomizados e controlados, que compararam terapia de substituição renal com início precoce àquela com início tardio em pacientes com lesão renal aguda, sem sintomas relacionados à insuficiência renal aguda que oferecessem risco à vida, como sobrecarga hídrica ou distúrbios metabólicos. Dois investigadores extraíram os dados a partir de estudos selecionados. Utilizaram-se a ferramenta Cochrane Risk of Bias, para avaliar a qualidade dos estudos, e a abordagem Grading of Recommendations Assessment, Development and Evaluation (GRADE), para testar a qualidade geral da evidência. Resultados: Incluíram-se seis estudos clínicos randomizados e controlados (1.292 pacientes). Não houve diferença estatisticamente significante entre o início precoce e tardio da terapia de substituição renal, no que se referiu ao desfecho primário (OR 0,82; IC95% 0,48 - 1,42; p = 0,488). Foi maior o risco de infecção da corrente sanguínea relacionada ao cateter quando a terapia de substituição renal foi iniciada precocemente (OR 1,77; IC95% 1,01 - 3,11; p = 0,047). A qualidade da evidência gerada por nossa metanálise para o desfecho primário foi considerada baixa, em razão do risco de viés dos estudos incluídos e da heterogeneidade entre eles. Conclusão: O início precoce da terapia de substituição renal não se associou com melhora da sobrevivência. Entretanto, a qualidade da evidência atual é baixa, e os critérios utilizados para início precoce e tardio da terapia de substituição renal foram demasiadamente heterogêneos entre os estudos.

ABSTRACT Objective: To evaluate whether early initiation of renal replacement therapy is associated with lower mortality in patients with acute kidney injury compared to delayed initiation. Methods: We performed a systematic review and meta-analysis of randomized controlled trials comparing early versus delayed initiation of renal replacement therapy in patients with acute kidney injury without the life-threatening acute kidney injury-related symptoms of fluid overload or metabolic disorders. Two investigators extracted the data from the selected studies. The Cochrane Risk of Bias Tool was used to assess the quality of the studies, and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to test the overall quality of the evidence. Results: Six randomized controlled trials (1,292 patients) were included. There was no statistically significant difference between early and delayed initiation of renal replacement therapy regarding the primary outcome (OR 0.82; 95%CI, 0.48 - 1.42; p = 0.488), but there was an increased risk of catheter-related bloodstream infection when renal replacement therapy was initiated early (OR 1.77; 95%CI, 1.01 - 3.11; p = 0.047). The quality of evidence generated by our meta-analysis for the primary outcome was considered low due to the risk of bias of the included studies and the heterogeneity among them. Conclusion: Early initiation of renal replacement therapy is not associated with improved survival. However, the quality of the current evidence is low, and the criteria used for -early- and -delayed- initiation of renal replacement therapy are too heterogeneous among studies.

Assessment of fluid responsiveness in spontaneously breathing patients: a systematic review of literature.

Patients who increase stoke volume or cardiac index more than 10 or 15% after a fluid challenge are usually considered fluid responders. Assessment of fluid responsiveness prior to volume expansion is critical to avoid fluid overload, which has been associated with poor outcomes. Maneuvers to assess fluid responsiveness are well established in mechanically ventilated patients; however, few studies evaluated maneuvers to predict fluid responsiveness in spontaneously breathing patients. Our objective was to perform a systematic review of literature addressing the available methods to assess fluid responsiveness in spontaneously breathing patients. Studies were identified through electronic literature search of PubMed from 01/08/2009 to 01/08/2016 by two independent authors. No restrictions on language were adopted. Quality of included studies was evaluated with Quality Assessment of Diagnostic Accuracy Studies tool. Our search strategy identified 537 studies, and 9 studies were added through manual search. Of those, 15 studies (12 intensive care unit patients; 1 emergency department patients; 1 intensive care unit and emergency department patients; 1 operating room) were included in this analysis. In total, 649 spontaneously breathing patients were assessed for fluid responsiveness. Of those, 340 (52%) were deemed fluid responsive. Pulse pressure variation during the Valsalva maneuver (∆PPV) of 52% (AUC ± SD: 0.98 ± 0.03) and passive leg raising-induced change in stroke volume (∆SV-PLR) > 13% (AUC ± SD: 0.96 ± 0.03) showed the highest accuracy to predict fluid responsiveness in spontaneously breathing patients. Our systematic review indicates that regardless of the limitations of each maneuver, fluid responsiveness can be assessed in spontaneously breathing patients. Further well-designed studies, with adequate simple size and power, are necessary to confirm the real accuracy of the different methods used to assess fluid responsiveness in this population of patients.

Sedation in mechanically ventilated patients-time to stay awake?

On June, 2016, Klompas and colleagues published an article in the Chest entitled "Associations between different sedatives and ventilator-associated events, length of stay, and mortality in patients who were mechanically ventilated", which investigated the effects of different sedatives on ventilator-associated events (VAEs), length of stay, and mortality in patients who were mechanically ventilated. This study used data of over 9,603 patients in order to investigate patients over the age of 18 who underwent mechanical ventilation for more than 3 days over a 7-year period in a large academic medical center. The investigators found that propofol and dexmedetomidine were associated with less time to extubation compared with benzodiazepines, but dexmedetomidine was also associated with less time to extubation vs. propofol. This study raises important questions about the sedation of critically ill patients.