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The digitalization of the Intensive Care Unit (ICU) led to an increasing amount of clinical data being collected at the bedside. The term "Big Data" can be used to refer to the analysis of these datasets that collect enormous amount of data of different origin and format. Complexity and variety define the value of Big Data. In fact, the retrospective analysis of these datasets allows to generate new knowledge, with consequent potential improvements in the clinical practice. Despite the promising start of Big Data analysis in medical research, which has seen a rising number of peer-reviewed articles, very limited applications have been used in ICU clinical practice. A close future effort should be done to validate the knowledge extracted from clinical Big Data and implement it in the clinic. In this article, we provide an introduction to Big Data in the ICU, from data collection and data analysis, to the main successful examples of prognostic, predictive and classification models based on ICU data. In addition, we focus on the main challenges that these models face to reach the bedside and effectively improve ICU care.

Background Electrical impedance tomography (EIT) is a noninvasive imaging method that identifies changes in air and blood volume based on thoracic impedance changes. Recently, there has been growing interest in EIT to measure stroke volume (SV). The objectives of this study are as follows: (1) to evaluate the ability of systolic impedance variations (ΔZsys) to track changes in SV in relation to a baseline condition; (2) to assess the relationship of ΔZsys and SV in experimental subjects; and (3) to identify the influence of body dimensions on the relationship between ΔZsys and SV. Methods Twelve Agroceres pigs were instrumented with transpulmonary thermodilution catheter and EIT and were mechanically ventilated in a random order using different settings of tidal volume (VT) and positive end-expiratory pressure (PEEP): VT 10 mL·kg and PEEP 10 cm H2O, VT 10 mL·kg and PEEP 5 cm H2O, VT 6 mL·kg and PEEP 10 cm H2O, and VT 6 mL·kg and PEEP 5 cm H2O. After baseline data collection, subjects were submitted to hemorrhagic shock and successive fluid challenges. Results A total of 204 paired measurements of SV and ΔZsys were obtained. The 4-quadrant plot showed acceptable trending ability with a concordance rate of 91.2%. Changes in ΔZsys after fluid challenges presented an area under the curve of 0.83 (95% confidence interval, 0.74-0.92) to evaluate SV changes. Conversely, the linear association between ΔZsys and SV was poor, with R from linear mixed model of 0.35. Adding information on body dimensions improved the linear association between ΔZsys and SV up to R from linear mixed model of 0.85. Conclusions EIT showed good trending ability and is a promising hemodynamic monitoring tool. Measurements of absolute SV require that body dimensions be taken into account.

RESUMO Objetivo: Definir o perfil epidemiologico e os principais determinantes de morbimortalidade dos pacientes cirurgicos nao cardiacos de alto risco no Brasil. Metodos: Estudo prospectivo, observacional e multicentrico. Todos os pacientes cirurgicos nao cardiacos admitidos nas unidades de terapia intensiva, ou seja, considerados de alto risco, no periodo de 1 mes, foram avaliados e acompanhados diariamente por, no maximo, 7 dias na unidade de terapia intensiva, para determinacao de complicacoes. As taxas de mortalidade em 28 dias de pos-operatorio, na unidade de terapia intensiva e hospitalar foram avaliadas. Resultados: Participaram 29 unidades de terapia intensiva onde foram realizadas cirurgias em 25.500 pacientes, dos quais 904 (3,5%) de alto risco (intervalo de confianca de 95% - IC95% 3,3% - 3,8%), tendo sido incluidos no estudo. Dos pacientes envolvidos, 48,3% eram de unidades de terapia intensiva privadas e 51,7% de publicas. O tempo de internacao na unidade de terapia intensiva foi de 2,0 (1,0 - 4,0) dias e hospitalar de 9,5 (5,4 - 18,6) dias. As taxas de complicacoes foram 29,9% (IC95% 26,4 - 33,7) e mortalidade em 28 dias pos-cirurgia 9,6% (IC95% 7,4 - 12,1). Os fatores independentes de risco para complicacoes foram Simplified Acute Physiology Score 3 (SAPS 3; razao de chance − RC = 1,02; IC95% 1,01 - 1,03) e Sequential Organ Failure Assessment Score (SOFA) da admissao na unidade de terapia intensiva (RC =1,17; IC95% 1,09 - 1,25), tempo de cirurgia (RC = 1,001; IC95% 1,000 - 1,002) e cirurgias de emergencias (RC = 1,93; IC95% 1,10 - 3,38). Em adicao, foram associados com mortalidade em 28 dias idade (RC = 1,032; IC95% 1,011 - 1,052) SAPS 3 (RC = 1,041; IC95% 1,107 - 1,279), SOFA (RC = 1,175; IC95% 1,069 - 1,292) e cirurgias emergenciais (RC = 2,509; IC95% 1,040 - 6,051). Conclusao: Pacientes com escores prognosticos mais elevados, idosos, tempo cirurgico e cirurgias emergenciais estiveram fortemente associados a maior mortalidade em 28 dias e mais complicacoes durante permanencia em unidade de terapia intensiva.

Describe the patterns of C-reactive protein relative changes in response to antibiotic therapy in critically ill cancer patients with healthcare-associated pneumonia (HCAP) and its ability to predict outcome.Secondary analysis of a prospective cohort of critically ill cancer patients with HCAP. CRP was sampled every other day from D0 to D6 of antibiotic therapy. Patients were classified according to an individual pattern of CRP-ratio response: fast - CRP at D4 of therapy was0.4 of D0 CRP; slow - a continuous but slow decrease of CRP; non - CRP remained ≥0.8 of D0 CRP; biphasic - initial CRP decrease to levels0.8 of the D0 CRP followed by a secondary rise ≥0.8.129 patients were included and septic shock was present in 74% and invasive mechanical ventilation was used in 73%. Intensive care unit (ICU) and hospital mortality rates were 47% and 64%, respectively. By D4, both CRP and CRP-ratio of survivors were significantly lower than in nonsurvivors (p0.001 and p=0.004, respectively). Both time-dependent analysis of CRP-ratio of the four previously defined patterns (p0.001) as ICU mortality were consistently different [fast 12.9%, slow 43.2%, biphasic 66.7% and non 71.8% (p0.001)].CRP-ratio was useful in the early prediction of poor outcomes in cancer patients with HCAP.

Background Scant information exists about the epidemiological characteristics and outcome of patients in the intensive care unit (ICU) at risk of acute respiratory distress syndrome (ARDS) and how ventilation is managed in these individuals. We aimed to establish the epidemiological characteristics of patients at risk of ARDS, describe ventilation management in this population, and assess outcomes compared with people at no risk of ARDS. Methods PRoVENT (PRactice of VENTilation in critically ill patients without ARDS at onset of ventilation) is an international, multicentre, prospective study undertaken at 119 ICUs in 16 countries worldwide. All patients aged 18 years or older who were receiving mechanical ventilation in participating ICUs during a 1-week period between January, 2014, and January, 2015, were enrolled into the study. The Lung Injury Prediction Score (LIPS) was used to stratify risk of ARDS, with a score of 4 or higher defining those at risk of ARDS. The primary outcome was the proportion of patients at risk of ARDS. Secondary outcomes included ventilatory management (including tidal volume [VT] expressed as mL/kg predicted bodyweight [PBW], and positive end-expiratory pressure [PEEP] expressed as cm H2O), development of pulmonary complications, and clinical outcomes. The PRoVENT study is registered at ClinicalTrials.gov, NCT01868321. The study has been completed. Findings Of 3023 patients screened for the study, 935 individuals fulfilled the inclusion criteria. Of these critically ill patients, 282 were at risk of ARDS (30%, 95% CI 27–33), representing 0·14 cases per ICU bed over a 1-week period. VTwas similar for patients at risk and not at risk of ARDS (median 7·6 mL/kg PBW [IQR 6·7–9·1] vs 7·9 mL/kg PBW [6·8–9·1]; p=0·346). PEEP was higher in patients at risk of ARDS compared with those not at risk (median 6·0 cm H2O [IQR 5·0–8·0] vs 5·0 cm H2O [5·0–7·0]; p

To assess fluid responsiveness in patients under spontaneous breathing activity ventilation remains a challenge for intensive care physicians. Much of the knowledge on heart-lung interactions and dynamic indexes of fluid responsiveness may not be useful for these patients. Historically, the most frequently used variables to guide fluid responsiveness on this population have been the static preload indexes. However, more recently, dynamic indexes from less invasive devices are being often used, even though their usefulness on spontaneously-breathing subjects remains controversial. The purpose of this article was to review evidences on the assessment of fluid responsiveness in patients under spontaneous ventilation. A search in literature showed poor evidence for use of static variables, such as filling pressures and ventricular end-diastolic volumes. Dynamic indexes, such as pulse pressure variation and other indexes had not been appropriately tested during spontaneous ventilation. Favorable results were found with central venous pressure variation and with transthoracic echocardiography or transesophageal Doppler dynamic indexes, especially when associated to passive lower limb elevation. We conclude that although central venous pressure variation and echocardiography variables could aid bedside clinicians in assessing fluid responsiveness during spontaneous ventilation, more studies on this subject are definitely required.

Objetivo: Este estudo teve como objetivo determinar a politica de visitacao predominante nas unidades de terapia intensiva e quais comodidades proporcionadas aos visitantes. Metodos: Foram enviados 800 convites a enderecos de e-mail de medicos e enfermeiros intensivistas listados nos grupos de pesquisa da Rede da Associacao de Medicina Intensiva Brasileira e da Rede Brasileira de Pesquisa em Terapia Intensiva. A mensagem por e-mail continha um link para um questionario de 33 itens a respeito do perfil de suas respectivas unidades de terapia intensiva. Resultados: Foram incluidos no estudo os questionarios de 162 unidades de terapia intensiva localizadas em todas as regioes do pais, mas foram predominantes as das Regioes Sudeste (58%) e Sul (16%). Apenas 2,6% das unidades de terapia intensiva relataram ter politicas liberais de visitacao, enquanto 45,1% das unidades de terapia intensiva possibilitavam dois periodos diarios de visitacao e 69,1% permitiam de 31 a 60 minutos de visita por periodo. Em situacoes especiais, como casos de fim de vida, 98,7% delas permitiam visitas em horarios flexiveis. Cerca de metade das unidades de terapia intensiva (50,8%) nao oferecia qualquer comodidade aos visitantes. Apenas 46,9% das unidades de terapia intensiva tinham uma sala de reuniao com familiares, e 37% nao dispunham de uma sala de espera. Conclusao: Nas unidades de terapia intensiva do Brasil, houve predominância de politicas restritivas de visitacao, sendo que a maioria delas so permite dois periodos diarios de visitacao. Tambem ha uma ausencia de comodidades para os visitantes.

Sepsis is the systemic inflammatory response syndrome secondary to a local infection, and severe sepsis and septic shock are the more devastating scenarios of this disease. In the last decade, considerable achievements were obtained in sepsis knowledge, and an international campaign was developed to improve the treatment of this condition. However, sepsis is still one of the most important causes of death in intensive care units. The early stages of sepsis are characterized by a variety of hemodynamic derangements that induce a systemic imbalance between tissue oxygen supply and demand, leading to global tissue hypoxia. This dysfunction, which may occur in patients presenting normal vital signs, can be accompanied by a significant increase in both morbidity and mortality. The early identification of high-risk sepsis patients through tissue perfusion markers such as lactate and venous oxygen saturation is crucial for prompt initiation of therapeutic support, which includes early goal-directed therapy as necessary. The purpose of this article was to review the most commonly used hemodynamic and perfusion parameters for hemodynamic optimization in sepsis, emphasizing the physiological background for their use and the studies that demonstrated their effectiveness as goals of volemic resuscitation.

A avaliação da responsividade a volume no paciente em ventilação espontânea representa um desafio para o intensivista. A maior parte dos conhecimentos adquiridos sobre interação coração-pulmão e o cálculo de índices dinâmicos de responsividade a fluidos podem não ser adequados para essa avaliação. Historicamente, as variáveis mais frequentemente utilizadas para guiar a responsividade a volume têm sido as medidas estáticas de pré-carga. Mais recentemente, índices dinâmicos obtidos por dispositivos menos invasivos têm sido mais usados, apesar de sua eficácia para esse fim em pacientes em ventilação espontânea ainda não ter sido adequadamente estabelecida. O objetivo deste estudo foi revisar as principais evidências sobre a avaliação da responsividade a volume nos pacientes em ventilação espontânea. A pesquisa na literatura demonstrou escassez nas evidências para utilização de medidas estáticas da volemia como as pressões de enchimento e o volume diastólico final dos ventrículos. Medidas dinâmicas como variação da pressão de pulso e outros índices também não foram adequadamente testados durante a ventilação espontânea. Resultados favoráveis foram obtidos com a variação dinâmica da pressão venosa central e com parâmetros dinâmicos que utilizam o ecocardiograma transtorácico ou doppler esofágico associado à elevação passiva dos membros inferiores. Conclui-se que embora a variação da pressão venosa central e variáveis obtidas com o ecocardiograma transtorácico ou doppler esofágico possam ser úteis na avaliação da responsividade a volume em pacientes sob ventilação espontânea, definitivamente são necessários mais estudos neste grupo de pacientes. To assess fluid responsiveness in patients under spontaneous breathing activity ventilation remains a challenge for intensive care physicians. Much of the knowledge on heart-lung interactions and dynamic indexes of fluid responsiveness may not be useful for these patients. Historically, the most frequently used variables to guide fluid responsiveness on this population have been the static preload indexes. However, more recently, dynamic indexes from less invasive devices are being often used, even though their usefulness on spontaneously-breathing subjects remains controversial. The purpose of this article was to review evidences on the assessment of fluid responsiveness in patients under spontaneous ventilation. A search in literature showed poor evidence for use of static variables, such as filling pressures and ventricular end-diastolic volumes. Dynamic indexes, such as pulse pressure variation and other indexes had not been appropriately tested during spontaneous ventilation. Favorable results were found with central venous pressure variation and with transthoracic echocardiography or transesophageal Doppler dynamic indexes, especially when associated to passive lower limb elevation. We conclude that although central venous pressure variation and echocardiography variables could aid bedside clinicians in assessing fluid responsiveness during spontaneous ventilation, more studies on this subject are definitely required.

Background An intensive care unit (ICU) admission is a stressful event for the patient and the patient’s family. Several studies demonstrated symptoms of anxiety, depression, and posttraumatic stress disorder in family members of patients admitted to ICU. Some studies recognize that the open visitation policy (OVP) is related to a reduction in symptoms of anxiety and depression for the patient and an improvement in family satisfaction. However, some issues have been presented as barriers for the adoption of that strategy. This study was designed to evaluate perceptions of physicians, nurses, and respiratory therapists (RTs) of an OVP and to quantify visiting times in a Brazilian private intensive care unit (ICU). Methods This observational and descriptive study was performed in the medical-surgical (22 beds) and neurologic ICU (8 beds) of Sírio-Libanês Hospital (HSL), São Paulo, Brazil. All physicians, nurses, and RTs from ICU were invited to participate in the study. A questionnaire was applied to all ICU workers who accepted to participate in the study. The questionnaire consisted of 22 questions about the visiting policy. During five consecutive days, we evaluated the time that the visitors stayed in the patient room, as well as the type of visitor. Results A total of 106 ICU workers participated in this study (42 physicians, 39 nurses, and 25 RTs). Only three of the questions exposed a negative perception of the visiting policy: 53.3% of the participants do not think that the OVP consistently increases family satisfaction with patient’s care; 59.4% of ICU workers think that the OVP impairs the organization of the patient’s care; 72.7% of participants believe that their work suffers more interruptions because of the OVP. The median visiting time per day was 11.5 hours. Conclusions According to physicians, nurses, and respiratory therapists, the greatest impact of OVP is the benefit to the patients rather than to the family or to the staff. Furthermore, they feel that they need communication training to better interact with family members who are present in the ICU 24 hours per day.

Introdução: A circulação por membrana extracorpórea veno-venosa (do inglês Extracorporeal Membrane Oxygenation - ECMO -) como suporte respiratório é caracterizada pela oxigenação sanguínea e remoção de gás carbônico através do bombeamento mecânico do sangue através de uma membrana onde ocorre a difusão dos gases. Contudo, vale ressaltar que o pulmão ainda mantém um importante papel na pressão arterial dos gases, funcionando como um segundo oxigenador, em série à ECMO. Em condições patológicas, a resposta adaptativa da circulação pulmonar frente a um desacoplamento entre ventilação e perfusão (V/Q) consiste na vasoconstrição de regiões pulmonares pobres em oxigênio, redirecionando o fluxo sanguíneo a regiões normalmente ventiladas com consequente atenuação do distúrbio V/Q. O principal modulador desta vasoconstrição pulmonar adaptativa é a própria pressão parcial de oxigênio local, através da Pressão Venosa de Oxigênio (PvO2) e da Pressão Alveolar de Oxigênio. Neste contexto, o uso da oxigenação por circulação extracorpórea tem o potencial de reduzir esta resposta adaptativa pulmonar e agravar o distúrbio V $Q ao elevar a PvO2. Assim, o objetivo deste estudo consiste em avaliar o efeito do suporte extracorpóreo e consequente aumento da PvO2 na perfusão pulmonar e hemodinâmica pulmonar em situações de hipoxemia e distúrbio V/Q. Métodos: Cinco suínos receberam monitorização e foram canulados para o suporte extracorpóreo. Utilizamos a Tomografia de Impedância Elétrica (TIE) para avaliar a ventilação e perfusão pulmonar ao longo das etapas do protocolo. Os efeitos do suporte com ECMO na hemodinâmica e perfusão pulmonar foram avaliados em um protocolo de 10 etapas sequenciais que simularam diferentes cenários de distúrbio V/Q. Variáveis hemodinâmicas, respiratórias, laboratoriais e da TIE ao longo das etapas foram analisadas através de comparações entre as etapas de interesse utilizando um modelo misto com o animal como fator randômico. Resultados: Aqui, fomos capazes de criar 2 situações distintas de distúrbio V $Q através da intubação pulmonar seletiva com colapso pulmonar e através de lavagem pulmonar seriada com depleção de surfactante. A TIE foi capaz de detectar variações da ventilação e perfusão pulmonar em todas as etapas do estudo, mesmo com circulação do sangue através do circuito de ECMO. No cenário de ventilação pulmonar unilateral com atelectasia pulmonar esquerda, o início do suporte com ECMO proporcionou um aumento da PvO2 e shunt pulmonar, com redução na Pressão Média de Artéria Pulmonar (PAPm). Por outro lado, não houve alteração da perfusão pulmonar após início do suporte com ECMO. No cenário de lesão pulmonar após lavagem pulmonar seriada e depleção de surfactante, pudemos notar uma redução na ventilação pulmonar posterior, secundária ao colapso de zonas dependentes. O suporte com ECMO nesta situação promoveu um aumento na PvO2 em associação à uma redução na PAPm, sem alteração no shunt pulmonar. Assim como no cenário anterior, o suporte com ECMO não alterou a perfusão pulmonar. Conclusão: Nossos dados sugerem que o suporte com ECMO veno-venosa, com consequente aumento da PvO2, é capaz de induzir uma redução na PAPm sem promover variação da perfusão pulmonar em diferentes situações clínicas de distúrbio V/Q Veno-venous Extracorporeal Membrane Oxygenation (ECMO) is characterized by blood oxygenation and removal of carbon dioxide by means of mechanically pumping the blood through an oxygenation membrane. However, during ECMO support, the native lungs still play an important role in regulating the arterial pressure of gases, functioning as a secondary oxygenator in series with ECMO. In pathological conditions, the adaptive response of pulmonary circulation in case of a decoupling between ventilation and perfusion (V/Q) consists of vasoconstriction of poorly oxygenated pulmonary regions, redirecting blood flow to normally ventilated regions with consequent attenuation of the V $Q mismatch. The main modulating factor of this adaptive pulmonary vasoconstriction is local partial oxygen pressure itself, through Venous Oxygen Pressure (PvO2) and Alveolar Partial Pressure. In this context, ECMO support has the potential to reduce this adaptive pulmonary response and worsen the V/Q mismatch by raising venous oxygen pressure. Thus, the objective of this study is to evaluate the effect of extracorporeal support and the consequent increase in PvO2 on pulmonary perfusion and pulmonary hemodynamic in situations involving hypoxemia and V/Q mismatch. Methods: Five animals were instrumented, monitored and submitted to extracorporeal membrane oxygenation. We used the Electrical Impedance Tomography (EIT) to evaluate lung ventilation and perfusion throughout all steps of the protocol. Effects of ECMO support on pulmonary hemodynamics and perfusion involving different situations of V/Q mismatch were tested in a ten-step protocol. Continuous data of hemodynamic, respiratory, lung perfusion/ventilation and laboratorial data over time were analyzed using interaction analyses with a fixed effect of a mixed generalized model using the animals as a random factor. Results: We were able to create two distinct situations of V/Q mismatch by inducing lung collapse with selective pulmonary intubation and by posterior serial lung lavage and surfactant depletion. The EIT was capable of detecting variations of lung ventilation and perfusion during all steps of the protocol despite blood circulation throughout the ECMO circuit. In the scenario of unilateral lung ventilation with left lung atelectasis, the initiation of ECMO support provided a significant increase in PvO2 and in pulmonary shunt with a reduction in Mean Pulmonary Artery Pressure (PAPm). On the other hand, left lung perfusion did not alter with the use of ECMO support. In the scenario of lavage induced lung injury and surfactant depletion we noticed a reduction in posterior lung ventilation secondary to lung collapse of dependent regions. ECMO support initiation increased PvO2 and reduced PAPm. ECMO support did not alter lung perfusion in this scenario. Conclusions: We found that the use of ECMO support with consequent increase in PvO2 in different scenarios of V/Q mismatch induces a significant drop PAPm. However, ECMO support did not affected lung perfusion during V/Q mismatch