Predictors of bleeding and thrombotic events among patients admitted to the hospital with COVID-19 and elevated D-dimer: insights from the ACTION randomized clinical trial.

Therapeutic anticoagulation showed inconsistent results in hospitalized patients with COVID-19 and selection of the best patients to use this strategy still a challenge balancing the risk of thrombotic and hemorrhagic outcomes. The present post-hoc analysis of the ACTION trial evaluated the variables independently associated with both bleeding events (major bleeding or clinically relevant non-major bleeding) and the composite outcomes thrombotic events (venous thromboembolism, myocardial infarction, stroke, systemic embolism, or major adverse limb events). Variables were assessed one by one with independent logistic regressions and final models were chosen based on Akaike information criteria. The model for bleeding events showed an area under the curve of 0.63 (95% confidence interval [CI] 0.53 to 0.73), while the model for thrombotic events had an area under the curve of 0.72 (95% CI 0.65 to 0.79). Non-invasive respiratory support was associated with thrombotic but not bleeding events, while invasive ventilation was associated with both outcomes (Odds Ratio of 7.03 [95 CI% 1.95 to 25.18] for thrombotic and 3.14 [95% CI 1.11 to 8.84] for bleeding events). Beyond respiratory support, creatinine level (Odds Ratio [OR] 1.01 95% CI 1.00 to 1.02 for every 1.0 mg/dL) and history of coronary disease (OR 3.67; 95% CI 1.32 to 10.29) were also independently associated to the risk of thrombotic events. Non-invasive respiratory support, history of coronary disease, and creatinine level may help to identify hospitalized COVID-19 patients at higher risk of thrombotic complications.ClinicalTrials.gov: NCT04394377.

Therapeutic versus prophylactic anticoagulation for patients admitted to hospital with COVID-19 and elevated D-dimer concentration (ACTION): an open-label, multicentre, randomised, controlled trial.

BACKGROUND: COVID-19 is associated with a prothrombotic state leading to adverse clinical outcomes. Whether therapeutic anticoagulation improves outcomes in patients hospitalised with COVID-19 is unknown. We aimed to compare the efficacy and safety of therapeutic versus prophylactic anticoagulation in this population. METHODS: We did a pragmatic, open-label (with blinded adjudication), multicentre, randomised, controlled trial, at 31 sites in Brazil. Patients (aged ≥18 years) hospitalised with COVID-19 and elevated D-dimer concentration, and who had COVID-19 symptoms for up to 14 days before randomisation, were randomly assigned (1:1) to receive either therapeutic or prophylactic anticoagulation. Therapeutic anticoagulation was in-hospital oral rivaroxaban (20 mg or 15 mg daily) for stable patients, or initial subcutaneous enoxaparin (1 mg/kg twice per day) or intravenous unfractionated heparin (to achieve a 0·3-0·7 IU/mL anti-Xa concentration) for clinically unstable patients, followed by rivaroxaban to day 30. Prophylactic anticoagulation was standard in-hospital enoxaparin or unfractionated heparin. The primary efficacy outcome was a hierarchical analysis of time to death, duration of hospitalisation, or duration of supplemental oxygen to day 30, analysed with the win ratio method (a ratio >1 reflects a better outcome in the therapeutic anticoagulation group) in the intention-to-treat population. The primary safety outcome was major or clinically relevant non-major bleeding through 30 days. This study is registered with ClinicalTrials.gov (NCT04394377) and is completed. FINDINGS: From June 24, 2020, to Feb 26, 2021, 3331 patients were screened and 615 were randomly allocated (311 [50%] to the therapeutic anticoagulation group and 304 [50%] to the prophylactic anticoagulation group). 576 (94%) were clinically stable and 39 (6%) clinically unstable. One patient, in the therapeutic group, was lost to follow-up because of withdrawal of consent and was not included in the primary analysis. The primary efficacy outcome was not different between patients assigned therapeutic or prophylactic anticoagulation, with 28 899 (34·8%) wins in the therapeutic group and 34 288 (41·3%) in the prophylactic group (win ratio 0·86 [95% CI 0·59-1·22], p=0·40). Consistent results were seen in clinically stable and clinically unstable patients. The primary safety outcome of major or clinically relevant non-major bleeding occurred in 26 (8%) patients assigned therapeutic anticoagulation and seven (2%) assigned prophylactic anticoagulation (relative risk 3·64 [95% CI 1·61-8·27], p=0·0010). Allergic reaction to the study medication occurred in two (1%) patients in the therapeutic anticoagulation group and three (1%) in the prophylactic anticoagulation group. INTERPRETATION: In patients hospitalised with COVID-19 and elevated D-dimer concentration, in-hospital therapeutic anticoagulation with rivaroxaban or enoxaparin followed by rivaroxaban to day 30 did not improve clinical outcomes and increased bleeding compared with prophylactic anticoagulation. Therefore, use of therapeutic-dose rivaroxaban, and other direct oral anticoagulants, should be avoided in these patients in the absence of an evidence-based indication for oral anticoagulation. FUNDING: Coalition COVID-19 Brazil, Bayer SA.

Effect of Dexamethasone on Days Alive and Ventilator-Free in Patients With Moderate or Severe Acute Respiratory Distress Syndrome and COVID-19: The CoDEX Randomized Clinical Trial.

Importance: Acute respiratory distress syndrome (ARDS) due to coronavirus disease 2019 (COVID-19) is associated with substantial mortality and use of health care resources. Dexamethasone use might attenuate lung injury in these patients. Objective: To determine whether intravenous dexamethasone increases the number of ventilator-free days among patients with COVID-19-associated ARDS. Design, Setting, and Participants: Multicenter, randomized, open-label, clinical trial conducted in 41 intensive care units (ICUs) in Brazil. Patients with COVID-19 and moderate to severe ARDS, according to the Berlin definition, were enrolled from April 17 to June 23, 2020. Final follow-up was completed on July 21, 2020. The trial was stopped early following publication of a related study before reaching the planned sample size of 350 patients. Interventions: Twenty mg of dexamethasone intravenously daily for 5 days, 10 mg of dexamethasone daily for 5 days or until ICU discharge, plus standard care (n =151) or standard care alone (n = 148). Main Outcomes and Measures: The primary outcome was ventilator-free days during the first 28 days, defined as being alive and free from mechanical ventilation. Secondary outcomes were all-cause mortality at 28 days, clinical status of patients at day 15 using a 6-point ordinal scale (ranging from 1, not hospitalized to 6, death), ICU-free days during the first 28 days, mechanical ventilation duration at 28 days, and Sequential Organ Failure Assessment (SOFA) scores (range, 0-24, with higher scores indicating greater organ dysfunction) at 48 hours, 72 hours, and 7 days. Results: A total of 299 patients (mean [SD] age, 61 [14] years; 37% women) were enrolled and all completed follow-up. Patients randomized to the dexamethasone group had a mean 6.6 ventilator-free days (95% CI, 5.0-8.2) during the first 28 days vs 4.0 ventilator-free days (95% CI, 2.9-5.4) in the standard care group (difference, 2.26; 95% CI, 0.2-4.38; P = .04). At 7 days, patients in the dexamethasone group had a mean SOFA score of 6.1 (95% CI, 5.5-6.7) vs 7.5 (95% CI, 6.9-8.1) in the standard care group (difference, -1.16; 95% CI, -1.94 to -0.38; P = .004). There was no significant difference in the prespecified secondary outcomes of all-cause mortality at 28 days, ICU-free days during the first 28 days, mechanical ventilation duration at 28 days, or the 6-point ordinal scale at 15 days. Thirty-three patients (21.9%) in the dexamethasone group vs 43 (29.1%) in the standard care group experienced secondary infections, 47 (31.1%) vs 42 (28.3%) needed insulin for glucose control, and 5 (3.3%) vs 9 (6.1%) experienced other serious adverse events. Conclusions and Relevance: Among patients with COVID-19 and moderate or severe ARDS, use of intravenous dexamethasone plus standard care compared with standard care alone resulted in a statistically significant increase in the number of ventilator-free days (days alive and free of mechanical ventilation) over 28 days. Trial Registration: ClinicalTrials.gov Identifier: NCT04327401.

Prospective, randomized, controlled trial assessing the effects of a driving pressure-limiting strategy for patients with acute respiratory distress syndrome due to community-acquired pneumonia (STAMINA trial): protocol and statistical analysis plan.

BACKGROUND: Driving pressure has been suggested to be the main driver of ventilator-induced lung injury and mortality in observational studies of acute respiratory distress syndrome. Whether a driving pressure-limiting strategy can improve clinical outcomes is unclear. OBJECTIVE: To describe the protocol and statistical analysis plan that will be used to test whether a driving pressure-limiting strategy including positive end-expiratory pressure titration according to the best respiratory compliance and reduction in tidal volume is superior to a standard strategy involving the use of the ARDSNet low-positive end-expiratory pressure table in terms of increasing the number of ventilator-free days in patients with acute respiratory distress syndrome due to community-acquired pneumonia. METHODS: The ventilator STrAtegy for coMmunIty acquired pNeumoniA (STAMINA) study is a randomized, multicenter, open-label trial that compares a driving pressure-limiting strategy to the ARDSnet low-positive end-expiratory pressure table in patients with moderate-to-severe acute respiratory distress syndrome due to community-acquired pneumonia admitted to intensive care units. We expect to recruit 500 patients from 20 Brazilian and 2 Colombian intensive care units. They will be randomized to a driving pressure-limiting strategy group or to a standard strategy using the ARDSNet low-positive end-expiratory pressure table. In the driving pressure-limiting strategy group, positive end-expiratory pressure will be titrated according to the best respiratory system compliance. OUTCOMES: The primary outcome is the number of ventilator-free days within 28 days. The secondary outcomes are in-hospital and intensive care unit mortality and the need for rescue therapies such as extracorporeal life support, recruitment maneuvers and inhaled nitric oxide. CONCLUSION: STAMINA is designed to provide evidence on whether a driving pressure-limiting strategy is superior to the ARDSNet low-positive end-expiratory pressure table strategy for increasing the number of ventilator-free days within 28 days in patients with moderate-to-severe acute respiratory distress syndrome. Here, we describe the rationale, design and status of the trial.

Exploring the association of two oxygenators in parallel or in series during respiratory support using extracorporeal membrane oxygenation. / Investigação da associação de dois oxigenadores em paralelo ou em série durante o suporte respiratório com oxigenação por membrana extracorpórea.

OBJECTIVE: To characterize the pressures, resistances, oxygenation, and decarboxylation efficacy of two oxygenators associated in series or in parallel during venous-venous extracorporeal membrane oxygenation support. METHODS: Using the results of a swine severe respiratory failure associated with multiple organ dysfunction venous-venous extracorporeal membrane oxygenation support model and mathematical modeling, we explored the effects on oxygenation, decarboxylation and circuit pressures of in-parallel and in-series associations of oxygenators. RESULTS: Five animals with a median weight of 80kg were tested. Both configurations increased the oxygen partial pressure after the oxygenators. The return cannula oxygen content was also slightly higher, but the impact on systemic oxygenation was minimal using oxygenators with a high rated flow (~ 7L/minute). Both configurations significantly reduced the systemic carbon dioxide partial pressure. As the extracorporeal membrane oxygenation blood flow increased, the oxygenator resistance decreased initially with a further increase with higher blood flows but with a small clinical impact. CONCLUSION: Association of oxygenators in parallel or in series during venous-venous extracorporeal membrane oxygenation support provides a modest increase in carbon dioxide partial pressure removal with a slight improvement in oxygenation. The effect of oxygenator associations on extracorporeal circuit pressures is minimal.

OBJETIVO: Caracterizar as pressões, as resistências, a oxigenação e a eficácia da descarboxilação de dois oxigenadores associados em série ou em paralelo durante o suporte com oxigenação veno-venosa por membrana extracorpórea. MÉTODOS: Usando os resultados de insuficiência respiratória grave em suínos associada à disfunção de múltiplos órgãos, ao modelo de suporte com oxigenação por membrana extracorpórea veno-venosa e à modelagem matemática, exploramos os efeitos na oxigenação, descarboxilação e pressões do circuito de associações de oxigenadores em paralelo e em série. RESULTADOS: Testaram-se cinco animais com peso mediano de 80kg. Ambas as configurações aumentaram a pressão parcial de oxigênio após os oxigenadores. O teor de oxigênio da cânula de retorno também foi ligeiramente maior, mas o efeito na oxigenação sistêmica foi mínimo, usando oxigenadores com alto fluxo nominal (~ 7L/minuto). Ambas as configurações reduziram significativamente a pressão parcial de dióxido de carbono sistêmico. Como o fluxo sanguíneo na oxigenação por membrana extracorpórea aumentou, a resistência do oxigenador diminuiu inicialmente, com aumento posterior, com fluxos sanguíneos mais altos, mas pouco efeito clínico. CONCLUSÃO: A associação de oxigenadores em paralelo ou em série durante o suporte com oxigenação veno-venosa por membrana extracorpórea proporciona um modesto aumento na depuração da pressão parcial de dióxido de carbono, com leve melhora na oxigenação. O efeito das associações de oxigenadores nas pressões de circuitos extracorpóreos é mínimo.

Safe and effective protocol for discharge 3 days after cardiac surgery.

The Enhanced Recovery After Surgery (ERAS) protocol affected traditional cardiac surgery processes and COVID-19 is expected to accelerate its scalability. The aim of this study was to assess the impact of an ERAS-based protocol on the length of hospital stay after cardiac surgery. From January 2019 to June 2020, 664 patients underwent consecutive cardiac surgery at a Latin American center. Here, 46 patients were prepared for a rapid recovery through a multidisciplinary institutional protocol based on the ERAS concept, the "TotalCor protocol". After the propensity score matching, 46 patients from the entire population were adjusted for 12 variables. Patients operated on the TotalCor protocol had reduced intensive care unit time (P < 0.025), postoperative stay (P ≤ 0.001) and length of hospital stay (P ≤ 0.001). In addition, there were no significant differences in the occurrence of complications and death between the two groups. Of the 10-central metrics of TotalCor protocol, 6 had > 70% adherences. In conclusion, the TotalCor protocol was safe and effective for a 3-day discharge after cardiac surgery. Postoperative atrial fibrillation and renal failure were predictors of postoperative stay > 5 days.

Oxygen delivery, carbon dioxide removal, energy transfer to lungs and pulmonary hypertension behavior during venous-venous extracorporeal membrane oxygenation support: a mathematical modeling approach. / Oferta de oxigênio, remoção de dióxido de carbono, transferência de energia aos pulmões e comportamento da hipertensão pulmonar durante o suporte com oxigenação por membrana extracorpórea: um modelo matemático.

OBJECTIVE: To describe (1) the energy transfer from the ventilator to the lungs, (2) the match between venous-venous extracorporeal membrane oxygenation (ECMO) oxygen transfer and patient oxygen consumption (VO2), (3) carbon dioxide removal with ECMO, and (4) the potential effect of systemic venous oxygenation on pulmonary artery pressure. METHODS: Mathematical modeling approach with hypothetical scenarios using computer simulation. RESULTS: The transition from protective ventilation to ultraprotective ventilation in a patient with severe acute respiratory distress syndrome and a static respiratory compliance of 20mL/cm H2O reduced the energy transfer from the ventilator to the lungs from 35.3 to 2.6 joules/minute. A hypothetical patient, hyperdynamic and slightly anemic with VO2 = 200mL/minute, can reach an arterial oxygen saturation of 80%, while maintaining the match between the oxygen transfer by ECMO and the VO2 of the patient. Carbon dioxide is easily removed, and normal PaCO2 is easily reached. Venous blood oxygenation through the ECMO circuit may drive the PO2 stimulus of pulmonary hypoxic vasoconstriction to normal values. CONCLUSION: Ultraprotective ventilation largely reduces the energy transfer from the ventilator to the lungs. Severe hypoxemia on venous-venous-ECMO support may occur despite the matching between the oxygen transfer by ECMO and the VO2 of the patient. The normal range of PaCO2 is easy to reach. Venous-venous-ECMO support potentially relieves hypoxic pulmonary vasoconstriction.

OBJETIVO: Descrever a transferência de energia do ventilador mecânico para os pulmões; o acoplamento entre a transferência de oxigênio por oxigenação por membrana extracorpórea venovenosa (ECMO-VV) e o consumo de oxigênio do paciente; a remoção de dióxido de carbono com ECMO; e o efeito potencial da oxigenação venosa sistêmica na pressão arterial pulmonar. MÉTODOS: Modelo matemático com cenários hipotéticos e utilização de simulações matemáticas por computador. RESULTADOS: A transição de ventilação protetora para ventilação ultraprotetora em um paciente com síndrome da angústia respiratória aguda grave e complacência respiratória estática de 20mL/cmH2O reduziu a transferência de energia do ventilador para os pulmões de 35,3 para 2,6 joules por minuto. Em um paciente hipotético, hiperdinâmico e ligeiramente anêmico com consumo de oxigênio de 200mL/minuto, é possível atingir saturação arterial de oxigênio de 80%, ao mesmo tempo em que se mantém o equilíbrio entre a transferência de oxigênio pela ECMO e o consumo de oxigênio do paciente. O dióxido de carbono é facilmente removido e a pressão parcial de dióxido de carbono normal é facilmente obtida. A oxigenação do sangue venoso, por meio do circuito da ECMO, pode direcionar o estímulo da pressão parcial de oxigênio na vasoconstrição pulmonar por hipóxia para valores normais. CONCLUSÃO: A ventilação ultraprotetora reduz amplamente a transferência de energia do ventilador para os pulmões. A hipoxemia grave no suporte com ECMO-VV pode ocorrer, a despeito do acoplamento entre a transferência de oxigênio, por meio da ECMO, e o consumo de oxigênio do paciente. A faixa normal de pressão parcial de dióxido de carbono é fácil de atingir. O suporte com ECMO-VV potencialmente alivia a vasoconstrição pulmonar hipóxica.

Extracorporeal membrane oxygenation for severe acute respiratory distress syndrome in adult patients: a systematic review and meta-analysis. / Oxigenação por membrana extracorpórea para síndrome do desconforto respiratório agudo grave em pacientes adultos: revisão sistemática e metanálise.

OBJECTIVE: The evidence of improved survival with the use of extracorporeal membrane oxygenation (ECMO) in acute respiratory distress syndrome is still uncertain. METHODS: This systematic review and meta-analysis was registered in the PROSPERO database with the number CRD-42018098618. We performed a structured search of Medline, Lilacs, and ScienceDirect for randomized controlled trials evaluating the use of ECMO associated with (ultra)protective mechanical ventilation for severe acute respiratory failure in adult patients. We used the Cochrane risk of bias tool to evaluate the quality of the evidence. Our primary objective was to evaluate the effect of ECMO on the last reported mortality. Secondary outcomes were treatment failure, hospital length of stay and the need for renal replacement therapy in both groups. RESULTS: Two randomized controlled studies were included in the meta-analysis, comprising 429 patients, of whom 214 were supported with ECMO. The most common reason for acute respiratory failure was pneumonia (60% - 65%). Respiratory ECMO support was associated with a reduction in last reported mortality and treatment failure with risk ratios (RR: 0.76; 95%CI 0.61 - 0.95 and RR: 0.68; 95%CI 0.55 - 0.85, respectively). Extracorporeal membrane oxygenation reduced the need for renal replacement therapy, with a RR of 0.88 (95%CI 0.77 - 0.99). Intensive care unit and hospital lengths of stay were longer in ECMO-supported patients, with an additional P50th 14.84 (P25th - P75th: 12.49 - 17.18) and P50th 29.80 (P25th - P75th: 26.04 - 33.56] days, respectively. CONCLUSION: Respiratory ECMO support in severe acute respiratory distress syndrome patients is associated with a reduced mortality rate and a reduced need for renal replacement therapy but a substantial increase in the lengths of stay in the intensive care unit and hospital. Our results may help bedside decision-making regarding ECMO initiation in patients with severe respiratory distress syndrome.

OBJETIVO: A evidência de melhora da sobrevivência com uso de oxigenação por membrana extracorpórea na síndrome do desconforto respiratório agudo ainda permanece incerta. MÉTODOS: Esta revisão sistemática e metanálise foi registrada na base de dados PROSPERO com o número CRD-42018098618. Conduzimos uma busca estruturada nas bases Medline, LILACS e ScienceDirect visando a ensaios randomizados e controlados que tivessem avaliado o uso de oxigenação por membrana extracorpórea associada com ventilação mecânica (ultra)protetora em pacientes adultos com síndrome do desconforto respiratório agudo grave. Utilizamos a ferramenta de riscos de viés da Cochrane para avaliar a qualidade da evidência. O desfecho primário consistiu em avaliar o efeito do uso oxigenação por membrana extracorpórea no último relato de mortalidade. Os desfechos secundários foram: falha terapêutica, tempo de permanência no hospital e necessidade de terapia de substituição renal em ambos os grupos. RESULTADOS: Incluíram-se na metanálise dois ensaios randomizados e controlados, compreendendo 429 pacientes, dos quais 214 receberam suporte respiratório extracorpóreo. A razão mais comum para a insuficiência respiratória foi pneumonia (60% - 65%). O suporte respiratório com oxigenação por membrana extracorpórea foi associado a uma redução na mortalidade e redução em falha terapêutica com taxas de risco (RR: 0,76; IC95% 0,61 - 0,95; RR: 0,68; IC95% 0,55 - 0,85, respectivamente). O uso de oxigenação por membrana extracorpórea reduziu a necessidade de terapia de substituição renal com uma RR de 0,88 (IC95% 0,77 - 0,99). O tempo de permanência na unidade de terapia intensiva e no hospital foram maiores no grupo de pacientes que recebeu suporte com oxigenação por membrana extracorpórea, com acréscimo de 14,84 (P25°-P75°: 12,49 - 17,18) e 29,80 (P25°- P75°: 26,04 - 33,56) dias, respectivamente. CONCLUSÃO: O suporte com oxigenação por membrana extracorpórea na síndrome do desconforto respiratório agudo grave está associado a uma redução da taxa de mortalidade e da necessidade de terapia de substituição renal, porém apresenta aumento substancial no tempo de permanência na unidade de terapia intensiva e no hospital. Nossos resultados podem ajudar no processo decisório junto ao leito quanto ao início do suporte com oxigenação por membrana extracorpórea na síndrome do desconforto respiratório agudo grave.

Prospective, randomized, controlled trial assessing the effects of a driving pressure-limiting strategy for patients with acute respiratory distress syndrome due to community-acquired pneumonia (STAMINA trial): protocol and statistical analysis plan / Estudo randomizado prospectivo e controlado de avaliação dos efeitos de uma estratégia de limitação da driving pressure em pacientes com síndrome do desconforto respiratório agudo devido à pneumonia adquirida na comunidade (estudo STAMINA): protocolo e plano de análise estatística

ABSTRACT Background: Driving pressure has been suggested to be the main driver of ventilator-induced lung injury and mortality in observational studies of acute respiratory distress syndrome. Whether a driving pressure-limiting strategy can improve clinical outcomes is unclear. Objective: To describe the protocol and statistical analysis plan that will be used to test whether a driving pressure-limiting strategy including positive end-expiratory pressure titration according to the best respiratory compliance and reduction in tidal volume is superior to a standard strategy involving the use of the ARDSNet low-positive end-expiratory pressure table in terms of increasing the number of ventilator-free days in patients with acute respiratory distress syndrome due to community-acquired pneumonia. Methods: The ventilator STrAtegy for coMmunIty acquired pNeumoniA (STAMINA) study is a randomized, multicenter, open-label trial that compares a driving pressure-limiting strategy to the ARDSnet low-positive end-expiratory pressure table in patients with moderate-to-severe acute respiratory distress syndrome due to community-acquired pneumonia admitted to intensive care units. We expect to recruit 500 patients from 20 Brazilian and 2 Colombian intensive care units. They will be randomized to a driving pressure-limiting strategy group or to a standard strategy using the ARDSNet low-positive end-expiratory pressure table. In the driving pressure-limiting strategy group, positive end-expiratory pressure will be titrated according to the best respiratory system compliance. Outcomes: The primary outcome is the number of ventilator-free days within 28 days. The secondary outcomes are in-hospital and intensive care unit mortality and the need for rescue therapies such as extracorporeal life support, recruitment maneuvers and inhaled nitric oxide. Conclusion: STAMINA is designed to provide evidence on whether a driving pressure-limiting strategy is superior to the ARDSNet low-positive end-expiratory pressure table strategy for increasing the number of ventilator-free days within 28 days in patients with moderate-to-severe acute respiratory distress syndrome. Here, we describe the rationale, design and status of the trial.

RESUMO Contexto: Em estudos observacionais sobre a síndrome do desconforto respiratório agudo, sugeriu-se que a driving pressure é o principal fator de lesão pulmonar induzida por ventilador e de mortalidade. Não está claro se uma estratégia de limitação da driving pressure pode melhorar os desfechos clínicos. Objetivo: Descrever o protocolo e o plano de análise estatística que serão usados para testar se uma estratégia de limitação da driving pressure envolvendo a titulação da pressão positiva expiratória final de acordo com a melhor complacência respiratória e a redução do volume corrente é superior a uma estratégia padrão envolvendo o uso da tabela de pressão positiva expiratória final baixa do protocolo ARDSNet, em termos de aumento do número de dias sem ventilador em pacientes com síndrome do desconforto respiratório agudo devido à pneumonia adquirida na comunidade. Métodos: O estudo STAMINA (ventilator STrAtegy for coMmunIty acquired pNeumoniA) é randomizado, multicêntrico e aberto e compara uma estratégia de limitação da driving pressure com a tabela de pressão positiva expiratória final baixa do protocolo ARDSnet em pacientes com síndrome do desconforto respiratório agudo moderada a grave devido à pneumonia adquirida na comunidade internados em unidades de terapia intensiva. Esperamos recrutar 500 pacientes de 20 unidades de terapia intensiva brasileiras e duas colombianas. Eles serão randomizados para um grupo da estratégia de limitação da driving pressure ou para um grupo de estratégia padrão usando a tabela de pressão positiva expiratória final baixa do protocolo ARDSnet. No grupo da estratégia de limitação da driving pressure, a pressão positiva expiratória final será titulada de acordo com a melhor complacência do sistema respiratório. Desfechos: O desfecho primário é o número de dias sem ventilador em 28 dias. Os desfechos secundários são a mortalidade hospitalar e na unidade de terapia intensiva e a necessidade de terapias de resgate, como suporte de vida extracorpóreo, manobras de recrutamento e óxido nítrico inalado. Conclusão: O STAMINA foi projetado para fornecer evidências sobre se uma estratégia de limitação da driving pressure é superior à estratégia da tabela de pressão positiva expiratória final baixa do protocolo ARDSnet para aumentar o número de dias sem ventilador em 28 dias em pacientes com síndrome do desconforto respiratório agudo moderada a grave. Aqui, descrevemos a justificativa, o desenho e o status do estudo.

Characterization of patients transported with extracorporeal respiratory and/or cardiovascular support in the State of São Paulo, Brazil. / Caracterização de pacientes transportados com suporte respiratório e/ou cardiovascular extracorpóreo no Estado de São Paulo − Brasil.

OBJECTIVE: To characterize the transport of severely ill patients with extracorporeal respiratory or cardiovascular support. METHODS: A series of 18 patients in the state of São Paulo, Brazil is described. All patients were consecutively evaluated by a multidisciplinary team at the hospital of origin. The patients were rescued, and extracorporeal membrane oxygenation support was provided on site. The patients were then transported to referral hospitals for extracorporeal membrane oxygenation support. Data were retrieved from a prospectively collected database. RESULTS: From 2011 to 2017, 18 patients aged 29 (25 - 31) years with a SAPS 3 of 84 (68 - 92) and main primary diagnosis of leptospirosis and influenza A (H1N1) virus were transported to three referral hospitals in São Paulo. A median distance of 39 (15 - 82) km was traveled on each rescue mission during a period of 360 (308 - 431) min. A median of one (0 - 2) nurse, three (2 - 3) physicians, and one (0 - 1) physical therapist was present per rescue. Seventeen rescues were made by ambulance, and one rescue was made by helicopter. The observed complications were interruption in the energy supply to the pump in two cases (11%) and oxygen saturation < 70% in two cases. Thirteen patients (72%) survived and were discharged from the hospital. Among the nonsurvivors, there were two cases of brain death, two cases of multiple organ dysfunction syndrome, and one case of irreversible pulmonary fibrosis. CONCLUSIONS: Transportation with extracorporeal support occurred without serious complications, and the hospital survival rate was high.

OBJETIVO: Caracterizar pacientes graves transportados em suporte respiratório ou cardiovascular extracorpóreo. MÉTODOS: Descrição de uma série de 18 casos registrados no Estado de São Paulo. Todos os pacientes foram consecutivamente avaliados por uma equipe multidisciplinar no hospital de origem. Os pacientes foram resgatados, sendo a oxigenação por membrana extracorpórea instalada in loco. Os pacientes foram, então, transportados para os hospitais referenciados já em oxigenação por membrana extracorpórea. Os dados foram recuperados de um banco de dados prospectivamente coletado. RESULTADOS: De 2011 até 2017, 18 pacientes com 29 (25 - 31) anos, SAPS3 de 84 (68 - 92), com principais diagnósticos de leptospirose e influenza A (H1N1) foram transportados no Estado de São Paulo para três hospitais referenciados. Uma distância mediana de 39 (15 - 82) km foi percorrida em cada missão, em um tempo de 360 (308 - 431) minutos. As medianas de um (0 - 2) enfermeiro, três (2 - 3) médicos e um (0 - 1) fisioterapeuta foram necessárias por missão. Dezessete transportes foram realizados por ambulância e um por helicóptero. Existiram intercorrências: em duas ocasiões (11%), houve falha de fornecimento de energia para a bomba e, em duas ocasiões, queda da saturação de oxigênio < 70%. Treze pacientes (72%) sobreviveram para a alta hospitalar. Dos pacientes não sobreviventes, dois tiveram morte encefálica; dois, disfunção de múltiplos órgãos; e um, fibrose pulmonar considerada irreversível. CONCLUSÕES: O transporte com suporte extracorpóreo ocorreu sem intercorrências maiores, com uma sobrevida hospitalar alta dos pacientes.

Investigação da associação de dois oxigenadores em paralelo ou em série durante o suporte respiratório com oxigenação por membrana extracorpórea / Exploring the association of two oxygenators in parallel or in series during respiratory support using extracorporeal membrane oxygenation

RESUMO Objetivo: Caracterizar as pressões, as resistências, a oxigenação e a eficácia da descarboxilação de dois oxigenadores associados em série ou em paralelo durante o suporte com oxigenação veno-venosa por membrana extracorpórea. Métodos: Usando os resultados de insuficiência respiratória grave em suínos associada à disfunção de múltiplos órgãos, ao modelo de suporte com oxigenação por membrana extracorpórea veno-venosa e à modelagem matemática, exploramos os efeitos na oxigenação, descarboxilação e pressões do circuito de associações de oxigenadores em paralelo e em série. Resultados: Testaram-se cinco animais com peso mediano de 80kg. Ambas as configurações aumentaram a pressão parcial de oxigênio após os oxigenadores. O teor de oxigênio da cânula de retorno também foi ligeiramente maior, mas o efeito na oxigenação sistêmica foi mínimo, usando oxigenadores com alto fluxo nominal (~ 7L/minuto). Ambas as configurações reduziram significativamente a pressão parcial de dióxido de carbono sistêmico. Como o fluxo sanguíneo na oxigenação por membrana extracorpórea aumentou, a resistência do oxigenador diminuiu inicialmente, com aumento posterior, com fluxos sanguíneos mais altos, mas pouco efeito clínico. Conclusão: A associação de oxigenadores em paralelo ou em série durante o suporte com oxigenação veno-venosa por membrana extracorpórea proporciona um modesto aumento na depuração da pressão parcial de dióxido de carbono, com leve melhora na oxigenação. O efeito das associações de oxigenadores nas pressões de circuitos extracorpóreos é mínimo.

ABSTRACT Objective: To characterize the pressures, resistances, oxygenation, and decarboxylation efficacy of two oxygenators associated in series or in parallel during venous-venous extracorporeal membrane oxygenation support. Methods: Using the results of a swine severe respiratory failure associated with multiple organ dysfunction venous-venous extracorporeal membrane oxygenation support model and mathematical modeling, we explored the effects on oxygenation, decarboxylation and circuit pressures of in-parallel and in-series associations of oxygenators. Results: Five animals with a median weight of 80kg were tested. Both configurations increased the oxygen partial pressure after the oxygenators. The return cannula oxygen content was also slightly higher, but the impact on systemic oxygenation was minimal using oxygenators with a high rated flow (~ 7L/minute). Both configurations significantly reduced the systemic carbon dioxide partial pressure. As the extracorporeal membrane oxygenation blood flow increased, the oxygenator resistance decreased initially with a further increase with higher blood flows but with a small clinical impact. Conclusion: Association of oxygenators in parallel or in series during venous-venous extracorporeal membrane oxygenation support provides a modest increase in carbon dioxide partial pressure removal with a slight improvement in oxygenation. The effect of oxygenator associations on extracorporeal circuit pressures is minimal.

Ultrasound-guided percutaneous dilational tracheostomy versus bronchoscopy-guided percutaneous dilational tracheostomy in critically ill patients (TRACHUS): a randomized noninferiority controlled trial.

PURPOSE: Percutaneous dilational tracheostomy (PDT) is routinely performed in the intensive care unit with bronchoscopy guidance. Recently, ultrasound has emerged as a potentially useful tool to assist PDT and reduce procedure-related complications. METHODS: An open-label, parallel, non-inferiority randomized controlled trial was conducted comparing an ultrasound-guided PDT with a bronchoscopy-guided PDT in mechanically ventilated critically ill patients. The primary outcome was procedure failure, defined as a composite end-point of conversion to a surgical tracheostomy, unplanned associated use of bronchoscopy or ultrasound during PDT, or the occurrence of a major complication. RESULTS: A total of 4965 patients were assessed for eligibility. Of these, 171 patients were eligible and 118 underwent the procedure, with 60 patients randomly assigned to the ultrasound group and 58 patients to the bronchoscopy group. Procedure failure occurred in one (1.7%) patient in the ultrasound group and one (1.7%) patient in the bronchoscopy group, with no absolute risk difference between the groups (90% confidence interval, -5.57 to 5.85), in the "as treated" analysis, not including the prespecified margin of 6% for noninferiority. No other patient had any major complication in either group. Procedure-related minor complications occurred in 20 (33.3%) patients in the ultrasound group and in 12 (20.7%) patients in the bronchoscopy group (P = 0.122). The median procedure length was 11 [7-19] vs. 13 [8-20] min (P = 0.468), respectively, and the clinical outcomes were also not different between the groups. CONCLUSIONS: Ultrasound-guided PDT is noninferior to bronchoscopy-guided PDT in mechanically ventilated critically ill patients.

Therapeutic versus prophylactic anticoagulation for patients admitted to hospital with COVID-19 and elevated D-dimer concentration (ACTION): an open-label, multicentre, randomised, controlled trial

BACKGROUND: COVID-19 is associated with a prothrombotic state leading to adverse clinical outcomes. Whether therapeutic anticoagulation improves outcomes in patients hospitalised with COVID-19 is unknown. We aimed to compare the efficacy and safety of therapeutic versus prophylactic anticoagulation in this population. METHODS: We did a pragmatic, open-label (with blinded adjudication), multicentre, randomised, controlled trial, at 31 sites in Brazil. Patients (aged ≥18 years) hospitalised with COVID-19 and elevated D-dimer concentration, and who had COVID-19 symptoms for up to 14 days before randomisation, were randomly assigned (1:1) to receive either therapeutic or prophylactic anticoagulation. Therapeutic anticoagulation was in-hospital oral rivaroxaban (20 mg or 15 mg daily) for stable patients, or initial subcutaneous enoxaparin (1 mg/kg twice per day) or intravenous unfractionated heparin (to achieve a 0·3­0·7 IU/mL anti-Xa concentration) for clinically unstable patients, followed by rivaroxaban to day 30. Prophylactic anticoagulation was standard in-hospital enoxaparin or unfractionated heparin. The primary efficacy outcome was a hierarchical analysis of time to death, duration of hospitalisation, or duration of supplemental oxygen to day 30, analysed with the win ratio method (a ratio >1 reflects a better outcome in the therapeutic anticoagulation group) in the intention-to-treat population. The primary safety outcome was major or clinically relevant non-major bleeding through 30 days. This study is registered with ClinicalTrials.gov (NCT04394377) and is completed. FINDINGS: From June 24, 2020, to Feb 26, 2021, 3331 patients were screened and 615 were randomly allocated (311 [50%] to the therapeutic anticoagulation group and 304 [50%] to the prophylactic anticoagulation group). 576 (94%) were clinically stable and 39 (6%) clinically unstable. One patient, in the therapeutic group, was lost to follow-up because of withdrawal of consent and was not included in the primary analysis. The primary efficacy outcome was not different between patients assigned therapeutic or prophylactic anticoagulation, with 28 899 (34·8%) wins in the therapeutic group and 34 288 (41·3%) in the prophylactic group (win ratio 0·86 [95% CI 0·59­1·22], p=0·40). Consistent results were seen in clinically stable and clinically unstable patients. The primary safety outcome of major or clinically relevant non-major bleeding occurred in 26 (8%) patients assigned therapeutic anticoagulation and seven (2%) assigned prophylactic anticoagulation (relative risk 3·64 [95% CI 1·61­8·27], p=0·0010). Allergic reaction to the study medication occurred in two (1%) patients in the therapeutic anticoagulation group and three (1%) in the prophylactic anticoagulation group. INTERPRETATION: In patients hospitalised with COVID-19 and elevated D-dimer concentration, in-hospital therapeutic anticoagulation with rivaroxaban or enoxaparin followed by rivaroxaban to day 30 did not improve clinical outcomes and increased bleeding compared with prophylactic anticoagulation. Therefore, use of therapeutic-dose rivaroxaban, and other direct oral anticoagulants, should be avoided in these patients in the absence of an evidence-based indication for oral anticoagulation.

Fluid and electrolyte overload in critically ill patients: An overview.

Fluids are considered the cornerstone of therapy for many shock states, particularly states that are associated with relative or absolute hypovolemia. Fluids are also commonly used for many other purposes, such as renal protection from endogenous and exogenous substances, for the safe dilution of medications and as "maintenance" fluids. However, a large amount of evidence from the last decade has shown that fluids can have deleterious effects on several organ functions, both from excessive amounts of fluids and from their non-physiological electrolyte composition. Additionally, fluid prescription is more common in patients with systemic inflammatory response syndrome whose kidneys may have impaired mechanisms of electrolyte and free water excretion. These processes have been studied as separate entities (hypernatremia, hyperchloremic acidosis and progressive fluid accumulation) leading to worse outcomes in many clinical scenarios, including but not limited to acute kidney injury, worsening respiratory function, higher mortality and higher hospital and intensive care unit length-of-stays. In this review, we synthesize this evidence and describe this phenomenon as fluid and electrolyte overload with potentially deleterious effects. Finally, we propose a strategy to safely use fluids and thereafter wean patients from fluids, along with other caveats to be considered when dealing with fluids in the intensive care unit.

Comparison between ultrasound- and bronchoscopy-guided percutaneous dilational tracheostomy in critically ill patients: a retrospective cohort study.

INTRODUCTION: Percutaneous dilational tracheostomy (PDT) is routinely performed in the intensive care unit with bronchoscopic guidance. Recently, ultrasound (US) has emerged as a new safety adjunct tool to increase the efficacy of PDT. However, the available data are limited to case series without any control group. Hence, a retrospective cohort study was designed to evaluate the efficacy of US-guided PDT compared with bronchoscopy-guided PDT. METHODS: All patients who were submitted to PDT after the standardization of US-guided PDT technique in our institution were analyzed. Demographic and procedure-related variables, complications, and clinical outcomes were collected and compared in patients undergoing US- or bronchoscopy-guided PDT. RESULTS: Sixty patients who had been submitted to PDT were studied, including 11 under bronchoscopy guidance and 49 under US guidance. No surgical conversion was necessary in any of the procedures, and bronchoscopy assistance was only required in 1 case in the US group. The procedure length was shorter in the US group than in the bronchoscopy group (12 vs 15 minutes, P = .028). None of the patients had any major complications. The minor complication rates were not significantly different between the groups, nor was the probability of breathing without assistance within 28 days, intensive care unit length of stay, or hospital mortality. CONCLUSION: Ultrasound-guided PDT is effective, safe, and associated with similar complication rates and clinical outcomes compared with bronchoscopy-guided PDT.

Oferta de oxigênio, remoção de dióxido de carbono, transferência de energia aos pulmões e comportamento da hipertensão pulmonar durante o suporte com oxigenação por membrana extracorpórea: um modelo matemático / Oxygen delivery, carbon dioxide removal, energy transfer to lungs and pulmonary hypertension behavior during venous-venous extracorporeal membrane oxygenation support: a mathematical modeling approach

RESUMO Objetivo: Descrever a transferência de energia do ventilador mecânico para os pulmões; o acoplamento entre a transferência de oxigênio por oxigenação por membrana extracorpórea venovenosa (ECMO-VV) e o consumo de oxigênio do paciente; a remoção de dióxido de carbono com ECMO; e o efeito potencial da oxigenação venosa sistêmica na pressão arterial pulmonar. Métodos: Modelo matemático com cenários hipotéticos e utilização de simulações matemáticas por computador. Resultados: A transição de ventilação protetora para ventilação ultraprotetora em um paciente com síndrome da angústia respiratória aguda grave e complacência respiratória estática de 20mL/cmH2O reduziu a transferência de energia do ventilador para os pulmões de 35,3 para 2,6 joules por minuto. Em um paciente hipotético, hiperdinâmico e ligeiramente anêmico com consumo de oxigênio de 200mL/minuto, é possível atingir saturação arterial de oxigênio de 80%, ao mesmo tempo em que se mantém o equilíbrio entre a transferência de oxigênio pela ECMO e o consumo de oxigênio do paciente. O dióxido de carbono é facilmente removido e a pressão parcial de dióxido de carbono normal é facilmente obtida. A oxigenação do sangue venoso, por meio do circuito da ECMO, pode direcionar o estímulo da pressão parcial de oxigênio na vasoconstrição pulmonar por hipóxia para valores normais. Conclusão: A ventilação ultraprotetora reduz amplamente a transferência de energia do ventilador para os pulmões. A hipoxemia grave no suporte com ECMO-VV pode ocorrer, a despeito do acoplamento entre a transferência de oxigênio, por meio da ECMO, e o consumo de oxigênio do paciente. A faixa normal de pressão parcial de dióxido de carbono é fácil de atingir. O suporte com ECMO-VV potencialmente alivia a vasoconstrição pulmonar hipóxica.

ABSTRACT Objective: To describe (1) the energy transfer from the ventilator to the lungs, (2) the match between venous-venous extracorporeal membrane oxygenation (ECMO) oxygen transfer and patient oxygen consumption (VO2), (3) carbon dioxide removal with ECMO, and (4) the potential effect of systemic venous oxygenation on pulmonary artery pressure. Methods: Mathematical modeling approach with hypothetical scenarios using computer simulation. Results: The transition from protective ventilation to ultraprotective ventilation in a patient with severe acute respiratory distress syndrome and a static respiratory compliance of 20mL/cm H2O reduced the energy transfer from the ventilator to the lungs from 35.3 to 2.6 joules/minute. A hypothetical patient, hyperdynamic and slightly anemic with VO2 = 200mL/minute, can reach an arterial oxygen saturation of 80%, while maintaining the match between the oxygen transfer by ECMO and the VO2 of the patient. Carbon dioxide is easily removed, and normal PaCO2 is easily reached. Venous blood oxygenation through the ECMO circuit may drive the PO2 stimulus of pulmonary hypoxic vasoconstriction to normal values. Conclusion: Ultraprotective ventilation largely reduces the energy transfer from the ventilator to the lungs. Severe hypoxemia on venous-venous-ECMO support may occur despite the matching between the oxygen transfer by ECMO and the VO2 of the patient. The normal range of PaCO2 is easy to reach. Venous-venous-ECMO support potentially relieves hypoxic pulmonary vasoconstriction.