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High spinal cord injured patients (SCI) are susceptible to respiratory muscle impairments. Transcranial direct current stimulation (tDCS) and peripheral electrical stimulation (PES) may influence the diaphragm's central control, but until now they are not described as a therapeutic resource for difficult weaning. We present two case reports of SCI patients (P1 and P2) with long-term tracheostomy (>40 days) and hospital stay (>50 days). In association with respiratory exercise, P1 received a combined application of anodal tDCS over the supplementary motor area plus sensory PES in the thoracic-abdominal muscles, and P2 received isolated excitatory PES in the abdominal muscles, applied daily except on weekends. Maximum inspiratory/expiratory pressure, peak cough flow, diaphragm excursion, and thickening fraction were measured in the first and last days of the protocol. Both patients had improvements, with clinical impact such as cough effectiveness, decannulated after 15 applications of stimulation. Augmentation of neural respiratory drive and corticospinal excitability is suggested.

Rationale: Obesity is characterized by elevated pleural pressure (Ppl) and worsening atelectasis during mechanical ventilation in patients with acute respiratory distress syndrome (ARDS). Objectives: To determine the effects of a lung recruitment maneuver (LRM) in the presence of elevated Ppl on hemodynamics, left and right ventricular pressure, and pulmonary vascular resistance. We hypothesized that elevated Ppl protects the cardiovascular system against high airway pressure and prevents lung overdistension. Methods: First, an interventional crossover trial in adult subjects with ARDS and a body mass index ≥ 35 kg/m2 (n = 21) was performed to explore the hemodynamic consequences of the LRM. Second, cardiovascular function was studied during low and high positive end-expiratory pressure (PEEP) in a model of swine with ARDS and high Ppl (n = 9) versus healthy swine with normal Ppl (n = 6). Measurements and Main Results: Subjects with ARDS and obesity (body mass index = 57 ± 12 kg/m2) after LRM required an increase in PEEP of 8 (95% confidence interval [95% CI], 7–10) cm H2O above traditional ARDS Network settings to improve lung function, oxygenation and V./Q. matching, without impairment of hemodynamics or right heart function. ARDS swine with high Ppl demonstrated unchanged transmural left ventricular pressure and systemic blood pressure after the LRM protocol. Pulmonary arterial hypertension decreased (8 [95% CI, 13–4] mm Hg), as did vascular resistance (1.5 [95% CI, 2.2–0.9] Wood units) and transmural right ventricular pressure (10 [95% CI, 15–6] mm Hg) during exhalation. LRM and PEEP decreased pulmonary vascular resistance and normalized the V./Q. ratio. Conclusions: High airway pressure is required to recruit lung atelectasis in patients with ARDS and class III obesity but causes minimal overdistension. In addition, patients with ARDS and class III obesity hemodynamically tolerate LRM with high airway pressure. Clinical trial registered with www.clinicaltrials.gov (NCT 02503241).

High spinal cord injured patients (SCI) are susceptible to respiratory muscle impairments. Transcranial direct current stimulation (tDCS) and peripheral electrical stimulation (PES) may influence the diaphragm's central control, but until now they are not described as a therapeutic resource for difficult weaning. We present two case reports of SCI patients (P1 and P2) with long-term tracheostomy (40 days) and hospital stay (50 days). In association with respiratory exercise, P1 received a combined application of anodal tDCS over the supplementary motor area plus sensory PES in the thoracic-abdominal muscles, and P2 received isolated excitatory PES in the abdominal muscles, applied daily except on weekends. Maximum inspiratory/expiratory pressure, peak cough flow, diaphragm excursion, and thickening fraction were measured in the first and last days of the protocol. Both patients had improvements, with clinical impact such as cough effectiveness, decannulated after 15 applications of stimulation. Augmentation of neural respiratory drive and corticospinal excitability is suggested.

Background Acute respiratory distress syndrome (ARDS) patients may present impaired in lung function and structure after hospital discharge that may be related to mechanical ventilation strategy. The aim of this study was to evaluate the association between functional and structural lung impairment, N-terminal-peptide type III procollagen (NT-PCP-III) and driving pressure during protective mechanical ventilation. It was a secondary analysis of data from randomized controlled trial that included patients with moderate/severe ARDS with at least one follow-up visit performed. We obtained serial measurements of plasma NT-PCP-III levels. Whole-lung computed tomography analysis and pulmonary function test were performed at 1 and 6 months of follow-up. A health-related quality of life survey after 6 months was also performed. Results Thirty-three patients were enrolled, and 21 patients survived after 6 months. In extubation day an association between driving pressure and NT-PCP-III was observed. At 1 and 6 months forced vital capacity (FVC) was negatively correlated to driving pressure (p

Objective: The aim of this study was to explore the factors associated with blood oxygen partial pressure and carbon dioxide partial pressure. Methods: The factors associated with oxygen - and carbon dioxide regulation were investigated in an apneic pig model under veno-venous extracorporeal membrane oxygenation support. A predefined sequence of blood and sweep flows was tested. Results: Oxygenation was mainly associated with extracorporeal membrane oxygenation blood flow (beta coefficient = 0.036mmHg/mL/min), cardiac output (beta coefficient = -11.970mmHg/L/min) and pulmonary shunting (beta coefficient = -0.232mmHg/%). Furthermore, the initial oxygen partial pressure and carbon dioxide partial pressure measurements were also associated with oxygenation, with beta coefficients of 0.160 and 0.442mmHg/mmHg, respectively. Carbon dioxide partial pressure was associated with cardiac output (beta coefficient = 3.578mmHg/L/min), sweep gas flow (beta coefficient = -2.635mmHg/L/min), temperature (beta coefficient = 4.514mmHg/oC), initial pH (beta coefficient = -66.065mmHg/0.01 unit) and hemoglobin (beta coefficient = 6.635mmHg/g/dL). Conclusion: In conclusion, elevations in blood and sweep gas flows in an apneic veno-venous extracorporeal membrane oxygenation model resulted in an increase in oxygen partial pressure and a reduction in carbon dioxide partial pressure 2, respectively. Furthermore, without the possibility of causal inference, oxygen partial pressure was negatively associated with pulmonary shunting and cardiac output, and carbon dioxide partial pressure was positively associated with cardiac output, core temperature and initial hemoglobin.

Introdução: A tomografia de impedância elétrica (TIE) é uma técnica de imagem não invasiva que mensura o potencial elétrico na superfície torácica através de eletrodos colocados ao redor do tórax. Essas medidas são transformadas em uma imagem bidimensional da distribuição da impedância elétrica no tórax. Esse instrumento detecta modificações da densidade pulmonar e distribuição do volume corrente. Entretanto, é necessário melhor avaliação da sua eficiência em estimar o volume corrente (VT) a cada ciclo ventilatório. O objetivo do estudo é avaliar a correlação do volume estimado pela TIE com o VT aplicado durante o suporte ventilatório mecânico. Métodos: Inicialmente, foram estudados cinco suínos da raça Landrace. Os animais foram sedados, intubados e monitorados com a TIE. Foram aplicados volumes incrementais (100, 250, 500, 750 e 1000 mL) com a seringa de precisão em ZEEP e com PEEP de 5, 10 e 20 cmH2O, antes e depois da promoção de lesão pulmonar com lavagem com solução salina. Posteriormente, outros cinco animais foram monitorados com a tomografia computadorizada de tórax por raios X (TC) e a TIE. Foram aplicados volumes incrementais (250, 500 e 1000 mL) com a seringa de precisão em ZEEP e com PEEP de 10 e 20 cmH2O, também antes e depois da promoção de lesão pulmonar. A amplitude da variação de impedância mensurada pela TIE foi convertida em volume e foi calculado o volume de ar na TC. Análises de correlação e concordância foram realizadas com o programa \"R\" (© R Foundation for Statistical Computing). Resultados: Em ZEEP, o coeficiente de correlação entre os volumes estimado pela TIE e calculado pela TC foram, respectivamente, 0,90 e 0,96 na comparação com a seringa de precisão. O coeficiente de determinação entre a TIE e a seringa de precisão foi progressivamente reduzindo (0,90; 0,89 e 0,81 com PEEP de 5; 10 e 20, respectivamente) com o aumento do volume pulmonar promovido pela elevação da PEEP. A TC mostrou um deslocamento progressivo do conteúdo aéreo no sentido caudal com o aumento do volume pulmonar. Conclusões: Há uma boa correlação entre o volume estimado pela TIE e o VT aplicado durante o suporte ventilatório mecânico quando utilizados volumes e pressões usuais na prática clínica Rationale: Electrical impedance tomography (EIT) is a noninvasive imaging tool that reconstructs a cross-sectional image of the lung\'s regional conductivity using electrodes placed circumferentially around the thorax. It is able to detect changes of lung air content and tidal volume (VT) distribution. However, better evaluation of its capacity to quantify VT variations is necessary. The aim of our study was to assess the correlation between volume estimated by EIT and tidal volume applied at different positive end-expiratory pressures (PEEP). Methods: Initially, in an experimental study five mechanically ventilated pigs monitored by EIT were studied. VT increments (100, 250, 500, 750 and 1000 mL) were applied with a calibrated syringe at zero end-expiratory pressure (ZEEP) and PEEP levels of 5, 10 and 20 cmH2O before and after lung-injury (induced by saline lavage). Another five pigs was monitored by EIT and x-ray computed tomography (CT). VT increments (250, 500 and 1000 mL) were applied with a calibrated syringe at zero end-expiratory pressure (ZEEP) and PEEP levels of 10 and 20 cmH2O before and after lung-injury. Lung air volume was calculated at CT scan and the amplitude of impedance change measured by EIT was converted to volume (mL). Correlation and agreement analysis was performed at \"R\" program (© R Foundation for Statistical Computing). Results: At ZEEP, volume estimated by EIT and volume calculated at CT obtained r2 = 0.90 and 0.96 respectively, when compared to calibrated syringe. The coefficient of correlation between EIT and calibrated syringe impaired (0.90; 0.89 and 0.81 with PEEP of 5; 10 and 20, respectively) with increase of the lung volume due to increased PEEP. CT showed a progressive displacement of the air content to the caudal thoracic levels with the increase of the lung volume. Conclusion: EIT is able to estimate tidal volume during mechanical ventilatory support when used volumes and pressures usually applied at bedside

Background: Acute respiratory distress syndrome (ARDS) survivors are at risk to a wide variety of disabilities, including physical dysfunction. Aim: Our aim was to quantify pectoralis muscle area (PMA) in ARDS survivors and evaluate the impact of PMA in lung function and quality of life after 6 months. Methods: We conducted a cohort study of 22 survivors of moderate-severe ARDS, recruited in Sao Paulo, Brazil. High-resolution CT (HRCT) scan of the lungs were performed after 1 and 6 months. If present, a HRCT obtained in ICU was also evaluated. At 6 months a pulmonary function test and a quality of life questionnaire (SF-36) were performed. PMA area was assessed using image J software. Results: 22 patients were followed-up for 6 months. 17 presented a HRCT at 1 and 6 months and were included. There was a reduction in PMA after 1 month compared with ICU (40.6 cm2 vs 30.4 cm2, p = 0.01), with an improvement after 6 months compared to 1 month (30.4 vs 35.1, p = 0.001). PMA at 6 months was related to age (r = -0.46, p=0.03), predicted body weight (r = 0.53, p = 0.03) and mechanical ventilation time (r = -0.44, p=0.04). There was a functional impact of PMA, with a correlation between PMA and residual volume/pulmonary total capacity at 6 months (r = -0.65, p=0.002), as well as an impact in quality of life, with PMA related to vitality dimension in SF-36 (r=0.72, p=0.02). Conclusions: There was a reduction in PMA 1 month after ARDS with recovery in 6 months. The analysis of PMA could be an easy and available tool to estimate sarcopenia in ARDS patients, but further study should evaluate the relationship with functional deficits and late outcomes.

To characterize the transport of severely ill patients with extracorporeal respiratory or cardiovascular support.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.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 saturation70% 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.Transportation with extracorporeal support occurred without serious complications, and the hospital survival rate was high.Caracterizar pacientes graves transportados em suporte respiratório ou cardiovascular extracorpóreo.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.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 oxigênio70%. 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.O transporte com suporte extracorpóreo ocorreu sem intercorrências maiores, com uma sobrevida hospitalar alta dos pacientes.

Background Utilization of extracorporeal membrane oxygenation (ECMO) has increased worldwide, but its use remains restricted to severely ill patients, and few referral centers are properly structured to offer this support. Inter-hospital transfer of patients on ECMO support can be life-threatening. In this study, we report a single-center experience and a systematic review of the available published data on complications and mortality associated with ECMO transportation. Methods We reported single-center data regarding complications and mortality associated with the transportation of patients on ECMO support. Additionally, we searched multiple databases for case series, observational studies, and randomized controlled trials regarding mortality of patients transferred on ECMO support. Results were analyzed independently for pediatric (under 12 years old) and adult populations. We pooled mortality rates using a random-effects model. Complications and transportation data were also described. Results A total of 38 manuscripts, including our series, were included in the final analysis, totaling 1481 patients transported on ECMO support. A total of 951 patients survived to hospital discharge. The pooled survival rates for adult and pediatric patients were 62% (95% CI 57–68) and 68% (95% CI 60–75), respectively. Two deaths occurred during patient transportation. No other complication resulting in adverse outcome was reported. Conclusion Using the available pooled data, we found that patient transfer to a referral institution while on ECMO support seems to be safe and adds no significant risk of mortality to ECMO patients. Electronic supplementary material The online version of this article (doi:10.1186/s13613-016-0232-7) contains supplementary material, which is available to authorized users.

OBJECTIVES: The aim of this manuscript is to describe the first year of our experience using extracorporeal membrane oxygenation support. METHODS: Ten patients with severe refractory hypoxemia, two with associated severe cardiovascular failure, were supported using venous-venous extracorporeal membrane oxygenation (eight patients) or veno-arterial extracorporeal membrane oxygenation (two patients). RESULTS: The median age of the patients was 31 yr (range 14-71 yr). Their median simplified acute physiological score three (SAPS3) was 94 (range 84-118), and they had a median expected mortality of 95% (range 87-99%). Community-acquired pneumonia was the most common diagnosis (50%), followed by P. jiroveci pneumonia in two patients with AIDS (20%). Six patients were transferred from other ICUs during extracorporeal membrane oxygenation support, three of whom were transferred between ICUs within the hospital (30%), two by ambulance (20%) and one by helicopter (10%). Only one patient (10%) was anticoagulated with heparin throughout extracorporeal membrane oxygenation support. Eighty percent of patients required continuous venous-venous hemofiltration. Three patients (30%) developed persistent hypoxemia, which was corrected using higher positive end-expiratory pressure, higher inspired oxygen fractions, recruitment maneuvers, and nitric oxide. The median time on extracorporeal membrane oxygenation support was five (range 3-32) days. The median length of the hospital stay was 31 (range 3-97) days. Four patients (40%) survived to 60 days, and they were free from renal replacement therapy and oxygen support. CONCLUSIONS: The use of extracorporeal membrane oxygenation support in severely ill patients is possible in the presence of a structured team. Efforts must be made to recognize the necessity of extracorporeal respiratory support at an early stage and to prompt activation of the extracorporeal membrane oxygenation team.

Introdução: A formação de atelectasia durante a indução anestésica pode ser um dos fatores responsáveis pela ocorrência de complicações pulmonares pós-operatórias (CPP). A aplicação de pressão positiva expiratória ao final da expiração (PEEP), uso criterioso de altas frações inspiradas de oxigênio e a utilização de manobras de recrutamento alveolar no período intra-operatório são recursos utilizados para a prevenção de atelectasia em procedimentos anestésicos. O objetivo deste estudo foi avaliar o modelo de ventilação mecânica adotado em procedimentos anestésicos de longa duração e suas correlações com as complicações pulmonares pós-operatórias. Métodos: Foram avaliadas em estudo observacional as cirurgias com mais de cinco horas de duração. No início do procedimento anestésico, na sala de cirurgia e após o seu término, na unidade de terapia intensiva, os parâmetros ventilatórios utilizados foram anotados e correlacionados com os achados das radiografias torácicas e saturação periférica de oxigênio (SpO2) em ar ambiente. Resultados: Cento e vinte e um pacientes foram observados. O tempo total de anestesia 499,4 ± 159,8 minutos. O volume corrente (VC) determinado no período intraoperatório foi 8,09 ± 2,15 mL/kg e a PEEP utilizada de 3,05 ± 2,31 cmH2O. Houve diferença para a mediana da SpO2 em ar ambiente (96% [95-97] vs 95% [92-96], p

Objective: To analyze the correlations of the blood flow/pump rotation ratio and the transmembrane pressure, CO2 and O2 transfer during the extracorporeal respiratory support. Methods: Five animals were instrumented and submitted to extracorporeal membrane oxygenation in a five-step protocol, including abdominal sepsis and lung injury. Results: This study showed that blood flow/pump rotations ratio variations are dependent on extracorporeal membrane oxygenation blood flow in a positive logarithmic fashion. Blood flow/pump rotation ratio variations are negatively associated with transmembrane pressure (R2 = 0.5 for blood flow = 1500mL/minute and R2 = 0.4 for blood flow = 3500mL/minute, both with p 6L/minute, p = 0.006), and the blood flow/pump rotation ratio is not associated with O2 transfer variations (R2 = 0.01 for blood flow = 1500mL/minute, p = 0.19, and R2 = - 0.01 for blood flow = 3500 mL/minute, p = 0.46). Conclusion: Blood flow/pump rotation ratio variation is negatively associated with transmembrane pressure and positively associated with CO2 transfer in this animal model. According to the clinical situation, a decrease in the blood flow/pump rotation ratio can indicate artificial lung dysfunction without the occurrence of hypoxemia. Objetivo: Analisar as correlacoes da taxa de fluxo sanguineo e rotacao da bomba com a pressao transmembrana e a transferencia de CO2 e O2 durante o suporte respiratorio extracorporeo.

An eighteen-year-old woman was admitted to therespiratory intensive care unit of the Hospital das Cli´nicasde Sa˜o Paulo, Brazil, with the diagnosis of pneumonia. Thechest X-ray is shown in Figure 1. She had a previous historyof advanced cystic fibrosis, was awaiting lung transplanta-tion and was in the fifth position on the Sa˜o Paulo Statewaiting list. During the first day of her respiratory intensivecare unit stay, her status deteriorated, she was intubated,and mechanical ventilation was started. In spite of theventilatory support, she developed severe hypoxemic andhypercapnic respiratory failure (Table 1), with no signsof hemodynamic compromise. Femoro-femoral venous-venous extracorporeal membrane oxygenation supportwas then initiated after ultrasound-guided placement ofthe cannulas. Arterial blood gases improved, promoting acomfortable spontaneous breathing pattern during mechan-ical ventilation. Trivial anticoagulation with heparin wasstarted and titrated to a ratio of activated thromboplastintime of 1.5–2.3. The clinical characteristics during thepatient’s respiratory intensive care unit stay are shown inTable 1. The patient was maintained awake with aRichmond Agitation Sedation Scale score ranging from -1to 0.The patient’s condition gradually improved, and dailyweaning from extracorporeal membrane oxygenation wasperformed by zeroing the sweeper flow of the oxygenationmembrane. Our criteria for extracorporeal membraneoxygenation removal are as follows: (1) the patient is awakeand comfortable throughout the test and (2) PaO

Introduction: Transmembrane pressure drop reflects the resistance of an artificial lung system to blood transit. Decreased resistance (low transmembrane pressure drop) enhances blood flow through the oxygenator, thereby, enhancing gas exchange efficiency. This study is part of a previous one where we observed the behaviour and the modulation of blood pressure drop during the passage of blood through artificial lung membranes. Methods: Before and after the induction of multi-organ dysfunction, the animals were instrumented and analysed for venous-venous extracorporeal membrane oxygenation, using a pre-defined sequence of blood flows. Results: Blood flow and revolutions per minute (RPM) of the centrifugal pump varied in a linear fashion. At a blood flow of 5.5 L/min, pre- and post-pump blood pressures reached -120 and 450 mmHg, respectively. Transmembrane pressures showed a significant spread, particularly at blood flows above 2 L/min; over the entire range of blood flow rates, there was a positive association of pressure drop with blood flow (0.005 mmHg/mL/minute of blood flow ) and a negative association of pressure drop with temperature (-4.828 mmHg/oCelsius). These associations were similar when blood flows of below and above 2000 mL/minute were examined. Conclusions: During its passage through the extracorporeal system, blood is exposed to pressure variations from -120 to 450 mmHg. At high blood flows (above 2 L/min), the drop in transmembrane pressure becomes unpredictable and highly variable. Over the entire range of blood flows investigated (0 – 5500 mL/min), the drop in transmembrane pressure was positively associated with blood flow and negatively associated with body temperature.

A case of a 30 year-old man presenting with severe systemic chickenpox with refractory hypoxemia, central nervous system vasculitis and anuric renal failure is described. Ambulance transportation and support using veno-venous extracorporeal membrane oxygenation were necessary until the patient recovered. Ultimately, the potential use of extracorporeal membrane oxygenation support in low-middle income countries to manage common diseases is discussed.

To investigate the hemodynamic, respiratory and metabolic impact of blood contact with a priming volume and extracorporeal membrane oxygenation circuit, before the initiation of oxygenation and ventilationFive animals were instrumented and submitted to extracorporeal membrane oxygenation. Data were collected at the baseline and 30 minutes after starting extracorporeal circulation, without membrane ventilatory (sweeper) flow.After starting extracorporeal membrane oxygenation, there was a non-significant elevation in pulmonary vascular resistance from 235 (178,303) to 379 (353,508) dyn.seg.(cm5)-1 (P=0.065), associated with an elevation in the alveolar arterial oxygen gradient from 235 (178,303) to 379 (353,508) mmHg (P=0.063). We also observed a reduction in the left ventricle stroke work from 102 (94,105) to 78 (71,87) (mL.mmHg)/beat (P=0.064), in addition to a reduction in cardiac output from 7.2 (6.8,7.6) to 5.9 (5.8,6.3) L/min (P=0.188). The right ventricle stroke work was counterbalanced between the pulmonary vascular resistance increment and the cardiac output reduction, maintaining a similar value.We presented an experimental model that is feasible and safe. Blood contact with the priming volume and extracorporeal membrane oxygenation circuit resulted in non-significant systemic or metabolic changes.

Em 2009, muitos casos de infecção pulmonar com hipoxemia grave refratária às estratégias ventilatórias habitualmente utilizadas e às manobras de resgate para a síndrome do desconforto respiratório agudo foram relatados durante a epidemia por influenza A (H1N1). Em muitos desses pacientes, o uso de extracorporeal membrane oxygenation (ECMO, oxigenação extracorpórea por membrana) foi necessário, fato que fez reacender o interesse na ECMO globalmente. O Grupo De Estudos em Suporte Extracorpóreo foi criado visando a aprender a técnica e a utilizar ECMO no tratamento de pacientes com hipoxemia grave. Neste artigo, são discutidas as indicações de ECMO e é relatado o caso de uma paciente com hipoxemia refratária que foi tratada através de ECMO de forma bem sucedida.

BACKGROUND: There are no reports on the long-term follow-up of patients with swine-origin influenza A virus infection that progressed to acute respiratory distress syndrome. METHODS: Four patients were prospectively followed up with pulmonary function tests and high-resolution computed tomography for six months after admission to an intensive care unit. RESULTS: Pulmonary function test results assessed two months after admission to the intensive care unit showed reduced forced vital capacity in all patients and low diffusion capacity for carbon monoxide in two patients. At six months, pulmonary function test results were available for three patients. Two patients continued to have a restrictive pattern, and none of the patients presented with abnormal diffusion capacity for carbon monoxide. All of them had a diffuse ground-glass pattern on high-resolution computed tomography that improved after six months. CONCLUSIONS: Despite the marked severity of lung disease at admission, patients with acute respiratory distress syndrome caused by swine-origin influenza A virus infection presented a late but substantial recovery over six months of follow-up.

INTRODUCTION: Early mobilization can be performed in critically ill patients and improves outcomes. A daily cycling exercise started from day 5 after ICU admission is feasible and can enhance functional capacity after hospital discharge. In the present study we verified the physiological changes and safety of an earlier cycling intervention (< 72 hrs of mechanical ventilation) in critical ill patients. METHODS: Nineteen hemodynamically stable and deeply sedated patients within the first 72 hrs of mechanical ventilation were enrolled in a single 20 minute passive leg cycling exercise using an electric cycle ergometer. A minute-by-minute evaluation of hemodynamic, respiratory and metabolic variables was undertaken before, during and after the exercise. Analyzed variables included the following: cardiac output, systemic vascular resistance, central venous blood oxygen saturation, respiratory rate and tidal volume, oxygen consumption, carbon dioxide production and blood lactate levels. RESULTS: We enrolled 19 patients (42% male, age 55 ± 17 years, SOFA = 6 ± 3, SAPS3 score = 58 ± 13, PaO2/FIO2 = 223 ± 75). The median time of mechanical ventilation was 1 day (02), and 68% (n=13) of our patients required norepinephrine (maximum concentration = 0.47 µg.kg(-1).min(-1)). There were no clinically relevant changes in any of the analyzed variables during the exercise, and two minor adverse events unrelated to hemodynamic instability were observed. CONCLUSIONS: In our study, this very early passive cycling exercise in sedated, critically ill, mechanically ventilated patients was considered safe and was not associated with significant alterations in hemodynamic, respiratory or metabolic variables even in those requiring vasoactive agents.

Different ventilatory strategies for the acute respiratory distress syndrome have been proposed. The Open Lung Approach (OLA) emphasizes the recruitment of airway units with avoidance of tidal recruitment. The ARDSnet strategy simply emphasizes the reduction of and hyperdistension. We studied the long-term VT consequences of both strategies in a controlled experiment where pigs where randomized and submitted to one of both strategies for 48 hours. Lung injury was induced by saline lavage followed by 3 hours of injurious mechanical ventilation. In the OLA arm, PEEP was selected by the EIT after a recruitment maneuver (RM), trying to keep lung collapse to a minimum, while the ARDSnet group followed a PEEP × FiO2 table. We scrutinized lung function at the end of a 48-hour period of lung protection, after a standardized RM. The concept was to provide equivalent conditions for lungs to perform, irrespective of lung history or treatment in previous days, in terms of gas exchange or alveolar stability during slow-deflation maneuvers. Before sacrifice and after maximum RM, we collected blood gases and expiratory pressure versus ΔZ (impedance changes by electric impedance tomography). Oxygenation and alveolar stability were equally impaired in both arms after injury. However, at the end of the 48 hours there was significant improvement in the capacity of oxygenation in the OLA arm (mean = 494 mmHg; P = 0.043), but not in the ARDSNet arm (mean = 278; P = 0.285). The potential to maintain airspace volumes improved along the protective period in the OLA arm, but deteriorated in the ARDSnet arm. (See Figure ​Figure11.) Figure 1

Background Extracorporeal membrane oxygenation (ECMO) is a technique widely used worldwide to improve gas exchange. Changes in ECMO settings affect both oxygen and carbon dioxide. The impact on oxygenation can be followed closely by continuous pulse oximeter. Conversely, carbon dioxide equilibrates much slower and is not usually monitored directly. Methods We investigated the time to stabilization of arterial carbon dioxide partial pressure (PaCO2) following step changes in ECMO settings in 5 apnoeic porcine models under veno-venous ECMO support with polymethylpentene membranes. We collected sequential arterial blood gases at a pre-specified interval of 50 min using a sequence of standardized blood and sweep gas flow combinations. Results Following the changes in ECMO parameters, the kinetics of carbon dioxide was dependent on sweep gas and ECMO blood flow. With a blood flow of 1500 mL/min, PaCO2 takes longer than 50 min to equilibrate following the changes in sweep gas flow. Furthermore, the sweep gas flow from 3.0 to 10.0 L/min did not significantly affect PaCO2. However, with a blood flow of 3500 mL/min, 50 min was enough for PaCO2 to reach the equilibrium and every increment of sweep gas flow (up to 10.0 L/min) resulted in additional reductions of PaCO2. Conclusions Fifty minutes was enough to reach the equilibrium of PaCO2 after ECMO initiation or after changes in blood and sweep gas flow with an ECMO blood flow of 3500 ml/min. Longer periods may be necessary with lower ECMO blood flows.