Effects of open lung concept following ARDSNet ventilatory strategy in patients with early acute lung injury (ALI) / acute respiratory distress syndrome (ARDS)

A utilização de baixos volumes correntes na Injuria Pulmonar Aguda (LPA) / Síndrome do Desconforto Respiratório Agudo (SDRA) está comprovadamente associada à redução de mortalidade. No entanto, a aplicação de manobras de recrutamento e a utilização de níveis elevados de PEEP ainda são controversos. O objetivo do presente estudo foi comparar os efeitos da estratégia ARDSnet e de uma estratégia baseada no Open Lung Concept (OLC), aplicadas de forma seqüencial, com relação à função pulmonar, imagem tomográfica e atividade inflamatória, em pacientes com LPA / SDRA. Dez pacientes que preencheram os critérios de LPA / SDRA segundo a Conferência de Consenso de 1994 com tempo de evolução até 48 horas foram incluídos. Para seleção definitiva, gasometria arterial para cálculo da relação PaO2/FIO2 foi coletada após 30 minutos de ventilação com volume corrente (VT) = 10 mL/kg, PEEP=5 cmH2O e FIO2 = 100%. Nas primeiras 24 horas os pacientes foram ventilados segundo o protocolo ARDSnet. Após este período, caso PaO2/FIO2 350, adotava-se a estratégia de OLC, que consistia na realização de manobra de recrutamento e titulação de PEEP. A manobra de recrutamento foi realizada em PCV, com delta de pressão de 20 cmH2O, com incrementos seqüenciais de PEEP em 5 cmH2O, partindo-se de 20 cmH2O até 30 cmH2O. O objetivo durante a titulação de PEEP foi alcançar PaO2/FIO2 > 350, sendo três níveis testados (17, 19 e 21 cmH2O). Ventilação segundo OLC (com PEEP determinado durante a titulação e VT = 6 ml/kg) foi mantida por 24 h adicionais. Após 24 h de cada estratégia, TC de todo o pulmão (1,25 mm de espessura com 15 mm de espassamento) foi realizada após 24 h de cada estratégia. A instituição de OLC foi necessária em 9 dos 10 pacientes estudados. PEEP foi significativamente superior com OLC (17 [17 - 19] vs. 8 cmH2O [7,25 - 11]; p = 0,007) e resultou em melhora significativa de oxigenação, sustentada após 24 h de seguimento, sem diferença na pressão de platô, pressão de distensão, complacência estática, ventilação-minuto, PaCO2 e pH (p > 0,05). OLC determinou redução significativa na percentagem de volume pulmonar total (VPT) não aerado (13% [10,5 22,5] vs. 37% [31 40,5]; p = 0,008), sem aumento significativo na percentagem de VPT hiperinsuflado (5% [1 13,5] vs. 2% [0 6,5]; p = 0,079). A análise baseada em massa pulmonar total (MPT) evidenciou resultados semelhantes: a percentagem de MPT não aerada com OLC foi significativamente menor (30% [23 48,5] vs. 58% [51 60]; p=0,008), sem aumento significativo na percentagem de MPT hiperinsuflada (1% [0 2] vs. 0 % [0 1]; p=0,084). Não houve diferenças significativas nas doses infundidas de vasopressores, balanço hídrico ou pressão arterial. Observou-se, também, redução significativa nos níveis plasmáticos de IL-6 com OLC (3,32 [2,16 9,46] vs. 4,11 ng/mL [3,26 11,02]; p=0,018) Concluimos que, quando comparada à ARDSnet, OLC melhorou a oxigenação, reduzindo a fração de regiões pulmonares não aeradas, sem aumento significativo nas regiões hiperinsufladas, com níveis semelhantes de pressão arterial e balanço hídrico.Low tidal volumes are associated with a reduction in mortality in ALI / ARDS. Nevertheless, the application of recruitment maneuvers and high levels of PEEP are still controversial. The aim of this study was to compare the ARDSnet protocol with a strategy based on Open Lung Concept (OLC), applied in a sequential way, in terms of pulmonary function, computed tomography images and inflammation, in patients with ALI / ARDS. Ten patients fulfilling criteria for ALI /ARDS, based on the American-European Consensus Conference, with less than 48 hours of evolution, were included. For definitive selection, blood gas collected after 30 min application of 5 cmH2O PEEP and VT = 10 mL/kg had to demonstrate a PaO2/FIO2 350 and three levels were tested: 17, 19 and 21 cmH2O. Ventilation according to OLC (VT = 6 mL/kg and PEEP´s level found during titration) was applied for the next 24 hours. Whole lung computed tomography images (1.25 mm thickness with 15mm gap) were acquired after 24 hours of each strategy. The institution of OLC was necessary in 9 of the 10 studied patients. The PEEP was significantly higher during OLC (17 [17-19] vs 8 cmH2O [8-11]; p=0,007) and resulted in a significant improvement on oxygenation sustained for 24 hours of follow-up, with no significant differences in plateau pressure, static compliance, minute-ventilation, PaCO2 and pH (p > 0.05). OLC resulted in a significant reduction of the fraction of total lung volume that was non-aerated, as compared to ARDSnet protocol (13% [10,5 22,5] vs. 37% [31 40,5]; p = 0,008), without a significant increase of the fraction of total lung volume that was hyperinsuflated (5% [1 13,5] vs. 2% [0 6,5]; p = 0,079). The results based on lung mass analysis were similar. OLC was associated with a reduction of the fraction of total lung mass that was non-aerated 30% [23 48,5] vs. 58% [51 60]; p=0,008), without a significant increase of the fraction of total lung mass that was hyperinsuflated (1% [0 2] vs. 0 % [0 1]; p=0,084). There was also a reduction in plasma levels of IL-6 with OLC (3,32 [2,16 9,46] vs. 4,11 ng/mL [3,26 11,02]; p=0,018). We concluded that, when compared with ARDSnet protocol, OLC improved oxygenation, reducing the fraction of non-aerated regions without significant increment in hyperinflated areas, with comparable levels of hemodynamics and fluid balanc

Effects of open lung concept following ARDSNet ventilatory strategy in patients with early acute lung injury (ALI) / acute respiratory distress syndrome (ARDS)

A utilização de baixos volumes correntes na Injuria Pulmonar Aguda (LPA) / Síndrome do Desconforto Respiratório Agudo (SDRA) está comprovadamente associada à redução de mortalidade. No entanto, a aplicação de manobras de recrutamento e a utilização de níveis elevados de PEEP ainda são controversos. O objetivo do presente estudo foi comparar os efeitos da estratégia ARDSnet e de uma estratégia baseada no Open Lung Concept (OLC), aplicadas de forma seqüencial, com relação à função pulmonar, imagem tomográfica e atividade inflamatória, em pacientes com LPA / SDRA. Dez pacientes que preencheram os critérios de LPA / SDRA segundo a Conferência de Consenso de 1994 com tempo de evolução até 48 horas foram incluídos. Para seleção definitiva, gasometria arterial para cálculo da relação PaO2/FIO2 foi coletada após 30 minutos de ventilação com volume corrente (VT) = 10 mL/kg, PEEP=5 cmH2O e FIO2 = 100%. Nas primeiras 24 horas os pacientes foram ventilados segundo o protocolo ARDSnet. Após este período, caso PaO2/FIO2 350, adotava-se a estratégia de OLC, que consistia na realização de manobra de recrutamento e titulação de PEEP. A manobra de recrutamento foi realizada em PCV, com delta de pressão de 20 cmH2O, com incrementos seqüenciais de PEEP em 5 cmH2O, partindo-se de 20 cmH2O até 30 cmH2O. O objetivo durante a titulação de PEEP foi alcançar PaO2/FIO2 > 350, sendo três níveis testados (17, 19 e 21 cmH2O). Ventilação segundo OLC (com PEEP determinado durante a titulação e VT = 6 ml/kg) foi mantida por 24 h adicionais. Após 24 h de cada estratégia, TC de todo o pulmão (1,25 mm de espessura com 15 mm de espassamento) foi realizada após 24 h de cada estratégia. A instituição de OLC foi necessária em 9 dos 10 pacientes estudados. PEEP foi significativamente superior com OLC (17 [17 - 19] vs. 8 cmH2O [7,25 - 11]; p = 0,007) e resultou em melhora significativa de oxigenação, sustentada após 24 h de seguimento, sem diferença na pressão de platô, pressão de distensão, complacência estática, ventilação-minuto, PaCO2 e pH (p > 0,05). OLC determinou redução significativa na percentagem de volume pulmonar total (VPT) não aerado (13% [10,5 22,5] vs. 37% [31 40,5]; p = 0,008), sem aumento significativo na percentagem de VPT hiperinsuflado (5% [1 13,5] vs. 2% [0 6,5]; p = 0,079). A análise baseada em massa pulmonar total (MPT) evidenciou resultados semelhantes: a percentagem de MPT não aerada com OLC foi significativamente menor (30% [23 48,5] vs. 58% [51 60]; p=0,008), sem aumento significativo na percentagem de MPT hiperinsuflada (1% [0 2] vs. 0 % [0 1]; p=0,084). Não houve diferenças significativas nas doses infundidas de vasopressores, balanço hídrico ou pressão arterial. Observou-se, também, redução significativa nos níveis plasmáticos de IL-6 com OLC (3,32 [2,16 9,46] vs. 4,11 ng/mL [3,26 11,02]; p=0,018) Concluimos que, quando comparada à ARDSnet, OLC melhorou a oxigenação, reduzindo a fração de regiões pulmonares não aeradas, sem aumento significativo nas regiões hiperinsufladas, com níveis semelhantes de pressão arterial e balanço hídrico.Low tidal volumes are associated with a reduction in mortality in ALI / ARDS. Nevertheless, the application of recruitment maneuvers and high levels of PEEP are still controversial. The aim of this study was to compare the ARDSnet protocol with a strategy based on Open Lung Concept (OLC), applied in a sequential way, in terms of pulmonary function, computed tomography images and inflammation, in patients with ALI / ARDS. Ten patients fulfilling criteria for ALI /ARDS, based on the American-European Consensus Conference, with less than 48 hours of evolution, were included. For definitive selection, blood gas collected after 30 min application of 5 cmH2O PEEP and VT = 10 mL/kg had to demonstrate a PaO2/FIO2 < 300 mmHg. The patients were initially ventilated for 24 hours according to the ARDSnet protocol. After this period, if the PaO2/FIO2 was 350, an OLC strategy was adopted, with recruitment maneuver and PEEP titration. The recruitment maneuver was applied in PCV, with sequential 5 cmH2O increments in PEEP, starting from 20 cmH2O until PEEP = 30 cmH2O, maintaining a delta pressure of 20 cmH2O. The aim of PEEP titration was to reach PaO2/FIO2 > 350 and three levels were tested: 17, 19 and 21 cmH2O. Ventilation according to OLC (VT = 6 mL/kg and PEEP´s level found during titration) was applied for the next 24 hours. Whole lung computed tomography images (1.25 mm thickness with 15mm gap) were acquired after 24 hours of each strategy. The institution of OLC was necessary in 9 of the 10 studied patients. The PEEP was significantly higher during OLC (17 [17-19] vs 8 cmH2O [8-11]; p=0,007) and resulted in a significant improvement on oxygenation sustained for 24 hours of follow-up, with no significant differences in plateau pressure, static compliance, minute-ventilation, PaCO2 and pH (p > 0.05). OLC resulted in a significant reduction of the fraction of total lung volume that was non-aerated, as compared to ARDSnet protocol (13% [10,5 22,5] vs. 37% [31 40,5]; p = 0,008), without a significant increase of the fraction of total lung volume that was hyperinsuflated (5% [1 13,5] vs. 2% [0 6,5]; p = 0,079). The results based on lung mass analysis were similar. OLC was associated with a reduction of the fraction of total lung mass that was non-aerated 30% [23 48,5] vs. 58% [51 60]; p=0,008), without a significant increase of the fraction of total lung mass that was hyperinsuflated (1% [0 2] vs. 0 % [0 1]; p=0,084). There was also a reduction in plasma levels of IL-6 with OLC (3,32 [2,16 9,46] vs. 4,11 ng/mL [3,26 11,02]; p=0,018). We concluded that, when compared with ARDSnet protocol, OLC improved oxygenation, reducing the fraction of non-aerated regions without significant increment in hyperinflated areas, with comparable levels of hemodynamics and fluid balanc

Ventilação mecânica na lesão pulmonar aguda / síndrome do desconforto respiratório agudo Mechanical ventilation in the acute lung injury/acute respiratory distress syndrome

JUSTIFICATIVA E OBJETIVOS: Em 2000, foi publicado o II Consenso Brasileiro de Ventilação Mecânica. Desde então, o conhecimento na área da ventilação mecânica avançou rapidamente, com a publicação de inúmeros estudos clínicos que acrescentaram informações importantes para o manuseio de pacientes críticos em ventilação artificial. Além disso, a expansão do conceito de Medicina Baseada em Evidências determinou a hierarquização das recomendações clínicas, segundo o rigor metodológico dos estudos que as embasaram. Essa abordagem explícita vem ampliando a compreensão e a aplicação das recomendações clínicas. Por esses motivos, a AMIB - Associação de Medicina Intensiva Brasileira - e a SBPT - Sociedade Brasileira de Pneumologia e Tisiologia - julgaram conveniente a atualização das recomendações descritas no Consenso anterior. Dentre os tópicos selecionados a Ventilação Mecânica na Síndrome do Desconforto Respiratório Agudo (SDRA) foi um dos temas propostos. O objetivo foi descrever os pontos mais importantes relacionados à ventilação mecânica na Síndrome do Desconforto Respiratório Agudo e discutir o papel das estratégias protetoras aplicada a esses pacientes. MÉTODO: Objetivou-se chegar a um documento suficientemente sintético, que refletisse a melhor evidência disponível na literatura. A revisão bibliográfica baseou-se na busca de estudos através de palavras-chave e em sua gradação conforme níveis de evidência. As palavras-chave utilizadas para a busca foram: mechanical ventilation e acute respiratory distress syndrome. RESULTADOS: São apresentadas recomendações quanto à utilização das estratégias protetoras (uso de baixos volumes-correntes e limitação da pressão de platô inspiratório), assim como, o estado atual da aplicação da PEEP e o papel das manobras de recrutamento. CONCLUSÕES: A ventilação mecânica na SDRA apresentou muitas mudanças nesses últimos anos e o uso de estratégias ventilatórias que preservem a micro-arquitetura pulmonar é a forma mais indicada no momento.<br>BACKGROUND AND OBJECTIVES: The II Brazilian Consensus Conference on Mechanical Ventilation was published in 2000. Knowledge on the field of mechanical ventilation evolved rapidly since then, with the publication of numerous clinical studies with potential impact on the ventilatory management of critically ill patients. Moreover, the evolving concept of evidence - based medicine determined the grading of clinical recommendations according to the methodological value of the studies on which they are based. This explicit approach has broadened the understanding and adoption of clinical recommendations. For these reasons, AMIB - Associação de Medicina Intensiva Brasileira and SBPT - Sociedade Brasileira de Pneumologia e Tisiologia - decided to update the recommendations of the II Brazilian Consensus. Acute Respiratory Distress Syndrome (ARDS) has been one of the updated topics. This objective was described the most important topics related to mechanical ventilation in patients with acute respiratory distress syndrome. METHODS: Systematic review of the published literature and gradation of the studies in levels of evidence, using the key words mechanical ventilation and acute respiratory distress syndrome. RESULTS: Recommendations on the use of lung protective strategies during mechanical ventilation based on reduced tidal volumes and limitation of plateau pressure. The state of the art of recruitment maneuvers and PEEP titration is also discussed. CONCLUSIONS: The mechanical ventilation of patients with ADRS changed in the last few years. We presented the role of lung protective strategies that could be applied to these patients

Fibrates for the Treatment of Primary Biliary Cholangitis Unresponsive to Ursodeoxycholic Acid: An Exploratory Study

Aim: Up to 40% of patients with primary biliary cholangitis (PBC) will have a suboptimal biochemical response to ursodeoxycholic acid (UDCA), which can be improved by the addition of fibrates. This exploratory study aims to evaluate the long-term real-life biochemical response of different fibrates, including ciprofibrate, in subjects with UDCA-unresponsive PBC.Methods: The Brazilian Cholestasis Study Group multicenter database was reviewed to assess the response rates to UDCA plus fibrates in patients with UDCA-unresponsive PBC 1 and 2 years after treatment initiation by different validated criteria.Results: In total, 27 patients (100% women, mean age 48.9 +/- 9.2 years) with PBC were included. Overall response rates to fibrates by each validated criterion varied from 39 to 60% and 39-76% at 12 and 24 months after treatment combination, respectively. Combination therapy resulted in a significant decrease in ALT and ALP only after 2 years, while GGT significantly improved in the first year of treatment. Treatment response rates at 1 and 2 years appear to be comparable between ciprofibrate and bezafibrate using all available criteria.Conclusion: Our findings endorse the efficacy of fibrate add-on treatment in PBC patients with suboptimal response to UDCA. Ciprofibrate appears to be at least as effective as bezafibrate and should be assessed in large clinical trials as a possibly new, cheaper, and promising option for treatment of UDCA-unresponsive PBC patients

P-29 CLINICAL FEATURES OF PRIMARY BILIARY CHOLANGITIS IN BRAZIL

Little is known about primary biliary cholangitis (PBC) in Latin America, where this disease is thought to be rare. To analyze clinical and biochemical features of Brazilian PBC patients. The Brazilian Cholestasis Study Group multicentre database was reviewed to assess demographics, clinical and laboratory features from PBC patients. 562 patients with PBC were included; 80 (14.2%) had overlapping syndrome with autoimmune hepatitis and were excluded. Most subjects were middle-aged women (95%; mean age 51 ± 11 years) with classical symptoms of pruritus and/or fatigue (65%) and jaundice (22%). Mean time to diagnosis was 2.5 years. Prevalence of antimitochondrial (AMA) and antinuclear antibodies was 82.8% and 72.1%, respectively. Concurrent autoimmune diseases occurred in 18.9%, mainly Hashimoto's thyroiditis and Sjogren syndrome. Celiac disease was diagnosed in 1:80 (1.2%). Osteopenia and osteoporosis were demonstrated in 42% and 26%, respectively. Liver pathology at diagnosis was available for 326 patients (67.6%). One third of them had advanced PBC. After a mean follow-up of 6.2 ± 5.3 years, 32% of the subjects had clinical, laboratory or imaging evidence of cirrhosis. Requirement for liver transplantation and liver-related deaths were reported in 6.6% and 3.2% of the patients, respectively. Hepatocarcinoma was diagnosed in 1.9% of the subjects. A higher predominance of PBC among females, compared to other populations, was observed, while AMA positivity was lower. Concurrent autoimmune, celiac and bone diseases are common and should be adequately screened. Prolonged time to diagnosis and high prevalence of advanced liver disease might reflect difficulties in health care access in Brazil

O-10 PRIMARY BILIARY CHOLANGITIS PATIENTS DIAGNOSED BY DIFFERENT COMBINATIONS OF THE DIAGNOSTIC CRITERIA PRESENT CLINICAL AND LABORATORY PECULIARITIES

Primary biliary cholangitis (PBC) diagnosis is based on international criteria, which requires two of the following: (i) elevated alkaline phosphatase (AP), (ii) anti-mitochondrial antibody (AMA) and (iii) liver biopsy (BX) suggestive of PBC. It is still unclear if patients diagnosed by different criteria combinations present peculiarities, especially in highly-admixed populations. To investigate if patients diagnosed with PBC by different combinations of validated criteria present clinical or laboratory particularities. The Brazilian Cholestasis Study Group database was reviewed to compare clinical, biochemical and histological characteristics of PBC between four groups diagnosed by: (1) AP ≥2x upper limit of normality (ULN) + presence of AMA, (2) AP ≥2x ULN + BX suggestive of PBC, (3) presence of AMA + BX suggestive of PBC and (4) all criteria. 482 patients with PBC were included (Table 1). Group-1 presented with higher levels of IgG, lower frequency of arterial hypertension (AH) and lower response to ursodeoxycholic acid (UDCA), while Group-2 had lower: age at diagnosis and HDL-C levels. Group-3 had higher: age at diagnosis, frequency of neoplasms, AH and response to UDCA; and lower: frequency of pruritus and jaundice, levels of aminotransferases, GGT and bilirubin, advanced liver disease and esophageal varices. Group-4 showed higher frequency of symptoms at presentation, especially pruritus. PBC patients diagnosed by different combinations of established criteria may present singular features that can possibly impact in disease presentation and progression

Response to Ursodeoxycholic Acid May Be Assessed Earlier to Allow Second-Line Therapy in Patients with Unresponsive Primary Biliary Cholangitis

Background Response to ursodeoxycholic acid (UDCA) in primary biliary cholangitis (PBC) has been traditionally assessed 1 to 2 years after treatment initiation. With the development of new drugs, some patients may benefit from an earlier introduction of second-line therapies. Aims This study aims to identify whether well-validated response criteria could correctly identify individuals likely to benefit from add-on second-line therapy at 6 months. Methods Analysis of a multicenter retrospective cohort which included only patients with clear-cut PBC. Results 206 patients with PBC (96.6% women; mean age 54 +/- 12 years) were included. Kappa concordance was substantial for Toronto (0.67), Rotterdam (0.65), Paris 1 (0.63) and 2 (0.63) criteria at 6 and 12 months, whereas Barcelona (0.47) and POISE trial (0.59) criteria exhibited moderate agreement. Non-response rates to UDCA was not statistically different when assessed either at 6 or 12 months using Toronto, Rotterdam or Paris 2 criteria. Those differences were even smaller or absent in those subjects with advanced PBC. Mean baseline alkaline phosphatase was 2.73 +/- 1.95 times the upper limit of normal (x ULN) among responders versus 5.05 +/- 3.08 x ULN in non-responders (p < 0.001). Conclusions After 6 months of treatment with UDCA, the absence of response by different criteria could properly identify patients who could benefit from early addition of second-line therapies, especially in patients with advanced disease or high baseline liver enzymes levels

Clinical features and treatment outcomes of primary biliary cholangitis in a highly admixed population

Introduction and objectives: Little is known about primary biliary cholangitis (PBC) in non-whites. The purpose of this study was to evaluate clinical features and outcomes of PBC in a highly admixed population. Material and methods: The Brazilian Cholestasis Study Group multicentre database was reviewed to assess demographics, clinical features and treatment outcomes of Brazilian patients with PBC. Results: 562 patients (95% females, mean age 51 ± 11 years) with PBC were included. Concurrent autoimmune diseases and overlap with autoimmune hepatitis (AIH) occurred, respectively, in 18.9% and 14%. After a mean follow-up was 6.2 ± 5.3 years, 32% had cirrhosis, 7% underwent liver transplantation and 3% died of liver-related causes. 96% were treated with ursodeoxycholic acid (UDCA) and 12% required add-on therapy with fibrates, either bezafibrate, fenofibrate or ciprofibrate. Response to UDCA and to UDCA/fibrates therapy varied from 39%-67% and 42-61%, respectively, according to different validated criteria. Advanced histological stages and non-adherence to treatment were associated with primary non-response to UDCA, while lower baseline alkaline phosphatase (ALP) and aspartate aminotransferase (AST) levels correlated with better responses to both UDCA and UDCA/fibrates. Conclusions: Clinical features of PBC in highly admixed Brazilians were similar to those reported in Caucasians and Asians, but with inferior rates of overlap syndrome with AIH. Response to UDCA was lower than expected and inversely associated with histological stage and baseline AST and ALP levels. Most of patients benefited from add-on fibrates, including ciprofibrate. A huge heterogeneity in response to UDCA therapy according to available international criteria was observed and reinforces the need of global standardization