How large is the lung recruitability in early acute respiratory distress syndrome: a prospective case series of patients monitored by computed tomography.

INTRODUCTION: The benefits of higher positive end expiratory pressure (PEEP) in patients with acute respiratory distress syndrome (ARDS) have been modest, but few studies have fully tested the "open-lung hypothesis". This hypothesis states that most of the collapsed lung tissue observed in ARDS can be reversed at an acceptable clinical cost, potentially resulting in better lung protection, but requiring more intensive maneuvers. The short-/middle-term efficacy of a maximum recruitment strategy (MRS) was recently described in a small physiological study. The present study extends those results, describing a case-series of non-selected patients with early, severe ARDS submitted to MRS and followed until hospital discharge or death. METHODS: MRS guided by thoracic computed tomography (CT) included two parts: a recruitment phase to calculate opening pressures (incremental steps under pressure-controlled ventilation up to maximum inspiratory pressures of 60 cmH2O, at constant driving-pressures of 15 cmH2O); and a PEEP titration phase (decremental PEEP steps from 25 to 10 cmH2O) used to estimate the minimum PEEP to keep lungs open. During all steps, we calculated the size of the non-aerated (-100 to +100 HU) compartment and the recruitability of the lungs (the percent mass of collapsed tissue re-aerated from baseline to maximum PEEP). RESULTS: A total of 51 severe ARDS patients, with a mean age of 50.7 years (84% primary ARDS) was studied. The opening plateau-pressure was 59.6 (±5.9 cmH2O), and the mean PEEP titrated after MRS was 24.6 (±2.9 cmH2O). Mean PaO2/FiO2 ratio increased from 125 (±43) to 300 (±103; P<0.0001) after MRS and was sustained above 300 throughout seven days. Non-aerated parenchyma decreased significantly from 53.6% (interquartile range (IQR): 42.5 to 62.4) to 12.7% (IQR: 4.9 to 24.2) (P<0.0001) after MRS. The potentially recruitable lung was estimated at 45% (IQR: 25 to 53). We did not observe major barotrauma or significant clinical complications associated with the maneuver. CONCLUSIONS: MRS could efficiently reverse hypoxemia and most of the collapsed lung tissue during the course of ARDS, compatible with a high lung recruitability in non-selected patients with early, severe ARDS. This strategy should be tested in a prospective randomized clinical trial.

Morbidity, mortality, and categorization of the risk of perioperative complications in lung cancer patients.

OBJECTIVE: To determine morbidity and mortality rates by risk category in accordance with the American College of Chest Physicians guidelines, to determine what role pulmonary function tests play in this categorization process, and to identify risk factors for perioperative complications (PCs). METHODS: This was a historical cohort study based on preoperative and postoperative data collected for cases of lung cancer diagnosed or suspected between 2001 and 2010. RESULTS: Of the 239 patients evaluated, only 13 (5.4%) were classified as being at high risk of PCs. Predicted postoperative FEV1 (FEV1ppo) was sufficient to define the risk level in 156 patients (65.3%); however, cardiopulmonary exercise testing (CPET) was necessary for identifying those at high risk. Lung resection was performed in 145 patients. Overall morbidity and mortality rates were similar to those reported in other studies. However, morbidity and mortality rates for patients at an acceptable risk of PCs were 31.6% and 4.3%, respectively, whereas those for patients at high risk were 83.3% and 33.3%. Advanced age, COPD, lobe resection, and lower FEV1ppo were correlated with PCs. CONCLUSIONS: Although spirometry was sufficient for risk assessment in the majority of the population studied, CPET played a key role in the identification of high-risk patients, among whom the mortality rate was seven times higher than was that observed for those at an acceptable risk of PCs. The risk factors related to PCs coincided with those reported in previous studies.

Morbidity, mortality, and categorization of the risk of perioperative complications in lung cancer patients / Mortalidade, morbidade e categorização de risco para complicações perioperatórias em pacientes com câncer de pulmão

OBJECTIVE: To determine morbidity and mortality rates by risk category in accordance with the American College of Chest Physicians guidelines, to determine what role pulmonary function tests play in this categorization process, and to identify risk factors for perioperative complications (PCs). METHODS: This was a historical cohort study based on preoperative and postoperative data collected for cases of lung cancer diagnosed or suspected between 2001 and 2010. RESULTS: Of the 239 patients evaluated, only 13 (5.4%) were classified as being at high risk of PCs. Predicted postoperative FEV1 (FEV1ppo) was sufficient to define the risk level in 156 patients (65.3%); however, cardiopulmonary exercise testing (CPET) was necessary for identifying those at high risk. Lung resection was performed in 145 patients. Overall morbidity and mortality rates were similar to those reported in other studies. However, morbidity and mortality rates for patients at an acceptable risk of PCs were 31.6% and 4.3%, respectively, whereas those for patients at high risk were 83.3% and 33.3%. Advanced age, COPD, lobe resection, and lower FEV1ppo were correlated with PCs. CONCLUSIONS: Although spirometry was sufficient for risk assessment in the majority of the population studied, CPET played a key role in the identification of high-risk patients, among whom the mortality rate was seven times higher than was that observed for those at an acceptable risk of PCs. The risk factors related to PCs coincided with those reported in previous studies. .

OBJETIVO: Determinar as taxas de morbidade e mortalidade por categoria de risco conforme as diretrizes do American College of Chest Physicians, verificar como exames funcionais participaram dessa categorização e identificar fatores de risco para complicações perioperatórias (CPOs). MÉTODOS: Estudo de coorte histórica a partir de avaliações pré e pós-operatórias de casos diagnosticados ou suspeitos de câncer de pulmão avaliados entre 2001 e 2010. RESULTADOS: Dos 239 pacientes avaliados, apenas 13 (5,4%) foram considerados como de alto risco para CPOs. O cálculo do VEF1 previsto para o pós-operatório (VEF1ppo) foi suficiente para a estratificação do risco em 156 pacientes (65,3%); entretanto, o teste de exercício cardiopulmonar (TECP) foi necessário para a identificação de alto risco. Foram operados 145 pacientes, e as taxas globais de morbidade e mortalidade encontradas foram semelhantes às de outros estudos. Entretanto, as taxas de morbidade e mortalidade para aqueles com risco aceitável foram de 31,6% e 4,3%, respectivamente, enquanto as taxas para aqueles com alto risco foram de 83,3% e 33,3%. Idade mais avançada, presença da DPOC, ressecção de um ou mais lobos e VEF1ppo mais baixo estiveram relacionados à ocorrência de CPOs. CONCLUSÕES: Embora a espirometria tenha sido suficiente para a determinação de risco na maioria da população estudada, o TECP teve papel fundamental na identificação de pacientes com risco alto, que apresentaram uma taxa de mortalidade sete vezes maior que os de risco aceitável. Os fatores de risco relacionados a CPOs coincidiram aos relatados em outros estudos. .

Escalas de risco de Torrington e Henderson e de Epstein: aplicabilidade e efetividade nas ressecções pulmonares / Torrington and Henderson and Epstein risk assessment scales: applicability and effectiveness in lung resection

OBJETIVO: Comparar a incidência de complicações pulmonares e cardiopulmonares estimadas, respectivamente, pelas escalas de Torrington e Henderson e de Epstein, em amostra populacional submetida à ressecção pulmonar para tratamento de câncer de pulmão. MÉTODOS: Dados de doentes submetidos à ressecção de um lobo pulmonar ou mais foram retirados de dois bancos de dados montados de forma prospectiva, oriundos de dois hospitais terciários. As medidas de desfecho analisadas foram complicações pulmonares, cardíacas e óbito. Teste exato de Fisher foi usado para avaliar a concordância das taxas de complicações obtidas com as estimadas previamente. RESULTADOS: A escala de Torrington e Henderson foi aplicada em 50 doentes (12 apresentaram risco leve, 32 moderado e 6 grave) e subestimou a taxa de complicações pulmonares nas categorias leve e moderado (p = 0,0003 e p = 0,0006, respectivamente), porém foi capaz de reconhecer os pacientes com alto risco de desenvolver complicações. A escala de Epstein foi aplicada em 38 doentes (4 apresentaram risco alto e 34 baixo) e também subestimou a taxa de complicações cardiopulmonares pós-operatórias da categoria de risco leve, que continha a maioria dos doentes (p < 0,0001), mas reconheceu, também, os pacientes com chance alta de complicar. CONCLUSÃO: As duas escalas não foram adequadas para estimar ocorrência de complicações pulmonares e cardiopulmonares na maioria dos doentes.

Avaliação pulmonar pré-operatória em cirurgias não-cardíacas e sem ressecção pulmonar / Preoperative pulmonary evaluation of non-cardiac surgery without pulmonary resection

Os clínicos reconhecem bem a importância e os fatores de risco para a ocorrência de complicações cardíacas no período pós-operatório, mas subestiman as complicações pulmonares pós-operatórias. Elas são muito importantes na análise do risco cirúrgico de doentes que serão submetidos a cirurgias não-cardiotorácicas, porque, além de não prevalentes quanto as complicações cardíacas, aumentam a morbidade e a mortalidade, o tempo de permanência hospitalar e, consequentemente, os custos. Fatores de risco relacionados ao procedimento operatório são mais importantes que os relacionados ao doente em predizer eventos pulmonares pós-operatórios, mas os clínicos devem avaliar ambos. O reconhecimento desses fatores é essencial para a prescrição de estratégias com reconhecida capacidade de reduzir a ocorrência dessas complicações pulmonares. As estrategias incluem otimização das doenças pulmonares crônicas...