Driving pressure, as opposed to tidal volume based on predicted body weight, is associated with mortality: results from a prospective cohort of COVID-19 acute respiratory distress syndrome patients / Driving pressure, em oposição ao volume corrente ajustado para o peso corporal predito, associa-se com a mortalidade: resultados de uma coorte prospectiva de pacientes com síndrome do desconforto respiratório agudo por COVID-19

ABSTRACT Objective: To evaluate the association between driving pressure and tidal volume based on predicted body weight and mortality in a cohort of patients with acute respiratory distress syndrome caused by COVID-19. Methods: This was a prospective, observational study that included patients with acute respiratory distress syndrome due to COVID-19 admitted to two intensive care units. We performed multivariable analyses to determine whether driving pressure and tidal volume/kg predicted body weight on the first day of mechanical ventilation, as independent variables, are associated with hospital mortality. Results: We included 231 patients. The mean age was 64 (53 - 74) years, and the mean Simplified Acute and Physiology Score 3 score was 45 (39 - 54). The hospital mortality rate was 51.9%. Driving pressure was independently associated with hospital mortality (odds ratio 1.21, 95%CI 1.04 - 1.41 for each cm H2O increase in driving pressure, p = 0.01). Based on a double stratification analysis, we found that for the same level of tidal volume/kg predicted body weight, the risk of hospital death increased with increasing driving pressure. However, changes in tidal volume/kg predicted body weight were not associated with mortality when they did not lead to an increase in driving pressure. Conclusion: In patients with acute respiratory distress syndrome caused by COVID-19, exposure to higher driving pressure, as opposed to higher tidal volume/kg predicted body weight, is associated with greater mortality. These results suggest that driving pressure might be a primary target for lung-protective mechanical ventilation in these patients.

RESUMO Objetivo: Avaliar a associação entre driving pressure e volume corrente ajustado pelo peso predito com a mortalidade em uma coorte de pacientes com síndrome do desconforto respiratório agudo por COVID-19. Métodos: Estudo prospectivo e observacional que incluiu pacientes com síndrome do desconforto respiratório agudo por COVID-19 admitidos em duas unidades de terapia intensiva. Foi realizada análise multivariada para determinar se a driving pressure e o volume corrente/kg de peso predito, aferidos no primeiro dia de ventilação mecânica, associavam-se de forma independente com a mortalidade hospitalar. Resultados: Foram incluídos 231 pacientes. A mediana de idade foi de 64 (53 - 74) anos, e a mediana do Simplified Acute and Physiology Score 3 foi de 45 (39 - 54). A mortalidade hospitalar foi de 51,9%. A driving pressure se associou de forma independente com a mortalidade hospitalar (razão de chance de 1,21; IC95% de 1,04 - 1,41 para cada cm H2O de aumento da driving pressure, p = 0,01). Com base na análise de dupla estratificação, encontrou-se que, para o mesmo nível de volume corrente/kg de peso predito, o risco de mortalidade hospitalar aumentava com o incremento da driving pressure. No entanto, mudanças no volume corrente/kg de peso predito não se associaram com a mortalidade quando não resultavam em aumento da driving pressure. Conclusão: Em pacientes com síndrome do desconforto respiratório agudo por COVID-19, exposição a maior driving pressure, ao contrário da exposição a maior volume corrente/kg de peso predito, associou-se com maior mortalidade hospitalar. Os resultados sugerem que a driving pressure poderia ser o alvo primário para a condução da ventilação mecânica protetora nesses pacientes.

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.

Association of biomarkers with successful ventilatory weaning in COVID-19 patients: an observational study / Associação entre biomarcadores e sucesso do desmame ventilatório em pacientes com COVID-19: um estudo observacional

ABSTRACT Objective: To evaluate the association of biomarkers with successful ventilatory weaning in COVID-19 patients. Methods: An observational, retrospective, and single-center study was conducted between March 2020 and April 2021. C-reactive protein, total lymphocytes, and the neutrophil/lymphocyte ratio were evaluated during attrition and extubation, and the variation in these biomarker values was measured. The primary outcome was successful extubation. ROC curves were drawn to find the best cutoff points for the biomarkers based on sensitivity and specificity. Statistical analysis was performed using logistic regression. Results: Of the 2,377 patients admitted to the intensive care unit, 458 were included in the analysis, 356 in the Successful Weaning Group and 102 in the Failure Group. The cutoff points found from the ROC curves were −62.4% for C-reactive protein, +45.7% for total lymphocytes, and −32.9% for neutrophil/lymphocyte ratio. These points were significantly associated with greater extubation success. In the multivariate analysis, only C-reactive protein variation remained statistically significant (OR 2.6; 95%CI 1.51 - 4.5; p < 0.001). Conclusion: In this study, a decrease in C-reactive protein levels was associated with successful extubation in COVID-19 patients. Total lymphocytes and the neutrophil/lymphocyte ratio did not maintain the association after multivariate analysis. However, a decrease in C-reactive protein levels should not be used as a sole variable to identify COVID-19 patients suitable for weaning; as in our study, the area under the ROC curve demonstrated poor accuracy in discriminating extubation outcomes, with low sensitivity and specificity.

RESUMO Objetivo: Avaliar a associação de biomarcadores com o sucesso do desmame ventilatório em pacientes com COVID-19. Métodos: Trata-se de estudo observacional, retrospectivo e de centro único realizado entre março de 2020 e abril de 2021. Foram avaliados a proteína C-reativa, os linfócitos totais e a relação neutrófilos/linfócitos durante o atrito e a extubação; mediu-se a variação desses valores de biomarcadores. O desfecho primário foi o sucesso da extubação. As curvas ROC foram desenhadas para encontrar os melhores pontos de corte dos biomarcadores segundo a sensibilidade e a especificidade. A análise estatística foi realizada por meio de regressão logística. Resultados: Dos 2.377 pacientes admitidos na unidade de terapia intensiva, 458 foram incluídos na análise, 356 no Grupo Sucesso do desmame e 102 no Grupo Fracasso do desmame. Os pontos de corte encontrados nas curvas ROC foram −62,4% para proteína C-reativa, +45,7% para linfócitos totais e −32,9% para relação neutrófilo/linfócito. Esses pontos foram significativamente associados ao maior sucesso da extubação. Na análise multivariada, apenas a variação da proteína C-reativa permaneceu estatisticamente significativa (RC 2,6; IC95% 1,51 - 4,5; p < 0,001). Conclusão: Neste estudo, uma diminuição nos níveis de proteína C-reativa foi associada ao sucesso da extubação em pacientes com COVID-19. Os linfócitos totais e a relação neutrófilos/linfócitos não mantiveram a associação após a análise multivariada. No entanto, uma diminuição nos níveis de proteína C-reativa não deve ser usada como única variável para identificar pacientes com COVID-19 adequados para o desmame; como em nosso estudo, a área sob a curva ROC demonstrou baixa precisão na discriminação dos resultados de extubação, com baixas sensibilidade e especificidade.

Lesão renal aguda e COVID-19 em adultos jovens na terapia intensiva / Lesión renal aguda y COVID-19 en adultos jóvenes en cuidados intensivos / Acute kidney injury and COVID-19 in young adults in intensive care

Resumo Objetivo Descrever a prevalência de lesão renal aguda em adultos jovens com diagnóstico da COVID-19 admitidos em unidade terapia intensiva. Métodos Estudo retrospectivo, quantitativo e analítico. A amostra foi de adultos jovens (20 a 40 anos) admitidos em unidades de terapia intensiva, com diagnóstico de infecção por SARS-CoV-2 entre março e dezembro de 2020. Os dados foram obtidos por meio do prontuário eletrônico, e a lesão renal aguda foi definida pelo valor da creatinina, segundo critérios das diretrizes da Kidney Disease Improving Global Outcomes. A significância estatística foi de p≤0,05. Resultados Foram internados 58 adultos jovens, sendo 63,8% do sexo masculino. A hipertensão arterial sistêmica esteve presente em 39,6%, a obesidade em 18,9% e o diabetes mellitus em 8,6%. A lesão renal aguda foi identificada em 55,1%, sendo o estágio 3 predominante em 43,1% deles. Nesses pacientes, o uso de ventilação mecânica e de drogas vasoativas foi significativo em 92%, assim como a disfunção orgânica respiratória (80%), seguida da renal (76%). Fatores de risco, como transplante renal ou doença renal crônica e obesidade, aumentaram em 12,3 e 9,0 vezes, respectivamente, a chance de desenvolver lesão renal aguda. Conclusão Este estudo demonstrou alta prevalência de lesão renal em adultos jovens e sua associação com comorbidades prévias. Obesidade, transplante renal e doença renal crônica elevaram a chance de o adulto jovem desenvolver lesão renal aguda, resultando em desfechos a favor da morbimortalidade.

Resumen Objetivo Describir la prevalencia de lesión renal aguda en adultos jóvenes con diagnóstico de COVID-19 admitidos en unidad de cuidados intensivos. Métodos Estudio retrospectivo, cuantitativo y analítico. La muestra fue de adultos jóvenes (20 a 40 años) admitidos en unidades de cuidados intensivos, con diagnóstico de infección por SARS-CoV-2 entre marzo y diciembre de 2020. Los datos se obtuvieron por medio de historias clínicas electrónicas, y la lesión renal aguda fue definida por el valor de la creatinina, de acuerdo con criterios de las directrices de la Kidney Disease Improving Global Outcomes. La significación estadística fue de p≤0,05. Resultados Hubo 58 adultos jóvenes internados, el 63,8 % de sexo masculino. La hipertensión arterial sistémica estuvo presente en el 39,6 %, la obesidad en el 18,9 % y la diabetes mellitus en el 8,6 %. Se identificó lesión renal aguda en el 55,1 %, de nivel 3 como predominante en el 43,1 % de los casos. En esos pacientes, el uso de ventilación mecánica y de drogas vasoactivas fue significativo en el 92 %, así como también la disfunción orgánica respiratoria (80 %), seguida de la renal (76 %). Los factores de riesgo, como trasplante renal o enfermedad renal crónica y obesidad, aumentaron 12,3 y 9,0 veces respectivamente la probabilidad de presentar lesión renal aguda. Conclusión Este estudio demostró alta prevalencia de lesión renal en adultos jóvenes y su asociación con comorbilidades previas. La obesidad, el trasplante renal y la enfermedad renal crónica aumentaron la probabilidad de que los adultos jóvenes presenten lesión renal aguda, lo que da como resultado desenlaces a favor de la morbimortalidad.

Abstract Objective To describe acute kidney injury prevalence in young adults diagnosed with COVID-19 admitted to the Intensive Care Unit. Methods This is a retrospective, quantitative and analytical study. The sample consisted of young adults (20 to 40 years old) admitted to Intensive Care Units, diagnosed with SARS-CoV-2 infection between March and December 2020. Data were obtained through electronic medical records, and kidney injury acute was defined by the creatinine value, according to the Kidney Disease Improving Global Outcomes guidelines criteria. Statistical significance was p≤0.05. Results A total of 58 young adults were hospitalized, 63.8% of whom were male. Hypertension was present in 39.6%, obesity in 18.9%, and diabetes mellitus in 8.6%. Acute kidney injury was identified in 55.1%, with stage 3 predominating in 43.1% of them. In these patients, the use of mechanical ventilation and vasoactive drugs was significant in 92% as well as respiratory organ dysfunction (80%), followed by renal organ dysfunction (76%). Risk factors such as kidney transplantation or chronic kidney disease and obesity increased by 12.3 and 9.0 times, respectively, the chances of developing acute kidney injury. Conclusion This study demonstrated a high kidney injury prevalence in young adults and its association with previous comorbidities. Obesity, kidney transplantation and chronic kidney disease increased the chance of young adults to develop acute kidney injury, resulting in outcomes in favor of morbidity and mortality.

Relationship between handgrip strength and inspiratory muscles with the success of the spontaneous breathing trial

Introduction: In critically ill patients on mechanical ventilation, the loss of inspiratory and peripheral muscle strength is associated with prolonged mechanical ventilation and failed weaning. Objective: To determine the relationship between handgrip strength and inspiratory muscle strength with the success of the Spontaneous Breathing Trial in adults with ventilatory support greater than 48 hours. Methodology: Prospective observational cross-sectional study performed at a tertiary hospital in Colombia. Handgrip strength and Maximal Inspiratory Pressure were measured once a day before Spontaneous Breathing Trial testing. Pearson's test and Cohen's D test were used to analyze correlations. Results: A total of 51 patients were included, 57% male, with a mean age of 51.9±20 years. A positive correlation was identified between Maximal Inspiratory Pressure and grip strength; and a negative correlation between grip strength and Maximal Inspiratory Pressure with the days of stay in the intensive care unit, (r -0.40; p<0.05) and (r -0.45; p<0.05). Conclusions: Handgrip strength and Maximal Inspiratory Pressure were positively correlated with Spontaneous Breathing Trial success. The importance of these measures to guide ventilator disconnection processes is highlighted.

Introducción: En el paciente críticamente enfermo con ventilación mecánica, la pérdida de la fuerza de los músculos inspiratorios y periféricos se asocia con ventilación mecánica prolongada y destete fallido. Objetivo: Determinar la relación entre la fuerza de prensión manual y la fuerza de músculos inspiratorios con el éxito de la prueba de respiración espontánea en adultos con soporte ventilatorio mayor a 48 horas. Metodología: Estudio prospectivo observacional de corte transversal realizado en un hospital de tercer nivel en Colombia. La fuerza de prensión manual y la presión inspiratoria máxima se midieron una vez al día antes de la prueba de prueba de respiración espontánea. Se utilizaron la prueba de Pearson y la prueba D de Cohen para analizar las correlaciones. Resultados: Se incluyeron 51 pacientes, 57 % de sexo masculino, con una edad promedio de 51,9 ± 20 años. Se identificó una correlación positiva entre Presión Inspiratoria Máxima y fuerza de la mano; y una correlación negativa entre la fuerza de la mano y la Presión Inspiratoria Máxima con los días de estancia en la Unidad de Cuidados Intensivos, (r -0,40; p < 0,05) y (r -0,45;p < 0,05). Conclusiones: La fuerza de prensión manual y la Presión Inspiratoria Máxima se correlacionaron positivamente con el éxito de la Prueba de Respiración Espontánea. Se destaca la importancia de estas mediciones para guiar procesos de desconexión del ventilador.

Effects of atelectatic areas on the surrounding lung tissue during mechanical ventilation in an experimental model of acute lung injury induced by lipopolysaccharide / Efeitos das áreas atelectásicas no tecido pulmonar circundante durante a ventilação mecânica em um modelo experimental de lesão pulmonar aguda induzida por lipopolissacarídeo

ABSTRACT Objective: To assess the effect of atelectasis during mechanical ventilation on the periatelectatic and normal lung regions in a model of atelectasis in rats with acute lung injury induced by lipopolysaccharide. Methods: Twenty-four rats were randomized into the following four groups, each with 6 animals: the Saline-Control Group, Lipopolysaccharide Control Group, Saline-Atelectasis Group, and Lipopolysaccharide Atelectasis Group. Acute lung injury was induced by intraperitoneal injection of lipopolysaccharide. After 24 hours, atelectasis was induced by bronchial blocking. The animals underwent mechanical ventilation for two hours with protective parameters, and respiratory mechanics were monitored during this period. Thereafter, histologic analyses of two regions of interest, periatelectatic areas and the normally-aerated lung contralateral to the atelectatic areas, were performed. Results: The lung injury score was significantly higher in the Lipopolysaccharide Control Group (0.41 ± 0.13) than in the Saline Control Group (0.15 ± 0.51), p < 0.05. Periatelectatic regions showed higher lung injury scores than normally-aerated regions in both the Saline-Atelectasis (0.44 ± 0.06 x 0.27 ± 0.74 p < 0.05) and Lipopolysaccharide Atelectasis (0.56 ± 0.09 x 0.35 ± 0.04 p < 0.05) Groups. The lung injury score in the periatelectatic regions was higher in the Lipopolysaccharide Atelectasis Group (0.56 ± 0.09) than in the periatelectatic region of the Saline-Atelectasis Group (0.44 ± 0.06), p < 0.05. Conclusion: Atelectasis may cause injury to the surrounding tissue after a period of mechanical ventilation with protective parameters. Its effect was more significant in previously injured lungs.

RESUMO Objetivo: Avaliar o efeito da atelectasia durante a ventilação mecânica nas regiões periatelectáticas e pulmonares normais em um modelo de atelectasia em ratos com lesão pulmonar aguda induzida por lipopolissacarídeo. Métodos: Foram distribuídos aleatoriamente 24 ratos em quatro grupos, cada um com 6 animais: Grupo Salina-Controle, Grupo Lipopolissacarídeo-Controle, Grupo Salina-Atelectasia e Grupo Lipopolissacarídeo-Atelectasia. A lesão pulmonar aguda foi induzida por injeção intraperitoneal de lipopolissacarídeo. Após 24 horas, a atelectasia foi induzida por bloqueio brônquico. Os animais foram submetidos à ventilação mecânica por 2 horas com parâmetros ventilatórios protetores, e a mecânica respiratória foi monitorada durante esse período. Em seguida, foram realizadas análises histológicas de duas regiões de interesse: as áreas periatelectásicas e o pulmão normalmente aerado contralateral às áreas atelectásicas. Resultados: O escore de lesão pulmonar foi significativamente maior no Grupo Controle-Lipopolissacarídeo (0,41 ± 0,13) do que no Grupo Controle-Solução Salina (0,15 ± 0,51), com p < 0,05. As regiões periatelectásicas apresentaram escores maiores de lesão pulmonar do que as regiões normalmente aeradas nos Grupos Atelectasia-Solução Salina (0,44 ± 0,06 versus 0,27 ± 0,74, p < 0,05) e Atelectasia-Lipopolissacarídeo (0,56 ± 0,09 versus 0,35 ± 0,04, p < 0,05). O escore de lesão pulmonar nas regiões periatelectásicas foi maior no Grupo Atelectasia-Lipopolissacarídeo (0,56 ± 0,09) do que na região periatelectásica do Grupo Atelectasia-Solução Salina (0,44 ± 0,06), p < 0,05. Conclusão: A atelectasia pode causar lesão no tecido circundante após um período de ventilação mecânica com parâmetros ventilatórios protetores. Seu efeito foi mais significativo em pulmões previamente lesionados.

Impact of vertical positioning on lung aeration among mechanically ventilated intensive care unit patients: a randomized crossover clinical trial / Impacto do posicionamento vertical na aeração pulmonar em pacientes de unidades de terapia intensiva ventilados mecanicamente: um estudo clínico transversal randomizado

ABSTRACT Objective: To assess the impact of different vertical positions on lung aeration in patients receiving invasive mechanical ventilation. Methods: An open-label randomized crossover clinical trial was conducted between January and July 2020. Adults receiving invasive mechanical ventilation for > 24 hours and < 7 days with hemodynamic, respiratory and neurological stability were randomly assigned at a 1:1 ratio to the sitting position followed by passive orthostasis condition or the passive orthostasis followed by the sitting position condition. The primary outcome was lung aeration assessed using the lung ultrasound score (score ranges from 0 [better] to 36 [worse]). Results: A total of 186 subjects were screened; of these subjects, 19 were enrolled (57.8% male; mean age, 73.2 years). All participants were assigned to receive at least one verticalization protocol. Passive orthostasis resulted in mean lung ultrasound scores that did not differ significantly from the sitting position (11.0 versus 13.7; mean difference, -2.7; [95%CI -6.1 to 0.71; p = 0.11). Adverse events occurred in three subjects in the passive orthostasis group and in one in the sitting position group (p = 0.99). Conclusion: This analysis did not find significant differences in lung aeration between the sitting and passive orthostasis groups. A randomized crossover clinical trial assessing the impact of vertical positioning on lung aeration in patients receiving invasive mechanical ventilation is feasible. Unfortunately, the study was interrupted due to the need to treat COVID-19 patients. ClinicalTrials.gov registry: NCT04176445

RESUMO Objetivo: Avaliar o impacto de diferentes posicionamentos verticais na aeração pulmonar em pacientes em ventilação mecânica invasiva. Métodos: Trata-se de ensaio clínico aberto, randomizado e transversal, realizado entre janeiro e julho de 2020. Adultos em ventilação mecânica invasiva por mais de 24 horas e menos de 7 dias com estabilidade hemodinâmica, respiratória e neurológica foram distribuídos aleatoriamente em uma proporção de 1:1 à postura sentada seguida da condição de ortostatismo passivo ou o ortostatismo passivo seguido de postura sentada. O desfecho primário foi a aeração pulmonar avaliada pelo lung ultrasound score. O escore varia de zero (melhor) a 36 (pior). Resultados: Foram selecionados 186 indivíduos; destes, 19 foram incluídos (57,8% do sexo masculino; média idade de 73,2 anos). Todos os participantes foram selecionados para receber pelo menos um protocolo de verticalização. O ortostatismo passivo resultou em escores médios de aeração pulmonar por ultrassonografia que não diferiram significativamente da postura sentada (11,0 versus 13,7; diferença média, -2,7; IC95% -6,1 a 0,71; p = 0,11). Ocorreram eventos adversos em três indivíduos no grupo ortostatismo passivo e em um no grupo postura sentada (p = 0,99). Conclusão: Esta análise não encontrou diferenças significativas na aeração pulmonar entre os grupos ortostatismo passivo e postura sentada. É factível conduzir um estudo clínico transversal randomizado para avaliar o impacto do posicionamento vertical na aeração pulmonar em pacientes em ventilação mecânica invasiva. Infelizmente, o estudo foi interrompido devido à necessidade de tratar pacientes com COVID-19. Registro ClinicalTrials.gov: NCT04176445

Manejo de la disfagia en pacientes con antecedente de infección severa por COVID-19 / Manejo de la disfagia en pacientes con antecedente de infección severa por COVID-19

de la deglución, los cuales representan todas las alteraciones del proceso fisiológico encargado de llevar el alimento desde la boca al esófago y después al estómago, salvaguardando siempre la protección de las vías respiratorias. OBJETIVO. Definir el manejo óptimo, de la disfagia en pacientes con antecedente de infección severa por COVID-19. METODOLOGÍA. Se realizó una revisión de la literatura científica en las bases de datos PubMed y Elsevier que relacionan el manejo de la disfagia y pacientes con antecedente de infección severa por SARS-CoV-2. Se obtuvo un universo de 134 artículos que cumplieron los criterios de búsqueda. Se seleccionaron 24 documentos, para ser considerados en este estudio. RESULTADOS. La incidencia de disfagia posterior a infección severa por SARS-CoV-2 fue del 23,14%, siendo la disfagia leve la más frecuente 48,0%. Los tratamientos clínicos más empleados en el manejo de la disfagia fueron rehabilitación oral y cambio de textura en la dieta en el 77,23% de los casos, mientras que el único tratamiento quirúrgico empleado fue la traqueotomía 37,31%. Un 12,68% de pacientes recuperó su función deglutoria sin un tratamiento específico. La eficacia de los tratamientos clínicos y quirúrgicos en los pacientes sobrevivientes de la infección severa por SARS-CoV-2 fue del 80,68%, con una media en el tiempo de resolución de 58 días. CONCLUSIÓN. La anamnesis es clave para el diagnóstico de disfagia post COVID-19. El tratamiento puede variar, desde un manejo conservador como cambios en la textura de la dieta hasta tratamientos más invasivos como traqueotomía para mejorar la función deglutoria.

INTRODUCTION. The difficulty to swallow or dysphagia is included within the problems of swallowing, which represent all the alterations of the physiological process in charge of carrying the food from the mouth to the esophagus, and then to the stomach, always taking into account the protection of the airways. OBJECTIVE. To define the optimal management, both clinical and surgical, for the adequate treatment of dysphagia produced as a consequence of severe SARS-CoV-2 infection. METHODOLOGY. A review of the scientific literature was carried out using both PubMed and Elsevier databases, which relate the management of dysphagia and patients with a history of severe SARS-CoV-2 infection. RESULTS. The incidence of dysphagia following severe SARS-CoV-2 infection was of 23,14%, with mild dysphagia being the most frequent 48,00%. The most frequently used clinical treatments for dysphagia management were oral rehabilitation and change in dietary texture in 77,23% of cases, while tracheotomy was the only surgical treatment used 37,31%. A total of 12,68% of patients recovered their swallowing function without specific treatment. The efficacy of clinical and surgical treatments in survivors of severe SARS-CoV-2 infection was 80,68%, with a mean resolution time of 58 days. CONCLUSION. An adequate medical history is key to the diagnosis of post-COVID-19 dysphagia. Treatment can range from conservative management such as changes in diet texture to more invasive treatments such as tracheotomy to improve swallowing function.

Fitness checklist model for spontaneous breathing tests in pediatrics / Modelo de checklist de, aptidão para teste de respiração espontânea em pediatria

ABSTRACT Objective: To evaluate whether a model of a daily fitness checklist for spontaneous breathing tests is able to identify predictive variables of extubation failure in pediatric patients admitted to a Brazilian intensive care unit. Methods: This was a single-center, cross-sectional study with prospective data collection. The checklist model comprised 20 items and was applied to assess the ability to perform spontaneous breathing tests. Results: The sample consisted of 126 pediatric patients (85 males (67.5%)) on invasive mechanical ventilation, for whom 1,217 daily assessments were applied at the bedside. The weighted total score of the prediction model showed the highest discriminatory power for the spontaneous breathing test, with sensitivity and specificity indices for fitness failure of 89.7% or success of 84.6%. The cutoff point suggested by the checklist was 8, with a probability of extubation failure less than 5%. Failure increased progressively with increasing score, with a maximum probability of predicting extubation failure of 85%. Conclusion: The extubation failure rate with the use of this model was within what is acceptable in the literature. The daily checklist model for the spontaneous breathing test was able to identify predictive variables of failure in the extubation process in pediatric patients.

RESUMO Objetivo: Avaliar se um modelo de checklist diário de aptidão para o teste de respiração espontânea é capaz de identificar variáveis preditivas de falha no processo de extubação em pacientes pediátricos internados em uma unidade de terapia intensiva brasileira. Métodos: Estudo unicêntricotransversal, com coleta prospectiva de dados. O modelo de checklist foi elaborado com 20 itens e aplicado para avaliação de aptidão para o teste de respiração espontânea. Resultados: A amostra foi composta de 126 pacientes pediátricos em ventilação mecânica invasiva, 85 do sexo masculino (67,5%), para os quais foram aplicadas 1.217 avaliações diárias à beira do leito. A pontuação total ponderada do modelo de predição apresentou o maior poder de discriminação para a realização do teste de respiração espontânea, com índices de sensibilidade e especificidade para a falha de aptidão de 89,7% ou sucesso de 84,6%. O ponto de corte sugerido pelo checklist foi 8, com probabilidade de falha de extubação inferior a 5%. Observou-se que a falha aumentou progressivamente com o aumento da pontuação obtida, com probabilidade máxima de predição de falha de extubação de 85%. Conclusão: A taxa de falha de extubação com a utilização desse modelo ficou dentro do que é aceitável na literatura. O modelo de checklist diário para aptidão do teste de respiração espontânea foi capaz de identificar variáveis preditivas de falha no processo de extubação em pacientes pediátricos.

Protocol-directed weaning versus conventional weaning from mechanical ventilation for neurocritical patients in an intensive care unit: a nonrandomized quasi-experimental study / Desmame da ventilação mecânica por protocolo versus desmame convencional em pacientes neurocríticos de uma unidade de terapia intensiva: um estudo quase experimental não randomizado

ABSTRACT Objective: To investigate whether protocol-directed weaning in neurocritical patients would reduce the rate of extubation failure (as a primary outcome) and the associated complications (as a secondary outcome) compared with conventional weaning. Methods: A quasi-experimental study was conducted in a medical-surgical intensive care unit from January 2016 to December 2018. Patients aged 18 years or older with an acute neurological disease who were on mechanical ventilation > 24 hours were included. All patients included in the study were ready to wean, with no or minimal sedation, Glasgow coma score ≥ 9, spontaneous ventilatory stimulus, noradrenaline ≤ 0.2μgr/kg/ minute, fraction of inspired oxygen ≤ 0.5, positive end-expiratory pressure ≤ 5cmH2O, maximal inspiratory pressure < -20cmH2O, and occlusion pressure < 6cmH2O. Results: Ninety-four of 314 patients admitted to the intensive care unit were included (50 in the Intervention Group and 44 in the Control Group). There was no significant difference in spontaneous breathing trial failure (18% in the Intervention Group versus 34% in the Control Group, p = 0.12). More patients in the Intervention Group were extubated than in the Control Group (100% versus 79%, p = 0.01). The rate of extubation failure was not signifiantly diffrent between the groups (18% in the Intervention Group versus 17% in the Control Group; relative risk 1.02; 95%CI 0.64 - 1.61; p = 1.00). The reintubation rate was lower in the Control Group (16% in the Intervention Group versus 11% in the Control Group; relative risk 1.15; 95%CI 0.74 - 1.82; p = 0.75). The need for tracheotomy was lower in the Intervention Group [4 (8%) versus 11 (25%) in the Control Group; relative risk 0.32; 95%CI 0.11 - 0.93; p = 0.04]. At Day 28, the patients in the Intervention Group had more ventilator-free days than those in the Control Group [28 (26 - 28) days versus 26 (19 - 28) days; p = 0.01]. The total duration of mechanical ventilation was shorter in the Intervention Group than in the Control Group [5 (2 - 13) days versus 9 (3 - 22) days; p = 0.01]. There were no diffrences in the length of intensive care unit stay, 28-day free from mechanical ventilation, hospital stay or 90-day mortality. Conclusion: Considering the limitations of our study, the application of a weaning protocol for neurocritical patients led to a high percentage of extubation, a reduced need for tracheotomy and a shortened duration of mechanical ventilation. However, there was no reduction in extubation failure or the 28-day free of from mechanical ventilation compared with the Control Group. ClinicalTrials.gov Registry:NCT03128086

RESUMO Objetivo: Investigar se o desmame por protocolo em pacientes neurocríticos reduz a taxa de falha de extubação (desfecho primário) e as complicações associadas (desfecho secundário) em comparação com o desmame convencional. Métodos: Realizou-se um estudo quase experimental em uma unidade de terapia intensiva médico-cirúrgica de janeiro de 2016 a dezembro de 2018. Foram incluídos pacientes com 18 anos de idade ou mais, com doença neurológica aguda e em ventilação mecânica > 24 horas. Todos os pacientes incluídos no estudo estavam prontos para o desmame, com nenhuma ou mínima sedação, escala de coma de Glasgow ≥ 9, estímulo ventilatório espontâneo, noradrenalina ≤ 0,2μgr/kg/minuto, fração inspirada de oxigênio ≤ 0,5, pressão expiratória positiva final ≤ 5cmH2O, pressão inspiratória máxima < -20cmH2O e pressão de oclusão < 6cmH2O. Resultados: Foram incluídos 94 dos 314 pacientes admitidos à unidade de terapia intensiva, sendo 50 no Grupo Intervenção e 44 no Grupo Controle. Não houve diferença significativa na falha do ensaio respiratório espontâneo (18% no Grupo Intervenção versus 34% no Grupo Controle, p = 0,12). Foram extubados mais pacientes no Grupo Intervenção do que no Controle (100% versus 79%; p = 0,01). A taxa de falha de extubação não foi significativamente diferente entre os grupos (18% no Grupo Intervenção versus 17% no Grupo Controle, risco relativo de 1,02; IC95% 0,64 - 1,61; p = 1,00). A taxa de reintubação foi menor no Grupo Controle (16% no Grupo Intervenção versus 11% no Grupo Controle; risco relativo de 1,15; IC95% 0,74 -1,82; p = 0,75). A necessidade de traqueotomia foi menor no Grupo Intervenção [4 (8%) versus 11 (25%) no Grupo Controle; risco relativo de 0,32; IC95% 0,11 - 0,93; p = 0,04]. Aos 28 dias, os pacientes do Grupo Intervenção tinham mais dias sem ventilador do que os do Grupo Controle [28 (26 - 28) dias versus 26 (19 - 28) dias; p = 0,01]. A duração total da ventilação mecânica foi menor no Grupo Intervenção do que no Controle [5 (2 - 13) dias versus 9 (3 - 22) dias; p = 0,01]. Não houve diferenças no tempo de internação na unidade de terapia intensiva, 28 dias sem ventilação mecânica, internação hospitalar ou mortalidade em 90 dias. Conclusão: Considerando as limitações de nosso estudo, a aplicação de um protocolo de desmame em pacientes neurocríticos levou à maior proporção de extubação, à menor necessidade de traqueotomia e à menor duração da ventilação mecânica. Entretanto, não houve redução na falha de extubação ou 28 dias sem ventilação mecânica em comparação com o Grupo de Controle. Registro ClinicalTrials.gov:NCT03128086

Construção e validação da escala de verificação da adesão às recomendações das Diretrizes Brasileiras de Ventilação Mecânica / Construction and validation of the scale for verifying adherence to the recom-mendations of The Brazilian Guidelines For Mechanical Ventilation / Construcción y validación de la escala para verificar la adherencia a las recomenda-ciones de Las Directrices Brasileñas Sobre Ventilación Mecánica

Objetivo: construir e validar uma escala de verificação da adesão às recomendações das Diretrizes Brasileiras de Ventilação Mecânica por profissionais da saúde. Método: estudo metodológico, conduzido no período entre setembro e dezembro de 2019 em um hospital público com 87 pacientes. Para a validação de conteúdo, adotou-se o Índice de Validação de Conteúdo; para a validade de critério, o Coeficiente de Correlação de Pearson; para a consistência interna, o alfa de Cronbach; e, para a confiabilidade interobservador, o Coeficiente Kappa e o Coeficiente de Correlação Intraclasse. Resultados: a escala identificou uma validade de conteúdo e consistência interna aceitável. A correlação de Pearson indicou uma correlação do escore de adesão com a saturação (r = 0,31; p≤0,005), o escore médio para o observador A e B resultou, respectivamente, em 88,89(±5,23) e 88,86(±5,34), e o intervalo de confiança foi de 0,96. Conclusão: a escala apresentou validade e confiabilidade para verificar a adesão às Diretrizes Brasileiras de Ventilação Mecânica dos profissionais.(AU)

Objective: to construct and validate a scale for verifying adherence to the recommendations of the Brazilian Guidelines for Mechanical Ventilation by healthcare professionals. Method: methodological study, conducted between September and December 2019 in a public hospital with 87 patients. For content validation, the Content Validation Index was adopted; for criterion validity, Pearson's Correlation Coefficient; for internal consistency, Cronbach's alpha; and, for interobserver reliability, the Kappa Coefficient, and the Intraclass Correlation Coefficient. Results: the scale identified acceptable content validity and internal consistency. Pearson's correlation indicated a correlation between adherence score and saturation (r = 0.31; p≤0.005), the average score for observer A and B resulted, respectively, in 88.89(±5.23) and 88.86(±5.34), and the confidence interval was 0.96. Conclusion: the scale showed validity and reliability to verify adherence to the Brazilian Guidelines for Mechanical Ventilation by professionals.(AU)

Objetivo: construir y validar una escala para verificar la adherencia a las recomendaciones de las directrices brasileñas sobre ventilación mecánica por parte de los profesionales de la salud. Método: estudio metodológico, realizado entre septiembre y diciembre de 2019 en un hospital público con 87 pacientes. Se adoptó el Índice de Validación de Contenido para la validación de contenido, para la validez de criterio, el Coeficiente de Correlación de Pearson, para la consistencia interna, el alfa de Cronbach y, para la fiabilidad interobservador, el Coeficiente Kappa y el Coeficiente de Correlación Intraclase. Resultados: la escala presentó una validez de contenido y una consistencia interna aceptables. La correlación de Pearson indicó una correlación de la puntuación de adherencia con la saturación (r = 0,31; p≤0,005), la puntuación media para el observador A y B resultó de 88,89(±5,23) y 88,86(±5,34), respectivamente, y el intervalo de confianza fue de 0,96. Conclusión: la escala presentó validez y confiabilidad para verificar la adherencia a las Directrices Brasileñas de Ventilación Mecánica de los profesionales.(AU)

Clinical characteristics and outcomes of patients with COVID-19 admitted to the intensive care unit during the first and second waves of the pandemic in Brazil: a single-center retrospective cohort study

ABSTRACT Objective To describe and compare the clinical characteristics and outcomes of patients admitted to intensive care units during the first and second waves of the COVID-19 pandemic. Methods In this retrospective single-center cohort study, data were retrieved from the Epimed Monitor System; all adult patients admitted to the intensive care unit between March 4, 2020, and October 1, 2021, were included in the study. We compared the clinical characteristics and outcomes of patients admitted to the intensive care unit of a quaternary private hospital in São Paulo, Brazil, during the first (May 1, 2020, to August 31, 2020) and second (March 1, 2021, to June 30, 2021) waves of the COVID-19 pandemic. Results In total, 1,427 patients with COVID-19 were admitted to the intensive care unit during the first (421 patients) and second (1,006 patients) waves. Compared with the first wave group [median (IQR)], the second wave group was younger [57 (46-70) versus 67 (52-80) years; p<0.001], had a lower SAPS 3 Score [45 (42-52) versus 49 (43-57); p<0.001], lower SOFA Score on intensive care unit admission [3 (1-6) versus 4 (2-6); p=0.018], lower Charlson Comorbidity Index [0 (0-1) versus 1 (0-2); p<0.001], and were less frequently frail (10.4% versus 18.1%; p<0.001). The second wave group used more noninvasive ventilation (81.3% versus 53.4%; p<0.001) and high-flow nasal cannula (63.2% versus 23.0%; p<0.001) during their intensive care unit stay. The intensive care unit (11.3% versus 10.5%; p=0.696) and in-hospital mortality (12.3% versus 12.1%; p=0.998) rates did not differ between both waves. Conclusion In the first and second waves, patients with severe COVID-19 exhibited similar mortality rates and need for invasive organ support, despite the second wave group being younger and less severely ill at the time of intensive care unit admission.

Quilotórax congénito en un recién nacido pretérmino extremo

Introducción: El quilotórax congénito es una rara afección respiratoria, sin embargo, es la causa más frecuente de derrame pleural en recién nacidos vivos. Objetivo: Presentar un caso de quilotórax congénito como causa infrecuente de distrés respiratorio en un recién nacido atendido en el Hospital Gineco-Obstétrico de Villa Clara. Caso clínico: Paciente masculino, que nació a las 26,2 semanas de edad gestacional, por parto eutócico, con tiempo de rotura de membranas de una hora, líquido amniótico meconial, otorgándose una puntuación de Apgar 7/8 (normal) y peso al nacer de 950 gramos; con diagnóstico de sepsis connatal fue necesario tratar con ventilación mecánica. A los seis días de vida presentó un deterioro clínico, con disminución del murmullo vesicular en el hemitórax derecho y en la radiografía de tórax se observó un pulmón derecho velado. El ultrasonido torácico confirmó el diagnóstico de derrame pleural derecho que fue puncionado y el estudio del líquido drenado mostró características propias del quilotórax. Se le indicó tratamiento conservador (con alimentación parenteral completa: traximín sin aporte lipídico) y luego con leche rica en ácidos grasos de cadenas corta y media (Enfaport® de la firma Nestlé). Se incorporó la leche materna a los 15 días del diagnóstico. Requirió ventilación mecánica prolongada. Con una evolución satisfactoria es egresado del centro hospitalario. Conclusiones: Se logró la resolución de esta enfermedad a través del tratamiento conservador, sin la presencia de recidiva.

Introduction: Congenital chylothorax is a rare respiratory disease; however, it is the most common cause of pleural effusion in live newborns. Objective: To present a case of congenital chylothorax as an uncommon cause of respiratory distress in a newborn treated at the Gyneco-Obstetric Hospital of Villa Clara. Case report: Male patient, who was born at 26.2 weeks of gestational age, by eutocic delivery, with membrane time rupture of an hour, meconium amniotic fluid, to whom was given an Apgar score of 7/8 (normal) and a birth weight of 950 grams; with diagnose of connatal sepsis was necessary to treat with mechanical ventilation. At six days of age presented a clinical deterioration, with decrease of the vesicular murmur in the right hemithorax and at chest X-ray was observed a veiled right lung. The chest ultrasound confirmed a right pleural effusion that was punctured and the study of the drained fluid showed characteristics of a chylothorax. Conservative treatment was indicated (with complete parenteral feeding: traximin without lipid intake) and subsequently with milk rich in short and medium chain fatty acids (Enfaport® from Nestlé Company). Breastmilk was incorporated 15 days after the diagnose. He required prolonged mechanical ventilation. With a satisfactory evolution, he was discharged from the hospital center. Conclusions: The resolution of this entity is achieved through conservative treatment, without the presence of recurrence.

Displasia broncopulmonar y severa restricción del crecimiento intrauterino en neonato de 850 gramos al nacer

Introducción: La displasia broncopulmonar es una enfermedad pulmonar crónica de inicio en edad neonatal. La restricción del crecimiento intrauterino se define como fracaso del feto para alcanzar su potencial de crecimiento genéticamente determinado. Objetivo: Describir el manejo interdisciplinario de la displasia broncopulmonar y revisar la literatura sobre el tema. Caso clínico: Se presenta el caso de un neonato hijo de madre adolescente producto de su primera gestación, la cual llevó un adecuado control prenatal. Presentó restricción del crecimiento intrauterino grado IV caracterizada por alteraciones en el ultrasonido Doppler en relación con insuficiencia placentaria severa y oligohidramnios, motivo por el cual se interrumpe el embarazo por parto distócico por cesárea a las 34+1 semanas, con bolsa rota al nacer, líquido amniótico claro y muy escaso. Nace en buenas condiciones clínicas con 850 gramos de peso. En los primeros días de vida, comenzó con manifestaciones clínicas de sepsis; se diagnosticó enterocolitis necrotizante luego presentó un súbito deterioro clínico debido a la aparición de hemorragia pulmonar. Con 695 gramos de peso, se inició tratamiento con ventilación mecánica invasiva, la cual se prolongó por un período de 30 días. Después del destete de la ventilación mecánica, el niño mantuvo una dependencia del oxígeno durante 71 días más; como manifestación de la displasia broncopulmonar. Se realizaron interconsultas con especialistas en Cardiología, Hematología, Imagenología, Nutrición, Inmunología y Genética; y, en colectivo, se decidió, la terapéutica desarrollada. El neonato evolucionó satisfactoriamente. Conclusiones: Se mostró el manejo interdisciplinario de la displasia broncopulmonar. Se consultó la bibliografía actualizada.

Introduction: Bronchopulmonary dysplasia is a chronic lung disease of neonatal age onset. Intrauterine growth restriction is defined as failure of the fetus to reach its genetically determined growth potential. Objective: To describe the interdisciplinary management of bronchopulmonary dysplasia and review the literature on the subject. Case report: The case of a newborn son of an adolescent mother, product of her first pregnancy, which had an adequate prenatal control, is presented. She presented grade IV intrauterine growth restriction characterized by alterations in the Doppler ultrasound in relation to severe placental insufficiency and oligohydramnios, which is why the pregnancy was terminated due to dystocic delivery by cesarean section at 34+1 weeks, with a ruptured bag at birth, liquid clear and very scanty amniotic. He was born in good clinical condition with a weight of 850 grams. In the first days of life, he began with clinical manifestations of sepsis; necrotizing enterocolitis was diagnosed, then he presented a sudden clinical deterioration due to the appearance of pulmonary hemorrhage. Weighing 695 grams, treatment with invasive mechanical ventilation was started, which lasted for a period of 30 days. After weaning from mechanical ventilation, the child remained oxygen dependent for a further 71 days; as a manifestation of bronchopulmonary dysplasia. Interconsultations were made with specialists in Cardiology, Hematology, Imaging, Nutrition, Immunology and Genetics; and, collectively, it was decided, the therapy developed. The neonate evolved satisfactorily. Conclusions: The interdisciplinary management of bronchopulmonary dysplasia was shown. The updated literature was consulted.

Effects of pressure controlled ventilation-volume guaranteed mode on intraoperative pulmonary ventilation and postoperative pulmonary complications in elderly patients undergoing thoracoscopic lobectomy / 肿瘤研究与临床

Objective:To explore the effects of pressure controlled ventilation-volume guaranteed (PCV-VG) mode on intraoperative pulmonary ventilation and postoperative pulmonary complications (PPC) in elderly patients undergoing thoracoscopic lobectomy.Methods:Sixty patients of American Society of Anesthesiologists (ASA) classification Ⅱor Ⅲ, aged 65-80 years old, with body mass index (BMI) 18-30 kg/m 2, received thoracoscopic lobectomy under general anesthesia from November 2021 to June 2022 in the Second Hospital of Shanxi Medical University were recruited. The patients were divided into PCV-VG and volume-controlled ventilation (VCV) groups using the randomized number table method, with 30 patients in each group. The ventilatory parameters of two-lung ventilation were set to respiratory rate (RR) at 10-12 breaths/min, with a tidal volume (VT) of 8 ml/kg (ideal body weight). The ventilatory parameters of one-lung ventilation (OLV) were set at 12-16 breaths/min, with a VT of 6 ml/kg (IBW). The peak airway pressure (Ppeak), plateau airway pressure (Pplat), driving pressure (ΔP), dynamic lung compliance (Cdyn), end-tidal carbon dioxide (ETCO 2), heart rate (HR), mean arterial pressure (MAP), partial pressure of oxygen (PaO 2) and partial pressure of carbon dioxide (PaCO 2) were obtained at 1 min before OLV (T 0), 30 min after OLV (T 1) and 60 min after OLV (T 2). The incidence and severity of PPC, chest tube duration time and postoperative hospital stay time were recorded. Results:The Ppeak, Pplat and ΔP were higher and Cdyn was lower in both groups at T 1-T 2 than at T 0 (all P<0.001). The Ppeak, Pplat and ΔP were higher and Cdyn was lower in PCV-VG group than in VCV group (all P<0.05). There were no statistical differences in HR, MAP, ETCO 2, PaO 2 and PaCO 2 between the two groups (all P > 0.05). There were no statistical differences in the incidence of PPC [43.3% (13/30) vs. 30.0% (9/30)] and chest tube duration time [(4.4±0.9) d vs. (4.2±1.2) d] between VCV group and PCV-VG group (all P>0.05). Compared with VCV group, the proportion of patients with ≥grade 2 PPC was lower in PCV-VG group [10.0% (3/30) vs. 36.7% (11/30), χ2=5.96, P<0.05]. The postoperative hospital stay time in PCV-VG group was shorter than that in VCV group [(6.4±1.3) d vs. (8.0±1.9) d, t = 4.85, P<0.05]. Conclusions:PCV-VG mode can effectively reduce the severity of PPC, shorten the postoperative hospital stay time and improve the prognosis in elderly patients undergoing thoracoscopic lobectomy.

Effects of antenatal dexamethasone and postnatal pulmonary surfactant combined with respiratory support on lung fluid clearance in preterm rabbits / 中华围产医学杂志

Objective:To explore the effects of prenatal dexamethasone (DEX), postnatal pulmonary surfactant (PS) and respiratory support on the lung fluid clearance in premature rabbits at gestational age (GA) of 25-28 d (full term: 31 d) and their relationship with dynamic compliance of respiratory system (Cdyn), pulmonary morphology and other parameters.Methods:In our previous publications, premature rabbits were divided into four groups according to the intervention strategy: control group, PS-only group, DEX-only group and DEX+PS group in which data of several parameters including wet-to-dry lung weight ratio (W/D), Cdyn and volume density of alveoli (Vv) were retrieved and the lung tissue sections were scanned to recalculate the ratio of perivascular sheath to vascular sectional area (S/V) and lung injury scores-edema (LIS-E). W/D, LIS-E, S/V and Vv were adjusted for birth weight (BW) (divided by BW, represented as W/D/BW, LIS-E/BW, S/V/BW and Vv/BW) and mean Cdyn (Cdyn-m) was adopted. Based on the grouping of previous studies, the intervention groups in this study were divided as DEX group and non-DEX group, and PS group and non-PS group to analyze the influence of DEX and PS on the above parameters. Two independent samples t-test, one-way analysis of variance, LSD test, Kruskal-Wallis H test, Mann-Whitney U test and Pearson correlation analysis were used for statistical analysis. Results:A total of 196 newborn rabbits receiving mechanical ventilation after birth were included in this study. (1) Effects of DEX: compared with the non-DEX group, the DEX group showed increased W/D/BW (489±69 vs 421±113, t=－2.09), LIS-E/BW (188±57 vs 138±55, t=－2.61) and Vv/BW (20.1±4.9 vs 14.2±4.7, t=－3.60), but decreased S/V (0.33±0.23 vs 0.51±0.25, t=2.23) and S/V/W/D (0.05±0.03 vs 0.07±0.04, t=2.22) at 25 d of gestation; at 26 d of gestation, W/D/BW (472±76 vs 303±44, t=－8.75), LIS-E/BW (189±63 vs 106±36, t=－5.23), Cdyn-m [(0.16±0.07) vs (0.05±0.03) ml/(kg?cmH 2O), 1 cmH 2O=0.098 kPa; t=－7.29] and Vv/BW increased (22.4±5.0 vs 12.2±3.8, t=－7.46), while S/V (0.23±0.19 vs 0.62±0.38, t=4.10), S/V/BW (15.7±12.4 vs 25.7±17.3, t=2.20), S/V/W/D (0.03±0.03 vs 0.08±0.05, t=3.92) and propensity scores decreased [(12.5±1.2) vs (15.1±1.2) scores, t=7.00]; at 27 d of gestation, Cdyn-m increased [(0.23±0.12) vs (0.16±0.07) ml/(kg?cmH 2O), t=－2.43], but S/V (0.32±0.23 vs 0.57±0.39, t=2.57) and S/V/W/D decreased (0.05±0.04 vs 0.09±0.06, t=2.55); at 28 d of gestation, W/D/BW (270±64 vs 162±33, t=－8.09), LIS-E/BW (72±32 vs 35±20, t=－5.17), S/V (0.90±0.60 vs 0.59±0.48, t=－2.81), S/V/BW (34.0±23.6 vs 15.2±12.7, t=－3.77) and Vv/BW increased (16.9±4.3 vs 9.2±2.9, t=－8.04); the differences were all statistically significant (all P<0.05). (2) Effects of PS: compared with the non-PS group, the PS group had decreased LIS-E/BW at 25, 26 and 27 d of gestation, increased Cdyn-m and Vv/BW at 25 and 27 d of gestation and higher propensity scores at 25 d of gestation (all P<0.05). (3) The correlation between gestational age and each index: gestational age was positively correlated with S/V ( r=0.31, P<0.05), but negatively correlated with W/D/BW and LIS-E/BW ( r=－0.73 and－0.63, both P<0.05). Conclusions:The pharmacological action of prenatal DEX on lung fluid clearance is mainly confined to preterm rabbits at the GA of 28 d which is supported by mechanical ventilation. Prenatal treatment with DEX and/or postnatal PS can improve the early respiratory function in preterm rabbits between GA of 25-27 d, but had no substantial impact on lung fluid clearance. The GA-related lung maturation appears to play a crucial role, in comparison with medications, in lung fluid clearance.

Effects of lung-protective ventilation strategies on postoperative pulmonary complications in patients undergoing long-time neurosurgery: a retrospective study / 中华麻醉学杂志

Objective:To retrospectively evaluate the effects of lung-protective ventilation strategies on postoperative pulmonary complications in the patients undergoing long-time neurosurgery.Methods:Based on the duration of anesthesia>8 h, the clinical data from patients underwent elective first craniotomy under general anesthesia from January 1, 2019 to December 31, 2021 were retrospectively collected. Patients were divided into lung-protective ventilation group (group L) and conventional mechanical ventilation group (group C) according to whether lung-protective ventilation was performed during operation. The baseline characteristics, intraoperative condition, postoperative pulmonary complications and hospitalization of patients in the two groups were recorded.Results:Compared with group C, the tidal volume was significantly decreased, positive end-expiratory pressure and respiratory rate were increased, the incidence of intraoperative hypoxemia was decreased, the number of patients with grade 1 according to the severity grade of postoperative pulmonary complications was significantly increased, and the length of hospital stay was shortened in group L ( P<0.05). There were no statistically significant differences in the baseline characteristics, incidence of postoperative pulmonary complications at 7 days after surgery and other parameters between group L and group C ( P>0.05). Conclusions:Lung-protective ventilation strategies can reduce the severity of postoperative pulmonary complications in the patients undergoing long-time neurosurgery.

Optimization efficacy of individualized LPVS based on P-V curve combined with PCV-VG mode for OLV in elderly patients undergoing radical resection of lung cancer / 中华麻醉学杂志

Objective:To evaluate the optimization efficacy of pressure-volume (P-V) curve-based individualized lung-protective ventilation strategy combined with pressure-controlled ventilation-volume guaranteed (PCV-VG) mode (LPVS+ PCV-VG) for one-lung ventilation (OLV) in elderly patients undergoing radical resection of lung cancer.Methods:Seventy American Society of Anesthesiologists Physical Status classificationⅡ-Ⅲ patients, aged 65-74 yr, with body mass index of 18-24 kg/m 2, undergoing elective thoracoscopic radical resection of lung cancer, were divided into 2 groups ( n=35 each) using a random number table method: PCV-VG group and LPVS+ PCV-VG group. Blood samples were collected from the radial artery for blood gas analysis before induction of general anesthesia (T 0), at 5 min of two lung ventilation after endotracheal intubation (T 1), at 30 min of OLV (T 2), at the end of OLV (T 3), and at 5 min of two lung ventilation in supine position (T 4). Ppeak, mean airway pressure (Pmean) and dynamic lung compliance (Cdyn) were recorded. The use of antibiotics, lung-related complications and rehabilitation were recorded within 7 days after operation. Results:Compared with PCV-VG group, PaO 2, PaCO 2 and Cdyn were significantly increased at T 2-4, Ppeak was decreased at T 2, 3, Pmean was increased at T 3, the requirement for antibiotics within 7 days after operation was decreased, the incidence of 1 grade lung-related complications was decreased, and the thoracic drainage tube indwelling time and length of hospital stay were shortened in LPVS+ PCV-VG group ( P<0.05). Conclusions:Individualized LPVS based on P-V curve combined with PCV-VG mode provides better efficacy for OLV in elderly patients undergoing radical resection of lung cancer.

Role of TRPV4 in dexmedetomidine-induced improvement in cognitive function in mice with mechanical ventilator-caused brain injury / 中华麻醉学杂志

Objective:To evaluate the role of transient receptor potential vanillic acid 4 (TRPV4) in dexmedetomidine-induced improvement in cognitive function in mice with mechanical ventilator-caused brain injury.Methods:Ninety clean-grade healthy male C57BL6 mice, weighing 20-25 g, aged 8-12 weeks, were divided into 5 groups ( n=18 each) using a random number table method: control group (group C), mechanical ventilation group (group V), HC-067047 group (group H), dexmedetomidine group (group D), and dexmedetomidine+ GSK1016790A group (group DG). In group C, the animals breathed air spontaneously for 6 h without mechanical ventilation. In group V, the animals were mechanically ventilated for 6 h. In group H, TRPV4 blocker HC-067047 10 mmol was injected into the cerebral ventricle at 3 and 6 h of mechanical ventilation. In D and DG groups, dexmedetomidine 50 μg/kg was intraperitoneally injected at 30 min before mechanical ventilation. In group DG, TRPV4 agonist GSK1016790A 5 μmol was injected into the cerebral ventricle at 60 min before mechanical ventilation. Morris water maze test was performed on 6 mice in each group at 1 day before mechanical ventilation and 3 and 7 days after mechanical ventilation. Six mice in each group were randomly selected and sacrificed at 1 day after mechanical ventilation, and the brain tissue was taken for determination of the neuronal apoptosis in hippocampal CA1 area by TUNEL method, and the apoptosis index was calculated. Six mice in each group were randomly selected and sacrificed at 1 day after mechanical ventilation, and the hippocampal tissues were taken for determination of the expression of TRPV4, serine-threonine protein kinase (Akt), phosphorylated Akt (p-Akt), Bcl-2, Bax and caspase-3 by Western blot. Results:Compared with group C, the escape latency was significantly prolonged and the number of crossing the original platform was reduced at 3 and 7 days after mechanical ventilation, the expression of TRPV4 and caspase-3 was up-regulated, the ratio of Bcl-2/Bax was decreased, and the apoptosis index of neurons was increased in group V and group DG ( P<0.05). Compared with group V, the escape latency was significantly shortened and the number of crossing the original platform was increased at 3 and 7 days after mechanical ventilation, the expression of TRPV4 and caspase-3 was down-regulated, the expression of p-Akt was up-regulated, the ratio of Bcl-2/Bax was increased, and the apoptosis index of neurons was decreased in group D and group H ( P<0.05). Compared with group D, the escape latency was significantly prolonged at 3 and 7 days after mechanical ventilation, the number of crossing the original platform was reduced, the expression of TRPV4 and caspase-3 was up-regulated, the expression of p-Akt was down-regulated, the ratio of Bcl-2/Bax was decreased, and the apoptosis index of neurons was increased in group DG ( P<0.05). Conclusions:TRPV 4 is involved in dexmedetomidine-induced improvement in cognitive function, which is related to up-regulation of p-Akt expression and inhibition of apoptosis in hippocampal neurons in mice with mechanical ventilation-caused brain injury.

Effects of open-lung strategy on postoperative delirium in elderly patients undergoing laparoscopic surgery / 中华麻醉学杂志

Objective:To evaluate the effect of open-lung strategy (OLS) on postoperative delirium (POD) in elderly patients undergoing laparoscopic surgery.Methods:Seventy-four elderly patients of both sexes, aged 65-80 yr, with body mass index of 18.5-30.0 kg/m 2, of American Society of Anesthesiologists Physical Status classification Ⅱ or Ⅲ, undergoing elective laparoscopic radical rectal cancer or radical prostate cancer surgery under general anesthesia, were divided into 2 groups ( n=37 each) by the random number table method: OLS group and non-OLS (NOLS) group. Patients in OLS group received small tidal volume ventilation, recruitment maneuvers, and individualized positive end-expiratory pressure. Fixed positive end-expiratory pressure 5 cmH 2O was given in NOLS group. Cerebral regional oxygen saturation (rSO 2), pH value, PaO 2, PaCO 2 and PaO 2/FiO 2 were recorded before induction of anesthesia (T 0, baseline value), at 10 min after tracheal intubation (T 1), at 1 and 2 h after pneumoperitoneum (T 2, 3) and at 10 min after extubation (T 4). The levels of serum interleukin-6 (IL-6), IL-10 and calcium-binding protein (S100β) were measured by enzyme-linked immunosorbent assay before surgery, at the end of surgery, and at 1 day after surgery. The development of POD was assessed using the delirium assessment scale at 1-3 days after surgery. Results:Compared with NOLS group, the pH value was significantly decreased at T 3, PaCO 2 was increased, PaO 2, PaO 2/FiO 2 and rSO 2 were increased at T 2-4, serum IL-6 and S100β concentrations were decreased after surgery and at 1 day after surgery, the serum IL-10 concentration was increased, and the incidence of POD was decreased in OLS group ( P<0.05). Conclusions:OLS can increase rSO 2, reduce the systemic inflammatory response, and decrease the risk of POD in elderly patients undergoing laparoscopic surgery.