Step tests are feasible, safe, and can be used to evaluate exercise capacity at home after hospitalization for COVID-19 / Os testes do degrau são viáveis, seguros e podem ser utilizados para avaliar a capacidade de exercício no domicílio após hospitalização por COVID-19

Abstract Introduction: Step-based tests are commonly utilized to assess the exercise capacity of individuals with respiratory diseases. However, the feasibility and safety of the step tests have not yet been studied in individuals after COVID-19. Objective: To investigate the feasibility and safety of the six-minute step test (6MST) and the modified incremental step test (MIST) in assessing exercise capacity at home in individuals after hospitalization for COVID-19, and to identify factors associated with performance in these tests. Methods: Cross-sectional multicenter study with individuals hospitalized for COVID-19 fifteen days after hospital discharge. Participants performed spirometry, 6MST, and MIST during a single home visit. Adverse events were registered during and immediately after the tests. Results: Sixty-five participants were studied (50 ± 10 years old, 55% male). The feasibility was 96.9% and the incidence of adverse events was 13.8% in 6MST and 6.2% in MIST. The individuals performed 76.9% of the predicted on the 6MST, with 40% of the participants reaching 80% of the maximum HR and 31% presenting exercise-induced oxygen desaturation. In the MIST, the individuals performed 20% of the predicted, 23% of the participants reached 80% of the maximum heart rate, and 17% presented exercise-induced oxy-gen desaturation. Length of hospital stay and the use of mechanical ventilation were associated with test performance. Conclusion: 6MST and MIST are feasible, safe, and can be used to assess exercise capacity in a home environment in individuals after hospitalization for COVID-19. The performance in these tests was associated with a prolonged hospital stay and the use of mechanical ventilation.

Resumo Introdução: Testes baseados em degraus são comumente utilizados para avaliar a capacidade de exercício de indivíduos com doenças respiratórias. No entanto, a viabilidade e segu-rança dos testes de degrau ainda não foram estudadas em indivíduos após hospitalização por COVID-19. Objetivo: In-vestigar a viabilidade e segurança do teste do degrau de seis minutos (TD6) e do teste do degrau incremental modificado (TDIM) na avaliação da capacidade de exercício no domicílio em indivíduos após hospitalização por COVID-19, e identificar fatores associados ao desempenho nesses testes. Métodos: Estudo transversal multicêntrico com indivíduos internados por COVID-19 quinze dias após a alta hospitalar. Os participantes realizaram espirometria, TD6 e TDIM durante uma única visita domiciliar. Eventos adversos foram registrados durante e ime-diatamente após os testes. Resultados: Foram estudados 65 participantes (50 ± 10 anos, 55% do sexo masculino). A via-bilidade foi de 96,9% e a incidência de eventos adversos foi de 13,8% no 6MST e 6,2% no TDIM. Os indivíduos realizaram 76,9% do previsto no TD6, sendo que 40% dos participantes atingiram 80% da frequência cardíaca máxima e 31% apresen-taram dessaturação de oxigênio induzida pelo exercício. No TDIM, os indivíduos realizaram 20% do previsto, 23% dos participantes atingiram 80% da frequência cardíaca máxima e 17% apresentaram dessaturação de oxigênio induzida pelo exercício. O tempo de internação e o uso de ventilação mecâni-ca estiveram associados ao desempenho do teste. Conclusão: O TD6 e o TDIM são viáveis, seguros e podem ser usados para avaliar a capacidade de exercício em ambiente domiciliar em indivíduos após hospitalização por COVID-19. O desempenho nesses testes esteve associado ao tempo prolongado de internação e ao uso de ventilação mecânica.

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.

Global research publications on cardiovascular and pulmonary rehabilitation and their alignment with population rehabilitation needs: An ecological study.

PURPOSE: Towards informing health research policy and planning, this article evaluates the relationship of the research publications in cardiac rehabilitation (CR) and pulmonary rehabilitation (PR) with the rehabilitation needs arising from cardiovascular diseases (except stroke) and chronic respiratory diseases, over time (1990-2017). METHODS: Ecological study using a secondary analysis and linear regressions of public domain data to associate two datasets of population-level data: (1) research publications for CR and PR (data from the PubMed database); and (2) global need for CR and PR (data from the Global Burden of Disease study). RESULTS: The percentage of both CR and PR publications (among total rehabilitation research) significantly decreased from 1990 to 2017 (both: p < 0.01). PR needs and research publications were aligned: around 5% of total rehabilitation needs and rehabilitation research. For CR needs (around 2%, but significantly increasing since 1990), we found a greater portion of CR research publications (6.5% or over). Finally, we found an inverse association among the percentage of CR research publications and CR needs (b = -6.08; r2  = 0.37, p = 0.001). CONCLUSION: The portion of CR and PR research (among total rehabilitation research) is declining over time. Yearly percentage of CR publications were greater than those of PR but for lower level of rehabilitation need, but the disparate trend was significantly decreasing over time. Population rehabilitation needs and their alignment with research volume must be one factor in the design of population-centred, equitable health research priorities.

Effect of a structured early mobilization protocol on the level of mobilization and muscle strength in critical care patients: A randomized clinical trial.

BACKGROUND: Few studies have evaluated the effects of structured early mobilization (EM) protocols on the level of mobilization in critical care patients. OBJECTIVE: To evaluate the impact of a structured EM protocol on the level of mobilization, muscle strength, and the level of activities of daily living (LADL) after intensive care unit (ICU) and hospital discharge. METHODS: This randomized clinical trial (U1111-1245-4840) included adults patients who were randomized into two groups: intervention (n = 40) and control (n = 45). The intervention group underwent conventional physiotherapy and structured EM protocols, and the control group underwent conventional physiotherapy. The level of mobilization from 0 (no mobilization) to 5 (walking), muscle strength (Medical Research Council scale), LADL (Katz Index), and incidence of complications were evaluated. RESULTS: The level of mobilization from day 1 to day 7 increased in the intervention group compared with the control group (p < .05). Muscle strength did not change during the protocol in the intervention and control groups {day 1 [effect size (r) = 0.15, p = .161], at ICU discharge [r = 0.16, p = .145], and after ICU discharge [r = 0.16, p = .191]}. The LADL did not differ between the intervention and control groups after ICU discharge [4 (1-6) vs. 3 (1-5), p = .702] or 30 days after hospital discharge [6 (5-6) vs. 6 (5-6), p = .945]. The structured EM protocol was safe, and no severe complications were observed during the protocol. CONCLUSION: A structured EM protocol increased the level of mobilization without improving muscle strength and the LADL compared with conventional physiotherapy.

Factors associated with postural balance in patients with end-stage renal disease on hemodialysis.

BACKGROUND: Patients with end-stage renal disease on hemodialysis have postural balance impairments due to uremic syndrome and hemodialysis complications. This study evaluated the factors associated with postural balance in patients on hemodialysis. METHODS: This cross-sectional study included patients on hemodialysis [n = 93, 62.0 (16.0) years]. Postural balance was evaluated using a force plate in a static position with eyes opened and eyes closed on a firm surface and with eyes opened on a foam surface to register the center of pressure path length. Physical function was assessed by isometric handgrip force, the 5-repetition sit-to-stand test, and gait speed. The level of physical activity and quality of life were evaluated by accelerometry and the 36-Item Short Form Health Survey, respectively. FINDINGS: After adjustment for potential confounders, the multiple linear regression analysis showed that the presence of diabetes mellitus and neurological disease and gait speed were significantly associated with the center of pressure path length in the eyes opened test (R2 = 0.263; p < 0.001). The center of pressure path length in the eyes closed test was significantly associated with the presence of neurological disease (R2 = 0.177; p = 0.002). The center of pressure path length in the eyes opened on a foam surface test was significantly associated with the presence of diabetes mellitus (R2 = 0.223; p < 0.001). INTERPRETATION: Poor postural balance was associated with the presence of diabetes mellitus and neurological disease and a slower gait speed in patients on hemodialysis.

Association Between Protocols of the Sit-to-Stand Test and Lower Limb Muscle Force Output in Patients on Hemodialysis and Subjects Without Chronic Kidney Disease.

OBJECTIVE: To evaluate the association of three protocols of the sit-to-stand (STS) test with muscle force output of knee extension (KE) and knee flexion (KF) in patients on hemodialysis and subjects without chronic kidney disease. METHODS: This cross-sectional study included a hemodialysis group [n = 60, 59.5 (16.8) years, 55% female] and a control group [n = 60, 43.0 (11.8) years, 50% female]. The assessments were performed in 2 days, and the participants were submitted to three protocols of STS test (5-repetition STS, 10-repetition STS and 30-s STS) or muscle force output of the KE and KF evaluation by handheld dynamometer based on randomization. RESULTS: The hemodialysis group presented reduced muscle force output of the KE and KF, a longer time to perform the 5 STS and 10 STS tests, and a lower number of repetitions in the 30-s STS test. The three STS tests were associated with muscle force output of the KE in the hemodialysis group, in which the 10-repetition STS test showed the best association (R2 = 0.47; adjusted R2 = 0.42). However, the only association between the STS test and muscle force output of the KE in the control group was found in the 10-repetition STS test (R2 = 0.20; adjusted R2 = 0.13). CONCLUSIONS: The three protocols of STS tests were associated with muscle force output of the KE in patients on hemodialysis. However, the 10-repetition STS test was the best protocol to estimate the quadriceps muscle torque in these patients.

Association between fear of falling and a history of falls in patients with end-stage renal disease on hemodialysis.

INTRODUCTION: Hemodialysis patients have complications that increase fear of falling (FOF). This study evaluated the association between FOF and a retrospective history of falls in hemodialysis patients and investigated the ability of the Fall Efficacy Scale-International (FES-I) to discriminate fallers from nonfallers. METHODS: A retrospective study was conducted with 183 patients to investigate the history of falls in the last 12 months and to evaluate FOF by the FES-I. RESULTS: The univariate linear regression model showed that the FES-I score was significantly associated with a history of falls (p = 0.01). After adjustment for potential confounders, this association remained significant (R2  = 0.19, p < 0.001). The FES-I score showed an area under the curve of 0.660 with a cutoff point of 25 (sensitivity-61.8%; specificity-62.2%). CONCLUSION: FOF was associated with a history of falls in the 12-month period in hemodialysis patients, and FOF assessed by the FES-I was able to discriminate fallers from nonfallers.

Effects of atelectatic areas on the surrounding lung tissue during mechanical ventilation in an experimental model of acute lung injury induced by lipopolysaccharide.

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.

Profile of professionals working in intradialytic exercise programs in Brazil: a national survey / Perfil dos profissionais que atuam em programas de exercício físico durante as sessões de hemodiálise: um estudo nacional

Abstract Objective: This survey was designed to assess the profile of professionals working in intradialytic exercise programs (IEPs) in Brazil and reveal the motivators and barriers they face. Methods: The survey was sent to physiotherapists and exercise physiologists working in IEPs in Brazil. Phone interviews and electronic forms were used to collect the answers to the survey questionnaire. Results: Forty-one of the 261 included dialysis centers had IEPs; 44 professionals answered the questionnaire over the phone and 26 used the electronic form to do it. A total of 70 professionals (mean age 33.4±7.4 years; 84.3% physiotherapists) answered the questionnaire. Resistance training was the preferred mode of therapy. Most of the IEPs were connected to research and were paid for by private health insurance. The desire to work in a different field (30.0%) and lack of resources (31.4%) were the most prevalent motivator and barrier cited by IEP professionals working in dialysis centers, respectively. Conclusion: The majority of the few professionals that work in IEPs in Brazil are physiotherapists. Lack of resources was the most commonly reported barrier faced by survey respondents.

Resumo Objetivo: Avaliar o perfil dos profissionais que atuam em programas de exercício físico intradialítico (EFI) no Brasil e as motivações e barreiras para a atuação desses profissionais. Métodos: Foram incluídos fisioterapeutas e profissionais de educação física que atuam em programas de EFI no Brasil. Para coletar os dados, foi aplicado um questionário por ligação telefônica ou formulário eletrônico. Resultados: Dos 261 centros de diálise analisados, 41 apresentaram programas de EFI, sendo que 44 profissionais responderam ao questionário por telefone e outros 26, por meio eletrônico. Foram avaliados 70 profissionais (33,4±7,4 anos, 84,3% fisioterapeutas). A modalidade terapêutica mais aplicada foi o treinamento resistido. A maioria dos programas de EFI está associada a atividades de pesquisa e é financiada pela saúde suplementar. A possibilidade de atuação em um novo campo de trabalho (30,0%) e a falta de recursos (31,4%) foram a motivação e a barreira mais prevalentes para atuação dos profissionais nos centros de diálise, respectivamente. Conclusão: Poucos profissionais atuam em programas de EFI no Brasil, sendo a maioria fisioterapeutas. A falta de recursos foi a barreira mais prevalente para a atuação desses profissionais.

Profile of professionals working in intradialytic exercise programs in Brazil: a national survey.

OBJECTIVE: This survey was designed to assess the profile of professionals working in intradialytic exercise programs (IEPs) in Brazil and reveal the motivators and barriers they face. METHODS: The survey was sent to physiotherapists and exercise physiologists working in IEPs in Brazil. Phone interviews and electronic forms were used to collect the answers to the survey questionnaire. RESULTS: Forty-one of the 261 included dialysis centers had IEPs; 44 professionals answered the questionnaire over the phone and 26 used the electronic form to do it. A total of 70 professionals (mean age 33.4±7.4 years; 84.3% physiotherapists) answered the questionnaire. Resistance training was the preferred mode of therapy. Most of the IEPs were connected to research and were paid for by private health insurance. The desire to work in a different field (30.0%) and lack of resources (31.4%) were the most prevalent motivator and barrier cited by IEP professionals working in dialysis centers, respectively. CONCLUSION: The majority of the few professionals that work in IEPs in Brazil are physiotherapists. Lack of resources was the most commonly reported barrier faced by survey respondents.

Exercise training during hemodialysis in Brazil: A national survey.

To evaluate the availability and characteristics of exercise training during hemodialysis in Brazil and to identify the reported barriers to exercise program implementation and maintenance. All dialysis units were assessed for eligibility using the database of the Brazilian Society of Nephrology. Each dialysis unit was contacted by telephone and the questions were administered. In dialysis units with exercise training, questions related to personnel involved, exercise components, and program delivery were included. Additionally, the barriers to exercise program implementation and maintenance were evaluated. This study included 261 dialysis units that responded to the survey. Forty-one dialysis units reported exercise training during hemodialysis in Brazil (prevalence of 15.7%). We identified 66 physiotherapists and 10 exercise physiologists in dialysis units with exercise training. Resistance training was the most common program component (92.7%). Hypotension (90.5%) and muscle cramps (85.7%) were the most common adverse events reported. In dialysis units with exercise training, poor patients' adherence to exercise was the most commonly reported barrier. The most prevalent barrier in dialysis units that tried or never tried to implement the exercise programs was a lack of resources. The number of dialysis units that have exercise training during hemodialysis in Brazil is low, and the most common program component is resistance training. A lack of resources was the most prevalent barrier in dialysis units that tried or never tried to implement the exercise programs.

Factors associated with fear of falling in hemodialysis patients.

PURPOSE: Fear of falling (FOF) has important clinical and psychological consequences. This study evaluated the factors associated with FOF in hemodialysis patients and compared with the FOF reported by age-gender matched individuals without chronic kidney disease. METHODS: This cross sectional study included hemodialysis group (n = 60, 55.4 ± 7.6 years, 55.0% male) and control group (n = 40, 55.1 ± 7.5 years, 52.5% male). FOF was assessed by the Falls Efficacy Scale International (FES-I). Physical function was evaluated using the Mini-Balance Evaluation Systems Test (Mini-BESTest), Timed Up and Go test, 4-m gait speed, isometric handgrip force and 10-repetition sit-to-stand test. The physical and mental components of quality of life was evaluated by 36-Item Short Form Health Survey. RESULTS: The FES-I score was higher in the hemodialysis group compared to the control group (28.2 ± 9.7 vs. 23.3 ± 5.1, p = 0.020). In addition, the prevalence of individuals with a higher concern about falling was greater in the hemodialysis group (41.7 vs. 17.5%, p = 0.033). Multiple linear regression showed that the FES-I score was associated with the Mini-BESTest score and the physical component summary of quality of life (coefficient of determination of 0.51 and an adjusted coefficient of determination of 0.46). CONCLUSION: FOF was associated with poor postural balance and reduced physical component of quality of life in patients on hemodialysis and these patients showed higher FOF compared to individuals without chronic kidney disease.

Protective mechanical ventilation in patients with risk factors for ARDS: prospective cohort study.

OBJECTIVE: To evaluate the association that protective mechanical ventilation (MV), based on VT and maximum distending pressure (MDP), has with mortality in patients at risk for ARDS. METHODS: This was a prospective cohort study conducted in an ICU and including 116 patients on MV who had at least one risk factor for the development of ARDS. Ventilatory parameters were collected twice a day for seven days, and patients were divided into two groups (protective MV and nonprotective MV) based on the MDP (difference between maximum airway pressure and PEEP) or VT. The outcome measures were 28-day mortality, ICU mortality, and in-hospital mortality. The risk factors associated with the adoption of nonprotective MV were also assessed. RESULTS: Nonprotective MV based on VT and MDP was applied in 49 (42.2%) and 38 (32.8%) of the patients, respectively. Multivariate Cox regression showed that protective MV based on MDP was associated with lower in-hospital mortality (hazard ratio = 0.37; 95% CI: 0.19-0.73) and lower ICU mortality (hazard ratio = 0.40; 95% CI: 0.19-0.85), after adjustment for age, Simplified Acute Physiology Score 3, and vasopressor use, as well as the baseline values for PaO2/FiO2 ratio, PEEP, pH, and PaCO2. These associations were not observed when nonprotective MV was based on the VT. CONCLUSIONS: The MDP seems to be a useful tool, better than VT, for adjusting MV in patients at risk for ARDS.

Factors Associated with Functional Capacity in CKD Patients.

To evaluate the factors associated with functional capacity in patients with chronic kidney disease (CKD). All patients were submitted to six-minute walk test (6MWT), 10-repetition sit-to-stand test (STS-10) and SF-36 health-related quality of life questionnaire (HRQoL). Patients with functional capacity ≥80% exhibited higher education level, family income, body mass index, estimated glomerular filtration rate, and lower age and STS-10 time. Multiple linear regression showed that gender, age, family income, chronic kidney disease stage, STS-10 time, and physical component summary of HRQoL were significantly associated with the 6MWT distance. Functional capacity was significantly associated with gender, age, family income, CKD stage, STS-10 time, and physical component of HRQoL. The progression of CKD has an impact on the decrease in functional capacity in these patients.

Protective mechanical ventilation in patients with risk factors for ARDS: prospective cohort study / Ventilação mecânica protetora em pacientes com fator de risco para SDRA: estudo de coorte prospectiva

ABSTRACT Objective: To evaluate the association that protective mechanical ventilation (MV), based on VT and maximum distending pressure (MDP), has with mortality in patients at risk for ARDS. Methods: This was a prospective cohort study conducted in an ICU and including 116 patients on MV who had at least one risk factor for the development of ARDS. Ventilatory parameters were collected twice a day for seven days, and patients were divided into two groups (protective MV and nonprotective MV) based on the MDP (difference between maximum airway pressure and PEEP) or VT. The outcome measures were 28-day mortality, ICU mortality, and in-hospital mortality. The risk factors associated with the adoption of nonprotective MV were also assessed. Results: Nonprotective MV based on VT and MDP was applied in 49 (42.2%) and 38 (32.8%) of the patients, respectively. Multivariate Cox regression showed that protective MV based on MDP was associated with lower in-hospital mortality (hazard ratio = 0.37; 95% CI: 0.19-0.73) and lower ICU mortality (hazard ratio = 0.40; 95% CI: 0.19-0.85), after adjustment for age, Simplified Acute Physiology Score 3, and vasopressor use, as well as the baseline values for PaO2/FiO2 ratio, PEEP, pH, and PaCO2. These associations were not observed when nonprotective MV was based on the VT. Conclusions: The MDP seems to be a useful tool, better than VT, for adjusting MV in patients at risk for ARDS.

RESUMO Objetivo: Avaliar a associação da ventilação mecânica (VM) protetora, com base no VT e na pressão de distensão máxima (PDM), com a mortalidade em pacientes com fator de risco para SDRA. Métodos: Este estudo de coorte prospectivo foi conduzido em uma UTI e incluiu 116 pacientes em VM que apresentavam pelo menos um fator de risco para o desenvolvimento de SDRA. Os parâmetros ventilatórios foram coletados duas vezes ao dia durante sete dias, e os pacientes foram divididos em dois grupos (VM protetora e VM não protetora) com base na PDM (diferença entre pressão máxima de vias aéreas e PEEP) ou no VT. Os desfechos foram mortalidade em 28 dias, mortalidade na UTI e mortalidade hospitalar. Os fatores de risco associados com a adoção da VM não protetora também foram avaliados. Resultados: A VM não protetora com base no VT e na PDM ocorreu em 49 (42,2%) e em 38 (32,8%) dos pacientes, respectivamente. A regressão multivariada de Cox mostrou que a VM protetora com base na PDM associou-se a menor mortalidade hospitalar (hazard ratio = 0,37; IC95%: 0,19-0,73) e em UTI (hazard ratio = 0,40; IC95%, 0,19-0,85), após ajuste para idade, Simplified Acute Physiology Score 3, uso de vasopressor e valores basais de PaO2/FiO2, PEEP, pH e PaCO2. Essas associações não foram observadas quando a VM não protetora foi baseada no VT. Conclusões: A PDM parece ser uma ferramenta útil, melhor do que o VT, para o ajuste da VM em pacientes sob risco para SDRA.