ABSTRACT Objective: To compare the diagnostic performance of maximal expiratory pressure with maximal expiratory pressure during induced cough for predicting extubation failure within 72 hours in patients who completed a spontaneous breathing trial (SBT). Methods: The study was conducted between October 2018 and September 2019. All patients aged over 18 years admitted to the intensive care unit who required invasive mechanical ventilation for over 48 hours and successfully completed a spontaneous breathing trial were included. The maximal expiratory pressure was assessed with a unidirectional valve for 40 seconds, and verbal encouragement was given. The maximal expiratory pressure during induced cough was measured with slow instillation of 2mL of a 0.9% saline solution. The primary outcome variable was extubation failure. Results: Eighty patients were included, of which 43 (54%) were male. Twenty-two patients [27.5% (95%CI 18.9 - 38.1)] failed extubation within 72 hours. Differences were observed in the maximal expiratory pressure during induced cough between the group who failed extubation, with a median of 0cmH2O (P25-75: 0 - 90), and the group without extubation failure, with a median of 120cmH2O (P25-75: 73 - 120); p < 0.001. Conclusion: In patients who completed a spontaneous breathing trial, the maximal expiratory pressure during induced cough had a higher diagnostic performance for predicting extubation failure within 72 hours. Clinicaltrials.gov Registry:NCT04356625

RESUMO Objetivo: Comparar o desempenho diagnóstico da pressão expiratória máxima com a pressão expiratória máxima durante a tosse induzida para prever a falha na extubação em 72 horas em pacientes que completaram o teste de respiração espontânea. Métodos: O estudo foi realizado entre outubro de 2018 e setembro de 2019. Foram incluídos todos os pacientes com mais de 18 anos admitidos à unidade de terapia intensiva que necessitavam de ventilação mecânica invasiva durante mais de 48 horas e completaram com sucesso o teste de respiração espontânea. A pressão expiratória máxima foi avaliada com uma válvula unidirecional durante 40 segundos, e foi dado encorajamento verbal. A pressão expiratória máxima durante a tosse induzida foi medida com instilação lenta de 2mL de solução salina a 0,9%. A variável do desfecho primário foi a falha na extubação. Resultados: Foram incluídos 80 pacientes, dos quais 43 (54%) eram do sexo masculino. Verificou-se falha na extubação de 22 pacientes [27,5% (IC95% 18,9 - 38,1)] em 72 horas. Observou-se diferença entre a pressão expiratória máxima durante a tosse induzida do grupo com falha na extubação, com mediana de 0cmH2O (P25-75 de 0 - 90) e do grupo sem falha na extubação, com mediana de 120cmH2O (P25-75 de 73 - 120), com p < 0,001. Conclusão: Em pacientes que completaram o teste de respiração espontânea, a pressão expiratória máxima durante a tosse induzida apresentou melhor desempenho diagnóstico para prever falha na extubação em 72 horas. Registro Cliniclatrials.gov:NCT04356625

ABSTRACT Objective: This paper sought to determine the accumulated incidence and analyze the risk factors associated with the development of weakness acquired in the intensive care unit and its relationship to inspiratory weakness. Methods: We conducted a prospective cohort study at a single center, multipurpose medical-surgical intensive care unit. We included adult patients who required mechanical ventilation ≥ 24 hours between July 2014 and January 2016. No interventions were performed. Demographic data, clinical diagnoses, the factors related to the development of intensive care unit -acquired weakness, and maximal inspiratory pressure were recorded. Results: Of the 111 patients included, 66 developed intensive care unit -acquired weakness, with a cumulative incidence of 40.5% over 18 months. The group with intensive care unit-acquired weakness were older (55.9 ± 17.6 versus 45.8 ± 16.7), required more mechanical ventilation (7 [4 - 10] days versus 4 [2 - 7.3] days), and spent more time in the intensive care unit (15.5 [9.2 - 22.8] days versus 9 [6 - 14] days). More patients presented with delirium (68% versus 39%), hyperglycemia > 3 days (84% versus 59%), and positive balance > 3 days (73.3% versus 37%). All comparisons were significant at p < 0.05. A multiple logistic regression identified age, hyperglycemia ≥ 3 days, delirium, and mechanical ventilation > 5 days as independent predictors of intensive care unit-acquired weakness. Low maximal inspiratory pressure was associated with intensive care unit-acquired weakness (p < 0.001), and the maximum inspiratory pressure cut-off value of < 36cmH2O had sensitivity and specificity values of 31.8% and 95.5%, respectively, when classifying patients with intensive care unit-acquired weakness. Conclusion: The intensive care unit acquired weakness is a condition with a high incidence in our environment. The development of intensive care unit-acquired weakness was associated with age, delirium, hyperglycemia, and mechanical ventilation > 5 days. The maximum inspiratory pressure value of ≥ 36cmH2O was associated with a high diagnostic value to exclude the presence of intensive care unit -acquired weakness.

RESUMEN Objetivo: Conocer la incidencia acumulada y analizar los factores riesgo asociados al desarrollo de debilidad adquirida en la unidad de cuidados intensivos y su asociación con la debilidad inspiratoria. Métodos: Estudio de cohorte prospectivo en un solo centro, unidad de cuidados intensivos médico-quirúrgica polivalente. Se incluyeron pacientes adultos, que hayan requerido ventilación mecánica ≥ 24 horas entre julio de 2014 y enero de 2016. No hubo intervenciones. Se registraron datos demográficos, diagnóstico clínico y factores relacionados con el desarrollo de debilidad adquirida en la unidad de cuidados intensivos y Presión inspiratoria máxima. Resultados: Ciento once pacientes incluidos, 66 desarrollaron debilidad adquirida en la unidad de cuidados intensivos, con una incidencia acumulada del 40,5% en 18 meses. El grupo con debilidad adquirida en la unidad de cuidados intensivos presentó mayor edad (55,9 ± 17,6 versus 45.8 ± 16.7), además de más días con ventilación mecánica (7 [4 - 10] versus 4 [2 - 7,3]), más días en unidad de cuidados intensivos (15,5 [9,2 - 22,8] versus 9 [6 - 14]). Hubo más pacientes con delirio (68% versus 39%), con hiperglucemia > 3 días (84% versus 59%); y con balance positivo > 3 días (73,3% versus 37%). Todas las comparaciones fueron significativas con p < 0,05. La regresión logística múltiple identificó a la edad, la hiperglucemia ≥ 3 días, el delirio y la ventilación mecánica > 5 días como predictores independientes para debilidad adquirida en la unidad de cuidados intensivos. La presión inspiratoria máxima baja se asoció a debilidad adquirida en la unidad de cuidados intensivos (p < 0,001) y el punto de corte presión inspiratoria máxima < 36cmH2O obtuvo una sensibilidad y especificidad del 31,8% y 95,5% para clasificar al grupo con debilidad adquirida en la unidad de cuidados intensivos. Conclusión: La debilidad adquirida en la unidad de cuidados intensivos es una condición con un alta incidencia en nuestro medio. El desarrollo de debilidad adquirida en la unidad de cuidados intensivos se asoció a la edad, delirio, hiperglucemia y la ventilación mecánica > 5 días. La presión inspiratoria máxima ≥ 36cmH2O demostró un alto valor diagnóstico para descartar la presencia de debilidad adquirida en la unidad de cuidados intensivos.