RESUMO
OBJECTIVES: To determine the association between mean airway pressure and 90-day mortality in patients with acute respiratory failure requiring mechanical ventilation and to compare the predictive ability of mean airway pressure compared with inspiratory plateau pressure and driving pressure. DESIGN: Prospective observational cohort. SETTING: Five ICUs in Lima, Peru. SUBJECTS: Adults requiring invasive mechanical ventilation via endotracheal tube for acute respiratory failure. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Of potentially eligible participants (n = 1,500), 65 (4%) were missing baseline mean airway pressure, while 352 (23.5%) were missing baseline plateau pressure and driving pressure. Ultimately, 1,429 participants were included in the analysis with an average age of 59 ± 19 years, 45% female, and a mean PaO2/FIO2 ratio of 248 ± 147 mm Hg at baseline. Overall, 90-day mortality was 50.4%. Median baseline mean airway pressure was 13 cm H2O (interquartile range, 10-16 cm H2O) in participants who died compared to a median mean airway pressure of 12 cm H2O (interquartile range, 10-14 cm H2O) in participants who survived greater than 90 days (p < 0.001). Mean airway pressure was independently associated with 90-day mortality (odds ratio, 1.38 for difference comparing the 75th to the 25th percentile for mean airway pressure; 95% CI, 1.10-1.74) after adjusting for age, sex, baseline Acute Physiology and Chronic Health Evaluation III, baseline PaO2/FIO2 (modeled with restricted cubic spline), baseline positive end-expiratory pressure, baseline tidal volume, and hospital site. In predicting 90-day mortality, baseline mean airway pressure demonstrated similar discriminative ability (adjusted area under the curve = 0.69) and calibration characteristics as baseline plateau pressure and driving pressure. CONCLUSIONS: In a multicenter prospective cohort, baseline mean airway pressure was independently associated with 90-day mortality in mechanically ventilated participants and predicts mortality similarly to plateau pressure and driving pressure. Because mean airway pressure is readily available on all mechanically ventilated patients and all ventilator modes, it is a potentially more useful predictor of mortality in acute respiratory failure.
Assuntos
Unidades de Terapia Intensiva/estatística & dados numéricos , Respiração por Pressão Positiva Intrínseca/fisiopatologia , Respiração Artificial/mortalidade , Síndrome do Desconforto Respiratório/terapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Mortalidade Hospitalar , Humanos , Intubação Intratraqueal , Masculino , Pessoa de Meia-Idade , Peru , Estudos Prospectivos , Volume de Ventilação PulmonarRESUMO
OBJECTIVE: To investigate the presence of airway obstruction by determining the FEV1/FVC and FEV1/slow vital capacity (SVC) ratios. METHODS: This was a quantitative, retrospective cross-sectional study. The sample comprised 1,084 individuals who underwent spirometry and plethysmography in a central hospital in Lisbon, Portugal. The study sample was stratified into six groups, by pulmonary function. RESULTS: The analysis of the FEV1/FVC ratio revealed the presence of airway obstruction in 476 individuals (43.9%), compared with 566 individuals (52.2%) for the analysis of the FEV1/SVC ratio. In the airway obstruction, airway obstruction plus lung hyperinflation, and mixed pattern groups, the difference between SVC and FVC (SVC - FVC) was statistically superior to that in the normal pulmonary function, reduced FEF, and restrictive lung disease groups. The SVC - FVC parameter showed a significant negative correlation with FEV1 (in % of the predicted value) only in the airway obstruction plus lung hyperinflation group. CONCLUSIONS: The FEV1/SVC ratio detected the presence of airway obstruction in more individuals than did the FEV1/FVC ratio; that is, the FEV1/SVC ratio is more reliable than is the FEV1/FVC ratio in the detection of obstructive pulmonary disease.
Assuntos
Obstrução das Vias Respiratórias/diagnóstico , Capacidade Vital/fisiologia , Adulto , Idoso , Estudos Transversais , Feminino , Volume Expiratório Forçado/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Pletismografia , Portugal , Respiração por Pressão Positiva Intrínseca/fisiopatologia , Estudos Retrospectivos , Índice de Gravidade de Doença , Espirometria , Estatísticas não ParamétricasRESUMO
OBJECTIVE: To investigate the presence of airway obstruction by determining the FEV1/FVC and FEV1/slow vital capacity (SVC) ratios. METHODS: This was a quantitative, retrospective cross-sectional study. The sample comprised 1,084 individuals who underwent spirometry and plethysmography in a central hospital in Lisbon, Portugal. The study sample was stratified into six groups, by pulmonary function. RESULTS: The analysis of the FEV1/FVC ratio revealed the presence of airway obstruction in 476 individuals (43.9%), compared with 566 individuals (52.2%) for the analysis of the FEV1/SVC ratio. In the airway obstruction, airway obstruction plus lung hyperinflation, and mixed pattern groups, the difference between SVC and FVC (SVC − FVC) was statistically superior to that in the normal pulmonary function, reduced FEF, and restrictive lung disease groups. The SVC − FVC parameter showed a significant negative correlation with FEV1 (in % of the predicted value) only in the airway obstruction plus lung hyperinflation group. CONCLUSIONS: The FEV1/SVC ratio detected the presence of airway obstruction in more individuals than did the FEV1/FVC ratio; that is, the FEV1/SVC ratio is more reliable than is the FEV1/FVC ratio in the detection of obstructive pulmonary disease. .
OBJETIVO: Investigar a ocorrência de obstrução das vias aéreas por meio da relação VEF1/CVF e da relação VEF1/capacidade vital lenta (CVL). MÉTODOS: Estudo do tipo quantitativo, retrospectivo e transversal. A amostra foi constituída por 1.084 indivíduos que realizaram espirometria e pletismografia num hospital central da região de Lisboa, Portugal. A amostra foi estratificada em seis grupos funcionais respiratórios. RESULTADOS: A análise da relação VEF1/CVF revelou a presença de obstrução das vias aéreas em 476 indivíduos (43,9%), enquanto a relação VEF1/CVL detectou a presença dessa em 566 indivíduos (52,2%). A diferença entre a CVL e a CVF (CVL − CVF) nos grupos relativos à obstrução brônquica, à obstrução brônquica com hiperinsuflação pulmonar e à alteração ventilatória mista foi estatisticamente superior àquela encontrada nos grupos sem alteração ventilatória, com diminuição dos FEFs e com restrição pulmonar. O parâmetro CVL − CVF apresentou correlação negativa significativa com VEF1 em % do previsto apenas no grupo com obstrução brônquica com hiperinsuflação pulmonar. CONCLUSÕES: A relação VEF1/CVL detectou a presença de obstrução das vias aéreas em um número maior de indivíduos que a relação VEF1/CVF, ou seja, a relação VEF1/CVL é mais confiável na detecção de alterações ventilatórias obstrutivas. .