Abstract
BACKGROUND: Few studies have investigated non-invasive positive pressure ventilation (NPPV) in acute respiratory distress syndrome (ARDS).
OBJECTIVE: To investigate variables predictive of NPPV success and prognosis factor in patients with ARDS.
DESIGN: prospective, three hospitals cohort study.
METHOD: Predictive factor of NPPV success were analyzed with logistic regression. Prognostic factor in patients with ARDS analyzed with Cox proportional hazard model. Prognostic factor of NPPV was examined using with Cox proportional model (CPHM). Two models were examined. Namely
Model1: all prognostic factors were time-independent factors
Model2: Respiratory care was time-dependent factor and others were time-independent factors
RESULTS: NPPV failed in 51% (19/37) of patients. Stepwise analysis identified arterial pH (OR 1.94, 95% CI 1.21-3.11) and respiratory rate (OR 0.86, 95% CI 0.78-0.96). Stepwise analysis in model 1 indentified arterial pH(0.1unit) (HR 5.96, 95%CI 2.03-17.5) a simplified acute physiologic score (SAPS II) (HR 1.15 95%CI 1.05-1.26) and arterial pCO2 (HR1.10 95%CI 1.01-1.21). However the interaction between pCO2 and arterial pH are significant at 0.05 level. Stepwise analysis in model 2 indentified respiratory care (HR 5.44 95%CI 1.19-24.9), arterial pH(0.1 unit) (HR 3.04 95%CI 1.19-7.81),and SAPS II(HR1.12 95%CI 1.03-1.22). There is no interaction of these factors.
CONCLUSION: Time-dependents covariates are useful for examining the prognostic factors of ARDS. We decide prognostic factors of ARDS in first-line NPPV are SAPS II and arterial pH.
- © 2013 ERS