Analysis of the clinical effect of noninvasive positive pressure ventilation in the treatment of acute respiratory distress syndrome

Abstract

Objective To evaluate the clinical efficacy of noninvasive positive pressure ventilation (NPPV) in the treatment of patients with acute respiratory distress syndrome (ARDS), and to look for the predictors of failure of NPPV. Methods A retrospective observation was conducted. ARDS patients underwent NPPV admitted to emergency intensive care unit (EICU) of Guangdong General Hospital from January 2013 to December 2015 were enrolled. The patients were divided into success group and failure group according to the clinical efficacy. The condition of the patients in the two groups was evaluated, and ARDS classification and acute physiology and chronic health evaluation Ⅱ (APACHE Ⅱ) score before treatment were recorded. Etiological composition of ARDS was analyzed. The parameters, including heart rate (HR), respiratory rate (RR), oxygenation index (PaO2/FiO2), arterial partial pressure of oxygen (PaO2), arterial partial pressure of carbon dioxide (PaCO2) and arterial oxygen saturation (SaO2), were recorded before and 2 hours after the treatment of NPPV. Multivariate logistic regression analysis was conducted for predicting the independent factors inducing the failure of NPPV treatment of patients with ARDS. Results The date of 137 patients with ARDS were collected, excluding the followed patients, 6 with coma, 18 with hemodynamic instability, 5 with severe hypoxia, and 5 with incomplete date. Finally, a total of 103 patients entered the statistics. There were 69 patients in NPPV success group, and 34 in failure group. Compared with success group, APACHE Ⅱ score in the failure group was higher (21.4±6.2 vs. 19.7±8.9), the ratios of patients with severe ARDS and those induced by pulmonary infection were higher [82.4% (28/34) vs. 5.8% (4/69), 32.4% (11/34) vs. 8.7% (6/69), respectively, both P < 0.05]. HR and RR before NPPV in the failure group were significantly higher than those of success group [HR (bpm): 124±13 vs. 117±12, RR (bpm): 39±5 vs. 33±4], and PaO2/FiO2, PaO2, PaCO2, and SaO2 were significantly lower than those of the success group [PaO2/FiO2 (mmHg, 1 mmHg = 0.133 kPa): 104±10 vs. 156±12, PaO2 (mmHg): 53±8 vs. 68±7, PaCO2 (mmHg): 31±5 vs. 37±7, SaO2: 0.83±0.07 vs. 0.91±0.05, all P < 0.05]. It was shown by logistic regression analysis that severe ARDS [odds ratio (OR) = 10.533, 95% confidence interval (95%CI) = 5.847-89.852, P = 0.000], pulmonary infection resulted ARDS (OR = 4.831, 95%CI = 1.688-13.825, P = 0.003) and PaO2/FiO2 < 140 mmHg 2 hours after treatment (OR = 7.049, 95%CI = 1.266-39.236, P = 0.026) were the independent risk factors of NPPV failure for the treatment of patients with ARDS. Conclusions Patients with severe ARDS and pulmonary infection derived ARDS were the risk factors of failure to NPPV in ARDS. Lack of improvement in oxygenation 2 hours after NPPV is the predictor of NPPV failure and change to invasive ventilation. Key words: Noninvasive positive pressure ventilation; Acute respiratory distress syndrome; Treatment failure; Risk factor