Risk assessment of acute exacerbation of chronic obstructive pulmonary disease treated by noninvasive mechanical ventilation

Abstract

Objective To analyze the risk factors for the failure of noninvasive mechanical ventilation (NIV) in the treatment of acute exacerbation of chronic obstructive pulmonary disease (AECOPD), and to help the clinical risk assessment and decision making. Methods A retrospective case control study was conducted. The patients with AECOPD undergoing NIV admitted to Kaifeng Emergency Center from June 2011 to March 2016 were enrolled, and they were divided into two groups according to whether NIV was successful or not within 12 hours. The nutritional status, blood gas analysis, serum electrolytes, D-dimer, renal function, serum pre-albumin, as well as kinetic vital signs, Glasgow coma scale (GCS) score, expression of respiratory distress, and spontaneous expectoration were recorded. Logistic forward stepwise regression analysis was used to analyze the factors for failure of NIV. Results 122 patients with the initial NIV were enrolled, with NIV failure in 41 patients within 12 hours, accounted for 33.6%. Compared with NIV success group, the percents of respiratory rate ≥ 25 breaths/min (75.6% vs. 17.3%), expectoration disorders (78.0% vs. 19.8%), circulatory disorders (61.0% vs. 18.5%), malnutrition (61.0% vs. 11.1%), decreased serum pre-albumin (58.5% vs. 17.3%), and GCS score < 12 (75.6% vs. 28.4%) in NIV failure group were significantly increased (all P < 0.05). But there were no significant differences in gender, age, body temperature, blood gas analysis, D-dimer, serum creatinine between two groups. It was shown by the results of binary logistic regression analysis that respiratory rate, expectoration disorders, circulatory disorders, malnutrition, serum pre-albumin, and GCS score were the factors of NIV failure [odds ratio (OR) values were 10.879, 6.338, 9.860, 23.273, 8.862, 6.774, and P values were 0.011, 0.038, 0.024, 0.003, 0.015, 0.041, respectively]. It was shown by the results of logistic stepwise regression analysis that respiratory rate ≥ 25 breaths/min, expectoration disorders, circulatory disorders, malnutrition, decreased serum pre-albumin, and GCS score < 12 were independent risk factors of NIV failure (OR values were 6.610, 5.403, 5.138, 8.153, 4.979, 5.100, and P values were 0.007, 0.013, 0.023, 0.007, 0.027, 0.023, respectively). Conclusions The multiple independent risk factors can induce NIV failure within 12 hours in emergency patients with AECOPD, i.e. increased respiratory rate, expectoration dysfunction, circulatory disorders, malnutrition, decreased serum pre-albumin, and decreased GCS score. Emergency physicians should pay attention to these early risk factors in AECOPD patients, which can be taken as correct judgment and guide. Key words: Acute exacerbation of chronic obstructive pulmonary disease; Noninvasive mechanical ventilation; Risk factor