Prognosis of patients with acute exacerbation of chronic obstructive pulmonary disease treated with invasive mechanical ventilation: Is the "40 percent rule" valid?
Abstract
Introduction: The prognosis of patients with chronic obstructive pulmonary disease (COPD) is affected by the frequency and severity of acute exacerbations (AEs). In the treatment of severe AEs of COPD, mechanical ventilation is used, with the non-invasive approach being preferred.
Patients treated with invasive mechanical ventilation (IMV) have a high risk of death and low one-year survival. According to our previous experience, about 40 % of patients die on the ventilator and about 40 % survive one year after intubation (a "40 percent rule").
Methods: Included in the study were patients with AEs of COPD treated with IMV at the Respiratory Intensive Care Unit of the Department of Pneumology, 22nd Faculty of Medicine, Charles University in Prague and University Hospital Motol between 2009 and 2014. Outcomes of IMV (weaning from the ventilator or death) and subsequent hospital stay (discharge to outpatient care or death) as well as the time spent on IMV and overall survival time from intubation were analyzed.
Potential predictors of IMV outcomes and one-year survival from intubation were also evaluated. Results: The study comprised 47 patients (25 males) with a median (IQR) age of 67.3 (62.7-76.9) years.
Fifteen patients (32 %) died during IMV. Among those weaned from the ventilator, another 10 patients (21 %) died during their subsequent hospital stay and only 22 (47 %) persons were discharged from the hospital.
In regression analysis with adjustment for age and sex, the presence of long-term oxygen therapy (LTOT) was an independent predictor of death during IMV (p = 0.049). The median (IQR) duration of IMV was 20 (10-43) days and the median (IQR) survival time from intubation was 0.51 (0.12-1.85) years.
Nineteen (40 %) patients survived one year after intubation. Conclusions: The prognosis of patients with AEs of COPD requiring treatment with IMV is unfavorable.
As many as 32 % of patients die during IMV and one-year survival is 40 %.