Characteristics and outcomes of patients with chronic obstructive pulmonary disease admitted to the intensive care unit due to acute hypercapnic respiratory failure

Abstract

Background: The study aimed to describe the clinical course, outcomes, and prognostic factors of chronic obstructive pulmonary disease (COPD) patients with acute hypercapnic respiratory failure. Methods: This retrospective study involved patients with acute hypercapnic respiratory failure due to COPD of any cause admitted to the intensive care unit (ICU) for non-invasive or invasive mechanical ventilation (IMV) support between December 2015 and February 2020. Results: One hundred patients were evaluated. The main causes of acute hypercapnic respiratory failure were bronchitis, pneumonia, and heart failure. The patients’ mean Acute Physiology and Chronic Health Evaluation (APACHE) II score was 23.0±7.2, and their IMV rate was 43%. ICU, in-hospital, and 90-day mortality rates were 21%, 29%, and 39%, respectively. Non-survivors had more pneumonia, shock within the first 24 hours of admission, IMV, vasopressor use, and renal replacement therapy, along with higher APACHE II scores, lower admission albumin levels and PaO2/ FiO2 ratios, and longer ICU and hospital stays than survivors. Logistic regression analysis identified APACHE II score (odds ratio [OR], 1.157; 95% confidence interval [CI], 1.017–1.317; P=0.026), admission PaO2/FiO2 ratio (OR, 0.989; 95% CI, 0.978–0.999; P=0.046), and vasopressor use (OR, 8.827; 95% CI, 1.650–47.215; P=0.011) as predictors of ICU mortality. APACHE II score (OR, 1.099; 95% CI, 1.021–1.182; P=0.011) and admission albumin level (OR, 0.169; 95% CI, 0.056–0.514; P=0.002) emerged as predictors of 90-day mortality. Conclusions: APACHE II scores, the PaO2/FiO2 ratio, vasopressor use, and albumin levels are significant short-term mortality predictors in severely ill COPD patients with acute hypercapnic respiratory failure.