How do COPD comorbidities affect ICU outcomes?

BACKGROUND AND AIM: Chronic obstructive pulmonary disease (COPD) patients with acute respiratory failure (ARF) frequently require admission to the intensive care unit (ICU) for application of mechanical ventilation (MV). We aimed to determine whether comorbidities and clinical variables present at ICU admission are predictive of ICU mortality.

METHODS: A retrospective, observational cohort study was performed in a tertiary teaching hospital's respiratory ICU using data collected between January 2008 and December 2012. Previously diagnosed COPD patients who were admitted to the ICU with ARF were included. Patients' demographics, comorbidities, body mass index (BMI), ICU admission data, application of noninvasive and invasive MV (NIV and IMV, respectively), cause of ARF, length of ICU and hospital stay, and mortality were recorded from their files. Patients were grouped according to mortality (survival versus non-survival), and all the variables were compared between the two groups.

RESULTS: During the study period, a total of 1,013 COPD patients (749 male) with a mean age (standard deviation) of 70 ± 10 years met the inclusion criteria. Comorbidities of the non-survival group (female/male, 40/131) were significantly higher compared with the survival group (female/male, 224/618): arrhythmia (24% vs 11%), hypertension (42% vs 34%), coronary artery disease (28% vs 11%), and depression (7% vs 3%) (P<0.001, P<0.035, P<0.001, and P<0.007, respectively). Logistic regression revealed the following mortality risk factors: need of IMV, BMI <20 kg/m(2), pneumonia, coronary artery disease, arrhythmia, hypertension, chronic hypoxia, and higher acute physiology and chronic health evaluation II (APACHE II) scores. The respective odds ratios, confidence intervals, and P-values for each of these were as follows: 27.7, 15.7-49.0, P<0.001; 6.6, 3.5-412.7, P<0.001; 5.1, 2.9-8.8, P<0.001; 2.9, 1.5-5.6, P<0.001; 2.7, 1.4-5.2, P<0.003; 2.6, 1.5-4.4, P<0.001; 2.2, 1.2-3.9, P<0.008; and 1.1, 1.03-1.11, P<0.001.

CONCLUSION: Patients with severe COPD and cardiac comorbidities and cachexia should be closely monitored in ICU due to their high risk of ICU mortality.