Factors affecting mortality in patients with COPD exacerbations requiring ICU admission

Abstract

Background: Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) often require hospital admission and have a significant mortality rate. Patients with AECOPD who need intensive care (ICU) have higher mortality rates. Identifying factors associated with increased mortality might change approaches to treatment and improve communication with patients’ families about prognosis.

Methods: Patients with AECOPD (ICD 9 code 491.21) directly admitted to the ICU between 1/1/2006 and 12/31/2010 were retrospectively reviewed. The inclusion criteria were age 45 years or older, diagnosis of AECOPD, and admission to an ICU. The exclusion criteria included any history of another respiratory disease or decompensated cardiac disease. The primary goal was to determine factors which affect survival.

Result: Two hundred and seventeen patients were included this study. The mean ages were 70.4±10.4 years in the in-hospital death group and 66.4±10.9 years in the survivors. The overall mortality rate was 12%.  Multivariate analysis showed that the mortality rate was significantly associated with a low mean arterial blood pressure (MAP) (odds ratio [OR] 0.91, 95% confidence interval [CI] 0.86-0.96), an intubation event (OR 6.12, 95% CI 1.24-30.87), and an elevated blood urea nitrogen (BUN) (OR 1.06, 95% CI 1.01-1.12) (p<0.05 for each factor).

Conclusion: This study identified clinical parameters associated with increased mortality in patients with AECOPD admitted to an ICU. These factors include a low MAP, intubation, and a high BUN and are easily obtained during the initial evaluation of the patient. They reflect the severity of the acute exacerbation and complications in other organ systems.