Intensive Care Unit and 12-month Mortality of Patients with Acute Respiratory Failure Admitted to the Intensive Care Unit: What is the Role of Comorbidities?

Objectives: There are limited data regarding the effect of comorbidities in the intensive care unit (ICU) and 12-month mortality rates of patients with acute respiratory failure (ARF) who are admitted to the ICU. The present investigation was designed to determine the effect of comorbidities and identify long-term mortality predictors in this patient group. Methods: A retrospective observational cohort study was performed in a 22-bed, tertiary ICU in a teaching and research hospital. All patients who were admitted to the ICU during 2012 were included in the study. Demographics, comorbidities, ICU data at the time of admission, and the last control were recorded. ICU mortality and 12-month mortality after ICU discharge were analyzed by Cox regression and Kaplan-Meier survival analysis. Results: During the study period, 1022 patients (362 females) were admitted to the ICU, and the ICU mortality was 20.8%. Older age, non-invasive mechanical ventilation failure, more invasive mechanical ventilation days, tachycardia, Acute Physiological and Chronic Health Evaluation (APACHE II) score at the time of admission, low albumin, and the ratio of partial arterial oxygen pressure to inspired fractionated oxygen were associated with increased mortality. Interestingly, the presence of chronic obstructive pulmonary disease (COPD) was associated with decreased mortality. The 12-month mortality rate of the 809 patients who were discharged from the ICU was 51.9% (n = 420). Half of these patients died within the first 2 months after discharge. Cancer, low albumin, and higher APACHE II score at the time of discharge were identified as mortality risk factors. Conclusion: Patients with ARF who are admitted to the ICU have a higher rate of mortality, and only half survive >1 year after discharge. COPD is a comorbid disease associated with an increased likelihood of long-term survival, whereas malignancy is associated with poor prognosis after ICU discharge.