Predictors of hospital outcome and intubation in COPD patients admitted to the respiratory ICU for acute hypercapnic respiratory failure

Abstract

Background: Mortality rate, the possible factors affecting mortality and intubation in patients with acute exacerbation of chronic obstructive pulmonary diseases (COPD) and hypercapnic respiratory failure (RF) are yet unclear.

Objective: To identify the possible factors affecting mortality and intubation in COPD patients.

Design: A prospective study using data obtained over the first 24h of respiratory intensive care unit (RICU) admission. Consecutive admissions of 656 patients were monitored and 151 of them who had acute exacerbation of COPD and hypercapnic RF were enrolled.

Setting: University hospital, Department of Chest Diseases, RICU.

Results: Mean age was 65.1 years. The mean APACHE II score was 23.7. Eighty-seven patients (57.6%) received mechanical ventilation (MV) via an endotracheal tube for more than 24 h. Twenty-two patients received non-invasive ventilation (NIV). Fifty patients died (33.1%) in hospital during the study period. The mortality rate was 52.9% in patients in need of MV. In the multivariate analysis, the need for intubation, inadequate metabolic compensation for respiratory acidosis, and low (=bad) Glasgow Coma Score (GCS) were determined as independent factors associated with mortality. The low GCS (OR: 0.61; CI: 0.48-0.78) and high APACHE II score (OR: 1.24; CI: 1.11-1.38) were determined as factors associated with intubation.

Conclusion: The most important predictors related to hospital mortality were the need for invasive ventilation and complications to MV. Adequate metabolic compensation for respiratory acidosis at admittance is associated with better survival. A high APACHE II score and loss of consciousness (low GCS) were independent predictors of a need to intubate patients.