The effects, of oxygen therapy in patients presenting to an emergency department with exacerbation of chronic obstructive pulmonary disease

Objective: To elucidate oxygen administration practices in the setting of acute exacerbations of chronic obstructive pulmonary disease (COPD) and compare these practices with those recommended in internationally accepted guidelines. Design: Retrospective audit. Participants and setting: 65 patients admitted to a Melbourne university teaching hospital via the emergency department (ED), identified through medical records by a discharge diagnosis (discharged between 1 June and 30 September 2005) of acute exacerbation of COPD (AECOPD). Those included had respiratory function test results consistent with British Thoracic Society guidelines for the diagnosis of COPD. Main outcome measures: Length of stay, need for high dependency unit (HDU) admission, use of non-invasive ventilation (NIV), and use of arterial blood gas (ABG) tests. Results: Our audit showed that 95% of patients defined as retaining carbon dioxide received oxygen at a flow rate greater than 2 L/min. This process began in the ambulance and continued in the ED, often without monitoring of ABG levels. Length of stay was significantly longer (P = 0.029); need for NIV on admission greater (P = 0.0124); and rate of admission to the HDU higher (P = 0.0124) in patients who achieved a partial pressure of arterial oxygen (PaO2) >= 74.5 mmHg compared with those with a PaO2 < 74.5 mmHg. Conclusions: The vast majority of patients with AECOPD presenting to our university teaching hospital receive oxygen therapy outside of internationally accepted guidelines, often without monitoring of ABG levels. The use of high-flow oxygen may contribute to an increased length of stay, more frequent admission to HDU and greater use of NIV among patients who achieve a higher PaO2.