Objective: To investigate the effect of oxygen therapy on outcome and on symptomatic hypercapnia.
Design: Randomized, controlled, single-blind study.
Setting: Multidisciplinary intensive care unit of a university teaching hospital.
Patients: Patients admitted with a clinical diagnosis of an acute exacerbation of chronic obstructive pulmonary disease and a PaO2 <6.6 kPa (50 mm Hg) and PaCO2 >6.6 kPa (50 mm Hg) on air.
Interventions: Patients received oxygen therapy titrated to increase arterial oxygen tension to >6.6 kPa (50 mm Hg) or >9 kPa (70 mm Hg). Patients in the low-oxygen tension group also received doxapram if they developed an acidosis with pH <7.2, whereas those in the high-oxygen tension group received doxapram if they developed symptomatic acidosis. Bronchodilator, steroid, and antibiotic therapy was standardized.
Measurements and main results: Two patients in the low-oxygen tension group (n = 17) required mechanical ventilation and another one died. No patients in the high-oxygen group (n = 17) had a poor outcome, but this difference was not significant. No patient in either group became comatose or developed an acute cardiac arrhythmia.
Conclusions: Traditional teaching related to oxygen therapy for hypercapnic patients with an acute exacerbation of chronic obstructive pulmonary disease may be incorrect. A large randomized, controlled study is required to confirm this impression.