A randomized controlled trial of supplemental oxygen versus air in cancer patients with dyspnea

The symptomatic benefits of oxygen in patients with cancer who have nonhypoxic dyspnea are not well defined.

To determine whether or not oxygen is more effective than air in decreasing dyspnea and fatigue and increasing distance walked during a 6-minute walk test.

Patients with advanced cancer who had no severe hypoxemia (i.e., had an O2 saturation level of > or = 90%) at rest and had a dyspnea intensity of > or = 3 on a scale of 0-10 (0 = no shortness of breath, 10 = worst imaginable shortness of breath) were recruited from an outpatient thoracic clinic at a comprehensive cancer center. This was a double-blind, randomized crossover trial. Supplemental oxygen or air (5 L/min) was administered via nasal cannula during a 6-minute walk test. The outcome measures were dyspnea at 3 and 6 minutes, fatigue at 6 minutes, and distance walked. We also measured oxygen saturation levels at baseline, before second treatment phase, and at the end of study.

In 33 evaluable patients (31 with lung cancer), no significant differences between treatment groups were observed in dyspnea, fatigue, or distance walked (dyspnea at 3 minutes: P = 0.61; dyspnea, fatigue, and distance walked at 6 minutes: P = 0.81, 0.37, and 0.23, respectively).

Currently, the routine use of supplemental oxygen for dyspnea during exercise in this patient population cannot be recommended.