Use of Supplemental Oxygen during Exercise Training
Oxygen saturation should be regularly monitored using a pulse oximeter especially during lower limb exercise training. This is particularly important at the start of a training program and when the intensity or the duration of exercise is increased.
Patients who desaturate below an oxygen saturation of 88% during exercise training, despite the use of interval training, should be assessed to determine the benefit of supplemental oxygen. These patients should be assessed in a hospital-based program to determine the benefit of oxygen and the required flow rate for exercise. Assessment for supplemental oxygen is done by providing oxygen via nasal prongs at a flow rate of 2-4 L/min during the specific exercise that causes desaturation.
If the patient is not on long term oxygen therapy (LTOT) but desaturates during exercise and shows an improved exercise tolerance or reduced dyspnoea when using oxygen, supplemental oxygen could be considered for use during exercise training. However, please not that a recent large randomised controlled trial evaluating PR with and without oxygen supplementation in people who desaturated during exercise (but who were not on LTOT) showed no differences in the improvements in exercise capacity or health-related quality of life with supplemental oxygen compared to medical air.23
Specific exercises that often cause desaturation in susceptible patients include moderate to high intensity walking, climbing stairs, step-ups and sit-to-stand.
In general, cycling induces less oxygen desaturation than walking in patients with COPD.
Desaturation during small muscle mass exercise (e.g. arm exercise) is not very common.
Patients receiving LTOT (long-term oxygen therapy) must train using supplemental oxygen. It is usually necessary to increase the flow rate by 1-2 L/min, above the prescribed flow rate, when the patient is exercising. Any guidelines and/or potential change to the patient’s prescribed O2 would need to be discussed with the patient’s medical practitioner whom prescribed oxygen.
Supplemental oxygen in patients with chronic lung disease is provided mainly for safety reasons and to decrease the work of the right heart (i.e. by minimising hypoxic vasoconstriction of the pulmonary vessels).
- For those on LTOT
- Methods available for transporting small portable oxygen cylinders include a portable trolley, small suitcase with handle and wheels such as can be taken on board a plane, or in the basket attached to a wheeled walker (rollator).
- Some patients may choose to carry their oxygen cylinder in a shoulder bag, however the cylinder, especially if a conservation device is also used, may limit exercise tolerance due to the additional weight.
- Portable oxygen concentrators are now available. However, it is necessary to regularly monitor oxygen saturation in patients using these when exercising to ensure that sufficient oxygen is delivered, especially if a conserving device is used.