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 supplementary 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 supplementary oxygen is done by providing oxygen via nasal prongs at a flow rate of 2-4 L/min for during the specific exercise that causes desaturation. If the patient shows improved oxygen saturation or improved exercise tolerance or reduced dyspnoea when using oxygen, supplementary oxygen should then be given in future exercise training sessions.
Specific exercises that often cause desaturation in susceptible patients include moderate to high intensity walking, climbing stairs, doing 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 found to benefit from supplementary oxygen should, where possible, be provided with supplementary oxygen to use during their unsupervised home exercise training program. These patients should be encouraged to use oxygen for all physical activity involving large muscle mass (eg. showering) within their home setting.
Patients receiving LTOT (long-term oxygen therapy) must train using supplementary 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.
Supplementary 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).
In patients who desaturate during exercise, the benefit of supplementary oxygen during exercise to enhance the training effect of exercise is not well established (see Nonoyama 2007).
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 chose 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.