The role of supplemental oxygen during submaximal exercise in patients with cystic fibrosis

Abstract

Repeated bouts of submaximal exercise are an important part of most pulmonary rehabilitation programmes. Patients with moderate-to-severe cystic fibrosis (CF) often demonstrate oxygen desaturation during submaximal exercise, which may limit their ability to participate in these programmes. This study examines whether arterial desaturation contributes to submaximal exercise limitation by testing whether supplemental O2improves submaximal exercise capacity.Eight patients with CF (mean forced expiratory volume in one second 41% predicted) each underwent two submaximal exercise tests on a bicycle ergometer at 80% of maximal workload. The two tests were identical except for the addition of supplemental O2(inspiratory O2fraction 39%) during one of the tests.Exercise duration was significantly longer in the supplemental O2studyversuscontrol (673±63 sversus835±99 s). Arterial O2saturation was also higher in the supplemental O2study than the control exercise test (96±0.3%versus86±1.5%). There was no statistical difference at end exercise between O2consumption, minute ventilation and heart rate. There was a significant relationship between improvement in exercise capacity and the amount of desaturation during the control exercise test.Results indicate that supplemental oxygen improves submaximal exercise capacity in patients with moderate-to-severe cystic fibrosis. Oxygen therapy may be an important intervention to improve participation and maximise the benefits of pulmonary exercise rehabilitation programmes.

Individualized supervised resistance training during nebulization in adults with cystic fibrosis

“…This protocol was designed to ensure that all patients trained with a consistent and progressive amount of resistive force. In an attempt to reduce exercise-induced hypoxemia and increase exercise tolerance, oxygen supply and adaptations, the exercise program was during the patients’ nebulizing times 6. In addition, this RT and nebulization protocol was performed concurrently in an attempt to relieve the time-burden of treatments on CF patients.…”

“…The concurrent use of RT would not only increase the efficacy of nebulization, but may itself provide additional benefits to the CF patient without resulting in an additional time burden on CF patients. In turn, the use of nebulization during RT could reduce exercise-induced hypoxemia and increase exercise tolerance, oxygen supply and adaptations6 and thus overcome the primary reason that many CF patients abstain from exercise. Interestingly, since dyspnoea limits the exercise adherence and intensity, RT, which causes less dyspnoea7, it could be an alternative mode of exercise for CF patients.…”

The repeatability of submaximal endurance exercise testing in cystic fibrosis

“…The incremental exercise test and test 1 were separated by 48 hr, submaximal tests one and two were separated by 5 days, while submaximal endurance tests two and three were separated by 28 days. Eighty percent of maximum workload as an endurance workload has been used by others in the past, 21,27 and was chosen based on the power-duration relationship described by others. 28 Sense of dyspnea was assessed using the Borg scale 29 in response to the question, ''How breathless do you feel?''…”

Clinical Exercise Testing in Children and Adolescents with Cystic Fibrosis

“… intensity 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 15 work may avoid arterial oxygen desaturation as well as improve exercise performance in patients with advanced pulmonary disease (66)(67)(68) …”