Exercise Endurance in Chronic Obstructive Pulmonary Disease Patients at an Altitude of 2640 meters Breathing Air and Oxygen (FIO2 28% and 35%): A Randomized Crossover Trial. (1st August 2014)

• Record Type: Journal Article
• Authors: Maldonado, Dario; González-García, Mauricio; Barrero, Margarita; Jaramillo, Claudia; Casas, Alejandro
• Is Part Of: COPD. Volume 11:Number 4(2014:Aug.)
• Page Start: 401
• Page End: 406
• Publication Date: 2014-08-01
• Subjects: Lungs -- Diseases, Obstructive -- Periodicals; 616.24
• DOI: 10.3109/15412555.2013.836480
• Languages: English
• ISSNs: 1541-2555

Abstract

<abstract> <title>Abstract</title> <p> <bold> <italic>Background:</italic> </bold> At Bogota's altitude (2640 m), the lower barometric pressure (560 mmHg) causes severe hypoxemia in COPD patients, limiting their exercise capacity. The aim was to compare the effects of breathing oxygen on exercise tolerance. <bold><italic>Methods:</italic></bold> In a blind, crossover clinical study, 29 COPD patients (FEV<sub>1</sub> 42.9 ± 11.9%) breathed room air (RA) or oxygen (FIO2 28% and 35%) during three treadmill exercise tests at 70% of their maximal capacity in a randomized order. Endurance time (ET), inspiratory capacity (IC), arterial blood gases and lactate were compared. <bold><italic>Results:</italic></bold> At the end of the exercise breathing RA, the ET was 9.7 ± 4.2 min, the PaO<sub>2</sub> 46.5 ± 8.2 mmHg, the lactate increased and the IC decreased. The oxygen significantly increased the ET (<italic>p</italic> < 0.001), without differences between 28% (16.4 ± 6.8 min) and 35% (17.6 ± 7.0 min) (<italic>p</italic> = 0.22). Breathing oxygen, there was an increase in the PaO<sub>2</sub> and SaO<sub>2</sub>, higher with FIO<sub>2</sub> 35%, and a decrease in the lactate level. <italic>At "isotime</italic>" (ET at RA), with oxygen, the SpO<sub>2</sub>, the oxygen pulse and the IC were higher and the heart rate lower than breathing RA (<italic>p</italic> < 0.05). <bold><italic>Conclusion:</italic></bold> Oxygen administration for COPD patients in Bogotá significantly increased ET by decreased respiratory load, improved cardiovascular performance and oxygen transport. The higher increases of the PaO<sub>2</sub> and SaO<sub>2</sub> with 35% FIO<sub>2</sub> did not represent a significant advantage in the ET. This finding has important logistic and economic implications for oxygen use in rehabilitation programs of COPD patients at the altitude of Bogotá and similar altitudes.</p> </abstract>