Lin H-C1, Lee C-T1, Lin J-S1, Chien J-Y2, Wu H-D3, Wang L-Y1,4
1School and Graduate Institute of Physical Therapy, College of Medicine, National Taiwan University, Taipei, Taiwan, 2Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan, 3Department of Integrated Diagnostics and Therapeutics, National Taiwan University Hospital, Taipei, Taiwan, 4Physical Therapy Center, National Taiwan University Hospital, Taipei, Taiwan
Background: Exercise desaturation is common among patients with chronic lung disease. Six-minute walk test (6MWT) provides a good index of the patient's ability to perform daily activities and has a high sensitivity for detecting exertional desaturation. Ambulatory oxygen is a common clinical practice to optimize saturations for mobile patients with exertional desaturation status, but there is a lack of standardized protocol for accessing ambulatory oxygen requirements in this patient population.
Purpose: To determine ambulatory supplementary oxygen requirements using a standard six-minute walk test.
Methods: From December 2017 to March 2018, a total of 258 patients referred to out-patient pulmonary rehabilitation at Physical Therapy Center (National Taiwan University Hospital) were included. All subjects performed a 6MWT using pulse oximetry to monitor pulse oxygen saturation (SpO2) and heart rate (HR) continuously. Blood pressure (BP), and perceived dyspnea were measured before and after 6MWT. If desaturations occurred ( 80% for patients with interstitial lung disease, and 85% for patients with chronic obstructive lung disease), the patients were stopped and followed by an oxygen titration 6MWT with supplemental oxygen being delivered through a nasal cannula at an increase of 2 L/min to maintain SpO2 above 88%.
Results: Among 258 patients, first 6MWT was stopped in 28 patients (11%) due to low saturations who then underwent 2nd 6MWT with O2 supplement (O2 titration group). The mean±SD age of the O2 titration group was 69.5(±9.4) yrs, and was with diagnosis of chronic obstructive pulmonary disease (COPD) stage 2 (n = 7), 3 (n = 10), 4 (n = 3) and idiopathic pulmonary fibrosis (IPF) (n = 8). The average stop time of the first 6MWT was 3 minutes and the average nadir of SpO2 was 83.4(±2.0)%. The number of titrations required to finish 2nd 6MWT was 1,2, and 3 for 15,7 and 6 patients, respectively. Dyspnea significantly decreased with O2 supplement in titration group during 2nd 6MWT (p = 0.027). The final mean supplemental O2 requirement was 3.4 (±1.6) L/min. No adverse events occurred during all tests.
Conclusion(s): Oxygen supplementation decrease dyspnea sensation in patients with exercise desaturation. Ambulatory O2 requirement could be assessed using a modified and easily performed 6MWT with O2 titration.
Implications: Whether ambulatory O2 requirement based on the results of 6MWT with O2 titration can be adapted for other clinical use, such as exercise training warrants further investigation.
Keywords: Chronic lung disease, Ambulatory oxygen assessment, Oxygen supplementation
Funding acknowledgements: No specific financial support was obtained for this study.
Purpose: To determine ambulatory supplementary oxygen requirements using a standard six-minute walk test.
Methods: From December 2017 to March 2018, a total of 258 patients referred to out-patient pulmonary rehabilitation at Physical Therapy Center (National Taiwan University Hospital) were included. All subjects performed a 6MWT using pulse oximetry to monitor pulse oxygen saturation (SpO2) and heart rate (HR) continuously. Blood pressure (BP), and perceived dyspnea were measured before and after 6MWT. If desaturations occurred ( 80% for patients with interstitial lung disease, and 85% for patients with chronic obstructive lung disease), the patients were stopped and followed by an oxygen titration 6MWT with supplemental oxygen being delivered through a nasal cannula at an increase of 2 L/min to maintain SpO2 above 88%.
Results: Among 258 patients, first 6MWT was stopped in 28 patients (11%) due to low saturations who then underwent 2nd 6MWT with O2 supplement (O2 titration group). The mean±SD age of the O2 titration group was 69.5(±9.4) yrs, and was with diagnosis of chronic obstructive pulmonary disease (COPD) stage 2 (n = 7), 3 (n = 10), 4 (n = 3) and idiopathic pulmonary fibrosis (IPF) (n = 8). The average stop time of the first 6MWT was 3 minutes and the average nadir of SpO2 was 83.4(±2.0)%. The number of titrations required to finish 2nd 6MWT was 1,2, and 3 for 15,7 and 6 patients, respectively. Dyspnea significantly decreased with O2 supplement in titration group during 2nd 6MWT (p = 0.027). The final mean supplemental O2 requirement was 3.4 (±1.6) L/min. No adverse events occurred during all tests.
Conclusion(s): Oxygen supplementation decrease dyspnea sensation in patients with exercise desaturation. Ambulatory O2 requirement could be assessed using a modified and easily performed 6MWT with O2 titration.
Implications: Whether ambulatory O2 requirement based on the results of 6MWT with O2 titration can be adapted for other clinical use, such as exercise training warrants further investigation.
Keywords: Chronic lung disease, Ambulatory oxygen assessment, Oxygen supplementation
Funding acknowledgements: No specific financial support was obtained for this study.
Topic: Cardiorespiratory
Ethics approval required: Yes
Institution: National Taiwan University Hospital, Taipei, Taiwan
Ethics committee: Research Ethics Committee (REC) of National Taiwan University Hospital
Ethics number: 201805017RINB
All authors, affiliations and abstracts have been published as submitted.
