Oxygen therapy for hypoxemic COPD patients improves survival, quality of life, and supports exercise training. Patients periodically desaturate throughout the day, as they neglect to adjust their O2 setting during exertion. This study evaluates the ability of an activity tracking/adaptive demand O2 delivery system (ADODS) to maintain SaO2 as patients change between rest and exertion.
10 stable hypoxemic COPD patients volunteered for the study. The ADODS (CHAD Therapeutics, Chatsworth CA), incorporating an activity detector that auto-adjusts O2 for rest and exertion, was compared with continuous flow (CF) at 7 alternating settings between resting and walking for 2 minute intervals –recording SpO2 and breath rate. Primary endpoint: to determine if the ADODS is able to maintain adequate SpO2 during each rest and exertion. Paired T-tests determined whether rest or exercise SpO2 differed from manually adjusted CF.
The patients were 73 + 6 yrs/old; FEV1 = 0.83 + .2 L; FVC = 2.1 + 0.7 L; FEV1/FVC = 42 + 14%. All patients maintained adequate SpO2 via both ADODS and CF. Resting SaO2 was 93.9 + 2.4% for CF and 94.0 + 2.0 for the ADODS. Exercise SpO2 was 93.4 + 1.9% for CF and 93.9 + 2.7% for ADODS. Differences were non-significant. For each delivery method there were occasional transient (<30 sec) desaturations below 90% during the rest period. Oxygen required at rest for CF and ADODS were 2200 ml and 374 ml respectively: Efficiency Gain = 5.9X. Oxygen required during exercise for CF and ADODS were 3200 ml and 576 ml respectively: Efficiency Gain = 5.6X.
The ADODS is able to track and adapt between activity and rest - maintaining adequate SpO2 during both conditions without relying on the patient to make timely changes. ADODS also minimizes O2 waste characteristic of CF.
The ADODS represents a more therapeutically effective approach to O2 therapy than supplementation because it is more physiologically responsive.
B.L. Tiep, CHAD Therapeutics Inc