Comparing supplementary oxygen benefits from a portable oxygen concentrator and a liquid oxygen portable device during a walk test in COPD patients on long-term oxygen therapy.
BACKGROUND
Differences in oxygen delivery between portable oxygen concentrators (POC) and liquid oxygen (LO) portable units, pose a question if POCs are equally effective as LOs in reducing exercise-induced hypoxaemia.


METHODS
Randomized, single-blind clinical trial.


METHODS
Thirteen COPD patients (means: age 66+/-11 year, FEV(1) 35.2+/-13.7% predicted) and respiratory failure (means: PaO2 52+/-5mmHg, PaCO2 51.3+/-7.5mmHg).


METHODS
All patients underwent a series of 6-min walk tests (6MWT) carried out in random order among one of the three devices: POC, LO cylinder and cylinder with compressed air (CA). Oxygen supplementation was 3lpm for LO and an equivalent to 3lpm in a pulse flow system for POC.


RESULTS
The mean SpO2 was equally improved at rest: 92.9+/-2.8% with POC and 91.7+/-2.0% with LO compared to CA-87.8+/-2.7% (POC and LO vs. CA p<0.05). POC and LO significantly improved oxygenation during 6MWT (mean SpO(2) was 84.3+/-5% and 83.8+/-4.2%, respectively) compared to breathing CA-77.6+/-7.4%, p<0.05. Mean 6MWT distance increased with LO (350+/-83m) and POC (342+/-96m) when compared to CA (317+/-84m), however, these differences were not statistically significant. Dyspnoea score assessed at the end of the exercise (Borg scale) was significantly lower when breathing oxygen (4.2+/-1.2 with POC and 4.1+/-1.7 with LO vs. 5.4+/-1.9 with CA, p<0.05).


CONCLUSIONS
Effectiveness of oxygen supplementation from a POC did not differ from the LO source during 6MWT in COPD patients with respiratory failure. Oxygen at 3lpm flow was not sufficient to prevent hypoxaemia during strenuous exercise.
Nasilowski
Jacek
J
Department of Internal Medicine, Pneumology and Allergology, Medical University of Warsaw, Banacha 1a, 02-097 Warsaw, Poland. jnasilek@amwaw.edu.pl
Przybylowski
Tadeusz
T
Zielinski
Jan
J
Chazan
Ryszarda
R
D000368:Aged; D000553:Ambulatory Care; D005080:Exercise Test; D017079:Exercise Tolerance; D005260:Female; D006801:Humans; D000860:Hypoxia / Q000517:prevention & control*; D008297:Male; D010100:Oxygen / Q000008:administration & dosage*; D010102:Oxygen Inhalation Therapy / Q000295:instrumentation / Q000379:methods*; D029424:Pulmonary Disease, Chronic Obstructive / Q000628:therapy*; D016896:Treatment Outcome; D016138:Walking / Q000502:physiology*
D010100:Oxygen