A Randomized Trial of Long-Term Oxygen for COPD with Moderate Desaturation

Warren Han, Mercer University College of Pharmacy

The Global Initiative for Chronic Obstructive Lung Disease guidelines suggest that long-term administration of oxygen (> 15 hours per day) is indicated for patients who have partial pressure of oxygen (PaO2) at or below 7.3 kPa (55 mmHg) or oxygen saturation (SaO2) at or below 88%, with or without hypercapnia, and confirmed twice over a three-week period.  It was also recommended when PaO2 was between 7.3 kPa (55 mmHg) and 8.0 kPa (60 mmHg), or with SaO2 of 88%, if there is evidence of pulmonary hypertension, peripheral edema suggesting congestive cardiac failure, or polycythemia (hematocrit > 55%). [1]

A Randomized Trial of Long-Term Oxygen for COPD with Moderate Desaturation [2]
Design Parallel-group, randomized, unblinded; N= 738  
Objective To test the benefits of long-term supplemental oxygen treatment in patients who were moderately saturated  
Study Groups No supplemental oxygen (n= 370); supplemental oxygen (n= 368)  
Methods A total of 47 clinical centers screened patients who had stable COPD. Patients were given 24-hour supplemental oxygen if their resting SpO2 was 89-93% and, in the no supplemental oxygen group, oxygen was given during sleep and exercise if original desaturation occurred only when exercising. Patients on 24-hour oxygen were directed to continue the use of oxygen regardless of increase in the SpO2 levels while the patients receiving no supplemental oxygen were told to avoid the use of oxygen unless severe resting desaturation (SpO2 ≤ 88%) or severe exercise-induced desaturation (SpO2 < 80% for ≥ 1 minute) developed.  
Duration January 2009 through August 2014  
Primary Outcome Measure Time-to-event analysis measured from time of randomization to the time of death or first hospitalization  
Baseline Characteristics   No supplemental Oxygen Supplemental oxygen  
Mean age, years ± SD 69.3 ± 7.4 68.3 ± 7.5  
Male, n (%) 276 (75) 266 (72)  
Black, n (%) 34 (9) 46 (12)  
White, n (%) 328 (89) 311 (85)  
Other, n (%) 11 (3) 17 (5)  
Medicare coverage, n (%) 273 (74) 268 (73)  
Current tobacco-cigarette smoker, n (%) 92 (25) 110 (30)  
Oxygen-desaturation type qualifying the patient for enrollment, n (%)  
Resting only 60 (16) 73 (20)  
Exercise only 171 (46) 148 (40)  
Resting and exercise 139 (38) 147 (40)  
Nadir oxygen saturation measured by pulse oximetry (SpO2) during 6-min walk while breathing ambient air, n/total n (%)  
< 86% 85/290 (29) 86/292 (29)  
86 to 88% 103/290 (36) 105/292 (36)  
> 88% 102/290 (35) 101/292 (35)  
Results   No supplemental oxygen Supplemental oxygen Hazard Ratio (95% CI) p-value  
Events, n 250 248 0.94 (0.79 to 1.12) 0.52  
Deaths, n 73 66 0.90 (0.64 to 1.25) 0.53  
Hospitalizations, n 237 229 0.92 (0.77 to 1.10) 0.37  
Adverse Events Common Adverse Events: tripping/falling over oxygen equipment (6.3%), nosebleed (2.4%), blisters/ear pain (0.8%)  
Serious Adverse Events: burn from liquid oxygen frost (1.1%), fires related to oxygen use (0.5%), burn from smoking around oxygen equipment (0.8%), burn from using oxygen equipment around open flame (0.3%)  
Percentage that Discontinued due to Adverse Events: N/A  
Study Author Conclusions Among patients with stable COPD and resting or exercise-induced moderate desaturation, it was found that long-term supplemental oxygen did not provide any benefit with respect to the time to death or first hospitalization.

 

Because the guidelines currently recommend desaturated patients receive 24-hour oxygen therapy, the trial may have benefited from including more desaturated patients.  The study was unblinded and adherence was self-reported thus introducing some doubt into the validity of these results.  Uniform methods of oxygen delivery were not used, which may have caused variability in the amount of oxygen delivered to patients.  The findings of this research may help lower the costs associated with COPD treatment through the lacking benefit of 24-hour oxygen therapy.

 

References

  1. Global Initiative for Chronic Obstructive Lung Disease. Global strategy for diagnosis, management, and prevention of COPD, 2016. http://goldcopd.org/global-strategy-diagnosis-management-prevention-copd-2016. Published January 2016. Accessed October 31, 2016.
  2. A Randomized Trial of Long-Term Oxygen for COPD with Moderate Desaturation. N Engl J Med. 2016;375(17):1617-1627.
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