Table 10. Randomized trials of long-term oxygen therapy in COPD.
Reproduced under the terms of the Creative Commons Attribution license.
PaO2: partial pressure of oxygen; ECG: electrocardiography; aVF: augmented vector foot; FEV1: forced expiratory volume in 1 second; h/d: hours per day; LTOT: long-term oxygen therapy; PaCO2: partial pressure of carbon dioxide; SpO2: oxygen saturation; MWT: maintenance of wakefulness test
[126]
| Study | Inclusion Criteria | Intervention/Comparator | Primary Outcome | Main Results |
| Severe hypoxemia | ||||
| NOTT [120] | 203 patients with COPD and PaO2 <55 mmHg, or PaO2 <59 mmHg with one of the following: 1) edema, 2) hematocrit >55%, or 3) P pulmonale on ECG: 3 mm in leads II, III, aVF. | Continuous oxygen (n = 101) vs. nocturnal oxygen (n = 102); frequent home and outpatient visits for both groups | Survival; adherence was monitored | At the two-year follow-up, the overall mortality of those receiving continuous oxygen was 22.4%, whereas it was 40.8% among those receiving nocturnal oxygen (P = 0.01) |
| MRC [121] | 87 patients, 70 yr, FEV1 ,1.2 L, PaO2 between 40 and 60 mmHg. | Oxygen for >15 h/d (n = 42) vs. usual care (n = 45); some home visits and frequent outpatient visits in both groups. | Survival; adherence was not monitored. | At the five-year follow-up, 19 (45%) of 42 patients receiving oxygen therapy had died, compared with 30 (66%) of the 45 control patients. |
| Moderate hypoxemia | ||||
| G ´orecka et al. [123] | 135 patients aged 40–80 yr, PaO2 56–65 mm Hg | Oxygen for >17 h/d (n = 68) vs. usual care (n = 67) | Survival; adherence was monitored | Cumulative survival rates were 88%, 77%, and 66% at the one-, two-, and three-year follow-up, respectively. No significant difference in survival rates was seen between those receiving LTOT and the control group. |
| Haidl et al. [124] | 28 patients with COPD and moderate hypoxemia (PaO2 at rest .55 mmHg) and reversible hypercapnia during the course of an exacerbation (PCO2 <45 mmHg at hospital discharge) | Oxygen for >15 h/d (n = 14) vs. usual care (n = 14) | Endurance time (cycle ergometry); survival; adherence was monitored | At the one-year follow-up, endurance time was improved among those receiving LTOT (7.1 vs. 4.9 min; P = 0.04); at the three-year follow-up, four patients receiving LTOT had died, compared with three control subjects. |
| LOTT [125] | 738 patients with COPD and moderate resting desaturation (SpO2: 89–93%) or moderate exercise-induced desaturation (during 6MWT, SpO2 >80% for >5 min and 90% for >10s) | Continuous oxygen (or oxygen only during sleep and exercise in those with exercise-induced desaturation only) (n = 368) vs. usual care (n = 370) | Composite outcome of time to death or first hospitalization; compliance was monitored | Supplemental oxygen did not result in a longer time until death or first hospitalization than no long-term supplemental oxygen |