Life's a gas: saturation should not be used for prescription of long-term oxygen therapy

Long term oxygen therapy (LTOT) has been shown to improve the survival rate in Chronic Obstructive Pulmonary Disease (COPD) patients with severe resting hypoxemia by NOTT and MRC studies, published more than 25 years ago. The improved survival was found in patients who received oxygen for more than 15 hours/day. The effectiveness of LTOT has been documented only in stable COPD patients with severe chronic hypoxemia at rest (PaO255%. In fact no evidence supports the use of LTOT in COPD patients with moderate hypoxemia (55<PaO2<65 mmHg), and in those with decreased oxygen saturation (SO2<90%) during exercise or sleep. Furthermore, it is generally accepted without evidence that LTOT in clinical practice is warranted in other forms of chronic respiratory failure not due to COPD when arterial blood gas criteria match those established for COPD patients. The prescription of oxygen in these circumstances, as for unstable patients, increases the number of patients receiving supplemental oxygen and the related costs. Comorbidities are likely to affect both prognosis and health outcomes in COPD patients, but at the moment we do not know if LTOT in these patients with complex chronic diseases and mild-moderate hypoxemia could be of any use. For these reasons a critical revision of the actual guide lines indications for LTOT in order to optimise effectiveness and costs, and future research in the areas that have not previously been addressed by NOTT and MRC studies, are mandatory.

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Impact of adherence to long-term oxygen therapy on patients with COPD and exertional hypoxemia followed for one year

Jornal Brasileiro de Pneumologia ◽

10.1590/s1806-37562017000000019 ◽

2018 ◽

Vol 44 (5) ◽

pp. 390-397 ◽

Cited By ~ 2

Author(s):

Carolina Bonfanti Mesquita ◽

Caroline Knaut ◽

Laura Miranda de Oliveira Caram ◽

Renata Ferrari ◽

Silmeia Garcia Zanati Bazan ◽

...

Keyword(s):

Quality Of Life ◽

Oxygen Therapy ◽

Severe Hypoxemia ◽

Bode Index ◽

One Year ◽

Long Term Oxygen Therapy ◽

Minute Walk

ABSTRACT Objective: To determine the impact of adherence to long-term oxygen therapy (LTOT) on quality of life, dyspnea, and exercise capacity in patients with COPD and exertional hypoxemia followed for one year. Methods: Patients experiencing severe hypoxemia during a six-minute walk test (6MWT) performed while breathing room air but not at rest were included in the study. At baseline and after one year of follow-up, all patients were assessed for comorbidities, body composition, SpO2, and dyspnea, as well as for anxiety and depression, having also undergone spirometry, arterial blood gas analysis, and the 6MWT with supplemental oxygen. The Saint George’s Respiratory Questionnaire (SGRQ) was used in order to assess quality of life, and the Body mass index, airflow Obstruction, Dyspnea, and Exercise capacity (BODE) index was calculated. The frequency of exacerbations and the mortality rate were noted. Treatment nonadherence was defined as LTOT use for < 12 h per day or no LTOT use during exercise. Results: A total of 60 patients with COPD and exertional hypoxemia were included in the study. Of those, 10 died and 11 experienced severe hypoxemia during follow-up, 39 patients therefore being included in the final analysis. Of those, only 18 (46.1%) were adherent to LTOT, showing better SGRQ scores, higher SpO2 values, and lower PaCO2 values than did nonadherent patients. In all patients, SaO2, the six-minute walk distance, and the BODE index worsened after one year. There were no differences between the proportions of adherence to LTOT at 3 and 12 months of follow-up. Conclusions: Quality of life appears to be lower in patients with COPD and exertional hypoxemia who do not adhere to LTOT than in those who do. In addition, LTOT appears to have a beneficial effect on COPD symptoms (as assessed by SGRQ scores). (Brazilian Registry of Clinical Trials - ReBEC; identification number RBR-9b4v63 [http://www.ensaiosclinicos.gov.br])

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