Corrado A, Renda T, Bertini S
Terapia Intensiva Pneumologica, Azienda Ospedaliera Universitaria Careggi Firenze, Italy.
Monaldi Arch Chest Dis. 2010 Mar;73(1):34-43. doi: 10.4081/monaldi.2010.311.
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 (PaO2 < 55 mmHg (7.3 kPa) or PaO2 ranging from 56 to 59 mmHg (7.4-7.8 kPa) in presence of signs of Cor Pulmonale, hematocrit > 55%. 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 (SO 2 <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 a-terial 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.
25 年多前发表的 NOTT 和 MRC 研究表明，长期氧疗（LTOT）可提高重度静息性低氧血症的慢性阻塞性肺疾病（COPD）患者的生存率。接受每日吸氧超过 15 小时的患者生存率得到改善。LTOT 的有效性仅在稳定的重度慢性静息性低氧血症（动脉血氧分压[PaO2]<55 mmHg（7.3 kPa）或 PaO2 在 56 至 59 mmHg（7.4 - 7.8 kPa）之间且存在肺心病体征、血细胞比容>55%）的 COPD 患者中得到证实。事实上，没有证据支持在中度低氧血症（55<PaO2<65 mmHg）的 COPD 患者以及运动或睡眠期间氧饱和度降低（SO2<90%）的患者中使用 LTOT。此外，在临床实践中，当动脉血气标准与为 COPD 患者确定的标准相符时，对于其他非 COPD 形式的慢性呼吸衰竭，在没有证据的情况下普遍认为 LTOT 是必要的。在这些情况下给氧，如同给不稳定患者吸氧一样，会增加接受补充氧气的患者数量和相关费用。合并症可能会影响 COPD 患者的预后和健康结局，但目前我们不知道在这些患有复杂慢性疾病和轻度至中度低氧血症的患者中 LTOT 是否有用。出于这些原因，必须对 LTOT 的现行指南指征进行严格修订，以优化有效性和成本，并对 NOTT 和 MRC 研究以前未涉及的领域进行未来研究。
