Table 1–

Guidelines for Continuous Oxygen Therapy in COPD^*

Hypoxemia	ATS-ERS	GOLD	NCCCC-NICE
Severe	Pao2< 7.3 kPa (55 mm Hg) or SpO2≤ 88%	Pao2< 7.3 kPa (55 mm Hg) or Spo2 ≤ 88%	Pao2< 7.3 kPa
Moderate	Pao2of 7.3 to 8.0 kPa (55 to 59 mm Hg) or Spo2 of 89% and at least one of the following: cor pulmonale; peripheral edema; hematocrit > 55%	Pao2 of 7.3 to 8.0 kPa (55 to 59 mm Hg) or Spo2 of 88% and at least one of the following: pulmonary hypertension; peripheral edema; hematocrit > 55%	Pao2 of 7.3 to 8.0 kPa (55–59 mm Hg) and at least one of the following: pulmonary hypertension; peripheral edema; secondary polycythemia; nocturnal desaturation > 30% of sleep
None	Pao2≥ 8.0 kPa (60 mm Hg) or SpO2> 90% with severe nocturnal desaturation and lung-related dyspnea responsive to oxygen	No recommendation given	No recommendation given

^*ATS-ERS = American Thoracic Society-European Thoracic Society;³ GOLD = Global Initiative for Chronic Obstructive Lung Disease;⁴ NCCCC-NICE = National Collaborating Centre for Chronic Conditions-National Institute for Health and Clinical Excellence.⁵