TABLE 3.

INDICATIONS FOR LONG-TERM OXYGEN THERAPY

Absolute	PaO2 ⩽ 55 mm Hg or SaO2 ⩽ 88%
In presence of cor pulmonale	PaO2 55–59 mm Hg or SaO2 ⩽ 89%, ECG evidence of right atrial enlargement, hematocrit > 55%, congestive heart failure
Only in specific situations	PaO2 ⩾ 60 mm Hg or SaO2 ⩾ 90%; with lung disease and other clinical needs such as sleep with nocturnal desaturation not corrected by CPAP
If the patient is normoxemic at rest but desaturates during exercise or sleep	O2 should be prescribed if PaO2 falls below 55 mm Hg during exercise or sleep; also consider nasal CPAP or bilevel positive airway pressure

Definition of abbreviations: CPAP = continuous positive airway pressure.

Adapted by permission from Criner GJ. Effects of long-term oxygen therapy on mortality and morbidity. Respir Care 2000:45:105–118.