Table 2

Results of hypoxic challenge test (15% Fio2 for 20 minutes) with AHCPR grading (Appendix 2)

Hypoxic challenge resultRecommendation
Pao2 >7.4 kPa (>55 mm Hg)Oxygen not required [B]
Pao2 6.6–7.4 kPa (50–55 mm Hg)Borderline; a walk test may be helpful [C]
Pao2 <6.6 kPa (<50 mm Hg)In-flight oxygen (2 l/min) [B]