Table 1

Pa o ₂ on air in COPD patients when stable

		Mean Pao₂	Range
Author	Patients (n)	(mm Hg)	(mm Hg)
Mithoefer et al, 1967⁵	7	44	38–52
Rudolf et al, 1979⁶	10	49	39.5–58.4
Schiff et al, 1967⁷	9	52	29–73
Bone et al, 1978⁸	10	75	49–104
Bone et al, 1978⁸	10	60	42–90