Table 2.

A comparison of physiological data between patients with and without PH^*

Variables	PH present n = 20	PH absent n = 76	P value
FVC, L	1.6 ± 0.7	2.6 ± 0.9	<0.0001
FVC, % predicted	56.9 ± 21.3	79.5 ± 20.9	<0.0001
FEV1, L	1.4 ± 0.6	2.1 ± 0.8	<0.0001
FEV1% predicted	57.9 ± 21.5	78.2 ± 21.0	<0.0001
TLC, L	3.2 ± 1.2	4.0 ± 1.1	0.03
TLC, % predicted	67.1 ± 17.9	79.6 ± 19.2	0.031
PaO2, mmHg	62.6 ± 13.4	73.4 ± 11.9	0.002
PaCO2, mmHg	42.4 ± 8.7	36.8 ± 5.3	0.002
6MWD, m†	313.2 ± 63.1	356.4 ± 71.6	0.071
Initial SpO2, %	93.0 ± 3.0	95.7 ± 2.21	0.001
Lowest SpO2, %	84.6 ± 10.6	92.1 ± 5.8	0.003

^*Data are presented as means ± SDs, unless otherwise indicated. FVC = forced vital capacity, FEV₁ = forced expiratory volume in 1 s, TLC = total lung capacity, PaO₂ = partial pressure of oxygen, PaCO₂ = partial pressure of carbon dioxide, , SpO₂ = oxygen saturation by pulse oximetry,

^†6MWD = 6-minute walk distance (PH present n = 13, PH absent n = 35)