. 2003 Feb 21;548(Pt 2):585–591. doi: 10.1113/jphysiol.2002.035956

Table 2.

Analysis of variance, effects of posture and gravity.

Variable	Prone/Supine	1/5 G	Interaction
Arterial P_O₂	—	—	0.03
S_aO₂ blood sampling	—	—	0.001
S_aO₂ pulse oximetry	—	—	<0.001
Alveolar P_O₂	0.03	<0.001	n.s.
End-tidal P_O₂	n.s.	<0.001	n.s.
Arterial P_CO₂	0.03	<0.001	n.s.
Haematocrit	n.s.	<0.001	n.s.
pH_a	0.02	<0.001	n.s.
Base excess	0.1	0.03	n.s.
Alveolar-to-arterial P_O₂	—	—	0.03
difference Ventilation	n.s.	0.002	n.s.
Respiratory rate	n.s.	<0.001	n.s.
Tidal volume	n.s.	n.s.	n.s.
Mean arterial pressure	n.s.	0.003	n.s.
Heart rate	0.02	<0.001	n.s.

Values are significance of effects of the two factors posture and gravity level. P_O₂ partial pressure of oxygen; S_aO₂, arterial oxygen saturation; n.s., not significant. Results are considered statistically significant if P < 0.05.