Table 2

Oxygen saturation measurements in physiological states

Intracuff pressure (cmH2O)
n
Oxygen saturation (%)





SpO2trachea
SvO2blood

0
20
70.2 ± 6.2 (57–76)
74.4 ± 4.3 (62.6–76.4)
10
20
74.2 ± 4.7 (62–77)
74.4 ± 4.4 (62.5–76.9)
20
20
74.2 ± 4.8 (62–77)
74.3 ± 4.3 (62.4–76.7)
40
20
74.2 ± 4.6 (61–76)
74.4 ± 4.3 (62.3–76.9)
60
20
74.2 ± 4.6 (62–77)
74.3 ± 4.4 (62.5–77.1)
Overall
100
72.5 ± 6.8 (57–77)
74.4 ± 6.3 (61.9–77.2)
Overall excluding 0 cmH2O
80
74.2 ± 4.2 (61–77)
74.4 ± 4.3 (61.2–77.6)

Values are means ± SEM (range). SpO2trachea, mixed venous oxygen saturation measured through the left main bronchus; SvO2blood, oxygen saturation from pulmonary artery samples.

Wang et al. Critical Care 2006 10:R7   doi:10.1186/cc3914