Table 2

Regional densitometries at end-expiration: apical and diaphragmatic slice

Region

Mode

Hyperinflation (%)

Normal aeration (%)

Poor aeration (%)

No aeration (%)

Interaction, HU range × ventilatory mode

Apex

Nondependent

SB-

0 ± 0

73 ± 17

26 ± 17

1 ± 1

P < 0.01

SB+

0 ± 0

85 ± 11

15 ± 11

0 ± 1

Dependent

SB-

0 ± 0

33 ± 19

50 ± 14

17 ± 18

ns

SB+

0 ± 0

48 ± 33

35 ± 21

16 ± 23

Diaphragm

Nondependent

SB-

0 ± 0

73 ± 23

25 ± 19

2 ± 5

P < 0.01

SB+

0 ± 0

88 ± 11

12 ± 11

0 ± 0

Dependent

SB-

0 ± 0

9 ± 9

43 ± 15

47 ± 20

P < 0.001

SB+

0 ± 0

25 ± 15

52 ± 14

23 ± 22

Data presented as mean ± standard deviation. Amount of hyperinflated, normally aerated, poorly aerated and nonaerated tissue (% of total lung volume) in dependent and nondependent regions of interest on transverse computed tomography scans (see Figure 1 for details). SB-, airway pressure release ventilation without spontaneous breathing; SB+, airway pressure release ventilation with spontaneous breathing; ns, not significant; HU, Hounsfield unit.

Wrigge et al. Critical Care 2005 9:R780   doi:10.1186/cc3908