Table 2

Comparison between tidal volume, oxygen saturation, dynamic compliance, and airway resistance at two different levels of apico-diaphragmatic ratio

RR < 20 breaths/minute (15 ± 3)

RR > 20 breaths/minute (26 ± 5)

ADR < 2

(n = 23)

ADR > 2

(n = 14)

P value

ADR < 2

(n = 17)

ADR > 2

(n = 23)

P value

Tidal volume

(ml)

577 ± 91

528 ± 101

NS

479 ± 109

483 ± 135

NS

Oxygen saturation

(%)

97 ± 3

97 ± 3

NS

97 ± 3

98 ± 2

NS

Compliance

(mL/mbar)

60 ± 25

42 ± 12

0.058

51 ± 25

48 ± 20

NS

Resistance

(mbar L/second)

15 ± 4

18 ± 7

NS

15 ± 3

16 ± 5

NS

Apico-diaphragmatic ratio (ADR) was defined as the ratio between the lung sound distribution in the apical lung areas (upper right (UR) + upper left (UL)) and the diaphragmatic lung areas (lower right (LR) + lower left (LL)) (ADR = (UL + UR)/(LL + LR)). Distribution was considered more heterogeneous if difference was larger than two, threshold derived from experience with healthy patients in supine position. P values are indicated (Wilcoxon two sample test) as well as non-significant (NS) data. RR = respiratory rate.

Lev et al. Critical Care 2009 13:R66   doi:10.1186/cc7871