Radiological pattern in ARDS patients: partitioned respiratory mechanics, gas exchange and lung recruitability

Annals of Intensive Care

Table 1 Baseline characteristics at 5 cmH₂O of PEEP in patients divided according to the radiological pattern

Characteristics	Focal group (n = 58)	Diffuse group (n = 110)	p
Age (years)	68 [60 to 76]	58 [44 to 69]	< 0.001
Male sex [% (n)]	72 (42)	70 (77)	0.882
BMI (kg/m²)	26 [23 to 29]	25 [22 to 28]	0.115
Origin of ARDS			0.001
Pulmonary [% (n)]	45 (26)	72 (79)
Extrapulmonary [% (n)]	55 (32)	28 (31)
ARDS severity			< 0.001
Mild [% (n)]	21 (12)	7 (8)
Moderate [% (n)]	69 (40)	58 (64)
Severe [% (n)]	10 (6)	35 (38)
SAPS II	43.5 [33 to 58]	39 [32 to 51]	0.091
Tidal volume (mL)	523 [458 to 600]	484 [410 to 542]	0.008
Tidal volume per ideal body weight (mL/kg)	8.1 [7.0 to 9.2]	7.4 [6.7 to 8.3]	0.003
Respiratory rate (breath per minute)	15 [12 to 17]	16 [14 to 20]	0.002
Minute ventilation (L/min)	8.3 [7.5 to 8.8]	8.4 [7.0 to 9.9]	0.685
End-inspiratory airway pressure (cmH₂O)	17 [14 to 20]	19 [16 to 21]	< 0.001
Driving pressure (cmH₂O)	11 [9 to 15]	14 [11 to 16]	0.001
Respiratory system elastance (cmH₂O/L)	21 [17 to 27]	28 [23 to 34]	< 0.001
Chest wall elastance (cmH₂O/L)	6 [4 to 9]	5 [3 to 8]	0.185
Lung elastance (cmH₂O/L)	14 [12 to 19]	22 [17 to 28]	< 0.001
PaCO₂ (mmHg)	41 [37 to 45]	48 [42 to 53]	< 0.001
PaO₂ (mmHg)	74 [65 to 86]	66 [58 to 75]	< 0.001
PaO₂/FiO₂	155 [126 to 187]	113 [84 to 147]	< 0.001
Physiological dead space	0.53 ± 0.10	0.66 ± 0.12	< 0.001

Continuous data are expressed as mean (SD) or median [interquartile range], while categorical data are expressed as % (number). Student t test or Mann–Whitney rank-sum test and Chi-square or Fisher exact test, were used as appropriate