Table 3.

Distribution of lung volumes in freely breathing and mechanically ventilated patients

Parameter		Free breathing	Mechanical ventilation	p
All patients
	Overall lung volume (dl)	30.4 IQR: 5.96	18.42 IQR: 12.60	0.012*
	Low-density volume (dl)	5.98 IQR: 1.70	2.22 IQR: 5.01	0.019*
	Medium-density volume (dl)	23.17 IQR: 12.52	16.76 IQR: 6.40	0.046*
	High-density volume (dl)	7.51 IQR: 5.39	12.26 IQR: 4.65	0.039*
	Low-density index	0.18 IQR: 0.14	0.08 IQR: 0.05	0.130
	PD15 (g/l)	71 IQR: 33.50	96 IQR: 20.50	0.405
Male
	Overall lung volume (dl)	32.73 IQR: 15.37	19.16 IQR: 7.05	0.040*
	Low-density volume (dl)	6.38 IQR: 1.25	2.22 IQR: 4.65	0.062*
	Medium-density volume (dl)	0.2 IQR: 0.12	0.08 IQR: 0.07	0.234
	High-density volume (dl)	29.59 IQR: 14.03	16.85 IQR: 5.76	0.094
	Low-density index	10.39 IQR: 4.82	13.11 IQR: 5.43	0.121
	PD15 (g/l)	0.2 IQR: 0.12	0.08 IQR: 0.07	0.234

Significant p-values are indicated by asterisks. PD15 – 15^th percentile of lung density