TABLE 2. Comparison between control and NIV groups in relation to lung function and inspiratory muscle strength.

Variables	Control group (n=25)	NIV group (n=25)	p
Inspiratory pressure
Preoperative	110,4±11,72	106,69±13,95	0,310
1POD	93,48±19,49	99,42±18,67	0,271
3POD	103,24±14,62	108,65±13,97	0,182
Respiratory frequency
Preoperative	16,36±2,40	16,88±2,61	0,459
1POD	19,24±2,82	18,81±4,40	0,677
3POD	15,56±1,61	15,96±1,87	0,415
Slow vital capacity
Preoperative	1842,69±505,42	1782,6±498,35	0,671
1POD	1033,85±253,16	1366,4±380,79	0,001*
3POD	1384,23±391,65	1541,8±415,68	0,170
Inspiratory capacity
Preoperative	1825,38±418,25	2197,6±490,01	0,005*
1POD	1125,0±208,0	1474,4±327,63	<0,0001*
3POD	1334,23±270,26	1557,6±266,94	0,005*
Minute volume
Preoperative	9,27±1,57	9,44±1,31	0,666
1POD	9,22±1,20	9,97±1,33	0,039*
3POD	9,37±1,21	9,61±1,01	0,450
Tidal volume
Preoperative	590,16±136,37	572,08±111,31	0,606
1POD	487,84±98,86	560,77±154,66	0,050
3POD	612,32±125,07	610,85±92,18	0,962
Peak expiratory flow
Preoperative	219,62±32,74	238,6±46,84	0,102
1POD	112,88±23,29	132,4±36,94	0,030*
3POD	148,65±32,84	203,92±53,76	<0,0001*

POD=postoperative day; NIV noninvasive ventilation; * =Student’s t-test p <0.05