Table 1. Comparison of lung function change after operation between two groups.

	Δ FEV1	Δ FEV1%pred	Δ FVC	Δ FVC%pred	Δ FEV1/FVC	Δ TLC	Δ RV	Δ FRC
Control group	0.58±0.7	17.9±23.8	0.93±0.63	28.9±14.7	4.36±19.57	1.15±0.83	0.39±0.59	0.5±0.43
NPPV group	0.39±0.57	17.4±20.4	0.59±0.61	22.3±14.3	3±12.8	1.31±1.2	0.78±1.23	0.55±1.19
P value	0.313	0.943	0.064	0.124	0.332	0.579	0.327	0.291