TABLE 2. VVM values for each group in the pre and postoperative periods, expressed in absolute values and predicted percentages, in mean and standard deviation.

		GPP (n=23)	GCI (n=22)
		Pre Post	Pre Post
VVM (L) p	M DP	108.61 84.21 ±17.29 ± 11.15 0.001	107.45 92.69 ±14.83 ±17.52 0.01
VVM (% prev) p	M DP	103.65 81.00 ±13.24 ±12.52 0.001	101.15 87.25 ±12.21 ±14.89 0.01

Pre=preoperative; post=postoperative; n=number of subjects; L=liter; GPP=positive pressure group; GCI=inspiratory loading group; VVM=maximal voluntary ventilation; % prev=percentage of predicted; M=average; SD=standard deviation; significant difference between the pre and postoperative periods=p<0.05