. 2008 Dec;3(4):737–743. doi: 10.2147/copd.s3454

Table 3.

Serial clinical and arterial blood gas parameters during the ICU course of the two groups receiving NIPPV

	ARF–COPD			ARF–others
	0 hour	1 hour	4 hour	0 hour	1 hour	4 hour
RR	34.1 (7.4)	31.7 (5.3)^a	29.1 (3.5)^b	38.2 (7.8)	33.7 (6.4)^a	29.4 (4.3)^b
HR	116.8 (16.9)	109.2 (11.7)^a	101 (10.2)^b	114.4 (19.3)	107.7 (17.7)^a	97.3 (11.9)^b
PH	7.27 (0.07)	7.337 (0.07)^a	7.378 (0.07)^b	7.36 (0.12)	7.376 (0.09)^a,^c	7.405 (0.06)^b,^d
PaO₂	55.6 (16.1)	61.5 (9.7)^a	64.2 (7.9)	52.9 (7.38)	64.1 (13.4)^a	70.4 (10.8)
PaCO₂	73.1 (24.3)	56.4 (16.5)^a	53.6 (14.9)	43.3 (16.1)	40.4 (14.2)^a,^c	43.1 (13.5)

Notes: value at 1 hour significantly different from that at baseline within the groups;

value at 4 hour significantly different from that at 1 hour within the groups;

value at 1 hour significantly different from that at baseline between the two groups;

value at 4 hour significantly different from that at 1 hour between the two groups. A p-value less than 0.05 were taken as significant. The differences between the means was analyzed using MANOVA with Bonferroni adjustment for multiple comparisons; the within-groups factor was time (0, 1 and 4 hours), and the between-groups factor was the etiology of ARF (COPD vs other causes of ARF).

Abbreviations: ARF, acute respiratory failure; COPD, chronic obstructive pulmonary disease; HR, heart rate; ICU, intensive care unit; NIPPV, noninvasive positive pressure ventilation; PaCO₂, partial pressure of carbon dioxide in arterial blood; PaO₂, partial pressure of oxygen in the arterial blood; RR, respiratory rate.