Table 3. Heart rates (beats per minute, averaged over 10 seconds immediately before each event) recorded at different events in treatment groups.

	CO2		CO2/O2		Isoflurane		PB
Baseline	414.6 ± 39.7		396.1 ± 34.6		437.7 ± 36.0		426.2 ± 30.2
Recumbency	173.0 ± 74.6	p = 0.0002 (158.1, 325.2)	193.0 ± 100.9	p = 0.005 (78.4, 327.9)	418.6 ± 31.1	p = 0.48 (-23.3, 61.4)	403.6 ± 45.5	p = 0.58 (-35.0, 80.3)
LORR	119.9 ± 57.6	p = 0.0001 (255.5, 334.0)	233.9 ± 119.3	p = 0.03 (20.5, 303.8)	425.4 ± 19.7	p = 0.71 (-25.2, 49.8)	399.1 ± 37.4	p = 0.32 (-21.4, 75.7)
ECoG	135.4 ± 49.2	p = 0.0001 (207.4, 351.0)	267.3 ± 80.6	p = 0.01 (31.4, 226.1)	351.3 ± 103.5	p = 0.21 (-43.1, 216.0)	320.1 ± 56.0	p = 0.01 (26.0, 186.3)
Apnea	91.6 ± 23.1	p = 0.0001 (262.8, 383.3)	124.8 ± 49.7	p = 0.0001 (202.3, 340.3)	190.6 ± 100.6	p = 0.0007 (136.1, 358.1)	249.2 ± 34.7	p = 0.0001 (137.5, 216.7)

Heart rates (beats per minute, averaged over 10 seconds immediately before each event) recorded at different events in treatment groups. PB = pentobarbital. LORR = loss of righting reflex. ECoG = isoelectric electrocorticograph. p values represent within group comparisons to baseline. Main effects were significantly different for all groups (p < 0.0001, all cases). Figures in parentheses are the 95% confidence intervals for the mean difference between baseline and event being compared. See text for results of between group comparisons. Data are mean ± SD.PB = pentobarbital. LORR = loss of righting reflex. ECoG = isoelectric electrocorticograph.