Table 1.

Mean ± SD of the cerebral metabolic rate of oxygen (CMRO₂), oxidative carbohydrate index (OCI), O₂ extraction fraction, and the net cerebral glucose uptake and lactate release, at baseline (BL), apnea onset, first involuntary breathing movement (IBM), and the end of a normal apnea (NM), apnea with prior hyperventilation (HV), and apnea with prior 100% oxygen hyperventilation (HX).

						3 × 4 ANOVA
		BL	Onset	IBM	End	Condition	Time	Interaction
CMRO2 (mL·min−1)	NM	50 ± 8	48 ± 10	47 ± 9	37 ± 13*	p > 0.05	p < 0.05	p < 0.05
	HV	47 ± 9	41 ± 14	48 ± 9	43 ± 11
	HX	50 ± 7	52 ± 13	44 ± 10	28 ± 8*
OCI (%)	NM	101 ± 22	95 ± 11	122 ± 65	97 ± 39	p > 0.05	p > 0.05	p > 0.05
	HV	111 ± 32	72 ± 24	101 ± 36	119 ± 71
	HX	100 ± 16	81 ± 9	110 ± 34	63 ± 33
O2 Extraction (%)	NM	43 ± 7	49 ± 8	32 ± 6*	31 ± 10	p < 0.05	p < 0.05	p < 0.05
	HV	38 ± 6	50 ± 17	36 ± 3	42 ± 8
	HX	40 ± 7	52 ± 19	21 ± 5*	11 ± 4*
Net Glu uptake (mmol·min−1)	NM	0.38 ± 0.08	0.39 ± 0.09	0.34 ± 0.13	0.32 ± 0.11	p > 0.05	p > 0.05	p > 0.05
	HV	0.35 ± 0.15	0.43 ± 0.12	0.40 ± 0.18	0.32 ± 0.11
	HX	0.38 ± 0.13	0.43 ± 0.23	0.33 ± 0.17	0.37 ± 0.19
Net La release (mmol·min−1)	NM	0.02 ± 0.04	0.03 ± 0.05	0.04 ± 0.06	0.14 ± 0.21	p > 0.05	p = 0.05	p < 0.05
	HV	0.02 ± 0.03	0.09 ± 0.07	0.07 ± 0.08	0.15 ± 0.12*
	HX	0.02 ± 0.06	0.12 ± 0.08	−0.01 ± 0.06	0.00 ± 0.10

^*Denotes significant change from baseline within trial. See text for individual differences where a main effect of condition and interaction is observed.