Table 2.

Values of the phase differences of phasors of deoxyhemoglobin (D) vs. arterial blood pressure (ABP), oxyhemoglobin (O) vs. ABP, total hemoglobin (T) vs. ABP, normalized cerebral blood flow (cbf) vs. normalized arterial blood pressure (abp), and D vs. O during normocapnia and hypercapnia.

		Phase difference (°)
		Normocapnia (NC)		Hypercapnia (HC)		HC − NC	p-values
∠D/ABP	SDI	−214	[−225, −195]	−259	[−323, −237]	−50 ± 33	$0.003**$	(n = 8)
	SDϕ	−208	[−219, −204]	−248	[−252, −234]	−34 ± 19	$0.0003***$	(n = 9)
	SSI	−211	[−235, −193]	−263	[−292, −239]	−59 ± 41	$0.001**$	(n = 10)
	DSI	−211	[−227, −200]	−263	[−285, −233]	−56 ± 38	$0.02*$	(n = 5)
	DSϕ	−211	[−217, −199]	−225	[−241, −220]	−21 ± 12	$0.005**$	(n = 5)
∠O/ABP	SDI	−37	[−51, −21]	−53	[−64, −36]	−14 ± 12	$0.001**$	(n = 10)
	SDϕ	−18	[−42, 3]	−50	[−62, −30]	−33 ± 23	$0.002**$	(n = 9)
	SSI	−28	[−43, −7]	−53	[−68, −34]	−26 ± 26	$0.02*$	(n = 9)
	DSI	−28	[−48, −2]	−63	[−66, −34]	−27 ± 24	$0.03*$	(n = 5)
	DSϕ	42	[24, 49]	−42	[−87, 1]	−78 ± 38	$0.01*$	(n = 4)
∠T/ABP	SDI	−47	[−68, −30]	−43	[−61, −31]	−1 ± 8	0.4	(n = 10)
	SDϕ	−10	[−34, 17]	−30	[−43, −19]	−22 ± 26	$0.02*$	(n = 8)
	SSI	−21	[−45, 7]	−42	[−55, −27]	−17 ± 27	0.09	(n = 9)
	DSI	−27	[−49, 8]	−28	[−56, −24]	−17 ± 17	$0.04*$	(n = 5)
	DSϕ	109	[62, 129]	83	[5, 114]	−20 ± 49	0.2	(n = 5)
∠cbf/abp	SDI	8	[−4, 27]	−22	[−39, 1]	−29 ± 19	$0.0006**$	(n = 10)
	SDϕ	16	[−5, 39]	−15	[−34, 2]	−34 ± 26	$0.006**$	(n = 9)
	SSI	10	[−4, 32]	−20	[−54, −2]	−40 ± 34	$0.006**$	(n = 9)
	DSI	12	[−7, 34]	−34	[−37, −1]	−36 ± 24	$0.01*$	(n = 5)
	DSϕ	30	[23, 41]	−22	[−31, 8]	−46 ± 24	$0.006**$	(n = 5)
∠D/O	SDI	−181	[−190, −149]	−207	[−250, −205]	−44 ± 30	$0.004**$	(n = 8)
	SDϕ	−193	[−197, −185]	−197	[−206, −189]	−1 ± 9	0.4	(n = 9)
	SSI	−186	[−187, −179]	−199	[−212, −193]	−26 ± 26	$0.03*$	(n = 8)
	DSI	−181	[−189, −179]	−201	[−203, −199]	−16 ± 5	$0.0007***$	(n = 4)
	DSϕ	−242	[−254, −232]	−192	[−220, −152]	56 ± 31	0.5	(n = 4)

Values are reported as median [25%, 75% quartiles] for phase measurements at normocapnia and hypercapnia. The differences in the phase values between hypercapnia and normocapnia are shown as means ± standard deviations. p-values from statistical test on angular means are shown and indicated in red color for significant values; * for p < 0.05; ** for p < 0.01; and *** for p < 0.001.