Transcranial color-coded duplex sonography assessment of cerebrovascular reactivity to carbon dioxide: an interventional study

Table 2 Physiological data

	Group 1			Group 2			Group 3
Parameter	Baseline	Short-term Hyperventilation	p	Baseline	Sustained Hyperventilation	p	Baseline	Sustained Hyperventilation	p
HR (b/min)	77 ± 14	78 ± 14	0.41	74 ± 18	75 ± 21	0.84	73 ± 17	72 ± 18	0.61
MAP (mmHg)	93 ± 8¹	93 ± 8²	0.94	76 ± 11³	78 ± 12⁴	0.62	93 ± 9	94 ± 11	0.60
MV (l/min)	n.a	n.a	-	6.4 ± 1.7	9.2 ± 2.7	< 0.001	7.1 ± 1.4	8.9 ± 1.7	0.0037
ETCO₂ (mmHg)	38.6 ± 3.7	30.8 ± 2.4	< 0.001	41.4 ± 6.9	34.4 ± 7.1	< 0.001	37.5 ± 5.5	31.8 ± 4.8	< 0.001
pH	n.a	n.a	-	7.36 ± 0.05	7.42 ± 0.05	< 0.001	7.37 ± 0.09	7.45 ± 0.02	< 0.001
paCO₂ (mmHg)	38.5 ± 3.6*	30.6 ± 2.4*	< 0.001	39.3 ± 4.6	33.3 ± 4.4	< 0.001	37.4 ± 5.5	31.8 ± 4.7	< 0.001
MFV MCA (cm/s)
Right	55 ± 10⁵	45 ± 7	0.0004	63 ± 25	51 ± 18	0.03	78 ± 22	65 ± 18	< 0.001
Left	55 ± 11⁶	47 ± 9	0.0003	65 ± 21	56 ± 14	0.04	78 ± 22	62 ± 12	0.005

Values are expressed as mean ± standard deviation
HR heart rate, MAP mean arterial pressure, MV minute ventilation, ETCO₂ end-tidal carbon dioxide, MFV mean flow velocity, MCA middle cerebral artery, n.a. not applicable
^* Assumption of ETCO₂ = paCO₂
¹p = 0.001 between group 1 and 2; ²p = 0.008 between group 1 and 2; ³p = 0.001 between group 2 and 3; ⁴p = 0.005 between group 2 and 3; ⁵p = 0.024 between group 1 and 3; ⁶p = 0.032 between group 1 and 3

ISSN: 1471-2377