. 2013 Jan 24;17(1):R15. doi: 10.1186/cc12486

Table 1.

Hemodynamic and respiratory variables for the seven steps of measures between the Normocapnia (n = 6) and the Hypercapnia (n = 6) groups

	H0	H12	H24	H36	H48	H60	H72
Minute ventilation (L/min)
Normocapnia	5.9 ± 0.8	4.4 ± 0.6	5.1 ± 0.6	4.9 ± 0.5	4.7 ± 0.4	4.8 ± 0.6	4.7 ± 0.8
Hypercapnia	4.6 ± 0.3	4.3 ± 0.1	5.1 ± 0.2	4.8 ± 0.3	4.2 ± 0.2	4.8 ± 0.2	4.3 ± 0.2
Tidal volume (ml)
Normocapnia	240 ± 40	220 ± 20	230 ± 20	230 ± 25	225 ± 25	230 ± 25	205 ± 10
Hypercapnia	230 ± 22	225 ± 15	235 ± 30	240 ± 15	235 ± 30	230 ± 20	240 ± 20
Respiratory rate (c/min)
Normocapnia	24 ± 3	20 ± 3	22 ± 2	22 ± 2	21 ± 1	21 ± 1	20 ± 1
Hypercapnia	20 ± 6	19 ± 5	19 ± 4	20 ± 3	18 ± 6	19 ± 4	18 ± 3
Peak pressure (cm H₂O)
Normocapnia	22 ± 1	23 ± 2	22 ± 1	21 ± 3	23 ± 2	22 ± 3	23 ± 3
Hypercapnia	22 ± 3	21 ± 2	20 ± 2	22 ± 2	20 ± 3	20 ± 3	20 ± 2
Plateau pressure (cm H₂O)
Normocapnia	14 ± 2	14 ± 3	13 ± 2	14 ± 3	13 ± 2	14 ± 4	15 ± 2
Hypercapnia	13 ± 1	14 ± 3	12 ± 3	13 ± 2	12 ± 4	13 ± 3	13 ± 3
pH
Normocapnia	7.52 ± 0.02	7.47 ± 0.06	7.46 ± 0.04	7.45 ± 0.01	7.44 ± 0.04	7.47 ± 0.04	7.44 ± 0.05
Hypercapnia	7.43 ± 0.07	7.31 ± 0.09^ab	7.29 ± 0.05^ab	7.30 ± 0.06^ab	7.27 ± 0.07^ab	7.25 ± 0.08^ab	7.22 ± 0.04^ab
PaO₂(mm Hg)
Normocapnia	99 ± 8	97 ± 6	95 ± 5	98 ± 3	95 ± 6	97 ± 5	101 ± 6
Hypercapnia	147 ± 8^a	148 ± 5^a	149 ± 4^a	132 ± 4^a	115 ± 8^a	146 ± 6^a	110 ± 9
PaCO₂(mm Hg)
Normocapnia	33 ± 6	39 ± 3	41 ± 3	40 ± 3	39 ± 3	38 ± 2	37 ± 3
Hypercapnia	44 ± 7^a	65 ± 8^ab	70 ± 3^ab	77 ± 8^ab	73 ± 10^ab	66 ± 7^ab	73 ± 4^ab
SaO₂(%)
Normocapnia	98 ± 2	99 ± 2	97 ± 3	100 ± 2	98 ± 2	97 ± 3	96 ± 4
Hypercapnia	99 ± 2	98 ± 1	97 ± 4	99 ± 2	99 ± 4	98 ± 3	99 ± 3
Plasma bicarbonate (mM)
Normocapnia	27 ± 4	29 ± 4	29 ± 5	29 ± 3	27 ± 3	30 ± 2	26 ± 2
Hypercapnia	28 ± 4	35 ± 5^ab	33 ± 3^ab	35 ± 2^ab	34 ± 5^ab	32 ± 4^b	32 ± 5^ab
Heart rate (c/min)
Normocapnia	101 ± 10	106 ± 12	107 ± 12	103 ± 10	97 ± 8	101 ± 14	101 ± 15
Hypercapnia	93 ± 18	96 ± 27	91 ± 26	118 ± 26^ab	123 ± 12^ab	118 ± 12^ab	114 ± 16^ab
Mean blood pressure (mm Hg)
Normocapnia	75 ± 7	80 ± 10	88 ± 7	86 ± 9	84 ± 13	83 ± 13	88 ± 14
Hypercapnia	83 ± 15	72 ± 14	76 ± 16	87 ± 18	86 ± 22	79 ± 15	77 ± 15
Cardiac Output (l/min)
Normocapnia	2.2 ± 0.3	2.7 ± 0.3	2.8 ± 0.5	2.8 ± 0.2	2.7 ± 0.2	2.7 ± 0.2	2.7 ± 0.3
Hypercapnia	2.8 ± 0.4	2.9 ± 0.6	3.1 ± 0.6	3.8 ± 0.5^ab	3.3 ± 0.7^ab	3.2 ± 0.6^ab	3.4 ± 0.7^ab
Stroke volume (ml)
Normocapnia	22 ± 7	27 ± 10	27 ± 11	28 ± 8	29 ± 10	27 ± 11	26 ± 12
Hypercapnia	28 ± 8	29 ± 12	32 ± 9	28 ± 14	27 ± 8	27 ± 10	30 ± 8

Data are expressed as mean ± SD. ^aP < 0.05 between Normocapnia and Hypercapnia groups; ^bP < 0.05 intragroup difference between time considered and baseline. PaO₂, arterial pressure of oxygen; PaCO₂, arterial pressure of carbon dioxide; SaO₂, oxygen saturation of arterial blood.