Table 2

CO₂ gradients and intramucosal pH during ischemic hypoxia (IH) and hypoxic hypoxia (HH), and in the sham group

Parameter

Group

Basal

30 minutes

60 minutes

90 minutes

Mixed venous–arterial PCO₂ (mmHg)

IH

8 ± 2

12 ± 3^*†

19 ± 5^**††

25 ± 4^**††

HH

7 ± 2

7 ± 3

8 ± 3

9 ± 3

SHAM

5 ± 2

7 ± 3†

6 ± 3‡‡

5 ± 3‡‡

Mixed venous–arterial CO₂ content (vol%)

IH

4.3 ± 1.6

7.2 ± 4.8

10.9 ± 2.5^*††

14.3 ± 3.6^*††

HH

4.6 ± 1.7

3.5 ± 1.4

3.4 ± 2.0

3.2 ± 1.0

SHAM

4.0 ± 4.8

5.7 ± 3.1

6.9 ± 2.1

2.7 ± 1.8‡‡

Mesenteric venous–arterial PCO₂ (mm Hg)

IH

9 ± 4

12 ± 3^*††

16 ± 4^**

19 ± 5††‡

HH

9 ± 5

5 ± 3

20 ± 10

6 ± 2

SHAM

6 ± 3

5 ± 2‡‡

6 ± 1‡‡

5 ± 2‡‡

Mesenteric venous–arterial CO₂ content (vol%)

IH

4.7 ± 1.2

7.2 ± 3.2

8.2 ± 2.4^*††

9.8 ± 2.2^*††

HH

6.6 ± 5.7

3.8 ± 2.6

3.4 ± 2.4

3.4 ± 2.3

SHAM

3.0 ± 1.9

3.3 ± 1.1

5.4 ± 2.4

2.6 ± 1.8‡‡

Intramucosal–arterial PCO₂ (mmHg)

IH

12 ± 10

19 ± 12^*†

32 ± 17^**††

40 ± 13^**††¶

HH

13 ± 6

8 ± 8

13 ± 11

10 ± 13

SHAM

8 ± 5

11 ± 3‡

10 ± 4‡‡

9 ± 6‡‡

Intramucosal–arterial CO₂ content (vol%)

IH

2.0 ± 0.4

2.4 ± 0.6††

2.8 ± 0.8^*††

3.3 ± 0.8^**††

HH

2.0 ± 0.5

0.7 ± 0.8

0.9 ± 0.9

0.3 ± 1.2

SHAM

1.7 ± 0.4

1.9 ± 0.7

2.1 ± 0.9

1.7 ± 0.5‡

Intramucosal Ph

IH

7.24 ± 0.14

7.16 ± 0.16^**

7.01 ± 0.22^**

6.84 ± 0.21^**

HH

7.26 ± 0.14

7.19 ± 0.13^**

7.10 ± 0.16^**

7.07 ± 0.18^**

SHAM

7.28 ± 0.06

7.26 ± 0.09

7.17 ± 0.08

7.25 ± 0.10§§

^*P < 0.05 versus basal; ^**P < 0.01 versus basal; † P < 0.05 versus hypoxic hypoxia; †† P < 0.01 versus hypoxic hypoxia; ‡ P < 0.05 versus ischemic hypoxia; ‡‡ P < 0.01 versus ischemic hypoxia; §P < 0.05 versus ischemic and hypoxic hypoxia; §§ P < 0.01 versus ischemic and hypoxic hypoxia (paired or unpaired t-tests with Bonferroni correction, after analysis of variance < 0.05).

Dubin et al. Critical Care 2002 6:514   doi:10.1186/cc1813