**7. Results**

#### **7.1. pH**

Under P anesthesia, significant LD differences in arterial pH were not found, and values remained at the same levels. Under K/X (p < 0.001) and Z (p < 0.001) anesthesias, the pH was significantly higher in the dark (active) versus the light part of the rat regimen day (**Table 4**, **Figure 2**). In the light part of the day, the pH values reflect acidosis, compared with the range calculated from other authors (**Table 1**) in all types of anesthesia, and there was no significant difference between individual types of anesthesia. In the dark part of the day, mean pH values were significantly higher in K/X (p < 0.05) and Z (p < 0.05) anesthesias compared with P anesthesia. The pH was acidic under P anesthesia, from normal to alkaline under K/X anesthesia and from acidic to normal under Z anesthesia.

**Pentobarbital**

**Light**

Acid-base parameter

*pH* *pCO2*

*pO2* *HCO3*

*stHCO3*

*ctCO2*

*BE* *BB* *ctO2* *SatO2* Data presented as mean

\*\*p <

\*\*\*p <

pressure of oxygen; HCO3

(%) – saturation of hemoglobin by oxygen.

**Table 4.**

− (mmol/l) – bicarbonate; stHCO3

0.01; and

 ± SD.\*p < 0.05;

87.25 ± 8.86

87.8 ± 10.34

9.22 ± 2.29

51.56 ± 2.23

51.13 ± 2.82 10.28 ± 2.72

48.34 ± 1.71 11.76 ± 5.11 84.66 ± 2.96

3.66 ± 2.12

3.43 ± 2.38

32.61 ± 4.15

*−*

26.67 ± 1.72

*−*

31.56 ± 2.73

8.36 ± 1.64

8.58 ± 1.22

7.31 ± 0.04

7.31 ± 0.07 8.64 ± 1.49 8.89 ± 2.86 31.31 ± 2.09 26.55 ± 2.01 31.66 ± 3.48

28.4 ± 2.69 0.06 ± 1.71

28.02 ± 4.57 24.16 ± 1.24

7.33 ± 0.04 6.76 ± 1.84 7.17 ± 0.37

7.43 ± 0.14\*\* 2.88 ± 0.72\*\* 10.75 ± 1.84\*\*\*

15.55 ± 5.62\*\*\*

19.22 ± 5.14\* 15.91 ± 5.93\*\*\*

−5.23 ± 6.34\*

42.44 ± 6.65\*

20.05 ± 0.56\* 93.29 ± 7.42\*\* 0.001 statistically significant differences between the light and dark parts of the rat regimen day. pCO2 (kPa) – partial pressure of carbon dioxide, pO2 (kPa) – partial

dissolved in plasma; BE (mmol/l) – base excess; BB (mmol/l) – total buffer bases; ctO2 – the sum of oxygen bound to hemoglobin and oxygen dissolved in plasma, satO2

Values of acid-base balance parameters for selected type of anesthesia in the light and dark parts of the rat regimen day.

− (mmol/l) – standard bicarbonate; ctCO2 – the sum of carbon dioxide bound to hemoglobin and carbon dioxide

Chronobiology of Acid-Base Balance under General Anesthesia in Rat Model

http://dx.doi.org/10.5772/intechopen.75174

117

7.32 ± 0.05 6.75 ± 0.93 10.06 ± 2.31

25.28 ± 1.3 22.95 ± 1.37 22.58 ± 1.05 −1.41 ± 1.58 46.39 ± 1.56 18.58 ± 1.34 89.96 ± 5.46

50.21 ± 1.34\*\*\*

19.17 ± 1.05 89.25 ± 4.64

2.21 ± 1.34\*\*\*

25.6 ± 2.23\*\*\*

27.0 ± 1.91\*\*\*

28.8 ± 2.11\*\*\*

8.46 ± 2.08\*

7.38 ± 0.06\*\*\*

6.65 ± 1.11

**Dark**

**Light**

**Dark**

**Ketamine/xylazine**

**Zoletil**

**Light**

**Dark**
