Table 1 Comparison of general information among the three groups

Age (yrs)

8.5 ± 1.6

8.7 ± 1.8

8.8 ± 1.7

Gender (M/F)

33/26

27/35

26/34

ASA grade (I/II)

45/14

52/10

48/12

BMI (kg/m²)

19.5 ± 4.5

18.2 ± 3.7

18.3 ± 5.5

Operation time (min)

18.7 ± 7.2

17.3 ± 5.5

17.1 ± 6.4

VT (ML)

191.8 ± 59.4

191.5 ± 57.1

181.6 ± 62.5

RR (beat/min)

19.5 ± 4.1

18.6 ± 3.6

18.3 ± 2.9

PETCO₂ (mmHg)

41(35–45)

40(35–45)

40(35–45)