Table 3 The correlation between ETCO₂ and P_aCO₂ in various conditions

All

150

34.3(95% CI; 32.5, 37.9)

29.9(95% CI; 26.7, 33.5)

0.716

0.000

0.512

Acidotic

25

40.6(95% CI; 37.5, 45.3)

29.5(95% CI; 25.6, 32.4)

0.374

0.02

0.613

Alkalosis

28

30.2(95% CI; 28.9,33.6)

27.9(95% CI; 24.8, 29.4)

0.171

0.037

0.029

Hypocapnia

118

29.9(95% CI; 26.4, 31.7)

28.1(95% CI; 25.8, 33.7)

0.738

0.000

0.544

Hypercapnia

32

50.3(95% CI; 48.1, 53.2)

36.8(95% CI; 34.5, 38.7)

-0.738

0.000

0.544

Pulmonary

43

40.3(95% CI 36.5, 43.2)

31.0(95% CI; 28.6, 33.4)

-0.336

0.000

0.113

Non-pulmonary

107

31.8(95% CI 27.4, 34.2)

29.5(95% CI; 26.7, 32.6)

0.336

0.000

0.113

Temperature (febrile)

29

32.6(95% CI; 30.1, 35.7)

30.4(95% CI; 27.2, 34.5)

0.074

0.370

0.005