Table 2 Differences in different markers of acid-base disorders at ICU admission between survivors and non-survivors (n = 6878)

1. Arterial pH

7.35 (7.29–7.39)

7.28 (7.17–7.37)

0.001

2. Arterial CO₂ tension, mmHg

40 (35–45)

40 (34–48.8)

0.022

3. Actual bicarbonate conc., mmol/L

21 (19–23)

18 (14–21.8)

0.001

4. Chloride conc., mmol/L

110 (107–113)

109 (105–114)

0.891

5. Lactate conc., mmol/L

1.5 (1.0–2.4)

2.7 (1.4–5.6)

0.001

6. Actual base excess, mmol/L

−3 (−6 to −1)

−7 (−12 to −3)

0.001

7. Anion gap, mmol/L

12.5 (10.1–15.0)

15.0 (11.9–19.5)

0.001

8. Anion gap albumin-corrected, mmol/L

15.5 (12.8–18.5)

18.7 (14.8–23.6)

0.001

9. SIG with lactate, mmol/L

4.2 (1.5–7.1)

6.5 (3.0–10.8)

0.001

10. SIG without lactate, mmol/L

2.2 (−0.3 to 5.0)

2.5 (−0.4 to 5.8)

0.028

11. SID-effective, mmol/L

33.5 (30.5–36.2)

30.7 (26.7–34.7)

0.001

12. Other unmeasured ions, mmol/L

2.1 (−1.0 to 4.9)

−1.5 (−7.3 to 2.5)

0.001