Skip to main content

Table 3 The areas under the receiver operating characteristic curve (AUROC) of the different markers of acid-base disorders at ICU admission, with and without combining with Admission Mortality Prediction Model (MPM0 III) predicted risks of mortality, in differentiating between hospital survivors and non-survivors (n = 6878)

From: A comparison of prognostic significance of strong ion gap (SIG) with other acid-base markers in the critically ill: a cohort study

Acid-base markers Mean AUROC (95 % confidence interval [CI])
  Without MPM0 III With MPM0 III
1. Arterial pH 0.655 (0.633–0.677) 0.805 (0.789–0.821)
2. Arterial CO2 tension 0.521 (0.499–0.544) 0.798 (0.782–0.814)
3. Actual bicarbonate conc. 0.676 (0.655–0.696) 0.812 (0.796–0.828)
4. Chloride conc. 0.517 (0.495–0.539) 0.801 (0.785–0.816)
5. Lactate conc. 0.701 (0.682–0.721) 0.824 (0.809–0.839)
6. Actual base excess 0.685 (0.664–0.706) 0.813 (0.797–0.829)
7. Anion gap 0.660 (0.639–0.680) 0.813 (0.798–0.828)
8. Anion gap albumin-corrected 0.665 (0.645–0.686) 0.818 (0.803–0.833)
9. Strong ion gap (SIG) with lactate 0.631 (0.611–0.652) 0.812 (0.797–0.827)
10. SIG without lactate 0.521 (0.500–0.542) 0.801 (0.786–0.817)
11. Strong ion difference-effective 0.634 (0.613–0.655) 0.809 (0.794–0.825)
12. Other unmeasured ions 0.679 (0.658–0.700) 0.820 (0.805–0.835)
  1. The AUROC for MPM0 III predicted risks of mortality alone was 0.799 (95 % CI 0.783–0.814) and SAPS III predicted risks alone was 0.833 (95 % CI 0.821–0.844). The AUROC for combining lactate with anion gap albumin-corrected and MPM0 III, and combining lactate with SIG and MPM0 III were 0.830 (95 % CI 0.816–0.845) and 0.829 (95 % CI 0.815–0.844), respectively