Table 5.
Relationships between abnormalities of select measured and calculated acid–base derangements and in‐hospital mortality
| Parameter | RI | OR | P | Sens (%) | Spec (%) | PPV (%) | NPV (%) |
|---|---|---|---|---|---|---|---|
| HCO3 − (mmol/L) | 20–25 | 1.41 | 0.038 | 35.8 | 71.7 | 80.2 | 25.9 |
| BEecf (mmol/L) | 0 to −4 | 1.59 | 0.017 | 24.9 | 82.8 | 82.2 | 25.6 |
| AG (mmol/L) | 13–25 | 1.63 | 0.003 | 76.9 | 32.8 | 78.5 | 30.8 |
| AGcorrected (mmol/L) | 13–25 | 1.60 | 0.005 | 77.3 | 32.0 | 78.4 | 30.6 |
| SIDapparent (mmol/L) | 31.4–45.7* | 2.02 | <0.0001 | 79.6 | 34.1 | 79.6 | 34.1 |
| SIDeffective (mmol/L) | 29.3–36.8* | 1.46 | 0.010 | 52.4 | 57.0 | 79.6 | 27.3 |
| SIG (mmol/L) | 3.3–15.3* | 1.15 | 0.383 | 63.2 | 40.2 | 77.2 | 25.5 |
| SIGsimplified (mmol/L) | −8.6 to 13.7* | 2.41 | <0.0001 | 92.7 | 16.0 | 77.9 | 40.6 |
Institutional reference intervals were available for the majority of values. Where local intervals were not available, ranges published by Vanova‐Uhrikova et al. (2017) were used, denoted by *. P‐values < 0.05 were considered significant and are denoted in bold type. AG, anion gap; BEecf, base excess (extracellular fluid); HCO3 −act, actual bicarbonate; NPV, negative predictive value; OR, odds ratio; PPV, positive predictive value; RI, reference interval; Sens, sensitivity; Spec, specificity; SID, strong ion difference; SIG, strong ion gap; XA−, unmeasured anions; Z, Z‐statistic.