Fig. 2:

30-day mortality by plasma levels of potassium, sodium, and creatinine. P-Potassium was rounded to the nearest value divisible by 0.1. Values ≤ 2.8 mmol/L were set at 2.8 mmol/L. Values ≥ 5 mmol/L were set at 5 mmol/L. P-Sodium was rounded to the nearest value divisible by 2. Values ≤ 122 mmol/L were set at 122 mmol/L. Values ≥ 148 mmol/L were set at 148 mmol/L. P-Creatinine was rounded to the nearest value divisible by 10. Values ≤ 50 micromole/L were set at 50 micromole/L. Values ≥ 200 micromole/L were set at 200 micromole/L. For P-Potassium and P-Sodium, the normal ranges were indicated by grey boxes on their respective axes