| Blood Gas Reference Ranges | ||||
| Critical Values | ||||
| Arterial | Venous | Lower Limit | Upper Limit | |
| pH | 7.35 - 7.45 | 7.32 - 7.42 | <7.20 | >7.60 |
| PCO2 | 35 - 45 mmHg | 41 - 51 mmHg | <20 mmHg | >65 mmHg |
| PO2 adults | 80 - 100 mmHg | 25 - 40 mmHg | <50 mmHg | |
| PO2 >65 yrs | 75 - 85 mmHg | |||
| PO2 infants | 60 - 70 mmHg | |||
| HCO3 | 22 - 26 mmol/L | 22 - 26 mmol/L | ||
| %O2Hb | 96 - 97% | 45 - 70% | <75% | |
| %COHb | 0 - 1.5% | 0 - 1.5% | >10% | |
| %METHb | 0 - 1.5% | 0 - 1.5% | >10% | |
| SODIUM | 132 - 146 mmol/L | 132 - 146 mmol/L | <120 mmol/L | >160 mmol/L |
| POTASSIUM | 3.5 - 5.0 mmol/L | 3.5 - 5.0 mmol/L | <2.5 mmol/L | >6.0 mmol/L |
| CHLORIDE | 98 - 108 mmol/L | 98 - 108 mmol/L | <80 mmol/L | >130 mmol/L |
| IONIZED CALCIUM | 1.12 - 1.30 mmol/L | 1.12 - 1.30 mmol/L | <0.75 mmol/L | >1.55 mmol/L |
| LACTATE | 0.5 - 2.2 mmol/L | 0.5 - 2.2 mmol/L | >5 mmol/L | |
| GLUCOSE | 73 - 115 mg/dL | 73 - 115 mg/dL | <40 mg/dL | >500 mg/dL |