TABLE 1

The patient’s laboratory values

Substance	Value	Reference range
Blood chemistry
Sodium	132 mmol/L	136–144
Potassium	4.8 mmol/L	3.7–5.1
Bicarbonate	16.0 mmol/L	22–30^a
Chloride	95 mmol/L	97–105
Blood urea nitrogen	23 mg/dL	7–21
Creatinine	1.3 mg/dL	0.58–0.96
Glucose	97 mg/dL	74–99
Lactate	1.1 mmol/L	0.5–2.2
Albumin	4.5 g/dL	3.9–4.9
Serum osmolality	318 mOsm/kg	275–295
Arterial blood gases
pH	7.25	7.35–7.45
$\text{[math]}$	28 mm Hg	34–46^b
Bicarbonate	16 mmol/L	22–26

↵a For acid-base problem-solving, a value of 25 mmol/L is considered normal.
↵b Healthier patients with better pulmonary function may attain lower $\text{[math]}$ values; for clinical problem-solving, a value of 40 mm Hg is considered normal.
$\text{[math]}$ = partial pressure of carbon dioxide