A 24-year-old man is brought to the emergency department by his roommate due to increasing lethargy and confusion over the past 12 hours. The patient has a history of type 1 diabetes mellitus and has not taken his insulin for the past week due to financial constraints. Vital signs show a temperature of C ( F), heart rate of 115/min, blood pressure of 105/68 mm Hg, and a respiratory rate of 28/min with deep, rapid breaths.
Laboratory studies reveal:
| Test | Result |
|---|---|
| Serum sodium | 140 mEq/L |
| Serum potassium | 4.8 mEq/L |
| Serum chloride | 104 mEq/L |
| Serum bicarbonate | 12 mEq/L |
| Blood glucose | 480 mg/dL |
Which of the following arterial values would best indicate an appropriate, isolated respiratory compensation for this patient's acid-base disturbance?
- A12 mm Hg
- B18 mm Hg
- 26 mm HgCevap
- D34 mm Hg
- E40 mm Hg
Cevap
26 mm Hg
The patient presents with diabetic ketoacidosis, which causes a primary high anion gap metabolic acidosis. To determine if the respiratory compensation (indicated by the patient's deep, rapid Kussmaul respirations) is appropriate and isolated, Winter's formula must be applied: expected . With a serum bicarbonate of mEq/L, the expected is mm Hg. Therefore, a value of mm Hg falls perfectly within this range, indicating an appropriate respiratory compensation without a superimposed secondary acid-base disorder.
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Anahtar Kavram
In patients with a primary metabolic acidosis, the appropriate respiratory compensation (hyperventilation) must be calculated using Winter's formula: expected .
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