A 19-year-old woman is brought to the emergency department by her roommate due to nausea, vomiting, and "ringing" in her ears. The roommate reports that the patient was distraught after a severe argument and ingested an unknown quantity of an over-the-counter pain medication approximately 5 hours ago. On physical examination, her temperature is 37.8°C (100.0°F), blood pressure is 112/68 mm Hg, pulse is 115/min, and respirations are 32/min. She appears agitated and is breathing deeply and rapidly. Her lungs are clear to auscultation bilaterally.
Laboratory studies show:
* Serum sodium: mEq/L
* Serum potassium: mEq/L
* Serum chloride: mEq/L
* Serum bicarbonate: mEq/L
* Blood urea nitrogen: mg/dL
* Serum creatinine: mg/dL
Arterial blood gas analysis on room air reveals:
* pH:
* : mm Hg
* : mm Hg
* : mEq/L
Based on the laboratory findings, which of the following best describes this patient's current acid-base disturbance?
- Concurrent primary high anion-gap metabolic acidosis and primary respiratory alkalosisCevap
- BPrimary high anion-gap metabolic acidosis with appropriate respiratory compensation
- CPrimary respiratory alkalosis with appropriate metabolic compensation
- DConcurrent primary high anion-gap metabolic acidosis and primary respiratory acidosis
- EConcurrent primary normal anion-gap metabolic acidosis and primary respiratory alkalosis
Cevap
To diagnose this mixed disorder systematically:
1. Calculate the anion gap (AG): mEq/L. An AG mEq/L confirms a primary high anion-gap metabolic acidosis.
2. Determine the expected respiratory compensation using Winter's formula: Expected mm Hg.
3. Compare actual vs expected : The actual is mm Hg, which is significantly lower than the expected range. This means the patient is blowing off more than can be explained by simple compensation, confirming an independent, concurrent primary respiratory alkalosis. Furthermore, simple compensation will never result in an overcorrection to an alkalemic pH ().