A 45-year-old woman is brought to the emergency department 20 minutes after being found lying on the pavement by passersby. She was not unconscious but felt very faint. Her pulse is 105/minute. Blood pressure while supine is 92/60. Physical examination shows poor skin turgor and dry mucous membranes. Serum HCO3– is 12 mEq/L; arterial pCO2 is 24 mm Hg. Which of the following is the most likely acid-base disturbance in this patient
Metabolic acidosis
Metabolic alkalosis
Mixed metabolic acidosis and respiratory acidosis
Mixed metabolic acidosis and respiratory alkalosis
Mixed metabolic alkalosis and respiratory acidosis
Mixed metabolic alkalosis and respiratory alkalosis
Respiratory acidosis
Respiratory alkalosis
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Cut-to-the-chase Answer (1:09):
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HY USMLE Answer (4:27):