A 24-year-old G4P2 woman at 34 weeks gestation complains of a cough and whitish sputum for the last three days. She reports that
everyone in the family has been sick. She reports a high fever last night up to 102°F (38.9°C). She denies chest pain. She smokes a half-pack of cigarettes per day. She has a history of asthma with no previous intubations. She uses an albuterol inhaler, although she has not used it this week. Vital signs are: temperature 98.6°F (37°C); respiratory rate 16; pulse 94; blood pressure 114/78; peak expiratory flow rate 430 L/min (baseline documented in the outpatient chart = 425 L/min). On physical examination, pharyngeal mucosa is erythematous and injected. Lungs are clear to auscultation. White blood cell count 8,700; arterial blood gases on room air (normal ranges in parentheses): pH 7.44 (7.36 - 7.44); PO2 103 mm Hg (>100), PCO2 26 mm Hg (28 - 32), HCO3 19 mm Hg (22 - 26). Chest x-ray is normal. What is the correct interpretation of this arterial blood gas?A. Acute metabolic acidosisB. Compensated respiratory alkalosisC. Compensated metabolic alkalosisD. HypoventilationE. Hyperventilation
