A 52-Year-Old Man Is Brought to the Emergency Department After

question 158

Multiple Choice

A 52-year-old man is brought to the emergency department after being found unresponsive on the street.  The patient's medical history is unknown.  Temperature is 36.2 C (97.2 F) , blood pressure is 108/62 mm Hg, and pulse is 72/min.  On physical examination, he is unresponsive to verbal and tactile stimuli but moans to deep sternal rub.  An arterial blood gas analysis on room air shows a partial pressure of oxygen of 60 mm Hg.  The partial pressure of oxygen in his alveoli is calculated to be 68 mm Hg.  Which of the following is the most likely cause of this patient's symptoms?

• A)Alveolar hypoventilation
• B)Dead space ventilation
• C)Diffusion impairment
• D)Intrapulmonary shunt
• E)Left-to-right shunt

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Definitions:

Heat Discoloration

A change in color of a material, typically metal, caused by the application of heat, which can indicate stress, fatigue, or damage.

Low Oil Level

A condition where the volume of oil in an engine or system is below the manufacturer's suggested minimum, potentially leading to increased wear or failure.

Twisted Mainshaft

A mainshaft in a gearbox or transmission that has been deformed or bent, affecting its ability to rotate smoothly.

Gear Ratio

The ratio of the rotational speeds of the first and last gears in a transmission, reflecting the difference between the input and output gears.