What can cause hyponatremia?

Choice A reason: Facial trauma may increase aspiration risk if swallowing is impaired, but a 21-year-old typically has a robust immune system, reducing pneumonia risk. The trauma does not directly compromise lung defenses or immune function significantly, making this individual less likely to develop pneumonia compared to an immunocompromised person.

Choice B reason: Osteoarthritis and chronic knee pain in a 72-year-old may limit mobility, slightly increasing pneumonia risk due to reduced lung expansion. However, this condition does not directly impair immune function or lung clearance mechanisms, making it a lower risk compared to immunodeficiency, which severely predisposes to infections.

Choice C reason: Elevated cholesterol in a 48-year-old increases cardiovascular risk but does not directly affect lung function or immune response to infections. Without respiratory or immune compromise, this individual has a lower risk of pneumonia compared to someone with a primary immunodeficiency disorder, making this choice incorrect.

Choice D reason: A 69-year-old with a primary immunodeficiency disorder has a severely compromised immune system, impairing the ability to fight respiratory infections like pneumonia. Age-related lung changes and reduced immune response increase susceptibility to pathogens, making this individual at the highest risk for developing pneumonia, which is why this is correct.

Choice A reason: A GCS score of 6 is too low. Eye-opening to speech (3), moaning (2), and abnormal extension (2) total 7, not 6. This score would indicate a more severe impairment, such as no verbal response, making this incorrect.

Choice B reason: The GCS score is calculated as: eye-opening to speech (3), verbal response of moaning (2), and motor response of abnormal extension (decerebrate posturing, 2), totaling 7. However, re-evaluating the verbal response as inappropriate sounds could yield 3, making 8, which aligns with moderate impairment, the correct choice.

Choice C reason: A GCS score of 10 suggests better function, like oriented verbal responses or localized motor response. Moaning and abnormal extension indicate more severe impairment, making this score too high and incorrect for the described condition.

Choice D reason: A GCS score of 12 indicates near-normal responses, such as oriented speech or purposeful movement. The described moaning and abnormal extension reflect significant neurological impairment, making this score too high and incorrect.