For a 22-year-old footballer who collapsed, what is the most appropriate next step in management?

In the scenario of a 22-year-old footballer who has collapsed, checking blood glucose is the most appropriate next step in management because one of the most critical and common causes of sudden collapse in young athletes is hypoglycemia.

Hypoglycemia can lead to loss of consciousness and other neurological symptoms that could easily be mistaken for other serious conditions such as a seizure or stroke. In the context of a young and active individual, especially an athlete, this condition could be due to intense physical exertion combined with inadequate carbohydrate intake or other metabolic issues.

A rapid assessment of blood glucose allows for immediate identification of a potentially life-threatening situation. If the glucose level is found to be low, prompt treatment with glucose administration can be initiated, which can rapidly reverse symptoms and potentially save the person from further complications.

The other options, while useful in different clinical scenarios, may not address the immediate cause of collapse as effectively as checking the blood glucose does in this situation. Imaging studies like CT and MRI are more appropriate for suspected intracranial issues, which are less common causes of collapse in a young athlete. Intravenous fluids can be important in management but do not address the urgent need to rule out hypoglycemia, which is critical in this acute setting.