The night before the USMLE Step 3

I, for no reason whatsoever, was struck by a severe asthma attack. I was wheezing so badly that I could barely talk, but was convinced that I didn't need medicine to get better. It wasn't until someone gave me nebulized albuterol and I recovered that I realized how bad my respiratory compromise had been.

Logically, my very next thought was, "I wonder what my PaO2 was during my attack!" (The PaO2, naturally, being the arterial partial pressure of oxygen measured in the blood.)