Should I be concerned

Had a really bizarre 'episode' at doctors surgery this aft and just wondered if anyone could relate to it or give any advice  

I have been struggling with a really bad cough for a few days with chest pain and difficulty getting breathe at times (I am asthmatic)

I put off going to doctor as long as i could but had a tough time coping with the cough and short of breath today so got an appt this aft. Well as I was sat with doctor I had a huge coughing fit then was asked to do a peak flow just after which set the coughing off again straight after doing the peak flow test he took my bp and while he was doing so I completely blanked out its like I lost 5-10 seconds because when I came round he had finished with bp and had took the cuff off but last I remember it was still inflating. It felt like an mini explosion had gone off in my head and I was then dazed, there was no pain with it and everything was fine afterwards apart from about 10 seconds of confusion, it had what I imagine as a stun grenade effect going off in my head, I assume this marked the end of the 'event' slightly confused when i came round and I tried figure out what had just happened 

He gave me prednisolone and amoxycillin to settle my asthma down and fix whatever was triggering the asthma/coughing. it was like there was a bit of a sonic boom In my head and time just skipped, it's not something that has ever happened before