In need of help!!

I am a Home Care nurse and have a pt that has recently had lower back surgery, since his surgery he has been having episodes of what his PCP thought was anxiety but I am not sure. He can be up moving like normal and then all of a sudden he becomes very short of breath and needs to sit down, episodes may last 5min or 10min but when over he is just wiped out. This never happens when laying down just when he gets up or when he becomes to tired. Recently he has had an episode where his body started shaking they can be mild or very severe. He has seen his Cardiologist that said it was not heart related and will see Pulmonary specialist tomorrow. Being a nurse I have seen anxiety problems but this does not appear to be his issue, was given anti-anxiety meds but not effective. Vitals also not very much out of the ordinary following episode, 02 sats are good. He just states he feels wiped out all the time but more so after episode almost like a seizure. Wondering if anyone has any idea's. Thought maybe some spinal trauma during his back surgery?? Help!!

It does sound like seizures. After one they always feel wiped out and will sleep for a very long time. The breathing problem , is something I'm going thru myself. I just had a ct scan on my chest and really nothing showed other than calcium spots. So I'm assuming it is my fibromyalgia. It also does it when laying down tho. The pulmonologist didn't know what it was so I just deal with it, but it's scary when it happens all ofca sudden for no reason. I hope they figure it out for him!!