Medic-lad reporting for duty.
In the case of severe panic attacks, respiratory and heart problems can arise which feeds a nasty loop. Because you start to feel your heart being weird and your breathing is bad, you think you'll die or something is wrong and it makes the panic attack even worse. Nausea is very common too, which caused people to start shitting themselves or puking. The medicines to treat these work very quickly if we can establish an IV. We used to push Ativan (anti-seizure and anxiety) and Zofran (anti-nausea) at the same time one after the other. You'd get results usually in 10 minutes by IV injection. Failing that you can ratchet up a higher tier of drugs, or start morphine to induce tiredness and a slight high. It might sound odd, but the point of emergency treatment is to stop the ongoing/current crisis. Not sort your long-term shit out. So we focused on stopping the immediate problem.
Then fluids to re-hydrate them. They may have lost a lot due to sweating, or diarrhea from the panic attack. Usually after that you ship them off to a primary care doctor who will diagnose mental issues or recommend a psych to do it depending on the cause of the panic attack and how frequent they are/history.