What can you do to open up your throat passage quick?

If your throat has closed up because of an allergic reaction, the remedy is to use an epi-pen, an injector of epinephrine (also known as adrenaline). If you have a serious allergy which could cause such a reaction, then you should always have an epi-pen with you.

If your throat passage is blocked for some other reason, there are other remedies. The most extreme remedy is a medical procedure called a tracheotomy, which involves cutting a hole in the throat and inserting a tube to allow air to enter, but that is something that only a trained medical professional should attempt.