That indeed sounds uncomfortable, lol.
Inflicting shock;
Seeing as you cannot control the reflex (I believe it is a reflex, correct me if I'm wrong) to hiccup it's clearly it is being caused by your autonomic nervous system, which if your body is in shock could be irritated and therefore (in lack of a better term) forget to hiccup. But that's just a theory I've read somewhere, quite a while ago.
Btw; are you a med student or something? o_o