My experience is if I give myself an injection after the second vomiting episode then I usually improve significantly. If I don't, I end up in hospital. Other people may find that other sequences/protocols work better for them but this is what I have discovered works for me quite effectively.
This past night (2am) I had two episodes of vomiting, as well as, diarrhoea and a low-grade fever, so I had one Solu-cortef injection and went back to bed and slept. This morning I still feel very nauseous and have a headache probably due to dehydration..so we'll wait and see if it develops further.
I find that once I get dehydrated it is very hard to drink enough fluids, when you are already feeling nauseous, to rehydrate, so that is a bit of a dilemma. Sometimes you do need to get into hospital for IV fluids.
It is very hazy often as to what is caused by a virus/bacteria, dehydration or an impending adrenal crisis. I think you have to have a protocol that you implement regardless of the cause of the vomiting - because in my experience you don't necessarily know. In some of the epsiodes that I have had, in hindsight, I know it has been dehydration leading up to the event. eg. Yesterday I was sooo thirsty in the afternoon when I took my mother out for a drive but I forgot to take water with me - so something was happening well before I started vomiting.
Glad that Rachel started to improve. How long had she been back on Dex before this episode happened? Sounds like she was quite depleted.