I lost the diagram I had before but here it is in HTML:

Stress (symptom: vomiting)
           |
  Give extra Cortef
     call Doctor
     wait ½ hour    -->  if vomiting stops --> then Emergency over
           |
 if vomiting continues
           |
    then Give shot,
      call doctor,
 and wait half an hour
    (unless doctor
  suggests otherwise)   -->  if vomiting stops --> then Emergency over
           |
 if vomiting continues
           |
 then go to Emergency Room!

Our doctor has said that the real purpose of the shot is to stabilize the person in order to get them to the emergency room. He still allow a half an hour to see if the shot will work, after that if the symptoms continue, he says we should get them to the ER.

An adrenal crisis is not something your wait 24 hours to see if the meds work. Doing that can very easily result in death.