Several unresponsive patients at once?!

Stay calm. Remember the golden rule. Some people won't die no matter what you do to them. Try to elevate their head some or roll them to their side to prevent aspiration if the start to vomit. Iv, cardiac monitor etc. Keep a family member with them if possible. They can be a big help. Then it becomes an issue of triage. You have to look around to see who is most sick. Who needs to be intubated. Who is breathing, who is not, etc.

I think if you are ACLS certified, the ACLS protocols should be able to be followed in a situation such as this. CPR and ventilation for sure but I would ask your ED leadership about ACLS guidelines in this situation.

I agree with the other posters. All you can do is run protocols, follow the ABCs, until a doctor is available. Help usually floods the ER (usually), i.e. ICU nurses, resp therapists (who can intubate if necessary) if we call for help.
I work in a level 2 Trauma center, and we have received multiple traumas at once, and it's the same. It's always a bad shift to work multiple critical patients or traumas at once, buy you do what you can. The doctor sees the sickest, most critical patient, stabilizes them and moves on to the next.

In the ER I work at, it is required to be ACLS certified, and in a situation of multiple critical patients arriving at the same time, we are able to give medications per ACLS protocols. I can't imagine having a patient go into a life-threatening dysrhythmia and not give meds, just because a doctor was tied up with another critical patient.
I once asked my PALS instructor why I needed to to learn how to intubate pediatrics patients when I would never be performing this procedure as a nurse. Her response was just what the OP proposed.
Her question was: What if a pediatric patient came in, stopped breathing, cardiac arrested and no doctor was available due to multiple traumas/critically ill patients coming in at once? What if bagging the baby was insufficient, pulse ox dropping, no chest rise or fall?
That would be a very difficult situation.
But, that is when I really understood why ACLS and PALS was so important.