I've been doing a lot of research about this lately; reading the AHA Coding Clinics for HCPCS procedures. The conclusion I came to is that hydration, if done with anything else is always listed as subsequent (90761) You don't use 90760 if any other therapy is done. Also, you need at least 30 min of hydration to code it.
In 2008, there is a new code 90776 (I think) that covers subsequent IVP's of the same drug, as long as at least 30 min have past between IVP's. This would be used for your subsequent Toradol inj.
I know chemo comes first, then I think IVPB, IVP/IM and then hydration. I'm confused about this, too; because in the ER they'll treat the symptoms first, then later, after they establish a diagnosis, maybe use antibiotics...so which is coded first? I always use the IVPB drugs (usually antiobiotics) first in case the insurances try to bundle I want to get that paid. Don't know if that's technically correct, though.
Sorry for the length....Hope it helps a little