Yeah he's what's considered "borderline low" blood pressure right now and my guess is it's from a combination of things. The hydromorphone being the main issue and my thought is probably dehydration...not due to lack of water but more to lack of electrolytes that would normally come from nutrition. So it's more then likely nutrition based.

Sodium and potassium deficiencies more then likely, which are easy to get. I'd start pumping him full of gatorade or powerade, you can also get potasium via supplements...those are a tricky thing too so before you supplement with pills ask your dr, but start immediately with gatorade or powerade.

As far as the finger test goes...don't worry about that if you can take his bp. If his bp get's to the 60/40 range take him to the ER.

Please note, I'm not a medical professional so please touch base with his Dr but monitor his BP and if it falls in the danger zone (60/40) take him to the ER.

Keep your chin up

Eric