Glad your fiance completed treatment, and is otherwise recovering. The Procrit injections can cause a fever, and so can Thrush, which is a fungal infection. Also, they usually don't give any injections after the hemaglobin goes above 12, and my local doctor stops at 10 due to the possibility of speeding up cancer, and tumor size, and not when a tumor was suspected. RBC have an average life cycle of 120 days, and continuously die off, so in three months the hemaglobin can start dropping again, as in my case for several years. The last drop was during my treatment, and my treatment hospital does not give procrit shots anymore, just tranfusions, which I had in November. Hopefully his bone marrow starts working properly after the chemo, if that is the cause, and doesn't need anymore.
I had a similar problem with my back molar being infected, 3 months after radiation. I had to do 30 HBOT, 20 before extraction, 10 after, to help prevent osteonecrosis due to having radiation to the mouth, jaw, and will need again for any extractions.
Good luck with everything.