Hemoglobin loss unknown

Hello. The patient is my dad, 86, PD currently at 6 exchanges, 1200ml fill volume, 9hrs (give or take). He keeps having prescription changes, the last due to hospitalization for pneumonia for 14 days. His hemoglobin since on PD has went from above 12 to 10 just before his hospital stay, to 8.6 (June 3) a little over 1 week after his discharge, to 5.9 (June 25) which sent him to the ER for a transfusion of 1 unit only bringing him up to 8.9 (Jun 27) down to 8.4 on July 1. I brought him to the ER July 13, he was 6.9 and 1 unit this time only brought him to 8.0. Lab draw done in his dialysis clinic on July 15 show 7.9.
His primary care doctor doesn’t know of any reason why this is occurring other than the treatment itself. His nephrologist doesn’t know of any reason why this is occurring other than nutritional, him not consuming enough red meat proteins, as he has been given Mircera on the June 25th visit and his visit on July 11 with her. Quite decent sized dosages I’m told. There is no bowel bleeding, no major nose bleeds, no signs of collecting blood anywhere, and he bruises so easily. From his pneumonia, he has been coughing up a nickel to a quarter size amount of old coagulated blood every day since discharge in May that doesn’t seem to concern his pulmonary doctor.
This major unknown has caused him to have two ER visits to deal with transfusion and additionally great stress because he also has a mitral valve backflow issue and an irregular heartbeat, so they want to do full work ups every time despite me telling them it is not necessary within a couple of weeks of a prior visit for THE SAME THING–a LOW HEMOGLOBIN count, not the heart or lungs or the kidneys. The poor man just settles in and lets me take the wheel.
He’s going back on hemo as soon as everything can get scheduled. But I still want to know…is there something else these doctors just aren’t seeing or looking for? I didn’t dare go out on google and search.

Thank you–angel

People with kidney failure often have anemia, but usually hemoglobin levels are not as low as your father’s. How are his other labs related to anemia? Here’s information from Kidney School on anemia.

Some patients on the Home Dialysis Central FB group have said they didn’t respond to Mircera and had to use a different drug. Is your dad getting IV iron? I’ve heard that oral iron isn’t well absorbed by people with kidney failure.

Has he seen a hematologist? That’s the specialist who deals with blood disorders. Has he had x-rays or scans to look for possible contributors to anemia?

Is your father being treated at a community hospital or at a teaching hospital. Teaching hospitals can sometimes identify strange problems that other hospitals and doctors can’t figure out.