Okay, here is what happened to ME when I went into surgery with low iron. I did not wake up easily from anesthetic. I remember them hurting me with sharp objects rubbing them into my sternum, pinching my nail beds, slapping my face, saying "BREATHE". I was in recovery for 2 hours while they stabilized me. Labs showed my hemoglobin (?) was 6, they said I needed transfusions STAT. I got 2 units as soon as they found my rare blood type, which wasn't until the next day (cross matching difficulties). In the meantime, before I got the blood, I COULD NOT BREATHE, even with oxygen. I felt like I was suffocating. I knew I was going to die, and nobody was listening to me. Finally, I got hold of my husband's shirt and yanked him to me and said "I am dying. Call a Priest". That scared him, and he started moving mountains to get my blood faster.
That happened during my hysterectomy/Tummy Tuck/Posterior repair surgery. I was under for 6 hours and my OB-GYN said mine was the worst posterior repair she had ever seen. Her exact words were "I was having kittens trying to sew you back together".
NOW, your FERRITIN must be high as well as your iron markers going into surgery. You MUST have iron infusions BEFORE surgery. Because afterwards, you will be dead, and iron infusions won't matter.
The blood in your urine could be a simple bladder infection. It might be something more sinister. An intelligent person would CANCEL surgery until this is resolved. Your surgeon, if he knows, will certainly cancel surgery for either blood in the urine or severe anemia. It is YOUR responsibility to SPEAK UP AND MAKE SURE HE KNOWS ABOUT THESE THINGS.
I could have died. I did not know then what I know now about iron. Looking back, the hysterectomy was done for excessive bleeding. But I should have had iron infusions before surgery. My recovery took MONTHS instead of the few weeks it should have taken. When you receive whole blood, you experience a "crash" about a week after, when the donor blood reaches it's end. I felt like cat shit for a VERY long time.