Renal question

This might be a common sense question or perhaps anatomy 101. Had a patient scheduled for Hemodialysis; prior to dialysis urine PVR was 250cc Dr order was to straight cath if PVR greater than 300. So I left it alone and told dialysis tech to start the HD tx. 2hrs past HD completed I again did bladder scan and to my surprise PVR resulted with 00cc of urine in the bladder. Where did the urine go? Patient did not void. No urine output noted at all. So what happened? Did the Dialysis remove the urine from the bladder? Im confused. I thought dialysis is like a big electronic kidney. Does it serve to remove all fluid from the body including urine?
Always double check the PVR from both sides. I was once told I had a PVR of 230, I was pretty sure I was empty. The nurse double-checked it from the other side, and it was ZERO.And why would you check the bladder post-dialysis? Did the patient void again? I'm a little confused about the second part...

Dialysis can (but does not have to) remove fluid from the circulatory system. Most patients are assigned a "dry weight" that is the weight the patient should be when he/she comes off the dialysis machine. I don't know where the fluid in the bladder would have gone-did you ask the patient if he/she voided? Any fluid lost during a dialysis treatment can be replaced if the patient is at his/her dry weight.

Sometimes bladder scanning isn't very accurate. Depending on the model of the scanner, it can be very "touchy." Also, bladder scanners can sometimes pick up fluids from other parts of the body. I've seen it happen in patients with ascities.

also some of the scanner needs to be set to female or male, if a patient had hysterectomy then set it to male.

Quote from merleeAlways double check the PVR from both sides. I was once told I had a PVR of 230, I was pretty sure I was empty. The nurse double-checked it from the other side, and it was ZERO.And why would you check the bladder post-dialysis? Did the patient void again? I'm a little confused about the second part...

Quote from dichiealso some of the scanner needs to be set to female or male, if a patient had hysterectomy then set it to male.

Sounds like a bladder scanner issue, +1 to checking on the male/female setting, or just general error. I've only ever witnessed bladder scanners, but have heard about their finickiness. And while I'm not in urology, bladder's not equiped to suck fluid back into the circulatory.

I dislike bladder scanners b/c they have to be reprogrammed on occasion and like most electronics, cannot guarantee to give you an accurate reading. They only real way to check for residuals is to straight cath and see what you get.