low HOB better for urine flow?

[unsaint77]

I know the following question is a newbie question. I do have a lot of newbie questions and becase of that I get a lot of unkind comments. Please just pass on if you don't feel like answering.

I was collecting U/c sample from foley catheter but the flow was minimal. My supervisor told me to lower the head of bed to help the flow. So, is that because when the HOB is lowered, the body is flatter therefore the urethra is straighter?

[classicdame, MSN, EdD]

or could be less constriction

We make an awful lot of urine while we sleep.

[canesdukegirl, BSN, RN]

Not so much that the urethra is straight, but the foley itself is not kinked or constricted, as classicdame suggested. Think about when you water your garden and you have to unspool the hose. You can get water out of the hose if it's still on the spool, but you get a much better flow if you pull the hose out a bit.

[trauma_lama, BSN]

My understanding is that is doesnt have to do with urethral positioning, but that perfusion to kidneys (and thus GFR) improves in a more supine position. See nocturia r/t HF and renal disease. Hope this helps.

[deftonez188]

Foggy here, but the only explanation I can offer (albeit my first instinct is that gravity = >GFR) is that when lying supine, the fluid distribution of the body isn't acted on toward solely the feet by gravity anymore. As a result, fluid that was 'compressed' toward the feet 'shifts' and more of it enters the central circulation, causing a greater GFR d/t increased volume.

Feel free to correct me if wrong, it's a foggy memory from way back when.

[leslie :-D]

hmmmm.

i've always sat my pts upright, when i didn't get urine...

and gave them something to drink.

i've always gotten results.

leslie

[CompleteUnknown]

Hmmmm too.

In that situation, I would think it's probably more the change in position than anything. Any urine that's there should already be in the bladder so it's more likely that the catheter tubing has unkinked slightly or the tip of the catheter has shifted position in the bladder when the patient moves.

[HollyGoLightlyRN]

I also seem to recall that HOB position at 10 degrees or less slows the release of ADH which would increase urine output.

[unsaint77]

I didn't know this. It's amazing. So, a bladder gets fuller at night. Thanks Skindigo.

ADH: The Test | Antidiuretic Hormone

ADH secretion increases when a person is standing, at night, and with pain, stress and exercise. Secretion decreases with hypertension and when someone is lying down.

[HollyGoLightlyRN]

Hey, thanks for the link to that lab test website. Great info.

[HouTx, BSN, MSN, EdD]

Baroreceptors located in the heart, vena cava, carotid sinus and aortic arch have an influence on secretion of ADH. More pressure = less ADH. Theoretically, lowering the HOB would increase pressure in these areas.