Diurese at night?

Nurses General Nursing

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Specializes in BNAT instructor, ICU, Hospice,triage.

I thought I remembered in nursing school that we diurese at night. I know that the fluid moves from your vascular space at night and then in the morning it moves back to your blood vessels and causes increased blood pressure right? OR do I have it all wrong, its been 20 years ago!

Specializes in ICU/CCU, Home Health/Hospice, Cath Lab,.
I thought I remembered in nursing school that we diurese at night. I know that the fluid moves from your vascular space at night and then in the morning it moves back to your blood vessels and causes increased blood pressure right? OR do I have it all wrong, its been 20 years ago!

Usually we want to diurese in the morning so the person is awake when they have to keep getting up and going to the bathroom. Doing it at night would keep them from getting any sleep.

Of course sometimes we have to do both and if they have a foley it can make sleeping easier.

I have never heard of fluid moving out of your vascular space at night and then back in. Fluid should stay in the vascular space unless you have damaged vessels or an electrolyte imbalance that causes a fluid shift. People usually have a higher blood pressure during the day because they are more active and stressed. During sleep everything tends to relax including the smooth muscles which leads to dilation of the arteries, or lower blood pressure (this is not 100% happens everytime, but more of a general trend).

Hope this helps

Pat

Cardiac events occur more frequently in the early morning hours. This was kind of glossed over in school and was explained as being related to an increase in BP/HR upon first waking or getting out of bed, or facing the stress of the day. I think that's a believable, but not very scientific theory. A quick google search brought up this article which is referencing a study published by the AHA showing a possible relationship between decreased vessel elasticity in the morning hours and early morning heart attacks. So, there's another possibility.

http://www.medicalnewstoday.com/articles/8924.php

As far as diuresing at night, that isn't a normal homeostatic function. It can happen in some circumstances though. For example, in patients with heart failure third spaced fluid may be reabsorbed into the vascular space while supine, causing nocturia. Also, if people drink too much before bed, or take their diuretics late in the day, they might diurese at night.

Specializes in Adult ICU (All over), NICU, Education.

In the Heart Failure patient:

Specializes in Adult ICU (All over), NICU, Education.

IN the heart failure patient;

Nocturia develops as edema fluid from dependent tissue is reabsorbed while the patient is supine.

A healthy person may have nocturia if the lower extremity valves are incompetent, or in my case, if you work on your feet all day and drink tons of water...The legs can store a lot of fluids (think about raising the legs on a hypotensive patient) and as you lay down that "stored" blood moves through the circulation and the kidneys making more urine. When I used to work the floor I tried to drink a lot of water...I would have to go to the bathroom a few more times a night after those days that on my days off.

Specializes in Med-Surg.

We were taught to give diuertics in the AM hours, and not after 6pm if possible. Studies have shown that the elderly have increased risk of falls when given diuertics at night. And, no, I don't have a source for that. Just a tidbit stuck in my head from nursing school.

Specializes in still to decide.

I seem to recall literature regarding the circardian rhythm and how it is responsible for surges in blood pressure during the sleep cycle and the increase in MI's etc., I also seem to recall that it was between 3ish - 5ish am....I could be wrong, but I always ensured my pt were always ok during this time on a night shift, just incase:-)

Specializes in CVICU.
I seem to recall literature regarding the circardian rhythm and how it is responsible for surges in blood pressure during the sleep cycle and the increase in MI's etc. I also seem to recall that it was between 3ish - 5ish am....I could be wrong, but I always ensured my pt were always ok during this time on a night shift, just incase:-)[/quote']

Yep, when I worked in the ER, we always expected our "5 AM chest pain" patient to come in... there is some evidence that it has to do with the body's natural fluctuation of cortisol during this time.

Specializes in ICU.

I was taught that increased return to the heart from the LE at night causes atrial stretch, which leads to release of atrial naturietic peptide, which causes diuresis. Wasn't able to find a citation, though.

I have a friend that takes her Lasix at night, because she says she has to get up every hour to pee anyway, so she might as well make it worthwhile.

:paw:

I thought when people sleep at night extra fluid in the extremities and such go back into circulation due to being prone?

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