When discussing complications of PD, there is no shortage of
information about infection-related issues such as exit-site-infections
and peritonitis. These are relatively common occurrences and require
immediate medical management. There is also no lack of advice regarding
managing mechanical dysfunction in PD—like how simple constipation can
stop-up the entire show, how much heparin to use, or the many ways to
manage pesky drain pains.
Those who are just starting off learning PD are bound to come across
some interesting things as they go, but the nuances of
discolored PD effluent are a concern many newer nurses have not
seen before, or even heard of yet.
Since this is a conversation we have been having recently with
patients on our Home Dialysis Central Facebook group, I thought it might
be a good idea to talk about what PD effluent should and
shouldn’t look like and hopefully explain some of the oddities
possible.
Clarity Matters
Let’s start with the most basic
rule: all peritoneal effluent should
be clear. Effluent that is not crystal
clear (see-through) and a normal yellow color needs to be reported
immediately and the cause identified.
What is CLEAR? When we say that the fluid should be clear, we are
referring to the clarity of the fluid, not the
color. I always feel like I’m explaining how diamonds are
graded when I teach this difference, but once you think of it in that
context, it’s much easier to visualize.
Crystal clear fluid means you can read printed text through
it. If the fluid is hazy and you are unable to see letters
through the bag, the fluid is not clear.
What is CLOUDY? Again, we’re talking about clarity here, not
color. If drained fluid is too turbid to read through,
it is cloudy, and that warrants an immediate work-up for
peritonitis. Every patient, care partner, and staff member managing PD
should immediately say “PERITONITIS!” when presented with cloudy
fluid.
There can be noninfectious causes of cloudy fluid, but until
infection is ruled out, the assumption of peritonitis must be made to
preserve the membrane. The cloudy appearance is caused by
infection-fighting white blood cells.
PD Effluent Color
Peritoneal effluent contains electrolytes and uremic toxins. If it
has been dwelling for a while, the drained fluid should be a
straw-yellow—like urine. Effluent that has been
dwelling for a long time may be darker than fluid that was recently
instilled. Hydration status plays a role in how dark or lightly colored
effluent is, too. When effluent does not look as expected, there is a
reason:
RED PD Effluent: This is hemoperitoneum. If
you are a PD nurse, before you send any younger female patients home on
PD, ask yourself if they might ovulate or menstruate at some
point. This doesn’t even have to be a regular occurrence, just
a general possibility. If the answer is in any way affirmative,
the patient needs to be told that releasing an egg, or shedding
some endometrial lining can (and really does) cause bleeding
into the peritoneum. The dwelling fluid then turns bright red.
This sight can be completely shocking and horrifying if the patient has
not been warned. It really looks like a lot of blood.
You can suggest irrigating the peritoneum with cool
dialysate or filling with cool fluid to discourage further bleeding. If
clots are present, your patient may need to add heparin to keep catheter flows
smooth.

There are other reasons for effluent to be bloody that aren’t as
normal and need to be evaluated. If the cause of the bleeding is not
routine and gynecological, the reason needs to be found. A
ruptured cyst (ovarian, renal, pancreatic, hepatic,
etc) can bleed into the peritoneum and cause pain and/or profound
bleeding. In addition to cysts, some types of cancers and
tumors can bleed internally in the same way and show up
unexpectedly in a drain.
Ruptured vessels can present this way too. Typically
this happens from a minor irritation (exercise or heavy lifting) and the
internal catheter rubbing on structures causing microtrauma and
capillary bleeding. Major vessel bleeds, like ruptured abdominal aortic
aneurysms can cause major life threatening hemorrhage and bleeding into
the peritoneum. This type of medical emergency is not caused by
dialysis, but the symptoms can be seen because of it.
ORANGE PD Effluent: The antibiotic
Rifampicin is used to treat mycobacterial infections
and tuberculosis. It has a side effect of turning bodily fluids
(tears, sweat, urine) orange. PD effluent is affected by this
too, and this might happen with other medications that change body fluid
colors. If a patient is prescribed a medication that has the potential
to change the color of their urine, it may also change the color of
their effluent even if this is not a known or stated side effect. They
should be made aware of the possibility before it causes
unnecessary panic.

RUST PD Effluent: If a patient on PD receives
rifampicin and IV iron together, the effluent from the antibiotic-iron combination turns a rusty shade
of orange-red. This is a harmless side effect.
BRIGHT YELLOW PD Effluent: Liver failure,
some cancers, or heart failure can cause extra free fluid to
build up in the abdomen. This can be very uncomfortable, depending on
how much fluid is produced. In the non-dialysis population, a full
abdomen can be drained with paracentesis—a tube is placed into
the peritoneum temporarily to relieve pressure. For those on PD who also
have ascites from liver failure, the peritoneal catheter offers a
sterile and regular manner to drain the fluid. This may not look
very different from regular effluent, but may be brighter
yellow in color, with more volume present than expected.
FLOURESCENT YELLOW-GREEN PD Effluent: The first time
I saw glow-in-the-dark effluent, I thought my patient
was playing a trick on me! I was in my office, and suddenly there was a
very alarmed man standing in my office holding a 3000 mL bag of effluent
that was so fluorescent, it looked radioactive. He had
just finished draining at home and ran right in so fast that
the fluid was still warm.
I had read about this before, and instantly knew what I was looking
at, but was really surprised that it was as…bright and vibrant as it
was. It’s remarkable: like the liquid inside of a glow-stick. Anyway,
even though it is a very cool thing to get to educate about
after it has happened and you have a giant bag full of proof
that diffusion really happens, it’s something everyone should be aware
of, lest you wonder if your patient is turning into
Spiderman. It actually does glow in the dark—I
checked! I had read that “some contrast dyes” can make it into the
peritoneal space, but since I had never seen it happen before, was
completely stunned. My patient had had an eye exam for glaucoma,
received IV fluorescein contrast, and dialyzed it out
through his peritoneum. Pretty neat, really, especially since it does
not cause harm.


GREEN PD Effluent: Effluent that is
yellow-green-brown points to a leak of
bile into the peritoneal cavity. Any leak in the GI
system is a risk for infection and may indicate that the patient has
cholecystitis that has perforated. Bile is green, and
if there is any leak in the biliary tree system, the effluent can turn
green. The hue can be dark and muddy. It doesn’t look
healthy, which is a really good tell that it needs further
evaluation right away.
GREEN PD Effluent with PARTICLES: can indicate
a perforated ulcer that is leaking food and gastric juices into the abdomen.

BROWN-GREEN PD Effluent with PARTICLES: If effluent
is brown or green with particles mixed in, it is possible the patient
has a perforated bowel and feces are leaking from the
gut and mixing with the dwelling fluid. Any leaking from the GI system
into the peritoneum is going to cause an infection if it hasn’t
already—so there are multiple things going on when this is seen.

BLUE/PURPLE PD Effluent: A few years ago, PD
patients in Europe were stunned when they began to drain and saw that
their effluent was a strange shade of purple or blue. An investigation
discovered that iodine in the PD catheter caps was reacting to
Extraneal PD fluid manufactured in Turkey. No harm came from
this, and it has not occurred since 2011.

CLEAR BROWN PD
Effluent: “Coca-Cola” colored effluent is a sign of
hemolysis. This can happen with pancreatitis, when
enzymes mixed with blood break down the cells, or with rhabdomyolysis.
Both are different from hemoperitoneum, as the red blood cells
have been destroyed.

BROWN-BLACK PD Effluent: Similar to the green
effluent, dark brown to black fluid indicates that bile is leaking.
There may also be bilirubin present, which can be tested for. The green
color from bile and the red-orange-yellow pigment from the bilirubin
combines to create very dark fluid. If the effluent has more bilirubin
than the blood does, the patient will most likely need an emergency
exploratory surgery to find the source of the leak. A gangrenous
gallbladder or pancreatic complications are possible.

MILK WHITE PD
Effluent: We are programmed to think of any opacity in PD fluid
to be “cloudy” and thus indicating an infection. This isn’t always the
case. Some effluent can be MILK WHITE and completely opaque.
This looks just like lipids—because that’s what it is.
High levels of triglycerides and a blockage of lymphatic chyle drainage
from the intestines causes fluid build-up into the peritoneum. This can
happen as the result of a high fat meal, trauma, or severe diseases like
lymphoma and congestive heart failure.

PEACH/PINK PD Effluent: What do you get when you
mix hemoperitoneum and a chyle build-up? I’m not sure
if there’s a word for this specifically, but the effluent can look
peach or pinkish in color when they mix. The cause of
the bleeding and lymphatic back-up need to be identified.
BLACK PD Effluent: As a heavily tattooed nurse, one
of my favorite ice-breaking conversations with new PD patients is one I
was told about many times by older-generation PD nurses. Apparently,
during colonoscopies, medical tattoo with India ink is sometimes used to
mark an area for future surveillance. Ink transfer
through the peritoneum is rare, but is something PD patients and staff
should be aware of.
I hope this post makes it a little bit easier for those involved with
PD to know what they’re looking at when presented with an inevitable
oddly-colored drain bag. In writing this, I noticed there was very
little quick and easy information out there about effluent anomalies
with photographic examples. The links to the articles containing the
photos used are listed below for reference.
Image sources are as follows:
Figures 1, 2, 4, 5, 6, and 10: https://onlinelibrary.wiley.com/doi/10.1111/sdi.12740
Figures 3 and 12: https://nephsim.com/case-10-diagnosis-conclusions/#CaseIndex
Figure 7: https://www.renalfellow.org/2010/02/01/green-peritoneal-dialysis-fluid/
Figure 8: https://doi.org/10.1186/s12882-018-0974-6
Figure 9: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3707724/
Figure 11: https://www.kidney-international.org/article/S0085-2538(20)31543-X/fulltext
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- Source: https://homedialysis.org/news-and-research/blog/581-the-rainbow-of-peritoneal-dialysis-effluent-possibilities