# CSF Test- has anyone been taugh this?



## Lifeguards For Life

Cerebrospinal Fluid Test
     Leakage of cerebrospinal fluid (CSF) from the ears, nose or mouth is an indication of skull fracture. CSF is a clear fluid that may be confused with other secretions. One way to determine true CSF is to test the glucose content of the fluid using a standard capillary glucometer. CSF contains glucose, but at a much lower concentration than the blood. If glucose is found in the clear fluid, suspect it is CSF.

does anyone actually utilize this particular CSF Test in the field, and do you feel it is validated?

We were "taught" this in class by one instructor, but then later told to disregard, as the it was a flawed test.


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## Lifeguards For Life

Lifeguards For Life said:


> Cerebrospinal Fluid Test
> Leakage of cerebrospinal fluid (CSF) from the ears, nose or mouth is an indication of skull fracture. CSF is a clear fluid that may be confused with other secretions. One way to determine true CSF is to test the glucose content of the fluid using a standard capillary glucometer. CSF contains glucose, but at a much lower concentration than the blood. If glucose is found in the clear fluid, suspect it is CSF.
> 
> does anyone actually utilize this particular CSF Test in the field, and do you feel it is validated?
> 
> We were "taught" this in class by one instructor, but then later told to disregard, as the it was a flawed test.



obviously, it would be wist to assume any clear fluid leaking from the ears nose or mouth is CSF, but would blood and snot mixed together not have the same BGL as CSF?

We were told this method is based around the fact that CSF has glucose in it, while snot does not


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## VentMedic

http://emedicine.medscape.com/article/861126-overview




> Glucose determination
> 
> A rapid but highly unreliable test is glucose-content determination with the use of glucose oxidase paper. This method of detecting CSF rhinorrhea is not recommended as a screening or confirming lab test to detect the presence of CSF in the nasal cavity for the following reasons:
> Reducing substances present in the lacrimal-gland secretions and nasal mucus may cause false-positive results.
> Glucose, at a concentration of 5 mg/dL, can lead to a positive result with this test.
> 
> Active meningitis can lower the glucose level in the CSF and may lead to false-negative readings.
> This test is not specific for the side or site of leak.


 
Nor is the halo test reliable.


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## Lifeguards For Life

VentMedic said:


> http://emedicine.medscape.com/article/861126-overview
> 
> 
> 
> 
> Nor is the halo test reliable.



"In patients with head trauma, a mixture of blood and CSF may make the diagnosis difficult. CSF separates from blood when it is placed on filter paper, and it produces a clinically detectable sign: the ring sign, double-ring sign, or halo sign. However, the presence of a ring sign is not exclusive to CSF and can lead to false-positive results. In contrast to unilateral rhinorrhea, bilateral rhinorrhea gives no clue of the laterality of the defect. However, even in this situation, exceptions can occur. Paradoxical rhinorrhea occurs when midline structures that act as separating barriers (eg, crista galli, vomer) are dislocated. This dislocation allows CSF to flow to the opposite side and manifest at the contralateral naris. The clinical findings most frequently associated with CSF rhinorrhea are meningitis (30%) and pneumocephalus (30%)."

Wow. we were taught the halo-test religiously. not checking halo was critical criteria for pateint assessment in both EMT and Medic school


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## VentMedic

Some of these tests may be good to confirm what you already suspect and if the test turns out to be positive...great.  However, if negative and other signs are present, I would not rely on the test as a definitive rule out.    

But, that can be said for many of the field diagnostic procedures and tests.  Even the pulse oximetry is not a definitive assessment for oxygenation especially at the tissue level.   It may only confirm what you might suspect but other assessment data should determine your treatment.


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## natrab

It seems to me that if you're concerned of head trauma of that magnitude, you don't need to be pulling out the glucometer to test fluid drainage for a result that can't really hold any weight.  The signs and symptoms of a head injury will be your best source of a working diagnosis.  Interesting information though.

As far as the halo test goes, I have noticed after unloading some serious traumas that their blood can make a little halo in our cloth sheets after moving the patient off the bed.  It's usually just confirming the fact that our patient had a head injury (in this case it was a GSW to the head).


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## medicdan

To echo others, its very interesting academically, and could be valuable to document on long transports, but is not going to change BLS (or ALS) treatment. Do you carry any drugs that impact ICP, and would your administration even change with this new information?
Even when getting to the hospital, before any definitive treatment (surgery), they would do a CT scan.


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## 18G

We were taught that you can test suspected CSF with the glucometer.... if it is half the value of the patients blood glucose level than it is considered positive.


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## bunkie

Yes, we were told we could use the glucometer as a way to confirm. We were also told it would wick away from blood on gauze.


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## Onceamedic

My instructor used the touch test...   snot strings...   CSF does not....


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## thegreypilgrim

We were taught not to rely on the "halo test" because the same thing happens with blood without any CSF in it. 

They mentioned the glucose test, but that you're supposed to compare the suspected blood-CSF mixture reading with a normal capillary sample, and if it's substantially less than the normal blood, then it likely is positive for CSF.

Also we were taught that blood mixed with CSF will take a lot longer to clot (if it clots at all) than normal blood - it might be hard to come up with a "test" process for this though.

Anyway, the best thing to do is to use a combination of signs/symptoms, mechanism of injury, and maybe one of these "CSF tests" (halo test probably the easiest one to do) to drive one's index of suspicion for skull fractures.


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## rescue99

Lifeguards For Life said:


> Cerebrospinal Fluid Test
> Leakage of cerebrospinal fluid (CSF) from the ears, nose or mouth is an indication of skull fracture. CSF is a clear fluid that may be confused with other secretions. One way to determine true CSF is to test the glucose content of the fluid using a standard capillary glucometer. CSF contains glucose, but at a much lower concentration than the blood. If glucose is found in the clear fluid, suspect it is CSF.
> 
> does anyone actually utilize this particular CSF Test in the field, and do you feel it is validated?
> 
> We were "taught" this in class by one instructor, but then later told to disregard, as the it was a flawed test.



Never used it in the field but I have seen it done in house a few times on kids with head injuries.


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## WannaBeFlight

I was taught two reliable ways:  Cotton 2x2, if it dries with a brown ring after a few minutes, then its positive for CSF. The other way was using Ph paper... if it is a certain color, then its positive. I would have to look that one back up. 

the only problem I see with using the glucometer is that there will be blood mixed in which could give a false reading with sugars naturally being in blood. Just my thought...


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## Jeffrey_169

I have not seen this particular test used before. I was always taught the Halo test, but in practice if you see it and are in doubt, assume skull fracture. There is no test, as far as I know, that is definitive in the field, but I could be wrong on this. We always treated it as a skull fracture when you see clear fluid coming from the ears.


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## wolfwyndd

I think emt.dan said it best.  Whether the CSF is SUSPECTED or CONFIRMED, does it really change your treatment of injury(ies) during the course of your transport?  Probably not.  So if you've got time to actual test for CSF, great, if not, move on.


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## NJFLGHTMDC

*csf*

Just taste it! lol
Its sweeter tasting than the blood. Just kidding, Don't do that


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## WannaBeFlight

Crazy Jerseyian, lol! 



NJFLGHTMDC said:


> Just taste it! lol
> Its sweeter tasting than the blood. Just kidding, Don't do that


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## MedicSqrl

Ditto on the halo test. Although I have never heard of anyone that has ever used it.


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## nomofica

Used the halo test (used a 4x4 pad of gauze) once and result was positive. Pt did in fact have a skull fracture, but my decision to treat as skull fracture was based simply off sheer doubt as to whether or not the fracture actually existed. "Better safe than sorry" thought process.


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## Tincanfireman

natrab said:


> It's usually just confirming the fact that our patient had a head injury (in this case it was a GSW to the head).


 
I would have accepted the hole in the skull as confirmation of a head injury...  =)


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## BLSBoy

WannaBeFlight said:


> Crazy Jerseyian, lol!



If you (willingly) reside in this state, you are crazy. h34r:


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## nomofica

Tincanfireman said:


> I would have accepted the hole in the skull as confirmation of a head injury...  =)



I got some funny looks from some of the boys after I laughed out loud at that one.


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## grich242

emt.dan said:


> To echo others, its very interesting academically, and could be valuable to document on long transports, but is not going to change BLS (or ALS) treatment. Do you carry any drugs that impact ICP, and would your administration even change with this new information?
> Even when getting to the hospital, before any definitive treatment (surgery), they would do a CT scan.




 I agree Dan... and here is my beef with tests like this... If the moi is enough to cause a fracture then treat it like one until proven otherwise. It's great to debate things academically but we dont for the most part we don't diagnose in the field. We in most cases do not have the tools to do so i.e. ct's x-rays labs, etc. We develop a clinical impression based on many factors. The same way doc's do ... and order tests for a definitive diagnosis. For medics with less experience the danger here is being distracted by trying to figure out if it is in fact csf and missing something else because they were distracted.


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## Shishkabob

emt.dan said:


> Do you carry any drugs that impact ICP, and would your administration even change with this new information?



Actually, yes, some places do carry drugs that impact ICP, namely Mannitol which is an osmotic diuretic use for ICP.


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