Low BUN - Liver problem?

[krissy82]

I had some blood work done a few days ago and am quite concerned because by BUN was low (3.5 mg). I recently have been on Vicodin ES - 1.5 tabs 3 times daily for 4 weeks for a miscarriage and D&C at 14 weeks pg. (I have also had several pelvic surgeries (5) in the last 5 years)My ALT is 10, AST is 14, Alk Phos is 72, Bilirubin Total is 0.3, Creatinine is 0.7, Total Protein is 6.6, Albumin is 4.0, Globulin is 2.6, Calcium is 9.8, Sodium is 140, Potassium is 5.2 (is this high???), Chloride is 105, and Carbon Dioxide is 25.6. A/G ratio is 1.5 and BUN/Creatinine ratio is 5.0! Urinalysis was normal. I have also been taking Vicodin ES regularly as perscribed by my doctor for 5 years because of the surgeries(never more than 4g per day and NO alcohol - I am 5'4 and 112 LBS). I have also had recent diarrhea for about 7 days. I read low BUN can mean LIVER FAILURE! Could this be the case or would the other Liver Function Tests be off?  In the past 6 months I have had EGD, Colonoscopy, Abdominal X-Ray, Abdominal CT, Brain MRI, and Small Bowel Follow Through - all these came back fine.  Please respond, I am a basket case over this.

[imkindly]

BUN stands for "blood urea nitrogen", a waste product normally excreted by the kidney.
Your BUN value represents how well the kidneys function.
BUN reflects the kidney’s ability to handle nitrogen (a product released from the breakdown of protein).
(High BUN means kidney trouble)

Here's some articles
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Urea nitrogen (BUN)

Serum urea nitrogen (BUN) is increased in acute and chronic intrinsic renal disease, in states characterized by decreased effective circulating blood volume with decreased renal perfusion, in postrenal obstruction of urine flow, and in high protein intake states.

Decreased serum urea nitrogen (BUN) is seen in high carbohydrate/low protein diets, states characterized by increased anabolic demand (late pregnancy, infancy, acromegaly), malabsorption states, and severe liver damage.

http://www.neosoft.com/~uthman/lab_test.html
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B.U.N. (Blood Urea Nitrogen):
The nitrogen component of urea, B.U.N. is the end product of protein metabolism and its concentration is influenced by the rate of excretion.

Increases can be caused by excessive protein intake, kidney damage, certain drugs, low fluid intake, intestinal bleeding, exercise or heart failure.

Decreased levels may be due to a poor diet, malabsorption, liver damage or low nitrogen intake.


BUN/CREATININE RATIO:
A high reading in this calculation is normally indicative of too much BUN being formed, and a low reading may show that the BUN is low or that the creatinine is not being cleared effectively by the kidney. This calculation is a good measurement of kidney and liver function.

Normal Adult Range: 6 -25 (calculated)
Optimal Adult Reading: 15.5

http://carbonbased.com/cbcblood.htm
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I'm not a doctor, but it sounds like (from the above) that your BUN/Creatinine Ratio is low because your BUN is low.

Your BUN could be low for several different reasons (above they list several possibilities---some as simple as diet.)

One thing to keep in mind is that every lab has their own "reference range".
You asked about your Potassium.
Some labs say that "normal" Potassium is 3.5 to 5.0
Other labs say that "normal" Potassium is 3.5 to 5.5

All of the blood tests that you mentioned can be found at these websites:
http://carbonbased.com/cbcblood.htm
http://www.neosoft.com/~uthman/lab_test.html

One more thing (hopefully to put your mind at ease a little)---your ALT, AST, Alkaline Phosphatase, Bilirubin, Protein, and Albumin look good! (Those tests would show liver trouble).

Hope this helps