What is normal serum ammonia level?

  1. 0
    Saunders book says 35-65mg/dL, CD 15-45, Kaplan 80-110. A bit too much difference for me.
  2. 4 Comments so far...

  3. 5
    first of all, you've stated the units incorrectly. saunders lists normal serum ammonia as 35 to 65 mcg/dl, that's micrograms, not milligrams (page 116). actually, the parameters are much wider than you are being quoted.
    ammonia levels rise when there are large amounts of protein being catabolized and the liver is unable for some reason to convert it into urea so it can be excreted through the kidneys. anything that interferes with the breakdown of ammonia in the system will increase serum levels. that includes such conditions as:
    • hepatic encephalopathy
    • hepatic coma
    • hepatocellular disease
    • portal hypertension
    • severe heart failure with congestive hepatomegaly
    • gi bleeding and/or obstruction with mild liver disease
    • erythroblastosis fetalis of the newborn
    • reye syndrome
    • asparagine intoxication
    • a genetic metabolic disorder of the urea cycle
    • http://www.labtestsonline.org/unders...onia/test.html
    most information came from pages 41-42, mosby's diagnostic and laboratory test reference, 4th edition, by kathleen deska pagana and timothy james pagana except where noted. when there is such wide variety in lab values there are two things the testing administrators are likely to do: (1) actually list the lab values they want you to apply to these kinds of questions in the test information instruction booklet which you should have already downloaded and read very carefully (they did this with our national crni exam where we were extensively tested over fluid and electrolytes), or (2) they will give you answer choices with lab values that are so widely spread out that it will be unmistakable which answers are right and which are wrong. they will not deliberately trick you with picayune answer choices like this on the nclex. it is better for you to know that ammonia levels are elevated in the diseases listed above, why and to know the broad range of test results than to try to determine which text is giving you absolute correct lab range results. the test makers are aware that there can be large variation in the lab ranges, so they are not likely to specifically question on this. an exception would be potassium. it is well-known and standard that 3.5 to 5.0 meq/liter is a normal level in adults. anything above or below results in grave consequences for the patient. normal potassium level is something you should know off the top your head.
  4. 0
    I've run into the same problem studying for boards. So how does 15-45 mcg/dL equal 80-110 g/dL?? Is there something I'm missing?
  5. 1
    Quote from mariaspapias
    i've run into the same problem studying for boards. so how does 15-45 mcg/dl equal 80-110 g/dl?? is there something i'm missing?
    nclex prints details of the what is on the test on their website so you know what to expect. this is the current one for the nclex-rn: https://www.ncsbn.org/2007_nclex_rn_..._candidate.pdf. on page 38 of this document regarding laboratory values it lists the following:
    • know laboratory values for abgs (ph, po2, pco2, sao2, hco3) bun, cholesterol (total) glucose, hematocrit, hemoglobin, hemoglobin a1c (hba1c), platelets, potassium, rbc, sodium, urine specific gravity and wbc
    • recognize deviations from normal for values of albumin (blood), alt (sgpt), ammonia, ast (sgot), bilirubin, bleeding time, calcium (total), cholesterol (hdl and ldl), creatinine, digoxin, esr, lithium, magnesium, ptt and aptt, inr, phosphorous/phosphate, protein (total), pt, urine (alb, ph, white blood cell count [wbc] and differential)
    • obtain specimens other than blood for diagnostic testing (e.g., wound cultures, stool, urine
    • specimens)
    • obtain blood specimens peripherally or through central line
    • notify primary health care provider about laboratory test results
    • monitor client laboratory values (e.g., glucose testing results for the client with diabetes)
    • provide client with information about the purpose and procedure of prescribed laboratory tests
    you don't need to convert any lab values. for ammonia, you merely need to know what the normal levels are and be able to recognize what is abnormal no matter what system of measurement is used. you need to get a lab reference that will give you the normal levels in various measurements. if you do not have a lab reference book with this information, try looking for it on any of these websites:
    the people who write the nclex are aware that the test is taken all over the country and that many different labs use different methods to test for these lab values. they are trying to keep the test fair, so they will not tie you down to something very, very specific. that is why they are going to ask for deviations from normal when it comes to ammonia levels.
    Last edit by Daytonite on Jul 23, '09
    srngrit11 likes this.
  6. 0
    Yes, when I got labs on NCLEX, they were very obviously wildly abnormal.


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