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Date of last update: 10/09/2017.

Forum Name: Renal Failure

Question: BUN and creatinine levels

 cockerham - Wed Feb 02, 2005 4:22 pm

Hi, I am a student nurse and I have a case study I am working on. the patient presents with extreme confusion, T-104F, P 86 (regular), respirations 18 (clear & unlabored), BP 90/40. lab values WBC=30,300 mm3; RBC=3.61 million/mme; Hgb=11.6 gm/dL; Hct=34.3%. started IV (1000mL) of 0.9% NS and gave 150 mg of Gentamycin IM and 1 g of Ampicillin IV. Skin is warm, dry and lacks turgor. no abd pain or chest pain and no cough. had hip surgery 4 mos prior and still had indwelling catheter. urine output 30mL/hour. Na=137 mEq/L; K=3.8mEq/l; chloride=106 mEq/L; CO2-18 mmol/L; BUN=19 mg/dL; creatinine=1.0 mg/dL. microscopic urinalysis revealed bacteria and high number of WBC; urine culter showed more than 100,000 oranisms/mL; chest X-ray was negative. With this information, especially the BUN and creatinine being WNL, is it possible that this patient has impaired renal functioning?
 Dr. Tamer Fouad - Wed Feb 02, 2005 4:51 pm

User avatar Hello,
The term renal impairment is not a very objective one. A patient is either is renal failure or not. Renal failure may be acute or chronic. If it is acute the renal function tests may return to normal or they may progress to irreversable renal failure (chronic). In order to answer your question you would be required to compare the patient's current renal function tests with his previous tests. A persistant increase in renal function test levels even if within normal range is indicative of deterioration in renal function. To diagnose renal failure properly you would need to perform a creatinine clearance test. Especially that creatinine is not a sensitive test for detection of early renal disease.
That said however, it is possible for a patient to have acute pyelonephritis without deterioration in renal function. Provided of course, it is quickly treated.

As for possible causes of confusion, you should ask yourself: How long has his blood
pressure been this low? How old is your patient? Is it possible that he has developed a stroke (given the low blood pressure and the dehydration)? Is there an obvious cause for his hypotension?
Hope this helps.

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