Evaluation of liver function in the inpatient setting: CMP vs BMP Updated Lecture 5/02/2017 Wajidah Abdul-Khabir PGY-02 DSR 2

Guidelines No guidelines for ordering of LFT Should not be a screening test for liver disease Population-based survey in the United States conducted between 1999 and 2002 estimated that an abnormal ALT was present in 8.9 percent of respondents ALT level correlates with body mass index (BMI) and waist circumference, and the BMI of Americans has increased significantly over time Am J Gastroenterol. 2006;101(1):76.

Abnormal serum aminotransferase levels (ALT >2 Abnormal serum aminotransferase levels (ALT >2.25 SD above normal; >55 int. unit/L) were detected in 99 of 19,877 (0.5 percent) Air Force recruits beginning basic training [7]. Of these, a cause was found in only 12 (including chronic hepatitis B and C, autoimmune hepatitis, and cholelithiasis). No specific diagnosis was established in the remaining 87 patients. Dig Dis Sci. 1993;38(12):2145.

Most likely Dx Another study focused on 81 of 1124 patients who were referred for abnormal serum aminotransferase levels in whom a diagnosis could not be inferred noninvasively [11]. A liver biopsy revealed steatosis or steatohepatitis in the majority of patients (84 percent); six patients had fibrosis or cirrhosis, and eight had normal histologic findings. Am J Gastroenterol. 1999;94(10):3010.

Fluctuations Individual patients can have baseline fluctuation in serum aminotransferase levels. In a large, cross-sectional population-based study, more than 30 percent of adults with abnormal LFTS were reclassified as being normal upon retesting [14]. Ann Intern Med. 2008;148(5):348.

False positive Normal reference values-arbitrarily determined to be 2 SD above the mean 5 percent of healthy individuals who have a single screening test will have an abnormal result (2.5 percent will have an abnormally high result). As more tests are ordered, the likelihood of a false positive test increases; a screening panel containing 20 independent tests in a patient with no disease will yield at least one abnormal result 64 percent of the time

Cross sectional Analysis All patients on a ward team on 05/02 Looked at number of days of admission How many patients got CMP on admission How many had an indication to get a CMP- to evaluate for liver abnormalities Presence of absence of transaminitis Prior comorbitities that could give patients transaminitis at baseline Development of transaminitis through their hospital course

17 patients on one Wards team reviewed Average length of stay =4.9 days 16/17 received CMP on admission 8/17 patients had indication to check CMP (example: abdominal pain, jaundice, nausea/vomiting history of cirrhosis) 6/16 had transaminitis on admission 3/6 had known liver disease- ie (liver metastasis, HCC) 1/17 developed transaminitis during their hospital course

Average length of stay ~ 5 days Cost of BMP= $44 Cost of CMP= $50 For each patient on that team of 17 patients that didn’t have an indication to get a CMP, if they got daily BMP instead, it would save: $30/admission stay/patient

Conclusions Most patients w/o indication for LFT’s--> order a BMP instead If indication develops, you can always then start ordering CMP or hepatic panel. Even for patients with an indication, you can often switch to every other day monitoring.