AKI vs lab error: pitfalls in creatinine measurement


    AKI vs lab error: pitfalls in creatinine measurement

    The Jaffe reaction, named for 19th century German biochemist Max Jaffe, is a colorometric assay used by most every clinical lab to measure creatinine. In an alkaline medium, creatinine reacts with picric acid to form a red colored compound; the amount of color change is proportional to the level of creatinine. Increases in creatinine make the final solution more red, but a number of other endogenously produced molecules interfere with the assay and make the color of the solution more red.

    Ketones. Ever notice an unusually large number of DKA patients with AKI’s? Both acetone and acetoacetate falsely elevate lab measurement of serum creatinine.

    Cephalosporins. Many are chromogens which falsely increase the redness of the Jaffe reaction, and result  in falsely elevated serum creatinine values

    Intralipid. This is not news. Lab values in patients after intralipid administration are notoriously unreliable. Serum creatinine values are falsely lower during severe lipemia.


    Calmarza, Pilar, and José Cordero. “Lipemia interferences in routine clinical biochemical tests.” Biochemia medica: Biochemia medica 21.2 (2011): 160-166.

    Samra, Manpreet, and Antoine C. Abcar. “False estimates of elevated creatinine.” The Permanente Journal 16.2 (2012): 51.

    • Welcome! This is the website for the Mount Sinai Emergency Ultrasound Division. It serves as an information resource for residents, fellows, medical students and others seeking information about point-of-care ultrasound. There is a lot ofRead more

    • Reach for the COWS

      Your patient in intake is miserable. Doubled over, complaining of pain everywhere, sweating, ill-appearing but not unstable. He tells you that the last time he used heroin was two nights ago, and he is askingRead more

    • Tis the season, summer edition

      As the late spring rains have begun to fade and the temperature rises mercilessly into the 80s and beyond, summer is finally upon us. And with summer comes a host of diseases for the emergencyRead more

    • Meet the newest member of your team

      We have a new resource in the Sinai ED. Say hello to your friendly ED pharmacist. In the past several years, the ED pharmacy has been centralized in a non-ED location. We all know wellRead more

    • In the spirit of roasts and fire-breathing dragons

      You’re on a lovely amble through the backcountry when suddenly you see smoke rising nearby and catch a whiff of a familiar scent that throws you back to your med school OR days: burning flesh.Read more

    • E-point Septal Separation in the Patient with Congestive Heart Failure

      Perhaps never explained so clearly, Cisewki and Alerhand’s article on EPSS is a wonderful read. Bottom line to remember: EPSS > 7 mm was 87% sensitive and 75% specific at identifying reduced EF (<50%).  This isRead more

    • Lidocaine for cough?

      Whether it’s asthma, a U.R.I., or post nasal drip as the cause, cough is a common enough complaint encountered by emergency physicians everywhere. Of course you must always rule out the dangerous causes of coughRead more

    • Measles redux!

      A quick search of sinaiem.org for the keyword measles brings up a solitary post from 2015, and it’s not actually about measles. With all the attention that measles has been getting in the news recently,Read more

    • The Apple Watch Heart Study

      Disclosure: I’m a huge Apple Fan. Unless you’ve been living under a rock, you’ve heard about the Apple watch, many of you reading this are wearing one right now. On April 24th, 2015 it joinedRead more