Procalcitonin: Sepsis Marker Extraordinaire?

Sepsis is one of the most common causes of significant morbidity and mortality in hospitalized patients as well as the most common cause of death in ICU patients.  In addition, the earlier sepsis is identified and treated, the better the prognosis for the patient. We actually do not have a biochemical marker which can be used to effectively diagnose sepsis. Sepsis diagnosis depends on finding microbial infection by culture, and while PCR methods do exist to quickly identify bacteremia, in most institutions cultures take at least 24 hours to grow.  To aid in the diagnosis, clinicians can check three biomarkers commonly considered “sepsis” markers: C-reactive protein (CRP), erythrocyte sedimentation rate (ESR) and procalcitonin (PCT).

Despite being very different tests, these three assays are ultimately indicators of inflammation or the inflammatory response. ESR is a simple manual test that measures how far red cells sediment out of a blood sample in one hour. It is used as a marker of inflammation but is quite unspecific; several conditions can cause inflammation. The ESR can tell a clinician that inflammation exists but not the cause of that inflammation CRP is an acute phase reactant protein. Its production by the liver increases in acute inflammation. However, its levels will be affected by liver dysfunction. PCT is a pro-hormone produced by extra-thyroidal immune cells within 2-4 hours of a bacterial insult or an inflammatory response.

Deciding whether a biomarker is a good indicator of sepsis is made difficult by its complex pathology. Studies that show one marker performs better are contradicted by other studies that show it does not. The utility of PCT for predicting sepsis remains controversial for this reason. However PCT has shown to be useful for predicting prognosis in sepsis. Increasing PCT concentrations correlate with increasing severity and a poor prognosis. Decreasing or low concentrations indicate a good prognosis. PCT is also being used to guide antibiotic therapy, although this use should be limited to non-surgical/trauma ICU patients, which is where the studies have been done. Thus although PCT proponents consider it to be the best available biomarker indicator of sepsis, none of the three tests have been shown to be good at diagnosing sepsis. Unfortunately, all three of these biomarkers are indicative of an inflammatory response and not specific for sepsis itself. However, once sepsis is known, all three biomarkers can be used to monitor its progression and response to therapy.

If you’d like to read more about PCT and sepsis, you can do so here:

http://www.nlm.nih.gov/medlineplus/ency/article/000666.htm

http://www.webmd.com/a-to-z-guides/sepsis-septicemia-blood-infection

http://www.medscape.com/viewarticle/720621_1

https://www.aacc.org/members/nacb/NACBBlog/lists/posts/post.aspx?ID=16#

 

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-Patti Jones PhD, DABCC, FACB, is the Clinical Director of the Chemistry and Metabolic Disease Laboratories at Children’s Medical Center in Dallas, TX and a Professor of Pathology at University of Texas Southwestern Medical Center in Dallas.

Hacking Pathology Residency Training

As we celebrate the Christmas season and gear up for 2014, I’ve been thinking about resolutions and things in my life that warrant change. And since I was able to go home this year for Christmas break, I’ve had some time to do something that I enjoy but haven’t been able to do in a while – watch TED videos. I recently watched this one given by a 13-year old about hackschooling at TedxUniversity of Nevada. Makes me wish I had done some when I was younger (my first aspiration was to be an artist) but of course, I was raised in a traditional Asian household that revered education and practicality (“you can do drawing as a hobby but you should be a doctor”). Don’t get me wrong, I do not blame my parents and now at this point in my life, it is my choices that will determine my future and happiness.

And so I’ve been thinking about my education, both personally and professionally. In terms of nurturing my creative side, I realize that I need to set aside some “me time” where I engage in my previous interests (though probably not during PGY-2). And for my social justice/service side, I know that I will eventually return to my community activities when I can consistently have time to give, although I still watch from the sidelines and contribute when I can. But in terms of my chosen profession, I often wonder if there is a way to “hack” our residency training to make it both more creative and effective and to be proactive rather than reactive?

Tying together some themes I have previously blogged about (competency evaluation and transforming our profession), I’d like to address some issues I see. Pathologists need to be more engaged, both within the system and within society or be left behind. With healthcare reform, gone will be the days when a physician can continue to practice the way s/he was trained – there will be a constant drive for life-long learning, both in terms of knowledge and utilization of new technologies, especially disruptive or exponential ones, than is present currently. I’m not going to argue for or against the finer points of the ACA or the recent cuts in pathology codes in the new physician fee schedule except to say that the landscape we residents will inherit will be vastly different than the one our attendings, or even we, now currently train.

But competency needs to be more than a checklist. We need to learn how to navigate and show our worth within the value-based systems where we will most likely work. First, of course, we need to learn our material well. We cannot interpret data, educate non-pathologists, or advocate for specific decisions if this foundation is lacking. But how do we residents take ownership and accomplish this in addition to the training we may or may not receive in our residencies? And how do we learn to be a patient advocate rather than just a reporter of results?

I will leave you these questions to ponder until my next blog where I will elaborate on some of my observations and ideas on this topic. For those of you who attended Eric Topol’s keynote at CAP ’13, I will leave you with similar talk by Dr. Daniel Kraft given at TedxMaastrict about 2.5 years earlier – http://www.ted.com/playlists/23/the_future_of_medicine.html– and hopefully, it’ll spark some ideas.

I hope everyone has a prosperous year in 2014!

 

Chung

Betty Chung, DO, MPH, MA is a second year resident physician at the University of Illinois Hospital and Health Sciences System in Chicago, IL.

Happy New Year—Making 2014 a Year to Remember

If you are one who likes to make a resolution for the New Year, let’s have a look at the word “resolve”:

re·solve:

verb:  settle or find a solution to (a problem, dispute, or conflict); to sort out, solve, deal with, rectify;  to decide firmly on a course of action; determine, decide, make up one’s mind, make a decision
noun: resolve, resolution; determination to do something, strength or decisive commitment

Or, another way to define it might be, “re – solve”.  Laboratory professionals are trained and skilled at solving problems, particularly analytical ones; why not “resolve” to “re – solve” something? Perhaps this is your year to make a commitment to giving back to your profession, your faith, your future. Consider volunteering, either at your laboratory, your hospital or clinic, your community, or perhaps even globally. There is no end to the list of opportunities for service, using skills and training to add value to improving health. If you want some ideas, just contact me at bsumwalt@pacbell.net and I’d be very happy to explore the idea with you!

This is one of my favorite quotes—let’s make 2014 a Year to Remember!

“How wonderful it is that nobody need wait a single moment before starting to improve the world.”  ~Anne Frank

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Beverly Sumwalt, MA, DLM, CLS, MT(ASCP) is an ASCP Global Outreach Volunteer Consultant.

Dangerous Beauty

Potentially deadly pathogens have never looked so good. A false-color electron-microscope slideshow on Discover depicts organisms such as Campylobacter and Streptococcus pyogenes in a whole new light. Apparently actresses and models aren’t the only ones who benefit from Photoshop.

 

Swails

Kelly Swails, MT(ASCP), is a laboratory professional, recovering microbiologist, and web editor for Lab Medicine.

Season’s Greetings—International Style

In this season of extending kindnesses and gifts and sharing the blessings of family and friends, I am reminded of something I have heard many times; World peace isn’t achieved in government board rooms or international caucuses…it is achieved quietly in each other’s homes, around the table, one-one-one, face to face.  I believe that is true; and some of the most lasting impressions I have of the world and the world’s people have been gifted to me in conversation, at the table, exchanging ideas, thoughts and building relationships and forging ways ahead to make health and care better globally.  This is the essence of change and the heart and soul of peace and prosperity.  May this season bring peace and joy, no matter where you live or what faith you follow, and may we all strive to sing the melody and the harmony together whenever we can.

Happy Holidays!

 

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Beverly Sumwalt, MA, DLM, CLS, MT(ASCP) is an ASCP Global Outreach Volunteer Consultant.

Harmonization

What does “harmony” mean to you? And how does it apply to lab testing?

One of the biggest problems that arise where lab testing is concerned is that tests run in two different labs will give you two different results unless the labs happen to be using the same equipment (and sometimes even then the results won’t match!) This is a huge problem for doctors of patients who use different laboratories for their testing or patients who move across the country and need to continue following lab test results.  A prime example of this dilemma is the current state of T4 testing. The same CAP sample when analyzed using different assay methods for thyroid stimulating hormone (TSH) can yield results which range anywhere from 2.66 to 8.84 mIU/L. Although CAP samples are not always commutable with patient samples, thyroid testing on patients shows this same lack of harmony.

This example underscores the need for harmonization. In our increasingly small world, where nearly everyone will soon be using the electronic medical record, and all lab results on a patient will be in one place whether they were all performed at the same place or not, it will be paramount that the lab results for any given test can be compared. Efforts to date have successfully harmonized several important analytes, including creatinine (IDMS-creatinine), cholesterol and hemoglobin A1c.  Efforts are on-going to harmonize vitamin D assays against the NIST standards. These harmonization efforts took a massive amount of coordination and work between the in vitro diagnostic industry, regulatory agencies and laboratory and clinical societies.

Laboratory professionals have long recognized this problem, and sought to inform non-laboratorians of the realities at every opportunity. Lack of comparable test results can lead to patient safety issues, including misdiagnoses and/or inappropriate treatment. Recently an international consortium has recognized the need for harmonization of all lab results and begun to work on the problem. Although this effort is just beginning and the road ahead is long until general test harmonization can occur, it is a road worth traveling.

 

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-Patti Jones PhD, DABCC, FACB, is the Clinical Director of the Chemistry and Metabolic Disease Laboratories at Children’s Medical Center in Dallas, TX and a Professor of Pathology at University of Texas Southwestern Medical Center in Dallas.

Happy Holidays from Lab Medicine

It’s going to be a little quiet here over the next few weeks while our team of mad scientist writers enjoy time with their families. We’ll be back in action after the New Year with lots of great information for you. In the meantime, the editors of Lab Medicine would like to wish you and yours a happy and safe holiday season.