Clinical Pearl: Procalcitonin and Lower Respiratory Tract Infections

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Author: Jordan Kaylor, MD PGY4
Northwestern/McGaw Medical Center

Procalcitonin (PCT) is a serum biomarker that, when paired with clinical judgment, may help guide management of lower respiratory tract infections (LRTIs) in the emergency department (ED). Procalcitonin levels can help clinicians distinguish between bacterial and viral infections and might subsequently guide decisions to initiate or discontinue antibiotics. Procalcitonin is a prohormone of calcitonin. It is an acute-phase reactant synthesized in many tissues and released in response to cytokines such as interleukin (IL)-1, IL-6, and tumor necrosis factor (TNF)-α.1 Normal serum concentrations are <0.05ng/mL, but in bacterial infections, PCT increases to detectable levels within three to four hours (earlier than ESR or CRP).[1] Elevations are not seen in noninfectious inflammatory conditions or viral infections, but are possible in Addisonian crises, malaria, severe fungal infections and medullary thyroid carcinoma.[1] In viral infections, interferon (INF)-ɣ probably decreases PCT release, leading to lower or undetectable serum levels.[2]

Five Things to Keep in Mind When Treating an Asthmatic

Image from Alan Levine

This post was peer reviewed.
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Author: Puja Gopal, MD
Emergency Medicine Resident
University of Illinois at Chicago
AAEM/RSA Publications Committee Member

Asthmatic patients present along a broad spectrum of severity. There are those who present with mild wheezing, have complete resolution with a single neb treatment, and go home with a refill of their albuterol inhaler. And then there are those patients who present unable to speak or breathe and become increasingly agitated and altered. Though presentations of asthmatic patients may vary greatly, there are some key things you can keep in mind with the asthmatics you see.

1. Monitor the patient and the 5 key vital signs closely – temperature, pulse, respiratory rate, blood pressure and oxygen saturation. Heart rate above 120 and respiratory rate above 30 are concerning for a severe asthma exacerbation. Also note that a decreasing respiratory rate can be concerning for the inability to maintain respiratory effort and possible decompensation. An oxygen saturation <90% is hypoxemia and requires your attention. Monitoring your patient’s mental status is of utmost importance to ensure they don’t become agitated or altered – both of which can occur with hypoxia and/or hypercapnia.[1]