ArtsAutosBooksBusinessEducationEntertainmentFamilyFashionFoodGamesGenderHealthHolidaysHomeHubPagesPersonal FinancePetsPoliticsReligionSportsTechnologyTravel

Procalcitonin in Sepsis: A Guide to Antibiotic Stewardship

Updated on February 10, 2018
docashp profile image

Docashp has been an intensivist for the past ten years. His areas of interest include hemodyamics and antibiotic stewardship.

Procalcitonin: A Biomarker For Sepsis

Procalcitonin is a highly specific biomarker for the diagnosis of sepsis. The word sepsis is derived from the Greek word "sepo" which means "I rot". The first mention of the word sepsis occurs in the poems of Homer. Although the mortality in sepsis has reduced from 50%-75% to a range of 30%-50% the incidence of sepsis has increased annually in the past forty years. This reduction in mortality is largely attributable to the discovery and use of antibiotics in the past hundred years of medicine. The total deaths sepsis causes is statistically similar to myocardial infarction.

Sepsis Epidemiology


Population: 2.4 to 3% incidence in general population.

ICU: 10-14% incidence in ICU patients.


ICU: 16% incidence in general population.

Brun-Buisson et al. JAMA 1995

S Todi et al. Crit Care 2007

Sands et al. JAMA 1997

Systemic Inflammatory Response Syndrome (SIRS): Not The Same As Sepsis

Systemic inflammatory response syndrome (SIRS) may occur in the absence of infection.

Two or more of the SIRS criteria are needed to document it-

  • Temperature more than 380C (100.40F) or less than 360C (96.80F).
  • Heart rate more than 90 beats/minute.
  • Respiratory rate more than 20 /min or PaCO2 < 32 mmHg.
  • White Blood Cell Count(WBC ) more than 12,000 cells/mm3 or 4,000 cells/mm3, or more than 10% immature (band) form of white blood cells.

So What Is Sepsis?

Sepsis –

Systemic response to infection – It is confirmed or suspected infection plus 2 SIRS criteria.

Severe Sepsis –

Sepsis associated with organ dysfunction, hypo perfusion, or hypo tension.

Septic Shock –

Severe Sepsis that cannot be resuscitated or stabilized with IV fluids alone.

Adapted from SCCM ACCP Consensus Guidelines BSI= Blood Stream Infections
Adapted from SCCM ACCP Consensus Guidelines BSI= Blood Stream Infections

Clinicians Dilemma

So if you have fever, a fast heart rate, fast breathing and increased white blood cells you do not necessarily have sepsis because these can occur in the presence of systemic inflammatory response syndrome. For sepsis the presence of infection (either suspected or confirmed by microbial techniques) is necessary. So medical conditions like pancreatitis, burns, trauma may present with fever, tachycardia, tachypnea and increased white cell count either due to SIRS or Sepsis and there is no objective way to differentiate one from another.

Biomarkers For Sepsis

More Than 150 Biomarkers For Sepsis:Why Procalcitonin?
More Than 150 Biomarkers For Sepsis:Why Procalcitonin?

What Is An Ideal Bio Marker?

A bio marker may be simply defined as a laboratory measurement that reflects the activity of a disease process. An ideal bio marker should not only help in the early diagnosis of a disease but also provide information regarding its severity and prognosis. Serial measurements of an ideal bio marker before and after the therapy should show decline to indicate the effectiveness of therapy. Erythrocyte Sedimentation Rate (ESR) is the oldest bio marker and is in use from the past ninety years. Other common bio marker is C reactive protein (CRP) which in use since the past 30 years.

Rangel et al. JAMA 1995
Rangel et al. JAMA 1995

Mortality In Sepsis

Seligman R et al.Crit. Care 2006 SS= Septic Shock
Seligman R et al.Crit. Care 2006 SS= Septic Shock

Why Do We Need A Bio Marker Like Procalcitonin?

A bio marker like procalcitonin may help differentiate SIRS from sepsis. This differentiation is of paramount importance because infection or sepsis would require antibiotics whereas inflammatory conditions do not require antibiotic treatment. A misdiagnosis may result in either cost escalation of treatment if antibiotics are administered to a person not suffering from sepsis whereas if antibiotics are delayed or denied in a patient of sepsis it will cause increased mortality or morbidity. So the best case scenario will be a bio marker which will objectively differentiate a infective cause of illness from a not infective one to guide the clinical decisions regarding antibiotic administration, thereby taking the guesswork out of the equation.

Procalcitonin Biochemistry

        Morgenthaler N. et al., Clin Lab 2002
Morgenthaler N. et al., Clin Lab 2002

Procalcitonin (PCT) : A Prohormone

It is a protein composed of a chain of 116 aminoacids. It is a pro-hormone of calcitonin and is secreted from all parenchymal tissues in response to bacterial infection. Calcitonin on the other hand is secreted by the C cells of the thyroid only. The regulation of procalcitonin is by the CALC-1 gene located on chromosome 11. A bacterial infection increases the CALC-1 gene expression and stimulates the release of procalcitonin. The normal serum procalcitonin level is less than 0.05 ng/ml.

Procalcitonin Normal Range

The level of procalcitonin in normal individuals is <0.5ng/ml. It can increase to very high values up to 1000 ng/ml. A PCT value of >2ng/ml is highly suggestive of an infectious process but the levels between 0.5-2 ng/ml lie within an equivocal range which neither confirm nor deny an infectious process. This group may include post surgical patients, polytrauma patients, newborn infants, patients with extensive burns, patients with viral infections or local infections or autoimmune diseases and neoplastic disease.

Procalcitonin Kinetics In Sepsis

Brunkhorst FM et al., Intens Care Med 1998
Brunkhorst FM et al., Intens Care Med 1998

Procalcitonin Kinetics in Sepsis

Procalcitonin levels start increasing within three hours of infection and levels peak in blood at six to twelve hours after infection. It has a half life of around twenty four hours after which levels start declining.

Role of Procalcitonin In Clinical Practice

Assist in the diagnosis of sepsis.

To monitor clinical course & therapy.

Predict prognosis of disease.

Prognostic Value Of Procalcitonin

The level of procalcitonin concentration in serum is higher in more severe infections but the decrease in concentration was more important for survival than the absolute values.

Karlsson et al. Critical Care 2010, 14:R205

Use Of Serum Procalcitonin Levels In Various Clinical Situations

Procalcitonin In Acute Respiratory Tract Infections

Procalcitonin guided therapy markedly reduced the use of antibiotics without affecting the patient outcome (Arch Intern Med. 2008; 168(18):2000-2007).

This has important clinical and epidemiological implications as antimicrobial drugs are often overused in self limiting respiratory infections.

Serum Procalcitonin Measurement For The Early Diagnosis Of Candidemia In Critically Ill Patients

Intensive Care Med (2006) 32:1577–1583
Procalcitonin levels do not increase in fungal infections. High procalcitonin level in a patient with clinical sepsis will unlikely be due to fungal infections. So if a critically ill patient has low serum PCT but clinically apparent sepsis patient should be further assessed and investigated for fungal infections.

Procalcitonin In HIV Infections (AIDS)

The level of procalcitonin does not increase even in advanced disease in HIV positive patients. It is only in the presence of sepsis that procalcitonin induction is observed. Infections like tuberculosis, cerebral toxoplasmosis, pneumocystis carinii pneumonia, viral and local bacterial and fungal infections do not increase the level of procalcitonin in HIV patients.

Procalcitonin In New Born Infants

Procalcitonin concentration peaks between 24 to 36 hours after birth and during this period markedly increased concentration can be observed even in the absence of relevant bacterial infection.

Clinical Chemistry 44, No. 6, 1998

Limitations of Procalcitonin As Biomarker

Procalcitonin may increase without sepsis
Procalcitonin may be normal in sepsis
New born less than 48 hours of birth
Bacterial Infection (If localized)
Early phase of sepsis
Viral Infections
Fungal Infections
Medullary C-cell cancers of the thyroid
Parasitic Infections
Bronchial Carcinoma
Pulmonary Small-Cell Carcinoma

Advantages of procalcitonin over C Reactive Protein

Secretion begins after infection
3 hours
8 hours
Response to treatment
Rapid fall
Protracted response
Effect of steroid & Non steriodal anti inflammatory drugs (NSAID’s)
Blunted response

To monitor clinical course & therapy

Significant reduction in antibiotic use

 number of prescriptions and

 duration of use

No impact on mortality, length of hospital stay

Arch Intern Med (2011); Clin Infect Dis (2011); Crit Care Med (2010); Infection (2009)

Systematic review and meta-analysis of procalcitonin guided antibiotic therapy

Good Antibiotic Stewardship

So procalcitonin may be used to assist in the more judicious use of antibiotics both inside and outside Intensive Care Units. A good antibiotic stewardship will prevent the emergence of multi drug resistance bacteria and help reduce the burden of sepsis.

Too Many Pills

Do you think you take antibiotics too often?

See results


    0 of 8192 characters used
    Post Comment

    No comments yet.


    This website uses cookies

    As a user in the EEA, your approval is needed on a few things. To provide a better website experience, uses cookies (and other similar technologies) and may collect, process, and share personal data. Please choose which areas of our service you consent to our doing so.

    For more information on managing or withdrawing consents and how we handle data, visit our Privacy Policy at:

    Show Details
    HubPages Device IDThis is used to identify particular browsers or devices when the access the service, and is used for security reasons.
    LoginThis is necessary to sign in to the HubPages Service.
    Google RecaptchaThis is used to prevent bots and spam. (Privacy Policy)
    AkismetThis is used to detect comment spam. (Privacy Policy)
    HubPages Google AnalyticsThis is used to provide data on traffic to our website, all personally identifyable data is anonymized. (Privacy Policy)
    HubPages Traffic PixelThis is used to collect data on traffic to articles and other pages on our site. Unless you are signed in to a HubPages account, all personally identifiable information is anonymized.
    Amazon Web ServicesThis is a cloud services platform that we used to host our service. (Privacy Policy)
    CloudflareThis is a cloud CDN service that we use to efficiently deliver files required for our service to operate such as javascript, cascading style sheets, images, and videos. (Privacy Policy)
    Google Hosted LibrariesJavascript software libraries such as jQuery are loaded at endpoints on the or domains, for performance and efficiency reasons. (Privacy Policy)
    Google Custom SearchThis is feature allows you to search the site. (Privacy Policy)
    Google MapsSome articles have Google Maps embedded in them. (Privacy Policy)
    Google ChartsThis is used to display charts and graphs on articles and the author center. (Privacy Policy)
    Google AdSense Host APIThis service allows you to sign up for or associate a Google AdSense account with HubPages, so that you can earn money from ads on your articles. No data is shared unless you engage with this feature. (Privacy Policy)
    Google YouTubeSome articles have YouTube videos embedded in them. (Privacy Policy)
    VimeoSome articles have Vimeo videos embedded in them. (Privacy Policy)
    PaypalThis is used for a registered author who enrolls in the HubPages Earnings program and requests to be paid via PayPal. No data is shared with Paypal unless you engage with this feature. (Privacy Policy)
    Facebook LoginYou can use this to streamline signing up for, or signing in to your Hubpages account. No data is shared with Facebook unless you engage with this feature. (Privacy Policy)
    MavenThis supports the Maven widget and search functionality. (Privacy Policy)
    Google AdSenseThis is an ad network. (Privacy Policy)
    Google DoubleClickGoogle provides ad serving technology and runs an ad network. (Privacy Policy)
    Index ExchangeThis is an ad network. (Privacy Policy)
    SovrnThis is an ad network. (Privacy Policy)
    Facebook AdsThis is an ad network. (Privacy Policy)
    Amazon Unified Ad MarketplaceThis is an ad network. (Privacy Policy)
    AppNexusThis is an ad network. (Privacy Policy)
    OpenxThis is an ad network. (Privacy Policy)
    Rubicon ProjectThis is an ad network. (Privacy Policy)
    TripleLiftThis is an ad network. (Privacy Policy)
    Say MediaWe partner with Say Media to deliver ad campaigns on our sites. (Privacy Policy)
    Remarketing PixelsWe may use remarketing pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to advertise the HubPages Service to people that have visited our sites.
    Conversion Tracking PixelsWe may use conversion tracking pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to identify when an advertisement has successfully resulted in the desired action, such as signing up for the HubPages Service or publishing an article on the HubPages Service.
    Author Google AnalyticsThis is used to provide traffic data and reports to the authors of articles on the HubPages Service. (Privacy Policy)
    ComscoreComScore is a media measurement and analytics company providing marketing data and analytics to enterprises, media and advertising agencies, and publishers. Non-consent will result in ComScore only processing obfuscated personal data. (Privacy Policy)
    Amazon Tracking PixelSome articles display amazon products as part of the Amazon Affiliate program, this pixel provides traffic statistics for those products (Privacy Policy)
    ClickscoThis is a data management platform studying reader behavior (Privacy Policy)