Diagnostic value and prognostic implications of serum procalcitonin after cardiac surgery: a systematic review of the literature

Christoph Sponholz,Frank Brunkhorst,Yasser Sakr,Konrad Reinhart

doi:10.1186/cc5067

Christoph Sponholz, Frank Brunkhorst + Show 2 more

Open Access

https://doi.org/10.1186/cc5067

Copy DOI

Abstract

IntroductionSystemic inflammatory response syndrome is common after surgery, and it can be difficult to discriminate between infection and inflammation. We performed a review of the literature with the aims of describing the evolution of serum procalcitonin (PCT) levels after uncomplicated cardiac surgery, characterising the role of PCT as a tool in discriminating infection, identifying the relation between PCT, organ failure, and severity of sepsis syndromes, and assessing the possible role of PCT in detection of postoperative complications and mortality.MethodsWe performed a search on MEDLINE using the keyword 'procalcitonin' crossed with 'cardiac surgery,' 'heart,' 'postoperative,' and 'transplantation.' Our search was limited to human studies published between January 1990 and June 2006.ResultsUncomplicated cardiac surgery induces a postoperative increase in serum PCT levels. Peak PCT levels are reached within 24 hours postoperatively and return to normal levels within the first week. This increase seems to be dependent on the surgical procedure and on intraoperative events. Although PCT values reported in infected patients are generally higher than in non-infected patients after cardiac surgery, the cutoff point for discriminating infection ranges from 1 to 5 ng/ml, and the dynamics of PCT levels over time may be more important than absolute values. PCT is superior to C-reactive protein in discriminating infections in this setting. PCT levels are higher with increased severity of sepsis and the presence of organ dysfunction/failure and in patients with a poor outcome or in those who develop postoperative complications. PCT levels typically remain unchanged after acute rejection but increase markedly after bacterial and fungal infections. Systemic infections are associated with greater PCT elevation than is local infection. Viral infections are difficult to identify based on PCT measurements.ConclusionThe dynamics of PCT levels, rather than absolute values, could be important in identifying patients with infectious complications after cardiac surgery. PCT is useful in differentiating acute graft rejection after heart and/or lung transplantation from bacterial and fungal infections. Further studies are needed to define cutoff points and to incorporate PCT levels in useful prediction models.

Highlights

Systemic inflammatory response syndrome is common after surgery, and it can be difficult to discriminate between infection and inflammation
Peak PCT levels are reached within 24 hours postoperatively and return to normal levels within the first week
PCT values reported in infected patients are generally higher than in non-infected patients after cardiac surgery, the cutoff point for discriminating infection ranges from 1 to 5 ng/ml, and the dynamics of PCT levels over time may be more important than absolute values

Summary

Introduction

Systemic inflammatory response syndrome is common after surgery, and it can be difficult to discriminate between infection and inflammation. Several studies have underscored its value in a variety of clinical conditions for identifying infectious processes [6,7,8], APACHE = acute physiology and chronic health evaluation; CABG = coronary artery bypass graft; CPB = cardiopulmonary bypass; CRP = C-reactive protein; CV = coefficient of variation; ICU = intensive care unit; IL-6 = interleukin-6; MIDCAB = minimally invasive direct coronary artery bypass; MODS = multiple organ dysfunction syndrome; OPCAB = off-pump coronary artery bypass; PCT = procalcitonin; ROC = receiver operating characteristic; SIRS = systemic inflammatory response syndrome; SOFA = sequential organ failure assessment; WBC = white blood cell. PCT values are available within 20 minutes with a functional assay sensitivity of 0.06 ng/ml, and 50 μl of blood serum or plasma is needed for measurement [20]. At a concentration between 0.1 and 0.3 ng/ml, the Kryptor Test has an intra-assay CV of less than or equal to 7% and an interassay CV of less than or equal to 10%, and at concentrations greater than 0.3 ng/ml the intra-assay CV is less than or equal to 3% and the interassay CV is less than or equal to 6% (data provided by BRAHMS AG)

Methods

Results

Conclusion