Use of biomarkers in the prediction of culture-proven infection in the surgical intensive care unit

Perioperative Procalcitonin in Predicting Infection in Children Undergoing Surgical Procedures

BACKGROUND

Procalcitonin (PCT) is a biomarker of bacterial infections with more sensitivity and specificity than commonly used inflammatory markers. PCT can be particularly helpful in the postsurgical population where the surgery itself often leads to noninfectious inflammation. We aimed to examine the utility of perioperative profiles of PCT in predicting infection in two pediatric surgical populations.

METHODS

We conducted a prospective observational study of perioperative PCT in children undergoing cardiac or neurosurgery. Consenting patients with no preoperative infection or immune deficiency were enrolled. We measured plasma PCT levels within 24 h preprocedure and 24-48 h postprocedure. Demographic, clinical, and laboratory data were collected from the medical records including clinical suspicion and confirmed infections. Perioperative PCT changes and their associations with these data are reported.

RESULTS

We enrolled 26 neuro and 15 cardiac surgery patients. There was postoperative clinical suspicion of infection in 3 neuro and 5 cardiac patients, and 1 neuro and 2 cardiac patients had subsequently confirmed infections. Cardiac patients had higher overall perioperative PCT increase than neuro cohort (P = 0.006). Neuro patient with infection had higher perioperative change in PCT (0.5 to 1.4 ng/mL) than noninfected neurosurgery patients. Cardiac patients with confirmed infections had higher postoperative levels which exceeded the previously described infection threshold of 2 ng/mL.

CONCLUSIONS

PCT is a useful early biomarker of postoperative infection in pediatric patients undergoing cardiac and neurosurgery. Patients who underwent cardiac surgery have significantly higher perioperative PCT rise than patients who underwent neurosurgery, and all patients with subsequently confirmed infections had at least 2-fold perioperative PCT increase.

Clinical Progress Note: Procalcitonin in the Diagnosis and Management of Community-Acquired Pneumonia in Hospitalized Adults

Community-acquired pneumonia (CAP) accounts for more than 1.5 million adult hospitalizations and 100,000 deaths each year in the United States.1 Antibiotic overuse in the hospital setting is an important contributor to the rise of antibiotic resistance, prompting increased efforts to limit inappropriate antibiotic use in hospitals.2 Procalcitonin, a precursor of the hormone calcitonin, is upregulated in bacterial infections and downregulated in viral infections. The US Food and Drug Administration has approved it as a serum biomarker to assist clinicians with decisions about using antibiotics.3 There is no consensus on how to best use procalcitonin in the management of CAP. We provide a practical update that includes a review of recent literature, added secondary analysis, and expert opinion surrounding the use of procalcitonin in the diagnosis and management of CAP in hospitalized adults.

Performance of plasma measurement of neutrophil gelatinase-associated lipocalin as a biomarker of bacterial infections in the intensive care unit

PURPOSE

To assess the value of dimeric neutrophil-gelatinase associated lipocalin (NGAL) as an early marker of bacterial infection and its response to antibiotic therapy in intensive care unit (ICU) patients.

MATERIALS & METHODS

We measured daily plasma dNGAL in 198 patients admitted to a mixed ICU. Likelihood of infection was determined with International Sepsis Forum criteria. We measured dNGAL in 145 healthy controls to establish normal values.

RESULTS

ICU patients had higher dNGAL than healthy controls. A suspected or confirmed infection was independently associated with 90% (95% CI 15-215%) higher dNGAL than absence of infection. We observed no association between acute kidney injury and dNGAL. Diagnostic accuracy at antibiotic treatment initiation, assessed with area under the receiver-operating characteristics curve (AUC-ROC), for dNGAL was 0.70 (95% CI 0.60-0.79). AUC-ROC for dNGAL 24 h before antibiotic treatment initiation was 0.54 (95% CI 0.41-0.66). The mean (95% CI) change of dNGAL in the first 2 days after appropriate antibiotic therapy initiation was -31 (-49,-13)%.

CONCLUSIONS

In our cohort of ICU patients, plasma dNGAL was associated with presence of bacterial infections independent of AKI but it performed poor as a predictor of infections. Following antibiotic therapy, dNGAL markedly decreased-supporting further exploration of dNGAL-guided antibiotic de-escalation.

Rules of anti-infection therapy for sepsis and septic shock

Objective:

Sepsis is a deadly infection that causes injury to tissues and organs. Infection and anti-infective treatment are the eternal themes of sepsis. The successful control of infection is a key factor of resuscitation for sepsis and septic shock. This review examines evidence for the treatment of sepsis. This evidence is combined with clinical experiments to reveal the rules and a standard flowchart of anti-infection therapy for sepsis.

Data Sources:

We retrieved information from the PubMed database up to October 2018 using various search terms and their combinations, including sepsis, septic shock, infection, antibiotics, and anti-infection.

Study Selection:

We included data from peer-reviewed journals printed in English on the relationships between infections and antibiotics.

Results:

By combining the literature review and clinical experience, we propose a 6Rs rule for sepsis and septic shock management: right patients, right time, right target, right antibiotics, right dose, and right source control. This rule encompasses rational decisions regarding the timing of treatment, the identification of the correct pathogen, the selection of appropriate antibiotics, the formulation of a scientifically based antibiotic dosage regimen, and the adequate control of infectious foci.

Conclusions:

This review highlights how to recognize and treat sepsis and septic shock and provides rules and a standard flowchart for anti-infection therapy for sepsis and septic shock for use in the clinical setting.