The evolving value of older biomarkers in the clinical diagnosis of pediatric sepsis.

Sepsis remains the leading cause of childhood mortality worldwide. The evolving definition of pediatric sepsis is extrapolated from adult studies. Although lacking formal validation in the pediatric population, this working definition has historically proven its clinical utility. Prompt identification of pediatric sepsis is challenging as clinical picture is often variable. Timely intervention is crucial for optimal outcome, thus biomarkers are utilized to aid in immediate, yet judicious, diagnosis of sepsis. Over time, their use in sepsis has expanded with discovery of newer biomarkers that include genomic bio-signatures. Despite recent scientific advances, there is no biomarker that can accurately diagnose sepsis. Furthermore, older biomarkers are readily available in most institutions while newer biomarkers are not. Hence, the latter's clinical value in pediatric sepsis remains theoretical. Albeit promising, scarce data on newer biomarkers have been extracted from research settings making their clinical value unclear. As interest in newer biomarkers continue to proliferate despite their ambiguous clinical use, the literature on older biomarkers in clinical settings continue to diminish. Thus, revisiting the evolving value of these earliest biomarkers in optimizing pediatric sepsis diagnosis is warranted. This review focuses on the four most readily available biomarkers to bedside clinicians in diagnosing pediatric sepsis. IMPACT: The definition of pediatric sepsis remains an extrapolation from adult studies. Older biomarkers that include C-reactive protein, procalcitonin, ferritin, and lactate are the most readily available biomarkers in most pediatric institutions to aid in the diagnosis of pediatric sepsis. Older biomarkers, although in varying levels of reliability, remain to be useful clinical adjuncts in the diagnosis of pediatric sepsis if used in the appropriate clinical context. C-reactive protein and procalcitonin are more sensitive and specific among these older biomarkers in diagnosing pediatric sepsis although evidence varies in different age groups and clinical scenarios.

Adult and child automated immature granulocyte norms are inappropriate for evaluating early-onset sepsis in newborns.

AIM: Automated haematology analysers are increasingly being used. Normal ranges for automated immature granulocyte counts (IG%) are described in adults and children as <1%, but are not reported for newborns, who often have complete blood count with differential in evaluation for early-onset sepsis. Therefore, this study aimed to describe IG% during the first 48 hours of life (HOL) in newborns and determine the clinical factors affecting IG%. METHODS: We carried out retrospective chart reviews for newborns ≥35 weeks gestational age with one or more complete blood count with differential in the first 48 HOL. Clinical history and automated haematology results were reviewed. RESULTS: Forty-seven of 215 subjects had two or more complete blood counts within 48 h. In the first 48 HOL, IG% ranged from 0 to 8.4% (95th percentile 5.2%). At <12 h, 70% of samples had IG% >1%. IG% appears to decrease over time. Earlier hour of life and higher birth weight were independently associated with higher IG%. CONCLUSION: Immature granulocyte counts in newborns appeared to be higher than reported for other age groups. Use of adult and child norms for IG% would not be appropriate for newborns being evaluated for early-onset sepsis.

A clinical strain of Escherichia coli possessing CMY-2 plasmid-mediated amp C beta-lactamase: an emerging concern in pediatrics?

A 5-year-old child was colonized by an isolate of Escherichia coli that transferred resistance to third-generation cephalosporins and cefoxitin. This resistance phenotype was encoded on a >75-kb plasmid pLRM 22. The transferable plasmid contained both blaCMY-2 and blaTEM-1b. Increasing reports of CMY-2 beta-lactamase in clinical isolates in children raise concerns about the empiric use of third-generation cephalosporins in this patient group.