Calicitonin Precusors and IL-8 as a Screen Panel for Bacterial Sepsis
Stryjewski GR, Nylen ES, Bell MJ, et al. Interleukin-6, interleukin-8, and a rapid and sensitive assay for calcitonin precursors for the determination of bacterial sepsis in febrile neutropenic children. Pediatr Crit Care Med. 2005;6:129-35.
Identification of sensitive and specific markers for serious bacterial infection (SBI) in children has commanded significant attention in recent literature. These researchers present a prospective cohort study of 56 children aged 5 months to 17 years (median 6.7 years) with fever (axillary temperature ≥37.5°C or oral temperature ≥38°C) and neutropenia (absolute neutrophil count ≤500/mm3) admitted to Children’s National Medical Center during a 15-month period. Researchers hypothesized that a highly sensitive assay for calcitonin precursors (CTpr) would detect levels of CTpr early in the course of illness, and that these levels in conjunction with measured levels of the cytokines interleukin (IL)-6 and IL-8 would provide a sensitive and specific set of markers for diagnosing bacterial sepsis in the study population. Markers were measured at admission, at 24 hours and at 48 hours. CTpr at 24 hours (adjusted odds ratio [95% confidence interval], 1.8 [1.2–2.8], p=.001) and IL8 (at 48 hours 1.08 [1.2–2.8], p=.02) were found to have association with bacterial sepsis. The authors conclude that based on the data generated, using cutoff values of 500 pg/mL for CTpr at 24 hours and 20 pg/mL for IL-8 at 48 hours would provide a sensitivity of 94% and specificity of 90%. Reliable biochemical markers that are highly associated with SBI and/or sepsis will likely improve the care of pediatric patients by guiding more specific therapy and potentially limiting exposure to unnecessary antibiotic . The results of this study cannot be generalized to all pediatric patients with fever and risk for SBI, due to the unique attributes of the study population. However, the study does provide information for future research into the development of markers and/or scoring systems to aid in the early diagnosis of SBI/sepsis in the general pediatric population.
Which Tests are Helpful and Cost-Effective in the Evaluation of Pediatric Syncope?
Steinberg LA, Knilans TK. Syncope in children: diagnostic tests have a high cost and low yield. J Pediatr. 2005;146:355-8.
Evaluation of syncope in children is not uncommon. This evaluation can often include multiple expensive tests, and evidence defining the most efficacious and cost-effective course of evaluation is lacking. Researchers from the Children’s Heart Center at St. Vincent Hospital in Indianapolis and the Division of Cardiology at Children’s Hospital Medical Center in Cincinnati present a retrospective review of 169 patients aged 4.5 to 18.7 years (mean, 13.1 ± 3.6) presenting to a tertiary care center for evaluation of transient loss of consciousness associated with loss of postural tone to describe the cost and utility of testing used to make a diagnosis. Costs were based on hospital costs for 1999 and did not include professional fees, the cost of clinic evaluations, or hospital admissions. There are significant limitations in the study design, and these are adequately discussed by the authors. A diagnosis was established in 128 patients (76%), and neurocardiogenic syncope was the most common diagnosis occurring in 116 patients (68%). Other diagnoses included seizure disorder (3 patients), pseudoseizure (2), anxiety disorder (2), psychogenic syncope (2) and 1 patient each with breathholding spells, long QT syndrome, and exertonal ventricular tachycardia. Tilt-testing had the highest diagnostic yield, although the researchers aptly point out that in the literature the specificity of tilt-testing ranges from 48 to 100% and that this test is rarely required to diagnose neurocardiogenic syncope, the most frequent diagnosis in this review. Loop memory cardiac monitoring had the lowest cost per diagnostic result. Electrocardiography had the lowest diagnostic yield and highest cost per test. Echocardiogram, chest radiograph, cardiac catheterization, electrophysiology studies, and evaluation of serum and body fluids were not diagnostic in this series. This respective review highlights the need for a consistent, evidence-based approach to this common presenting problem while emphasizing the importance of judicious testing guided by a thorough history and physical exam.