Procalcitonin, C-reactive protein, neutrophil gelatinase-associated lipocalin, resistin and the APTT waveform for the early diagnosis of serious bacterial infection and prediction of outcome in critically ill children.

OBJECTIVE: Bacterial Infections remains a leading cause of death in the Paediatric Intensive Care Unit (PICU). In this era of rising antimicrobial resistance, new tools are needed to guide antimicrobial use. The aim of this study was to investigate the accuracy of procalcitonin (PCT), neutrophil gelatinase-associated lipocalin (NGAL), resistin, activated partial thromboplastin time (aPTT) waveform and C-reactive protein (CRP) for the diagnosis of serious bacterial infection (SBI) in children on admission to PICU and their use as prognostic indicators. SETTING: A regional PICU in the United Kingdom. PATIENTS: Consecutive PICU admissions between October 2010 and June 2012. MEASUREMENTS: Blood samples were collected daily for biomarker measurement. The primary outcome measure was performance of study biomarkers for diagnosis of SBI on admission to PICU based on clinical, radiological and microbiological criteria. Secondary outcomes included durations of PICU stay and invasive ventilation and 28-day mortality. Patients were followed up to day 28 post-admission. MAIN RESULTS: A total of 657 patients were included in the study. 92 patients (14%) fulfilled criteria for SBI. 28-day mortality was 2.6% (17/657), but 8.7% (8/92) for patients with SBI. The combination of PCT, resistin, plasma NGAL and CRP resulted in the greatest net reclassification improvement compared to CRP alone (0.69, p<0.005) with 10.5% reduction in correct classification of patients with SBI (p 0.52) but a 78% improvement in correct classification of patients without events (p <0.005). A statistical model of prolonged duration of PICU stay found log-transformed maximum values of biomarkers performed better than first recorded biomarkers. The final model included maximum values of CRP, plasma NGAL, lymphocyte and platelet count (AUC 79%, 95% CI 73.7% to 84.2%). Longitudinal profiles of biomarkers showed PCT levels to decrease most rapidly following admission SBI. CONCLUSION: Combinations of biomarkers, including PCT, may improve accurate and timely identification of SBI on admission to PICU.

Viridans Group Streptococcal Infections in Children After Chemotherapy or Stem Cell Transplantation: A 10-year Review From a Tertiary Pediatric Hospital.

Viridans Group Streptococci (VGS) are associated with high mortality rates in febrile neutropenia; yet there are no recent European pediatric studies to inform antimicrobial therapy. The aim of this study was to describe the characteristics, outcome, and resistance patterns of children with VGS bacteremia (VGSB) undergoing treatment of malignancy or hematopoietic stem cell transplant. Patients aged 0 to 18 years, admitted to a tertiary pediatric hemato-oncology center with VGSB, from 2003 to 2013, were included in the study. All data were collected retrospectively from medical records. A total of 54 bacteremic episodes occurred in 46 patients. The most common underlying diagnosis was relapsed acute lymphoblastic leukemia. Streptococcus mitis was the most frequent organism. A total of 30% of isolates were resistant to penicillin and 100% sensitive to vancomycin. There were 8 episodes (14.8%) of Viridans Group Streptococcal Shock Syndrome; 6 resulted in admission to intensive care and 3 of these patients died of multiorgan failure. The potentially fatal nature of VGSB is confirmed. The high risk in relapsed acute lymphoblastic leukemia is of note. Research is needed to develop risk-stratification scores that identify children at risk of Viridans Group Streptococcal Shock Syndrome to guide empirical antimicrobial therapy in febrile neutropenia.

Febrile neutropenia in children treated for malignancy.

Febrile neutropenia (FN) in children treated for malignancy is a common and direct sequela of chemotherapy. Episodes of FN can be life-threatening, and demand prompt recognition, assessment and treatment with broad spectrum antibiotics. While in the majority of episodes no causal infection is identified, 10-20% are secondary to a bloodstream infection (BSI). A reduction in episodes of BSI could be achieved through robust infection prevention strategies, such as CVL care bundles. Alongside good antimicrobial stewardship, these strategies could reduce the risk of emergent, multi-drug resistant (MDR) infections. Emerging bacterial pathogens in BSI include Viridans Group Streptococci (VGS) and Enterobacteriaceae such as Klebsiella spp. which are known for their ability to carry MDR genes. There is also increased recognition of the role of invasive fungal infection (IFI) in FN, in particular with Aspergillus spp. Novel diagnostics, including multiplex blood and respiratory polymerase chain reaction assays can identify infections early in FN, facilitating targeted therapy, and reducing unnecessary antimicrobial exposure. Given appropriate, and sensitive rapid diagnostics, potential also exists to safely inform the risk assessment of patients with FN, identifying those at low risk of complication, who could be treated in the out-patient setting. Several clinical decision rules (CDR) have now been developed and validated in defined populations, for the risk assessment of children being treated for cancer. Future research is needed to develop a universal CDR to improve the management of children with FN.