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Prediction of severe bacterial infection in children with an emergency department diagnosis of infection
  1. Christiane Vorwerk1,
  2. Karen Manias1,
  3. Ffion Davies2,
  4. Timothy J Coats1
  1. 1Academic Unit of Emergency Medicine, University of Leicester, Leicester, UK
  2. 2Emergency Department, Leicester Royal Infirmary, Leicester, UK
  1. Correspondence to Dr Christiane Vorwerk, Emergency Department, Leicester Royal Infirmary, Leicester LE1 5WW, UK; cv28{at}


Objective To determine the relationship between near-patient-test (NPT) lactate, white blood cell count (WBC) and C-reactive protein (CRP) and severe bacterial infection (SBI) in children presenting to the emergency department (ED) with infection.

Methods An observational cohort study was undertaken in a paediatric emergency department of a large urban teaching hospital. Data were collected from January 2007 until December 2007. Inclusion criteria were age <16 years, blood test including NPT lactate obtained in the ED and infection-related ED diagnosis. Patients were pre-assigned to risk groups according to their NPT lactate, WBC and CRP.

Results 506 children were included in the study, of which 42 (8.3%) had SBI. NPT lactate, WBC and CRP were significantly higher in the SBI cohort. High-risk NPT lactate (≥4 mmol/l) had a sensitivity of 38.1% (95% CI 23.6% to 54.4%) and a specificity of 89.7% (95% CI 86.5% to 92.3%); high-risk WBC (<5 or ≥15×109/l) had a sensitivity of 51.2% (95% CI 35.1% to 67.1%) and a specificity of 73.8% (95% CI 69.4% to 77.8%); and high-risk CRP (≥50 mg/l) had a sensitivity of 36.8% (95% CI 21.8% to 54.1%) and a specificity of 83.6% (95% CI 79.4% to 87.2%) for SBI. All three high-risk markers combined yielded a sensitivity of 5.3% (95% CI 1.5% to 17.3%) and a specificity of 99.2% (95% CI 97.6% to 99.7%) for SBI.

Conclusion The data from our study suggest that NPT lactate provides early diagnostic information about the risk of SBI in children presenting to the ED with a suspected infection. Combining NPT lactate with WBC and CRP resulted in a promising rule-in-tool for SBI in children in the ED which, with prospective validation, has the potential to aid early identification of SBI in children.

  • Lactate
  • serious bacterial infection
  • emergency department
  • white blood cell count
  • C reactive protein
  • emergency care systems
  • emergency departments
  • infectious diseases
  • bacterial
  • management
  • risk management
  • paediatrics
  • paediatric emergency med
  • wounds
  • infection

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  • Competing interests None.

  • Ethics approval After consulting a National Research Ethics Service Information officer, we were advised that formal ethics committee approval was not required for this study owing to its observational nature.

  • Provenance and peer review Not commissioned; externally peer reviewed.