Prediction of severe bacterial infection in children with an emergency department diagnosis of infection.
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 ≥15×10(9)/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.


CONCLUSIONS
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.
Northern Health Centre, Islington PCT, London, UK. cv28@le.ac.uk
Christiane
C
Vorwerk
Karen
K
Manias
Ffion
F
Davies
Timothy J
TJ
Coats
D019540:Area Under Curve; D001424:Bacterial Infections / Q000175:diagnosis*; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000032:analysis; D002675:Child, Preschool; D015331:Cohort Studies; D004636:Emergency Service, Hospital; D005260:Female; D006784:Hospitals, Teaching; D006786:Hospitals, Urban; D006801:Humans; D019344:Lactic Acid / Q000032:analysis / Q000097:blood*; D007958:Leukocyte Count; D008297:Male; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity
D015415:Biomarkers; D019344:Lactic Acid; D002097:C-Reactive Protein