Validation of a laboratory risk score for the identification of severe bacterial infection in children with fever without source

Galetto-Lacour A, Zamora S, Andreola B, Bressan S, Lacroix L, Da Dalt L and Gervaix A

Arch Dis Child 2010; 95: 968-973

Dr Vanessa Craven

Procalcitonin

Healthy Individuals

Local Infections

Systemic Infections (Sepsis)

Severe Sepsis

Septic Shock

0.05 ng/ml

0.5 ng/ml

2 ng/ml

Brunkhorst FM et al. Intens. Care Med 1998; 24: 888-892

Pediatr Infect Dis J 2008; 27: 654-6• 202 7- 36 months• Rectal temp >38°C & no focus

• IOS• Urine MC&S• WCC, CRP & PCT• LP ‘when meningitis suspected’• Clinical follow up within 48 hours

Results• SBI 54 (27%)

• PCT: OR 37.6 (5.8 - 243)• CRP: OR 7.8 (2 - 30.4)• Urine dipstick: OR 23.2 (5.1 - 104.8)

Predictor Points

PCT (ng/ml)

< 0.5 ≥ 0.5 ≥ 2.0

024

CRP (mg/ml)

< 40 40-99 ≥ 100

024

Urine dipstick

Negative Positive

01

AIM• External validation• More children• 2007 Italian population

• Laboratory score ≥ 3

Methodology• Prospective enrolment - 408 children• Data from Italian study• May 2004 - October 2005• 7 days (>38C) to 36 months (>39.5°C)

7 days to 36 months

Fever without source

Exclusion criteria

Looking for severe bacterial infection (defined) – diagnosis ‘at end of follow up’

SBI vs ‘benign viral infection’

Retrospective (5 years)Using another study’s cohort

Reasonable age definition & exclusion criteria

Using another study’s data set

Higher temperature cut off than used in practice?

Laboratory measurements

Who confirmed FWS?

ALL were assessed at 72 hours (including telephone contact) – no details

Cultures would be back but not always reliable

What happened to the classification of children that did not improve? Or had focal infection and did not get Abx

DMSA to diagnose pyleonephritis (1/52)

Who did the assessments?Who followed up?

ALL were followed upNo details about - follow up length - locationWas 72 hr review conclusive in allAny need Abx/admissionWhat happened to the ‘focal bacterial infection’ 15.8%?

SBI in 92 (22.7%)

Score ≥3: Sens 86% (77-92%)

Spec: 83% (79-87%)

Sens ↑and spec ↓ with age

WBC: Sens 52%, Spec 75%

CRP: Sens 52%, Spec 75%

PCT: Sens 75%, Spec 76%

Missed 13 cases

Very large confidence intervals!

Large confidence intervalsSelected population

BUT referral pathway different

WCC poor predictorPediatr Infect Dis J 2008; 27: 654-6Results comparable to derivation set

Summary & Conclusion

There is insufficient evidence to support the sole use of the lab score to identify those with severe bacterial

infection