Patient selection: infant < 3 months of age presenting with fever of unknown origin (FUO)
Parameters:
(1) leukocyte count per µL
(2) serum C-reactive protein (CRP) in mg/L
(3) procalcitonin ng/mL (mg/L)
|
Parameter
|
Finding
|
Points
|
|
white blood cell count
|
<= 15,000 per µL
|
0
|
|
|
> 15,000 per µL
|
1
|
|
CRP
|
< 30 mg/L
|
0
|
|
|
>= 30 mg/L
|
1
|
|
procalcitonin
|
< 0.5 ng/mL
|
0
|
|
|
>= 0.5 ng/mL
|
1
|
where:
• A CRP >= 20 mg/L and leukocyte count > 10,000 per µL are suspicious for SBI.
• A significant number of SBI are urinary tract infections, so urinalysis should be part of the workup.
number of risk factors for a serious bacterial infection =
= SUM(points for all 3 parameters)
X =
= (0.09 * (WBC count per µL) / 1000) + (1.84 * (points for CRP)) + (1.89 * (points for procalcitonin))
probability of serious bacterial infection =
= 1 / (1 + EXP((-1) * X))
Procalcitonin was valuable for:
(1) invasive bacterial infections (sepsis, bacteremia, meningitis)
(2) infections < 12 hours in duration
