NOTE: Both Rackoff et al and Baorto et al (above) used the absolute monocyte count to determine the risk of a significant infection.
Patient selection: pediatric oncology outpatient with fever (oral or equivalent temperature > 38.5°C once or > 38°C on 2 or more occasions durig a 12 hour period) and neutropenia (absolute neutrophil count < 500 per µL)
Low risk group for significant bacterial infection - all of the following at presentation:
(1) absolute monocyte count >= 100 per µL
(2) no comorbid condition (no medical condition that independently requires inpatient observation such as hypotension, respiratory distress, intravenous rehydration, etc)
(3) "not abnormal" chest X-ray
The risk of a significant bacterial infection was 8% if the absolute monocyte count was >= 100 per µL (5% chance of bacteremia).
Factors associated with a significant bacterial infection on multivariate analysis:
(1) bone marrow disease
(2) looks unwell on general appearance on initial examination
(3) absolute monocyte count < 100 per µL
(4) peak oral (or equivalent) temperature > 39°C
