Patient selection:
(1) newborn infant >= 1,500 grams with a bacterial infection
(2) received antibiotic prophylaxis for Group B streptococci (ampicillin or others)
Organisms involved:
(1) mostly E. coli (10 out of 17 infections)
(2) Staphylococcus aureus, other Enterobacteriaceae, Pseudomonas species, Hemophilus influenzae, Acinetobacter
Parameters:
(1) duration of intrapartum antibiotic therapy
(2) clinical chorioamnionitis
(3) duration for rupture of membranes
|
Parameter
|
Finding
|
Odds Ratio
|
|
duration of antibiotic therapy prior to delivery
|
< 24 hours
|
1
|
|
|
>= 24 hours
|
9.2
|
|
clinical chorioamnionitis
|
no
|
1
|
|
|
yes
|
4.8
|
|
duration for rupture of membranes
|
< 18 hours
|
1
|
|
|
>= 18 hours
|
1.9
|
cumulative odds ratio =
= PRODUCT(odds ratios for all 3 risk factors)
Interpretation:
• minimum cumulative odds ratio: 1
• maximum cumulative odds ratio: 83.9
• The higher the product the greater the risk of infection with an ampicillin-resistant organism.
• An infected neonate with none of the risk factors can be treated with ampicillin and gentamicin.
