Preemies: Count age by estimated postconception date (not by actual delivery date) for 1st-90d
For all infants (toxic and well-appearing)
Toxic or Well
CBC
Blood cultures
Urinalysis, Urine culture
LP-CSF
CXR
+/- Stool studies (if diarrhea)
If <14 days, Ampicillin 50 mg/kg/dose AND (Gentamicin 4 mg/kg/dose or Cefepime 30mg/kg/dose)
If >14 days, Ampicillin 50 mg/kg/dose AND Ceftriaxone^^ 50-100mg/kg/dose
Acyclovir^ 20 mg/kg/dose
Ill appearing: 13%–21%
Not ill appearing: <5%
^Acyclovir if:
HSV infection in baby or mother
CSF pleocytoisis
Concerning skin lesions
Seizures
Abnormal LFTs
Note:
CXR is optional if no resp sx and another<unk>  identified
LP is necessary even if another<unk>  identified due to immature blood-brain barrier
Do not give ceftriaxone to children <28d as may cause hyperbilirubinemia
For toxic infants, treat for sepsis and admit
For well-appearing infants, see below algorithm

For toxic infants, treat for sepsis and admit
For well-appearing infants, see below algorithm

For toxic infants, treat for sepsis and admit
For well-appearing infants, see below algorithm

CBC
Blood cultures
Urinalysis, urine culture
LP-CSF
CXR^
Ceftriaxone (50-100mg/kg/dose) AND
Consider vancomycin (15mg/kg)^^^^
(No Prevnar or <4 weeks post 1st Prevnar dose)
Urinalysis, Urine culture
CBC
+/- CXR
Ceftriaxone 50mg-100mg/kg (also then consider blood culture and LP, especially in <6mo old)
(2 Prevnar or ≥4 weeks post 1st Prevnar dose)
Urine workup (UA, urine culture) for:
Circumcised males <6 months
Uncircumcised males <12 months
All females
+/- CXR
Circumcised males <6 months
Uncircumcised males <12 months
All females
Consider CXR for:
Respiratory symptoms<unk>  >48 hrs
Tachypnea
Hypoxia
Respiratory symptoms<unk>  >48 hrs
Tachypnea
Hypoxia
Non-UTI SBI incidence of <.4% in children >6 mo
Pediatric fever of uncertain source
Upper respiratory infection 
AIDS fever of unknown origin
UTI
Lemierre's syndrome
Sepsis
Multisystem inflammatory syndrome in children
Meningitis