One of the most important factors driving the medical workup on a well appearing, febrile infant is the prevalence of serious bacterial infection (SBI) . This number changes depending on age and immunization status (pneumococcus vaccine having the most impact in North America.) The higher the likelihood of disease, the more aggressive the workup and treatment.
Prevalence of serious bacterial infection/meningitis by age
- 0-14 days (pre-vaccine) 1/10
- 14-28 days 1/20
- 28-60 days (pre-vaccine) 1/100
- 28-60 days (post-vaccine) 1/1,000
- 60-90 days 1/1,000-1/10,000
- >90 days 1/>10,000
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Pediatric Fever Trivia
Many parents will bring their febrile infant to the emergency department because the fever is not responding to antipyretics. Does response to antipyretics make SBI less likely?
No. This has been extensively studied and no relationship has been found between response to antipyretics and severity of illness or presence of bacteremia.
Should a chest X-ray be ordered on a febrile child < 3 months of age without respiratory symptoms?
The data to date would suggest no. The likelihood of finding an infiltrate on CXR is extremely low in the absence of ANY of the following exam findings:
- tachypnea > 50 bpm
- cough
- nasal flaring
- stridor
- grunting
- wheezing
- ronchi
- rales
- hypoxia
- coryza (runny nose)
If you see even one of these criteria in a febrile infant or neonate, it’s a mandatory CXR, although I still find runny nose a bit of a hard sell indicating a lower respiratory tract infection. Caveat: a child >3 months with a WBC >20,000 should get a CXR to evaluate for occult pneumonia (even if asymptomatic)
What age groups of children are at higher risk for urinary tract infection?
0-6 months circumcised males
0-12 months uncircumcised males
0-24 months females
The term fever without a source implies that a child looks well yet still has a fever. When we want to say that a fever is caused by something we can identify on clinical presentation, what are the recognized/acceptable sources?
- HSV/Gingivostomatits
- Herpangina/Ulcerative Stomatits
- RSV
- Croup
- Influenza
- Varicella
- Viral Exanthum (rash)
- Enterovirus, coxsackie HFM dz, echovirus, rhinovirus, enterovirus
In the emergency department, it’s virtually impossible to identify the exact type of virus causing an upper respiratory infection or gastroenteritis. A little sniffle or drop of mucous from one nostril doesn’t stop the workup, but a copious river of rhinorrhea and a hacking cough in a febrile 3 month old seal the deal.
The Workup
It all comes down to what tests to order and what treatment to give for the different age groups. The following age based guidelines are based on Dr. Sloas’ approach to the febrile infant as laid out in the podcast. If you disagree with any of this, send us a note or leave a comment on our google voice line. There’s nothing like a feud over pediatric fever.
Reference ABNORMAL values in the febrile infant
- WBC<5 or >15, Band/neutrophil >0.2, Bandemia >1,500 mm3, absolute neutrophil count of >10,000
- CSF > 8 WBC or positive gram stain
- UA > 10 WBC or positive gram stain
- Stool WBCs or heme
- Infiltrate on CXR
Age 0-28 days
Temp > 100.4 or 38C
Workup
CBC, blood cx, cath UA, CXR (I still do it), lumbar puncture, stool studies if needed
Disposition: Automatic admission and antibiotics
Antibiotics
Ampicillin 50mg/kg plus
Gentamicin – Dose varies by age. Give if child is under 9 days old or
Cefotaxime – 50mg/kg. Give if child is 9-28 days.
Possible add ons
Vancomycin 15-20mg/kg
Acyclovir 60mg/kg/day divided q8hrs
The below presume that the child is well appearing, is on the recommended vaccination schedule and does not have an identifiable source of infection
Age 29-60 days
temp >100.4 F or 38C
Workup
cbc, blood cx, cath UA, possible CXR, spinal tap, stool studies if needed
Disposition:
Admit for anything positive in workup, unable to get follow-up
Antibiotics:
50mg/kg ceftriaxone or
If Workup completely negative, no antibiotics and next day follow-up
Age 60-90 days
If the temp is <39C, no testing and followup the next day
Temp >102.2F or 39C
Workup
Start with CBC and UA
If both CBC and UA are normal, no antibiotics. Have patient follow-up next day.
Option 1
If either the CBC or UA are abnormal then proceed with LP and blood culture. And then…
If just the CBC is abnormal, give 50mg/kg ceftriaxone and follow-up next day
If UA is abnormal, give 50mg/kg ceftriaxone, and prior to discharge, initiate oral antibiotics for urinary pathogens (E. coli is the main player) cefixime orTMP/Sulfa. There are many other antibiotic choices for oral agents. The best choice often depends on resistance patterns in your region.
Option 2
There is wide variability in philosophy regarding LP with an abnormal CBC or UA in the 60-90 day age group. Many community ED docs and pediatricians will send blood culture after an abnormal CBC/UA but do not subscribe to the idea that all patients in this cohort need a spinal tap.
Age 3-6 months
Temp >102.2F or 39C
Workup:
Cath UA
Treat if positive
Just listened to the pedi fever episode and enjoyed it greatly. But I see the suggested dose for ceftriaxone is 50 per kilo but i thought the correct dose is 100 per kg for meningitis. What is correct?
Also could you comment on how you choose who the best person to hold is? What is the best method to hold?
Hi Don,
The dose is 50mg/kg for non-meningitis and 100mg/kg for meningitis.
On your other point, the best person to hold is the one in the ED with the most experience in doing it. Absolutely not a parent. In our ED, it usually ends up being one of the techs or nurses. Their ability to keep the infant still makes all the difference. As far as best method, can you be more specific?
i meant is there a preferred instruction you give to the holder? like where to put hands/how much pressure/ do you have pressure on iliac crests or just hand over neck/head and thighs? i actually have no problem with neonates but it is the 2year olds that i often need to sedate. do you? as for the dose of antibiotic presumably when we give an empiric dose we are covering for meningitis or that is what we are really worried about so shouldn’t that be the dose?
On another line, when you were talking about atropine drops for hyphema you discussed the fact that it lasts for 2 weeks ( the cyloplegia) and yet were discussing dispensing the medicine and repeat dosing? why would you have to do that? do you?
don
Don, If the child is beyond infant/neonate and has to have a lot of pressure, I am giving some form of sedation. The last 2 year old I did an LP on without sedation was probably a decade ago.
As far as instructions to the holder…one hand over the upper back/lower neck and the other on the lower back/buttocks/hamstrings.
For the empiric dose of abx… if I am really worried about meningitis, I order 100mg/kg as soon as the line is in and cultures are drawn. If I am doing a septic workup because of fever without a source but the child looks good, I wait for the spinal fluid.
For atropine drops, I have never sent a patient home with them. If they need them, I want them to see an ophthalmologist.
A couple of comments on this great episode:
1) Do you think this is how its done in the pediatrician’s office? If I bring my 45 day old to the office with a fever, looks great, will he/she do any testing?
As a personal note, I understand <28 days gets everything. If my 45 day old looks great with a fever, I am not sure that I would want to poke with an IV
Derek, I share your sense of incredulousness at the two different pathways for working up the same patient. That in and of itself could, and probably will be, a future podcast. But to answer your question, I think that the answer, in the majority of cases, is no. In my experience, most peds offices do not do full septic workups on well looking febrile 45 day olds. Then again, I am not in those offices day in and out to truly speak for them.
Thanks for an awesome podcast. I have a couple of questions in relation to the talk pediatric fever
1. Do you order CRP and procalcitonin in addition to a CBC?
2. Does the result of CRP and/or procalcitonin influence your management or dispostion?
I do not order CRP or procalcitonin on peds patients. I’ve been ordering procalcitonin on adults but am increasingly underwhelmed by its utility. As far as CRP, that takes about 4 hours to come back in our shop, so has limited utility in the ED workup.
Rob, I’ve noticed that more docs are ordering only single blood cultures on peds. I’m not talking about the <28 days, where 2 are still routine. But pediatricians in the community seem to be supportive of the single blood cx concept in older kids. My thoughts are that with the immunized kids and herd immunity, since the incidence of SBI is so low, we (the general med community) have anecdotally determined that the utility of blood cultures is low. My practice is to order 2 cultures, in patients that I think need them. Otherwise, I don't order any. I am unaware of any evidence to support the one culture practice. Any thoughts on this?