HipPEMcrates Mailbag, Vol. 3: Febrile Infants, Head Trauma, and the World Cup

Here is Philadelphia, it finally seems like summer volumes have arrived…just in time for the World Cup, America250, and the Baseball All-Star Game to roll through the City of Brotherly Love. Should make for a quiet summer! Welcome to the third edition of the HipPEMcrates Mailbag – where we continue to explore common questions from the Pediatric Emergency Department. These are the topics that come up during busy shifts, the clinical pearls shared during signout, and the thoughtful questions from learners that prompt us to pause and review the evidence behind our everyday practice.

If you missed our first two mailbags, check out Part 1 (where we covered serum sickness-like reactions, the hypothermic infant, and dexamethasone for sore throat) and Part 2 (the febrile infant, pneumonia, the future of the ER). By the way, we are always accepting questions for the mailbag. Thanks to those who submitted to HipPEMcrates@gmail.com. Let’s get into it.

Q: You seem to really like talking about the 2-3 month old infant. Did you get burned once? What’s the deal?

Jon, Emergency Medicine, Louisville, KY

JB: Fair point, Jon – I have written a lot about the febrile infant, especially in the third month of life. Truth is, while I have a little bit of an origin story for my interest in this age group, one of the things I enjoy most about our field is “the gray zone.” It’s easy enough “following the pathway,” both literally and figuratively – at this point, an AI bot can pretty much tell you how to manage a 6-week-old febrile infant or a febrile patient who has a central line. For those of us clinicians who love the cognitive challenge, deciding how to manage cases in which there is conflicting evidence or no evidence – now that is the art of medicine. And the 2-3 month febrile infant is the quintessential example of the “gray zone” patient – their risk of bacterial infection is lower than younger infants, but how much lower? Does a few weeks – or even a few days – really make that much of a difference?

The latest paper you need to read about this patient population comes from Dr. Brett Burstein and colleagues up in Canada: Prevalence of Invasive Bacterial Infections Among Febrile Infants Aged 60 to 90 Days: A Systematic Review and Meta-Analysis. Here are the high points:

• The analysis included 20 cohorts including 34,835 previously healthy, well-appearing febrile infants aged 60-90 days.
• The pooled prevalence of IBI (Bacteremia or Bacterial Meningitis) was 1.11% (95% CI 0.84-1.47%).
• Bacteremia accounting for nearly all IBI cases (1.01%, 95% CI 0.76-1.34%).
• Bacterial meningitis was uncommon, occurring in just 0.11% of infants (95% CI 0.08-0.16%).

My takeaway? This large meta-analysis really shows us that bacteremia in well-appearing, febrile infants in their third month of life is quite rare (~1%), with bacterial meningitis exceedingly rare. Bringing this into my practice, I think it will be the exception rather than the rule for me to get bloodwork on these children. While the risk is still there – I certainly do not want to miss an IBI in this age group – two statements from Brett’s group bring home the learning points from this analysis:

• “A reported 20% to 30% of hospitalized febrile infants experience complications due to testing, treatments, or the hospitalization itself.”
• “This pretest probability [of 1.11% IBI prevalence] resides in a risk range where practice depends on shared parent and clinician risk tolerance for missed infection vs harms of overtesting.”

Q: Be honest: how many of us quote PECARN confidently while secretly wondering if this is the one kid who didn’t read the rule?

Kate, Pediatric Emergency Medicine, Los Angeles, CA

I think about this question a lot. The data will say what it says, but each time I walk into the room of my patient, my n is 1. We all are familiar with the PECARN Head Trauma rule – probably my most googled item while I am at work, most of the time to show the MDCalc Calculator to parents to explain my recommendation – but what are those things that make me push for the scan even when PECARN says I don’t need to? I’ll give you my top 3:

1. Parental request/desire – A lot of what we do in the Peds ER is “shared-decision making.” When it comes to obtaining a head CT in a PECARN middle risk (0.9% risk of clinically important Traumatic Brain Injury) patient, I phrase it to parents in this way: “The data suggests that observation is recommended over imaging in this case. A CT contains radiation, so we always think critically about its need. That being said, if you are going to go home and not be able to sleep tonight because you will be up worrying, then we can consider doing a CT.” In my view, as long as you are clear about your suspicion, what the evidence suggests, and what the risks are, parents can often make the appropriate decision for what is best for them and their child.
2. Repeated vomiting – PECARN data suggests that the number of vomiting episodes does not meaningfully correlate with a higher risk of TBI. That being said, I find it a little difficult to not obtain head imaging when a child with blunt head trauma continues to vomit in front of me in the ED, especially if they’re vomiting through Zofran.
3. Questionable but suspected loss of consciousness – How often is it that by the time the patient is in front of you after a head injury, there’s been a telephone-game-like process to deliver you the exact story. “Well the patient was at school, so his friends saw what happened, and told the nurse, who told his teacher, who then texted me; so I don’t really even know what happened.” While I know that loss of consciousness is a “yellow zone” PECARN risk factor that would put the patient into the likely observation recommendation, when the story is not quite clear or the patient does not remember the entire episode, I tend to be a little more liberal with imaging.

Q: I’ve watched enough World Cup soccer already that I can feel at my core what Dani Rojas was saying in Ted Lasso. Give me some World Cup-to-PEM analogies I can entertain my team with during my next shift.

Alexander, Pediatric Emergency Medicine, Westchester, NY

Love this from Alexander. I’m all about timely puns – and as a relatively new father, I have fully embraced that I am in my Dad Joke Era. As I am write this, I am actually watching the World Cup (and there’s another goal by Germany…), so here’s a few to entertain your new interns with.

• Penalty Shootout = Febrile Infant workup

The 31 day old on one side. Your ANC and Procalcitonin on the other. Everyone’s heart rate is up. Will we get normal values and just move on? Or will an ANC of 5000 send everyone into a frenzy, finding your LP needles and getting the Sweet-Ease ready?

• Video Assisted Replay = The attending saying, “Let’s go see the patient together.”

The resident thought this was a cut-and-dry case. Your intuition (and your bedside nurse) tells you otherwise. Time for a thorough review of how much workup the patient really needs.

• Stoppage Time

Times ticking down (or up, if you’re actually playing soccer), but your shift isn’t over quite yet. There’s still time to do some work. That croup kid you can Dex-and-dc? Ear pain who just needs antibiotics? Game and shift isn’t over until you hear that welcoming screech – TIME FOR SIGN OUT!

Q: Can I sleep tonight if the ultrasound couldn’t see the appendix, the kid looks great, and the parents live 10 minutes away?

Joshua, Pediatric Emergency Medicine, Philadelphia, PA

Ok, I admit, I snuck this one in. I often struggle, as I am sure many of you do, with what exactly our role is in the ED. We hate to miss a diagnosis. After all, we are diagnosticians at heart. And we have all of the tools to often make the diagnosis. But we can’t (and we don’t) order every test for every patient. As I said earlier in this mailbag, that is the art of medicine. So when it comes to appendicitis, how far do we go to not miss it?

I’m not going to lie, I don’t have a great answer for you (hence why I asked the question!). I would say my guiding principles are generally the following:

• Every patient and family is different! You need to personalize your approach to the clinical exam and the situation.
• If you can come up with three (legitimate) reasons why it is not appendicitis (and likely something else), discharge with close follow up may be ok.
• Did symptoms just start within the last 4-6 hours? If the exam is not super convincing for appendicitis, it might be ok to give strict return precautions and acknowledge that there’s a chance this is very early appendicitis.
• Are you a teen with focal right lower quadrant pain? You’re not leaving the ED until I definitively rule out appendicitis.

As with a lot of things in the Peds ER, shared-decision making is typically the name of the game. If I have low (but not zero) suspicion for appendicitis and am discharging a patient, I will explain that appendicitis (at least in my experience) typically doesn’t wax and wane. If the patient has steadily worsening pain, and certainly if that pain becomes more focal to the RLQ, it’s time to come back to the ED. If the family understands that and is willing to come back promptly should things worsen, I think there’s a case for discharging with close follow up.

That’ll be it for our third mailbag! How did it go? Share your thoughts below or send us an email at HipPEMcrates@gmail.com! Until next time, may your appendixes be visualized, your toddlers take oral meds, and your discharge paperwork print on the first try.

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