Meningitis (pediatrics): Clinical sciences

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Introduction0:00–0:37

Meningitis refers to the inflammation of the meninges, which are protective membranes that surround the brain and spinal cord.
Meningitis commonly occurs as a result of bacterial infection. In newborns, the most frequent causative pathogens include Group B streptococci, Escherichia coli, and Listeria monocytogenes; while in children and teens, more common causes include Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria meningitidis.
Finally, if there are no bacteria, consider aseptic forms of meningitis, such as viral meningitis!Now, if your patient presents with a chief concern suggesting meningitis, perform an ABCDE assessment to determine whether the patient is unstable or stable.

Unstable Patient0:37–1:08

If unstable, stabilize their airway, breathing, and circulation. Next, obtain IV access, start IV fluids, and put the patient on continuous vital sign monitoring, including blood pressure, heart rate, and pulse oximetry.
Finally, if needed, don’t forget to provide supplemental oxygen.Now, let’s go back and take a look at stable patients. First, assess your patient’s age, since the diagnostic evaluation and management are age-dependent.

Stable Patient1:08–1:23

The main cut-off is at age 60 days.Let’s start with patients 60 days of age and younger. Start by obtaining a focused history and physical exam.

Age 60 days or less1:23–1:58

History typically reveals non-specific symptoms, such as fussiness, inconsolability, sleepiness, weakness, or even apnea.
Additionally, caretakers might report vomiting, poor feeding, and, in some cases, even seizures. The physical exam typically reveals temperature instability, poor tone, irritability when moved, and lethargy.
In some cases, you might notice increased head circumference, as well as full or bulging anterior fontanelle. At this point, you should suspect meningitis!

Suspect meningitis1:58–3:02

Begin your diagnostic workup by ordering labs, including blood cultures, a CBC, and inflammatory markers, including CRP and procalcitonin.
Additionally, perform lumbar puncture to obtain CSF for analysis, which includes a gram stain, culture, and cell count, as well as glucose and protein levels.
Once you obtain these labs, begin treatment with intravenous empiric antibiotics, including ampicillin to cover for Listeria, in combination with cefotaxime or gentamicin to cover for other potential bacterial causes.
Remember, if there’s high suspicion for bacterial meningitis, and your patient is critically ill, don’t delay administering antibiotics for the sake of performing a lumbar puncture first!Here’s a high-yield fact!
Although ceftriaxone is the antibiotic of choice in other age groups, it should be avoided in neonates, since it displaces bilirubin from albumin binding sites, putting the patient at risk for kernicterus.Next, assess the initial lab results.

Aseptic/viral meningitis3:02–4:11

First, let’s focus on infants with aseptic meningitis. The CBC typically reveals a normal or low white blood cell count, with or without a low platelet count.
In addition, in most cases, the CRP is elevated and the PCT is normal. Meanwhile, the CSF gram stain will be negative, and CSF fluid analysis will reveal a lymphocytic pleocytosis, with normal glucose and normal to high protein.
At this point, you should suspect aseptic meningitis, so your next step is to order a CSF viral PCR, and then assess the PCR and culture results.
If PCR identifies a viral pathogen, and CSF and blood cultures remain negative, you can diagnose viral meningitis. At this point, you can discontinue antibiotics.
Management primarily consists of supportive care, but be sure to begin IV acyclovir if CSF PCR is positive for HSV!Here’s a high-yield fact!
Because acyclovir can cause kidney damage, patients on this medication should receive IV fluids to ensure adequate renal perfusion.Okay, now let’s go back to our labs and discuss bacterial meningitis.

Bacterial Meningitis4:11–5:10

In this case, the CBC usually reveals a normal or low white blood cell count, with or without a low platelet count, and almost always elevated CRP and procalcitonin levels.
Next, the CSF gram stain will usually be positive, with gram-positive cocci suggesting Group B Streptococcus, or Streptococcus agalactiae; gram-negative rods suggesting E.
coli; or gram-positive bacilli suggesting Listeria monocytogenes. Additionally, CSF analysis reveals neutrophilic pleocytosis, low glucose, and high protein levels.
The presence of these findings should make you suspect bacterial meningitis, so your next step is to assess culture results!
A positive CSF culture, with or without a positive blood culture, confirms the diagnosis of bacterial meningitis, so make sure to tailor the antibiotic regimen based on culture results.Now, let’s go all the way back to the age assessment and look at patients over 60 days of age.

Age more than 60 days5:10–6:47

Again, start with a focused history and physical examination. The history often reveals a child with fever, headache, photophobia, irritability, and confusion.
Affected children might report nausea and vomiting, back pain, and a stiff neck, and some may even have seizures. Keep in mind that these findings can be progressive over several days, or rapid.The physical exam of a child with meningitis is often significant for nuchal rigidity, and sometimes you may check for the Brudzinski sign and Kernig sign.
To check for the Brudzinski sign, place your patient on their back and passively flex their neck. If the child’s hips and knees bend with neck flexion, the Brudzinski sign is positive.
On the flip side, to check for the Kernig sign, flex one of the child’s legs so the hip and knee are both at 90 degrees.
Next, passively extend the knee, and if you can’t extend it to 135 degrees without resistance or pain, or if passive knee extension causes the opposite knee to bend, the Kernig sign is positive.
Either of these signs, when positive, suggest meningeal irritation. Keep in mind that, in children less than 12 months old, these physical signs are not reliable; in fact, they are frequently absent in a toddler with meningitis!Also, be especially alert for signs of increased intracranial pressure, such as papilledema, diplopia, cranial nerve paralysis; as well as the Cushing triad, which includes hypertension, bradycardia, and respiratory depression.
The presence of any of these findings should lead you to suspect meningitis, so again, proceed with labs, including blood cultures, a CBC, CRP, and procalcitonin.

Labs6:47–7:52

Lab findings will likely include normal or high WBCs, with or without low platelets, and elevated CRP. Finally, in some cases, procalcitonin could be elevated, which is highly suggestive of bacterial meningitis!
Next, you have to determine whether you can safely perform a lumbar puncture or not.In a patient with increased ICP, lumbar puncture can precipitate brain herniation, so before you proceed, assess for contraindications to this procedure.
These include the presence of papilledema, diplopia, cranial nerve paralysis, or a focal neurologic finding on physical exam.
Other important contraindications include immunodeficiency, or a history of a central nervous system condition like a ventriculoperitoneal shunt, hydrocephalus, or mass lesion.
Lastly, consider cardiopulmonary compromise, and skin infection over the insertion site where you plan to perform the procedure.Let’s see what you should do if lumbar puncture, or LP, is contraindicated.

LP contraindicated7:52–8:31

Start empiric IV antibiotics, usually vancomycin plus cefotaxime or ceftriaxone, to cover the most common pathogens. Then, order a head CT, and if findings suggest increased intracranial pressure, you can make a presumptive diagnosis of bacterial meningitis.
In that case, you should continue empiric antibiotics. In addition, to reduce intracranial pressure, elevate the head of your patient’s bed, consider hyperventilation if your patient is receiving mechanical ventilation, and administer mannitol.
On the other hand, let’s see what happens if the head CT has no findings suggesting increased intracranial pressure, or, if the lumbar puncture was not contraindicated in the first place.

LP not contraindicated8:31–9:06

If that’s the case, you can safely perform a lumbar puncture. Next, obtain CSF, and send it for analysis, which includes gram stain, culture, and cell count, as well as glucose and protein levels.
Once you obtain CSF, begin empiric intravenous antibiotics if you haven’t already. These again include vancomycin plus cefotaxime or ceftriaxone.

CSF results - Aseptic/viral meningitis9:06–9:51

Now, assess the PCT as well as CSF and blood culture results. If the PCT is normal, the gram stain is negative, and the CSF shows a lymphocytic pleocytosis, with a normal glucose, and normal to high protein, suspect aseptic meningitis and order a CSF viral PCR.
Next, assess the PCR and culture results and if the PCR identifies a viral pathogen and the CSF and blood cultures remain negative, diagnose viral meningitis.
At this point, you can discontinue antibiotics. Management primarily consists of supportive care, but be sure to begin IV acyclovir if CSF PCR is positive for HSV!Finally, let’s look at the lab findings you'd expect to see in bacterial meningitis.

CSF results - Bacterial meningitis9:51–10:42

Typically, the PCT is elevated and the CSF gram stain is positive, with gram-positive diplococci suggesting Streptococcus pneumoniae, gram-negative coccobacilli suggesting Haemophilus influenzae, or gram-negative diplococci suggesting Neisseria meningitidis.
Other CSF findings include a neutrophilic pleocytosis, as well as low glucose and high protein. At this point, you should suspect bacterial meningitis.Next, assess the culture results, and if the CSF culture is positive, with or without a positive blood culture, you can confirm the diagnosis of bacterial meningitis.
Once you diagnose it, tailor the antibiotic regimen based on CSF and blood cultures.Alright, as a quick recap… If you suspect meningitis, first consider your patient’s age.

Review10:42–11:53

Infants 60 days and younger should receive empiric IV antibiotics, including ampicillin in combination with cefotaxime or gentamicin, pending culture results.
If labs suggest aseptic meningitis, order a CSF PCR to identify viral pathogens, provide supportive care, and add acyclovir if PCR identifies HSV.
However, if labs suggest bacterial meningitis, continue antibiotics. Regarding children over 60 days of age, if LP is contraindicated, begin empiric antibiotics, including vancomycin plus cefotaxime or ceftriaxone, and order a head CT.
If CT suggests increased ICP, make a presumptive diagnosis of bacterial meningitis, and continue antibiotics. If LP isn’t contraindicated, or if head CT doesn’t suggest increased ICP, perform an LP and begin empiric antibiotics.
If CSF studies suggest viral meningitis, stop antibiotics and provide supportive care. However, if CSF analysis suggests bacterial meningitis,