Pneumonia (pediatrics): Clinical sciences

Pneumonia is an infection of the lower respiratory tract that involves the airways and surrounding lung tissue. In all age groups, one of the most common causes of pneumonia is Streptococcus pneumoniae. Other common causes include viruses in young infants, and atypical organisms such as Mycoplasma pneumoniae and Chlamydophila pneumoniae in children ages 5 and older.

When a pediatric patient presents with a chief concern suggesting pneumonia, first, perform an ABCDE assessment to determine if the patient is unstable or stable. If unstable, stabilize their airway, breathing, and circulation, and you may even need to intubate your patient. Next, obtain IV access, and consider starting IV fluids. Begin continuous vital sign monitoring, including respiratory rate, pulse oximetry, and cardiac monitoring, and administer supplemental oxygen as needed. Finally, administer empiric antibiotics early on.

Now, let’s go back to the ABCDE assessment and take a look at stable patients. In this case, first, obtain a focused history and physical exam, and measure your patient’s oxygen saturation using pulse oximetry.

Infants and children with pneumonia commonly present with fever and a cough. The physical exam usually reveals an elevated respiratory rate and an increased work of breathing, with nasal flaring or grunting commonly seen in young infants, as well as intercostal or subcostal retractions in all age groups. Meanwhile, auscultatory findings may include crackles, rhonchi, or decreased breath sounds, and pulse oximetry might show an oxygen saturation below 90%. A combination of these findings should make you suspect pneumonia.

The next step is to assess the criteria for hospitalization, which include an age less than 6 months, oxygen saturation below 90%, respiratory distress or signs of dehydration, an ill or toxic appearance, if the patient is unable to maintain oral hydration, if they’ve already received and failed outpatient treatment, or social factors which might prevent effective outpatient treatment.

If criteria for hospitalization are met, you should suspect moderate to severe pneumonia, and begin a diagnostic workup, starting with labs. Order a CBC, CRP, and procalcitonin, as well as a blood culture, and consider ordering a respiratory viral PCR. In addition, order an AP and lateral chest X-ray. To determine the next steps, first assess your patient’s age.

Patients younger than 3 months of age frequently present with vague symptoms such as apnea, lethargy, or isolated fever, so you have to evaluate your patient for sepsis, which includes ordering additional testing, such as a urinalysis, urine culture, as well as CSF analysis and culture. Next, admit your patient to the hospital, start supportive care with IV fluids, and begin empiric parenteral antibiotics, such as ampicillin and cefotaxime.

Let's now look at lab and imaging findings. Viral PCR could be positive, while CRP and procalcitonin could be elevated or normal, depending on the underlying cause of pneumonia. Additionally, you might get positive blood culture results, but keep in mind that urinalysis, urine cultures, CSF analysis, and cultures are typically negative.

Finally, imaging may reveal findings associated with bacterial pneumonia, which typically appears as a round or fluffy consolidation with a lobar distribution; or viral pneumonia, which typically lacks a round appearance and often appears as increased peribronchial markings near the hilum. At this point, you can diagnose pneumonia, so continue supportive care, and don’t forget to tailor antibiotics if the patient’s cultures are positive for growth!

Here’s a high-yield fact! If your patient is between 2 weeks and 3 months of age and presents with a staccato cough and conjunctivitis, the absence of fever, and scattered crackles on physical exam, consider Chlamydia trachomatis or other atypical bacterial pneumonia.

Lab findings may include elevated WBCs with eosinophilia, and the chest X-ray typically demonstrates bilateral diffuse interstitial infiltrates with hyperinflation. If these findings are present, make a clinical diagnosis of afebrile pneumonia, and treat your patient with a macrolide antibiotic like azithromycin, with supportive care and close follow up.

On the other hand, let’s look at patients 3 months or older. You should admit your patient to the hospital and begin IV ampicillin, and then assess the lab and imaging results to determine the type of pneumonia; viral, typical bacterial or MRSA.