Pneumonia (peds)

Background

• Most common site of infection in neonates
• Fever and tachypnea are Sn but not Sp

Causes

Neonatal Pneumonia

Etiology	Clinical Presentation	Management Approach
Bacterial [group BStreptococcus (most common),Escherichia coli, Listeria monocytogenes, Haemophilus influenzae B, S. pneumoniae,Klebsiella species, Enterobacter aerogenes]	Fulminant illness w/ onset w/in 48hr of life, w/ infection likely acquired in utero from contaminated amniotic fluid environment.	Full evaluation for sepsis (blood and urine cultures, chest radiographs, and complete blood count). The blood culture results are typically negative. Two culture samples may increase diagnostic yield fourfold.
	Respiratory distress, unstable temperature (high or low), irritability or lethargy, tachycardia and poor feeding may be present.	A lumbar puncture should be done if there are no contraindications.
		Hospitalization, supportive care (O2), and parenteral antibiotics (ampicillin and gentamicin, adjusts as per culture and sensitivities when available).
Nosocomial infections in premature infants (Staphylococcus aureus,Pseudomonas aeruginosa)	Same as for common bacterial etiology.	Same as for common bacterial etiology.
Chlamydia	Develops in 3%–16% of exposed neonates (in colonized mothers).	Sepsis evaluation as indicated.
		CXR may show hyperinflation with interstitial infiltrates.
	Usually occurs after 3 wk of age, accompanied by conjunctivitis in one half of cases. Often afebrile, tachypneic, with prominent "staccato" cough. Wheezing uncommon.	Definitive diagnosis by nasopharyngeal swab PCR or cultures.
		Eosinophilia may be seen on peripheral blood count.
		Treatment: macrolide (erythromycin, clarithromycin, or azithromycin).
Bordetella pertussis	In addition to pneumonia, may causes paroxysms of cough, ± cyanosis and post-tussive emesis in otherwise well-looking infant. Characteristic whoop is not present in neonates. Apnea may be the only symptom. Suspect when adult caregiver also has persistent cough.	Sepsis evaluation as indicated.
		Diagnosis via nasopharyngeal swab for PCR and/or culture.
		Lymphocytosis in peripheral blood count is nonspecific but supports the diagnosis.
		Macrolides are efficient against B. pertussis but is not approved by the U.S. Food and Drug Administration for infants <6 mo.
		No available data on efficacy of azithromycin or clarithromycin in infants <1 mo old, but case series show less adverse effects with azithromycin.
		Neonates need to be admitted during treatment and monitored for severe adverse effects.
Mycobacterium tuberculosis	Half of infants born to actively infected mothers develop TB if not immunized or treated.	Sepsis evaluation as for bacterial pneumonia.
		CXR, culture of urine, gastric and tracheal aspirates.
	May be acquired via transplacental means, aspiration/ingestion of infected amniotic fluid, or postnatal airborne transmission.	Skin testing not sensitive in neonates.
		Routine anti-TB treatment.
		Supportive treatment as needed.
	Often presents with nonspecific systemic symptoms with multi-organ involvement (fever, failure to thrive, respiratory distress, organomegaly).
Viral pneumonia (respiratory syncytial virus, adenovirus, human metapneumovirus, influenza, parainfluenza)	Initial upper respiratory illness progressing to respiratory distress and feeding difficulty.	Sepsis evaluation as indicated.
		Viral testing (direct antigen detection/PCR/cultures) of nasopharyngeal washings (swab).
	Hypoxia and apnea may be present.
	Often indistinguishable from bronchiolitis.	Rate of concurrent bacterial infections in confirmed viral infection is low.
		CXR for significant respiratory distress.
		Supportive therapy; monitoring for apnea in young and premature infants.

Common Causes

1. Viruses
   1. RSV, adeno, para/influenza
2. Mycoplasma
3. Chlamydia - pneumoniae and trachomatis
4. Bacteria
   1. 1. Group B strep, E. coli, listeria, H. flu, strep pneumo, kleb

Uncommon Causes

1. Viruses
   1. Zoster, Corona, Entero, Coxsackie, Echo, CMV, EBV, Mumps, HSV
2. Chlamydia psittaci
3. Coxiella
4. Bacteria
   1. Strep pyogenes, anaerobic mouth, hflu, pertussis, klebsiella, ecoli, listeria, nesseria, legionella, pseudomonas, tularremia, brucella, leptospira,
5. Fungi- cocci, histo, blasto

Diagnosis

1. CXR cannot differentiate between viral and bact (but lobar infiltrate more often bacterial)

WHO Criteria

1. Tachypnea
   1. RR >50 (<1 yr old)
   2. RR >40 (>1 yr old)
2. Retractions

Treatment

tx with azithromycin or clarithromycin after 3 months

Disposition

ADMIT

1. <3months old
2. SaO2 <91%
3. severe dehydration
4. moderate dehydration and unable to hydrate themselves orally after intravenous (IV) hydration
5. moderate or severe respiratory distress
6. failed outpatient antibiotic treatment

Sources

Tintinalli