Pneumonia

Morgan, Carrie I.; Shah, Samir S.

Respiratory diagnoses continue to make up a large number of admissions to the pediatric intensive care unit (PICU), most notably lower respiratory infections including pneumonia. This chapter will focus on pediatric community-acquired pneumonia (CAP), immunocompromised pneumonia, and aspiration pneumonia. The pathogenesis for developing pneumonia varies; it can occur by direct inhalation of infectious particles in the air or aspiration, direct extension from the upper airways, and hematogenous spread. There are multiple levels of defense against pathogen invasion including anatomic barriers, as well as innate and adaptive immunity, which may be compromised in PICU patients. The etiologies of pediatric pneumonia vary depending on age, host condition, and environmental factors like time of year and location. Viruses remain the most common form of lower respiratory tract infection in children, especially in neonates. Community-acquired bacterial pneumonia continues to be most prevalent in younger children as well, most often affecting children less than 5 years of age who are otherwise healthy. Despite immunizations and public health initiatives, the most common bacterial causes of CAP have remained largely unchanged over the last several decades and include: Streptococcus pneumoniae, Staphylococcus aureus, Haemophilus influenzae (including non-typable strains) and Moraxella catarrhalis. Pulmonary infection in an immunocompromised host provides a much broader differential and must be aggressively treated without delay. This chapter will also address various imaging modalities and typical findings with pediatric pneumonia. Methods for pathogen identification are broad and range from non-specific markers of illness to invasive techniques for culture. The mainstay of therapy continues to be antibiotics tailored to the patient and presumed etiology; more novel therapies may include corticosteroids or macrolide antibiotics for immune modulation. In those patients with pneumonia with effusion or empyema, drainage therapies with thoracostomy tubes or a VATS procedure may be indicated.