Pocket Pediatrics: The Massachusetts General Hospital for Children Handbook of Pediatrics (Pocket Notebook Series), 2 Ed.

PEDIATRIC PNEUMONIA

(N Engl J Med 2002;346:429; AAP Red Book 2009, IDSA/PIDS guidelines: Clin Infect Dis 2011;53(7):e25–76)

Definition

• Pulm infxn beyond terminal bronchioles, including alveoli; whereas bronchitis involves proximal to distal bronchioles

Clinical Manifestations

• Fever, cough, dyspnea, &/or hypoxia

• Viral PNA often preceded by URI sx; diffuse bilaterally abnormal lung exam; interstitial infiltrates

• Bacterial PNA suggested by leukocytosis, chills, may show signs of sepsis

• Atypical PNA often w/ gradually worse cough (“walking PNA”), interstitial infiltrates, malaise, myalgia, headache

• Nonspecific in younger children: Fever, irritability, poor feeding, restless

• Abn lung exam (rhonchi, ↓ breath sounds, dullness to percussion, ↑ tactile fremitus)

• Rhonchi (low-pitched coarse) more common in broncho PNA (larger airways involved)

• Inspiratory rales more common in lobar PNA and bronchiolitis (alveoli involved)

• Diminished or bronchial breath sounds in consolidation

• Expiratory wheezes in bronchiolitis and viral interstitial pneumonitis

Etiologies

Diagnostic Studies

• CBC diff (leukocytosis w/ left-shift, occ leucopenia); consider ESR/CRP, blood cultures in moderate to severe infections

• Sputum GS and culture (if productive cough)

• CXR (preferably PA/lateral; lateral decubitus if suspect pleural effusion)

• Not necessary for dx of simple outpatient CAP, recommended for: Hypoxemia or significant respiratory distress. Routine CXR for follow-up not recommended

• Lobar PNA (single lobe or lobar segmental) classic for pneumococcal PNA

• Pleural effusion, cavitation/pneumatoceles, sepsis, ↑ WBC, chills suggest bact PNA

• BronchoPNA (1° airways & surrounding parenchyma): Group A strep & Staph. aureus

• Necrotizing pneumonia: Aspiration pneumonia, S. pneumoniae, Staph. aureus

• Interstitial: Suggests viral or atypical etiology

• Interstitial w/ 2° parenchymal infil: Classic for viral PNA → c/b bacterial PNA

• Rare to have complete lobar consolidation in infants

• CXR improvement typically lags behind clinical improvement (up to 1 mo)

• Mycoplasma IgM/IgG complement; fixation or PCR (cold agglutinins not clinically useful); pertussis culture/antibody/antigen PCR

Admission Criteria

• Hypoxia (sat <90% consistently), dehydration, respiratory distress (infant RR >60, children RR >40, grunting, retractions), toxic appearance (↑ common in bacterial PNA), serious underlying disease (e.g., cardiopulmonary), empyema/effusion – requires further evaluation/treatment, failed outpatient therapy (24–72 hr)

Management

aSend diagnostic studies for Mycoplasma when results available in clinically-relevant time-frame.

bFluoroquinolones associated with arthropathy, use w/ caution in the pediatric population.

• For C. trachomatis or B. pertussis Rx w/ macrolides

• PCP (Pneumocystis j.): Seen in immunocompromised; Rx w/ TMP/SMX and add corticosteroids if hypoxic/or ↑ A-a gradient

Complications

• Rpt CXR 2–3 wk after d/c for complicated comm.-acquired PNA or if persistent sx

• Parapneumonic effusion (initially sterile) → empyema (pus); U/S is excellent screening

• Broaden antibiotic coverage and thoracentesis to determine effusion etiology (evid of pus, (+)GS, pH < 7, ↑↑ LDH, ↓ glucose suggest empyema)

• Chest tube if empyema or for severe effusion → VATS if no improvement after 48 hr of chest tube (remove loculations/adhesions); alt fibrinolytics

• Lung abscess: Aspiration/IR drainage if no improv after 72 hr Rx; lobectomy only after >3 wk appropriate Abx therapy