Author:
Gary D.Zimmer
Karen P.Zimmer
Description
- Infection of the lower respiratory tract infections diagnoses marked by the presence of fever, respiratory symptoms and lung involvement (by physical examination and /or radiography)
- Viral and bacterial causes are more prevalent during winter months and seasonal. Pathogen not confirmed in as many as 25% of cases
- Spread is by droplet exposure, oropharyngeal aspiration and hematogenous
- Lower socioeconomic status (household crowding), attendance at school/daycare, inadequate immunizations, and exposure to tobacco smoke are significant risk factors
- As many as half of children under 5 years of age with pneumonia require hospitalization
Etiology
- <3 wk:
- Group B Streptococcus species
- Enteric gram-negative organisms
- Viruses (RSV, CMV, HSV)
- L. monocytogenes
- Maternal transmission: T. pallidum, Genital mycoplasma or ureaplasma
- 3 wk-3 mo:
- 3 mo-5 yr:
- Viral (predominate):
- RSV
- Parainfluenza virus
- Influenza virus
- Adenovirus
- Rhinovirus
- S. pneumoniae
- H. influenza in unimmunized children
- M. pneumoniae (>4 yr predominantly)
- S. aureus
- M. tuberculosis
- >5 yr:
- M. pneumoniae most common
- Viral
- S. pneumoniae
- Chlamydophila pneumoniae
- Recent immigrants from developing countries:
- Mycoplasma tuberculosis
- H. influenza
- B. pertussis
- Immunocompromised (e.g., HIV, cancer):
- P. carinii
- Mycoplasma avium complex
- M. tuberculosis
- Klebsiella pneumoniae
- Pseudomonas aeruginosa
- Less common:
- Identified patterns:
- Lobar: S. pneumoniae
- Bronchopneumonia: Sometimes associated with S. pyogenes and S. aureus
- Necrotizing: Aspiration, S. pyogenes, S. pneumoniae, S. aureus
- Caseating granuloma: M. tuberculosis
- Interstitial/peribronchial with secondary parenchymal infection: Viral pneumonia with superinfection
Signs and Symptoms
- General (in all ages):
- Cough
- Rales
- Fever
- Hypoxia
- Tachycardia
- Tachypnea, retractions, grunting
- Rash (up to 10% of cases); usually maculopapular
- Nonspecific symptoms of toxicity
- Pulmonary exam:
- Decreased breath sounds, ventilation
- Dullness to percussion
- Wheezing, rhonchi, rales
- Infants <6 mo:
- Altered behavior: Listless, irritable
- Apnea (esp RSV in premature infants)
- Conjunctivitis (Chlamydia<1 mo old)
- Cyanosis
- Grunting/respiratory distress
- Tachypnea
- Poor feeding
- Temperature instability (hypothermia/hyperthermia)
- Vomiting, often with coughing
- Cough
- Nasal congestion
- Nasal flaring
- Wheezing
- Staccato cough (Chlamydia)
- Children >5 yr:
- Pleuritic chest pain
- Productive cough
- Rigors, chills
- The absence of cough is a useful negative predictor, while moderate hypoxemia and increased work of breathing (grunting, flaring, retractions) are associated with pneumonia
History
- Immunization status
- Past medical history including immune status, episodes of bronchiolitis or asthma, atopy
- Exposures
- Progression of signs and symptoms
Physical Exam
- Pulmonary exam findings:
- Often non-specific, particularly in infants and neonates
- Decreased breath sounds
- Wheezing
- Bronchial breath sounds
- Dullness to percussion
- Peripheral and central cyanosis should be assessed
- Evidence of respiratory compromise, distress, failure
Essential Workup
- Pulse oximetry
- Chest radiograph:
- Gold stand ard for diagnosis
- Should be ordered for patients with signs of lower respiratory tract infection and patients <36 mo old with marked leukocytosis or neutrophilia (WBC >15,000 or absolute neutrophil count [ANC] >9,000)
- Much overlap between viral and bacterial findings
- Viral and M. pneumoniae tend to show interstitial infiltrates, often perihilar and peribronchial
- Bacterial pneumonias may show focal lobar consolidation, focal alveolar infiltrates, and possibly effusion or pneumatocele
- Round pneumonia pathognomonic of S. pneumonia
- Lateral decubitus films may aid in demonstrating effusion
Diagnostic Tests & Interpretation
Lab
- CBC with differential:
- Patients with bacteremia tend to have leukocytosis with left shift
- Sensitivity and specificity are poor
- Patients with WBC ≥20,000 or ANC >9,000 are at increased risk of pneumococcal bacteremia
- B. pertussis usually has elevated WBC with lymphocytosis
- Nasopharyngeal and sputum cultures may be considered in seriously ill children to assist in identifying pathogen. Viral panels are increasingly available for epidemiologic surveillance but have little utility in guiding treatment
- Rapid assay for influenza viruses seasonally
- Blood culture:
- Low yield (<10-20%)
- Recommended in children <36 mo
- Probably worthwhile in toxic patients requiring hospitalization
- Arterial blood gas may be useful in determining degree of respiratory insufficiency in critically ill patients
- Electrolytes to exclude syndrome of inappropriate antidiuretic hormone secretion and in hypotensive children
- Mycoplasma IgM or cold agglutinin titers:
- Useful if suspecting this organism
- More likely positive with severe illness
- Nasopharyngeal washes for direct fluorescent antibody and culture:
- Identify RSV, C. trachomatis, and B. pertussis infections
Imaging
- Chest radiographs are still the imaging modality of choice:
- Posteroanterior and lateral films should be obtained whenever possible
- CT provides additional detail and better identification of underlying lung pathology but adds little as an initial testing modality
Diagnostic Procedures/Surgery
In severe cases requiring critical care: Pleural fluid (if present) for culture, Gram stain, protein, glucose, and cell counts. Consider bronchoscopy with bronchoalveolar lavage in specific circumstances
Differential Diagnosis
- Reactive airway disease (asthma [age <2 yr])
- Bronchiolitis
- Aspiration:
- Gastroesophageal reflux
- Vascular ring
- H-type tracheoesophageal fistula
- Foreign body
- Hydrocarbon
- Congestive heart failure
- Congenital:
- Cystic fibrosis
- Sequestered lobe
- Congenital lobe absence
- Hemangioma
- Neoplasm
- Sepsis
Prehospital
- Pulse oximetry
- Administer high-flow oxygen for respiratory distress
- IV fluids (0.9% normal saline [NS] 20 mL/kg initial bolus) for volume depletion, hypotension, or poor oral intake
- Support and intubation for respiratory failure
Initial Stabilization/Therapy
- If moderately or severely ill:
- Secure airway, as appropriate; intubate for clinical respiratory failure. Children with severe sepsis or septic shock benefit from aggressive airway management
- High-flow oxygen
- IV hydration (0.9% NS 20 mL/kg initial bolus) and resuscitation if in shock or hypovolemic
- Monitor
- Ongoing pulse oximetry
- Arterial blood gas if inadequate ventilation
- Check bedside glucose in severely ill-appearing infants and toddlers:
- If hypoglycemic, administer glucose D25 at 2 mL/kg IV for toddlers or D10 at 5 mL/kg IV for neonates
ED Treatment/Procedures
- Continue prehospital and initial stabilization therapy
- Early antibiotic therapy should be broad enough to address local resistance patterns in your area
- Often have concurrent reactive airway disease that needs specific treatment with bronchodilator (albuterol) therapy. A clinical trial may be useful to determine the clinical response:
- This is particularly important if the hypoxia is disproportionate to the findings on CXR, air movement is decreased, or there is a patient/family history of atopy or asthma/bronchiolitis
- Perform thoracentesis if pleural effusion is compromising respiratory function or for diagnostic tests. Often done under radiographic imaging
Antibiotic Therapy
- Empiric therapy with oral antibiotics for most well-appearing children ≥6 mo:
- Infants <2 mo:
- Outpatient treatment generally not recommended unless child has no respiratory distress or associated conditions or issues
- Children 3 mo-5 yr:
- Children 5-18 yr:
- First Line:
- Macrolide (azithromycin or clarithromycin)
- Initiate IV antibiotic therapy for moderate to severely ill children who require admission:
- Neonate:
- Infants 1-2 mo:
- Ampicillin and cefotaxime
- Azithromycin or erythromycin for suspected C. trachomatis or B. pertussis
- Children ≥3 mo:
- Unusual organisms require specific therapy in coordination with infectious disease consultation
Medication
- Albuterol (0.5% solution or 5 mg/mL): Nebulizer 0.015 mg (0.03 mL)/kg per dose up to 5 mg per dose q10-20min as needed; metered dose inhaler (with spacer; 90 mg per puff) 2 puffs q10-20min up to total of 10 puffs over several hours
- Amoxicillin: 80 mg/kg/24 h q12h PO
- Amoxicillin-clavulanate: 30 mg/kg/24 hr q12h PO
- Ampicillin: 100-150 mg/kg/24 hr q6h IV
- Azithromycin: 10 mg/kg/24 hr daily for 1 d, then 5 mg/kg/24 hr daily for 4 d
- Cefotaxime: 50-75 mg/kg/24 hr q8h IV, max 2 g q8h
- Ceftriaxone: 100 mg/kg/24 hr q12-24 h IV, max 2 g q12h
- Cefuroxime: 100 mg/kg/24 hr q8h IV, max 2 g q8h
- Clarithromycin: 15 mg/kg/24 hr q12h PO, max 500 g q12h
- Clindamycin: 30-40 mg/kg/24 hr q6-8h IV
- Gentamicin: 5-7.5 mg/kg/24 hr q8-12h IV
- Trimethoprim-sulfamethoxazole: 8-10 mg/kg/24 hr as TMP q12h PO
- Vancomycin: 10-15 mg/kg/24 hr q8-12h IV; max 1,000 mg
Disposition
Admission Criteria
- Toxic appearance
- Respiratory distress or failure
- Dehydration/vomiting
- Apnea
- Infants <2 mo
- Infants <6 mo with likely bacterial pneumonia
- Hypoxia (O2 saturation <92% on room air [sea level])
- Concern for virulent pathogen such as MRSA
- Pleural effusion
- Poor response to outpatient oral therapy
- Immunocompromised children
- Concern about noncompliant parents
Discharge Criteria
- Most cases are mild and can be discharged home if no evidence of hypoxia, significant work of breathing, dehydration, vomiting, or noncompliance
- Ensured follow-up within 1-2 d
Issues for Referral
Respiratory failure, effusion, toxicity, or slow response to appropriate therapy
Follow-up Recommendations
Clinical resolution should be ensured through follow-up
- BradleyJS, ByingtonCL, ShahSS, et al. The management of community-acquired pneumonia in infants and children older than 3 months of age: Clinical practice guidelines by the Pediatric Infectious Diseases Society and the Infectious Diseases Society of America . Clin Infect Dis. 2011;53(7):e25-e76.
- GottliebM, HeinrichSA. How reliable are signs and symptoms for diagnosing pneumonia in pediatric patients? . Ann Emerg Med. 2018;71:725-727.
- JainS, WilliamsDJ, ArnoldSR, et al. Community-acquired pneumonia requiring hospitalization among US children . N Engl J Med. 2015;372(9):835-845.
- KronmanMP, HershAL, FengR, et al. Ambulatory visit rates and antibiotic prescribing for children with pneumonia, 1994-2007 . Pediatrics. 2011;127:411-418.
- ManiCS. Acute pneumonia and its complications. In: LongSS, ProberCG, FischerM, eds. Principles and Practice of Pediatric Infectious Disease. 4th ed.Philadelphia, PA: Elsevier; 2018.
- ShahSS, DuganMH, BellLM, et al. Blood cultures in the emergency department evaluation of childhood pneumonia . Pediatr Infect Dis J. 2011;30:475-479.
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