Basics
Description
Pneumonia is an infection of the lungs involving the alveoli and distal airways. � �
Epidemiology
Incidence
- Highest incidence in children <5 years of age (annual incidence 3 " �4%)
- Viral pneumonias still generally comprise a large proportion of pediatric pneumonia.
Risk Factors
- Immune deficiency
- Immunocompromised status
- Sickle cell anemia
- Increased aspiration risk
- Altered mental status
- Tracheoesophageal fistula
- Cerebral palsy
- Seizure disorder
- Compromised lung function/anatomy
- Cystic fibrosis
- Congenital pulmonary malformations
- Bronchopulmonary dysplasia
- Asthma
Etiology
- Etiology of bacterial pneumonia differs by age:
- Neonates: group B Streptococcus, enteric gram-negative rods (e.g., Escherichia coli), Listeria monocytogenes, Haemophilus influenzae, Bordetella pertussis
- 1 " �3 months: neonate organisms + Staphylococcus aureus, Streptococcus pneumoniae, Chlamydia trachomatis
- 4 months to 4 years: Streptococcus pneumoniae, Staphylococcus aureus, H. influenzae
- >5 years of age: Streptococcus pneumoniae, H. influenza, Staphylococcus aureus, Mycoplasma pneumoniae, Mycobacterium tuberculosis
- Etiology can also differ based on risk factors:
- Aspiration as etiology increases the risk for oral flora including anaerobes such as Bacteroides and Peptostreptococcus.
- Ventilator-dependent patients are at increased risk for Pseudomonas or Klebsiella infections and infection with other gram-negative rods.
- Cystic fibrosis increases the risk for Pseudomonas and other more unusual organisms.
Diagnosis
History
- Fever and/or chills
- Rapid breathing is a sensitive but nonspecific finding in bacterial pneumonia.
- Difficulty breathing or shortness of breath is common (can be associated with difficulty feeding in infants).
- Poor feeding or apnea in young infants
- Cough is often seen in bacterial pneumonia. B. pertussis pneumonia often presents after a catarrhal phase with a paroxysmal cough and posttussive vomiting.
- Pleuritic chest pain
- Abdominal pain and/or vomiting: most often seen with lower lobe pneumonia.
- Irritability, lethargy, and/or malaise
- Birth history, including maternal infections (e.g., C. trachomatis can be transmitted to an infant through a mother 's genital tract at delivery)
- Immunization status: In a fully immunized child, H. influenzae type b, B. pertussis, and S. pneumoniae infections are less common.
- Recent history of upper respiratory tract infection (URI) or RSV can predispose to bacterial pneumonia.
- History of repeated bacterial infections may suggest immunodeficiency or cystic fibrosis (both are risk factors for bacterial pneumonia).
- Exposure to contacts with pertussis, tuberculosis, or history of recent travel
- Travelers, health care workers, and persons working in prisons or institutional settings are at greater risk for tuberculosis.
Physical Exam
- Most common findings: oxygen saturation <95%, elevated respiratory rate, nasal flaring, fever, and ill appearance
- General examination can range from mildly ill appearing to toxic in appearance.
- Infants may have a paucity of exam findings disproportionate to their appearance and tachypnea.
- Patients may be dehydrated or in shock.
- Most children with bacterial pneumonia have fever.
- Patients with atypical bacterial pneumonia and pertussis are sometimes afebrile.
- Tachypnea or increased work of breathing: nasal flaring, grunting, and/or retracting
- Decreased oxygen saturation; therefore, oxygen saturation should be obtained by pulse oximetry in children with tachypnea or other signs of distress.
- Localized rales, crackles, rhonchi, decreased breath sounds, or wheezing
- With increasing consolidation, dullness to percussion and decreased breath sounds may be noted.
- In patients who are actively wheezing, it may be difficult to distinguish rales from other auscultated sounds.
Diagnostic Tests & Interpretation
- Not indicated for patients with uncomplicated pneumonia
- In toxic-appearing infants, blood, urine, and CSF cultures (i.e., a sepsis workup) should be considered.
- Viral testing for RSV, influenza, and other respiratory viruses if readily available can help exclude viral diagnoses in children who are candidates for outpatient therapy.
Lab
- Blood culture
- Not indicated in healthy, immunized children with uncomplicated pneumonia
- Rarely leads to identification of pathogen causing pneumonia
- Should be obtained in children not responding to antibiotic therapy or moderate to severe pneumonia requiring hospitalization
- Bacteremia has been noted in up to 30% of patients with pneumococcal pneumonia.
- Elevated peripheral WBC or range 15,000 " �40,000/mm3 is associated with bacterial pneumonia or even higher WBC in pertussis but should not be relied upon to distinguish etiology of pneumonia.
- Testing for M. pneumoniae may be considered to guide antibiotic therapy if with signs or symptoms of atypical bacteria.
- Acute-phase reactants such as ESR, CRP, or others may provide useful information for clinical management in serious disease but cannot distinguish between viral and bacterial etiologies
- Purified protein derivative (PPD) test or an interferon-gamma release assay (e.g., quantiFERON) should be obtained in all patients in whom M. tuberculosis is suspected.
Imaging
- Chest radiograph (CXR), upright
- A CXR is not required for diagnosis if clinical symptoms and examination findings are consistent with uncomplicated pneumonia.
- A CXR (PA and lateral) is recommended if pneumonia is suspected but clinical findings are unclear, if the patient has hypoxemia or significant respiratory distress, if a pleural effusion is suspected, or if the patient is not responding to treatment.
- Characteristic CXR patterns include "alveolar or lobar infiltrate " � with air bronchograms. "Round " � infiltrates may be seen with S. pneumococcus. "Diffuse " � interstitial infiltrates and hyperinflation may be seen with atypical pneumonia such as M. pneumoniae or chlamydial pneumonias.
- More commonly, CXR cannot be reliably used to distinguish between viral and bacterial disease.
- An infiltrate may not be seen (negative CXR) if the disease is diagnosed early or if the patient is dehydrated.
- CXR, lateral decubitus: more sensitive than an upright radiograph in detecting pleural effusions or foreign body aspiration
- CT scan: not recommended as 1st-line imaging for suspected pneumonia. CT is mainly used as adjunct imaging for patients who are worsening (not improving) despite treatment or have complications.
Diagnostic Procedures/Other
If diagnosis is unclear, consider the following: � �
- Tracheal aspirates for Gram stain and culture if intubation necessary
- In immunocompetent children, bronchoscopy, bronchoalveolar lavage, percutaneous lung aspiration, or lung biopsy should be reserved for severe pneumonia if initial tests are not diagnostic.
Differential Diagnosis
- Infectious
- Sepsis
- Viral pneumonia
- Infants: cytomegalovirus (CMV), metapneumovirus, herpes simplex virus (HSV)
- From 1 to 3 months: CMV, respiratory syncytial virus (RSV), metapneumovirus
- From 4 months to 4 years: RSV, adenovirus, influenza, metapneumovirus
- Bronchiolitis
- URI
- Croup (laryngotracheobronchitis)
- Fungal infection (if immunodeficiency or exposure history)
- Parasitic infection (if immunodeficiency or exposure history)
- Pulmonary
- Asthma
- Atelectasis
- Pneumonitis (i.e., chemical)
- Pneumothorax
- Pulmonary edema
- Pulmonary hemorrhage
- Pulmonary embolism
- Congenital
- Pulmonary sequestration
- Congenital pulmonary airway malformation
- Genetic: cystic fibrosis
- Tumors
- Lymphoma
- Primary lung tumor
- Metastatic tumor
- Cardiac: CHF
- GI: gastroesophageal reflux disease
- Miscellaneous
- Foreign body aspiration
- Sarcoidosis
Treatment
Medications
Outpatient: empiric treatment � �
- Nontoxic, uncomplicated pneumonias in patients older than 3 " �6 months of age and anticipated to comply with antibiotic therapy may be managed as outpatients.
- Infants and preschool children (<5 years old)
- Amoxicillin 80 " �100 mg/kg/24 h (max 3 g/24 h) PO divided q8 " �12h
- School-aged children ( ≥5 years old)
- Amoxicillin 80 " �100 mg/kg/24 h (max 3 g/24 h) PO divided q8 " �12h
- Consider for additional coverage of atypical bacterial pathogens
- Azithromycin 10 mg/kg/dose (max 500 mg) PO � � 1 day then 5 mg/kg/dose (max 250 mg) PO once daily � � 4 days
- May consider clarithromycin 15 mg/kg/24 h (max 1 g/24 h) PO divided q12h or doxycycline 4.4 mg/kg/24 h (max 200 mg/24 h) PO divided by 2 doses in patients 7 years of age or older.
- If specific pathogen is known or suspected, use appropriate antibiotic therapy.
- For patients with more severe disease, may consider combining � �-lactam antibiotic and macrolide
Inpatient Considerations
- Patients with moderate to severe pneumonia as defined by respiratory distress and hypoxemia (<90%), infants younger than 3 " �6 months of age, children and infants with pneumonia caused by a pathogen with increased virulence (e.g., community-associated MRSA), and failed outpatient therapy should be hospitalized
- Intubation and positive pressure ventilation, if clinically indicated
- Empiric antibiotic treatment
- All ages
- Ampicillin 200 " �400 mg/kg/24 h (max 12 g/24 h) IV divided q6h (or penicillin 250,000 U/kg/24 h [max 24 million U/24 h] IV divided q6h)
- Ceftriaxone 50 " �100 mg/kg/24 h (max 2 g/24 h) IV divided q12 " �24h or cefotaxime 200 mg/kg/24 h (max 12 g/24 h) IV divided q8h
- If atypical pathogens suspected, may add macrolide or use as alternative: azithromycin IV or PO using the same initial empiric dosage regimen from above
- For seriously ill patients, add vancomycin 15 mg/kg/dose IV q6 " �8h.
- For antistaphylococcal coverage, add vancomycin 15 mg/kg/dose IV q6 " �8h or clindamycin 30 mg/kg/24 h IV/PO divided q8h.
- May also consider macrolides or clindamycin as alternative for cephalosporin-allergic patients
Ongoing Care
Follow-up Recommendations
Patient Monitoring
- Children on appropriate therapy should show improvement within 48 " �72 hours.
- If worsening or not responding to treatment, consider repeated or additional diagnostic studies. For example, persistent fever may be due to loculated pleural fluid or an empyema.
- For additional antibiotic guidance for children not improving, consider pediatric infectious disease consultation.
- CXR may be abnormal for up to 10 weeks after successful treatment. Consider follow-up CXR only if indicated for severe disease, clinical progression, or suspected complications (e.g., effusion, empyema).
- For children with recurrent bacterial pneumonia, consider an underlying anatomic or immunologic disorder (e.g., abnormal antibody production, cystic fibrosis, tracheoesophageal fistula, pulmonary sequestration).
Complications
- Pleural effusion
- Empyema
- Lung abscess
- Pneumatoceles
- Pneumothorax
- Bacteremia/sepsis
Additional Reading
- Bradley � �JS, Byington � �CL, Shah � �SS, 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. � �[View Abstract]
- Kabra � �SK, Lodha � �R, Pandey � �RM. Antibiotics for community acquired pneumonia in children. Cochrane Database Syst Rev. 2006;(3):CD004874. � �[View Abstract]
- Lee � �GE, Lorch � �SA, Sheffler-Collins � �S, et al. National hospitalization trends for pediatric pneumonia and associated complications. Pediatrics. 2010;126(2):204 " �213. � �[View Abstract]
- McIntosh � �K. Community-acquired pneumonia in children. N Engl J Med. 2002;346(6):427 " �437. � �[View Abstract]
- Ranganathan � �SC, Sonnappa � �S. Pneumonia and other respiratory infections. Pediatr Clin North Am. 2009;56(1):135 " �156. � �[View Abstract]
Codes
ICD09
- 482.9 Bacterial pneumonia, unspecified
- 482.32 Pneumonia due to Streptococcus, group B
- 482.82 Pneumonia due to escherichia coli [E. coli]
- 482.2 Pneumonia due to Hemophilus influenzae [H. influenzae]
- 482.0 Pneumonia due to Klebsiella pneumoniae
- 482.1 Pneumonia due to Pseudomonas
- 482.89 Pneumonia due to other specified bacteria
- 482.49 Other Staphylococcus pneumonia
- 484.3 Pneumonia in whooping cough
ICD10
- J15.9 Unspecified bacterial pneumonia
- J15.3 Pneumonia due to streptococcus, group B
- J15.5 Pneumonia due to Escherichia coli
- J14 Pneumonia due to Hemophilus influenzae
- J15.0 Pneumonia due to Klebsiella pneumoniae
- J15.8 Pneumonia due to other specified bacteria
- J15.7 Pneumonia due to Mycoplasma pneumoniae
- J15.1 Pneumonia due to Pseudomonas
- A37.11 Whooping cough due to Bordetella parapertussis w pneumonia
SNOMED
- 53084003 Bacterial pneumonia (disorder)
- 195886008 Group B streptococcal pneumonia (disorder)
- 51530003 Pneumonia due to Escherichia coli
- 70036007 Haemophilus influenzae pneumonia
- 59475000 Pneumonia in pertussis (disorder)
- 41381004 Pneumonia due to Pseudomonas (disorder)
- 233607000 Pneumococcal pneumonia (disorder)
- 64479007 Pneumonia due to Klebsiella pneumoniae
- 22754005 Staphylococcal pneumonia (disorder)
FAQ
- Q: What are the indications for admission and inpatient treatment of pneumonia in children?
- A: Failure of outpatient therapy, moderate to severe pneumonia as defined by respiratory distress and hypoxemia, infants younger than 3 " �6 months of age, children and infants with pneumonia caused by a pathogen with increased virulence (e.g., community-associated MRSA)
- Q: What is the appropriate duration of therapy for bacterial pneumonia?
- A: Empiric treatment courses of 10 days have been studied the most, although shorter courses may be effective in uncomplicated disease. Pneumonias caused by some pathogens (e.g., CA-MRSA) may require longer duration.
- Q: What is the most common causative organism of pulmonary abscess, and what is the appropriate treatment?
- A: S. aureus is the most common causative organism. Treatment includes IV vancomycin, IV or PO clindamycin, or PO linezolid. If MSSA is confirmed cefazolin, nafcillin, or cefuroxime may be used.
- Q: Which children are most likely to have systemic complications from community-acquired pneumonia? Local complications?
- A: An analysis of inpatient data from pediatric hospitals from 1997 to 2006 suggests that children <1 year of age are more likely to have systemic complications (e.g., sepsis, acute respiratory failure), whereas patients aged 1 " �5 years are more likely to have local complications (e.g., empyema, abscess).
- Q: What are risk factors for invasive pneumococcal disease?
- A: Conditions associated with invasive pneumococcal disease include congenital immune deficiency (e.g., B- or T-lymphocyte deficiencies) asplenia/functional hyposplenism, complement deficiency, diseases associated with immunosuppressive therapy or radiation therapy (including malignancies), and solid organ transplantation and chronic cardiac disease.