ABDULLAH M. AL-OLAYAN MBBS, SBP, ABP. ASSISTANT PROFESSOR OF PEDIATRICS. PEDIATRIC PULMONOLOGIST. PNEUMONIA

OBJECTIVES ① Recall the epidemiology and etiology of community acquired pneumonia in children. ② Discuss the clinical manifestations, diagnosis and treatment of pneumonia. ③ Briefly discuss the aspiration pneumonias in children.

DEFINITIONS Pneumonia is an infection of the lower respiratory tract that involves the airways and parenchyma with consolidation of the alveolar spaces. Lower respiratory tract infection is often used to encompass bronchitis, bronchiolitis, pneumonia, or any combination of the three. Pneumonitis is a general term for lung inflammation that may or may not be associated with consolidation.

Lobar pneumonia describes pneumonia localized to one or more lobes of the lung. Bronchopneumonia refers to inflammation of the lung that is centered in the bronchioles and leads to the production of a mucopurulent exudate that obstructs some of these small airways and causes patchy consolidation of the adjacent lobules. Atypical pneumonia describes patterns typically more diffuse or interstitial than lobar pneumonia. DEFINITIONS

EPIDEMIOLOGY Immunizations have had a great impact on the incidence of pneumonia caused by : ① Pertussis. ② Diphtheria. ③ Measles. ④ Haemophilus influenza type b. ⑤ S. pneumoniae. ⑥ TB (BCG Vaccine).

Risk factors : ① Gastroesophageal reflux. ② Neurologic impairment (aspiration). ③ Immunocompromised states. ④ Anatomic abnormalities of the respiratory tract. ⑤ Residence in residential care facilities. ⑥ Hospitalization, especially in an intensive care unit. EPIDEMIOLOGY

CLINICAL MANIFESTATIONS ① Fever. ② Chills. ③ Tachypnea. ④ Cough. ⑤ Malaise. ⑥ Pleuritic chest pain. ⑦ Retractions.

Dullness to percussion may be due to lobar or segmental infiltrates or pleural fluid. Auscultation may be normal in early or very focal pneumonia, but the presence of localized crackles, rhonchi, and wheezes may help one detect and locate pneumonia. Physical examination findings cannot reliably distinguish viral and bacterial pneumonias. CLINICAL MANIFESTATIONS

LABORATORY AND IMAGING STUDIES In otherwise healthy children without life- threatening disease, invasive procedures to obtain lower respiratory tissue or secretions usually are not indicated. (WBC) count with viral pneumonias is often normal or mildly elevated, with a predominance of lymphocytes, whereas with bacterial pneumonias the WBC count is elevated with a predominance of neutrophils.

LABORATORY AND IMAGING STUDIES Blood cultures should be performed on hospitalized children to attempt to diagnose a bacterial cause of pneumonia. Blood cultures are positive in 10% to 20% of bacterial pneumonia and are considered to be confirmatory of the cause of pneumonia if positive for a recognized respiratory pathogen.

LABORATORY AND IMAGING STUDIES Viral respiratory pathogens can be diagnosed using polymerase chain reaction (PCR) or rapid viral antigen detection. CMV and enterovirus can be cultured from the nasopharynx, urine, or bronchoalveolar lavage fluid. M. pneumoniae can be confirmed by Mycoplasma PCR.

LABORATORY AND IMAGING STUDIES Frontal and lateral CXRs are required to localize disease and adequately visualize retrocardiac infiltrates. they are not necessary to confirm the diagnosis in well- appearing outpatients. Decubitus views or ultrasound should be used to assess size of pleural effusions and whether they are freely mobile. (CT) is used to evaluate serious disease, pleural abscesses, bronchiectasis, and effusion characteristics.

LABORATORY AND IMAGING STUDIES

DIFFERENTIAL DIAGNOSIS ① Allergic pneumonitis. ② Asthma. ③ Cystic fibrosis. ④ Pulmonary edema.

TREATMENT ① Supportive. ② Specific treatment and depends on the degree of illness, complications, and knowledge of the infectious agent likely causing the pneumonia. Most cases of pneumonia in healthy children can be managed on an outpatient basis.

Indications of Hospitalization : ① Hypoxemia. ② Inability to maintain adequate hydration. ③ Moderate to severe respiratory distress. ④ Infants under 6 months with suspected bacterial pneumonia. ⑤ Concern exists about a family’s ability to care for the child. TREATMENT

1.Parapneumonic effusion. 2. Empyema. 3. Pneumatocele. 4. Bronchiectasis. 5.Lung abscess. 6. Bronchiolitis obliterans(esp. with adenovirus). 7. Unilateral hyperlucent lung ( Swyer-James syndrome). COMPLICATIONS AND PROGNOSIS

Most children recover from pneumonia rapidly and completely, although radiographic abnormalities may take 6 to 8 weeks to return to normal.

PREVENTION Annual influenza vaccine is recommended for all children over 6 months of age. Universal childhood vaccination with conjugate vaccines for H. influenzae type b and S. pneumoniae has greatly diminished the incidence of these pneumonias.

ASPIRATION PNEUMONIA Aspiration of material that is foreign to the lower airway produces a varied clinical spectrum ranging from an asymptomatic condition to acute life- threatening events. Clinical Findings : 1.Fever. 2.Cough. 3.Respiratory distress. 4.Hypoxemia.

Right side especially the right upper lobe in the supine patient is commonly affected. ASPIRATION PNEUMONIA

RISK FACTORS

TREATMENT Supportive treatment is the only recommended therapy. Antimicrobial therapy for patients who are acutely ill from aspiration pneumonia includes coverage for gram-negative anaerobic organisms. Clindamycin is appropriate initial coverage.

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