This study evaluates the prognostic role of the change of arborescent air bronchogram, a typical ultrasonographic finding of lung consolidation due to pneumonia, in the management of pediatric CAP.

This is a single-center prospective study to evaluate the prognostic role of the change of arborescent air bronchogram, a typical ultrasonographic finding of lung consolidation due to pneumonia, in the management of CAP in terms of: 1) impact on rate of uncomplicated respiratory infections [rate of uncomplicated CAP], 2) relationship to the time of resolution of clinical signs [time to resolution of fever], 3) change of antibiotic therapy not guided by microbiological examinations and, 4) length of hospitalization.

At admission, the Pediatric will evaluate clinical signs of respiratory distress, request microbiologic tests (nasopharyngeal swab specimens and pneumococcal urinary antigen) to detect causative pathogens of CAP, and laboratory tests (complete blood cell count, acute-phase reactants C-reactive protein). Finally, all children will undergo chest radiography (CXR). If CXR should be performed before the admission to Pediatric Unit, the radiological exam will be not repeated.

Ultrasonographic evaluation will be performed by Pulmonologists. The first examination will be performed within 12 hours from admission. The Pulmonologists will be blind to clinical and radiological data.

In order to characterize the lung consolidation, a grading system based on the presence and the features of air bronchogram [static, dynamic, dynamic with areas of lung recruitment] will be adopted. The operator will collect and store images and videos (10seconds), these findings will be reviewed by an expert Clinician in chest US blind to other data.

After 48h from the admission, all children will undergo follow-up laboratory tests and lung US.

In case of clinical deterioration, children will undergo further ultrasonographic evaluations according pediatric indications.

Finally, all children will undergo lung US after 7 ± 2 days from discharge.

Inclusion Criteria:

• Suspected CAP
• Age from 1 to 16 years old
• Admission to Pediatric Unit
• Radiographic evidence of lung consolidation
• Written informed consent from parents

Exclusion Criteria:

• Gestational age < 36 weeks
• Previous diagnosis of cystic fibrosis
• Congenital pulmonary disease.
• Refusal to participate.

Patients with a clinical diagnosis of CAP and radiographic evidence of lung consolidation.