INTRODUCTION:
The incidence of community-acquired pneumonia (CAP) is gradually decreasing due to appropriate antibiotic therapy, vaccination, and improvements in community health services1. CAP is one of the most important causes of morbidity and mortality particularly in children aged below 5 years2. The hospitalization rate of children with CAP is between 9.5% and 42%, and the average hospitalization duration is 9 days3. In 10% of hospitalized patients, CAP is accompanied by simple parapneumonic effusion (PPE) (≤10 mm, without fibrous septation4,5. Regardless of the need for hospitalization, CAPs are associated with complicated community-acquired pneumonia (CCAP) with local complications, such as PPE, empyema (EMP), necrotizing pneumonia (NP), lung abscess (LA), and bronchopleural fistula (BPF)4 In approximately 7% of patients, CAP progresses to NP, characterized by consolidation and parenchymal necrosis6. Then, NP may rapidly worsen to cavitation (pneumatocele) with peripheral and single lobe involvement and BPF when the pleural space is affected; therefore, patients should be closely monitored for complications7.
CCAP causes include immune deficiencies, malnutrition, congenital cystic lung malformations, and foreign body aspiration (FBA). However, it is also observed in previously healthy children8. CCAP risk factors include prolonged fever before hospitalization; antipyretic, acetaminophen, and ibuprofen use; age <2 years; asymmetric chest pain during the initial admission; high acute phase reactant levels; leukopenia; and iron deficiency anemia9-11.
CAP and CCAP patients present with consolidation, atelectasis, cavitation, and effusion are observed on chest radiography (CXR). Hence, imaging can provide important information. However, consolidation may not be clearly observed on CXR during the early stages of NP7,. Nevertheless, thoracic USG is performed to assess low-volume effusions that are overlooked on CXR. Therefore, it can be used as a guide during thoracentesis and GT insertion12. Thoracic computed tomography (CT) scan is conducted to obtain differential diagnosis including tumor and congenital airway malformations and to facilitate surgical planning for large pneumatoceles that are unresponsive to treatment,13. In addition, by appropriately identifying CT, LA, and NP, the duration, content and treatment type can be modified13.
BPF should be considered in NP patients who had persistent (>24 h) air leakage during follow-up14,15. LA is characterized by subfebrile fever and chest pain. Further, it has a less noisy clinic than NP and may cause pneumothorax similar to NP and BPF. However, mediastinal shift is rarely observed. NP and/or LA patients subsequently experience clinical and radiological improvements. In addition, surgical intervention is commonly required due to complications such as pneumothorax, BPF, and pneumatocele14-16.
With appropriate antibiotic therapy and supportive treatments, simple pleural effusion can improve in CAPs patients15 Due to local and systemic complications and surgical interventions (mainly NP and LA), CCAP patients require long-term antibiotic treatment15,17. NPs and LAs are managed with similar antibiotic protocols; however, as the healing process in LA is slow, it requires longer antibiotic treatment18.
Chest tube drainage is the primary approach for symptomatic patients, even in those with small pleural effusion and loculations18,19. If adequate pleural fluid drainage cannot be achieved with GT in septal pleural effusion and EMP patients, the hospitalization duration is shortened using fibrinolytics20. Video-assisted thoracic surgery (VATS) can be performed when adequate drainage cannot be achieved with CDF21. Since there is a BPF risk during CDF, particularly when accompanied by NP and LA, treatment should be discontinued immediately22. VATS in the early period is associated with a lower BPF risk in NPs with EMP and septal pleural effusion23,24. Aspiration and drainage can be applied if there is no clinical improvement with antibiotic therapy and if complications including mediastinal shift develop in LA patients. The risk of fistulation into the pleural space after drainage is lower than that of NPs24. However, advanced surgical intervention should be considered in large pneumatoceles that do not respond to conservative treatment for severe BPF6,25,26.
The current study aimed to examine the CCAP progression risk factors by assessing the clinical and laboratory characteristics of children with CAP and the treatment strategies used for managing complications in patients who are unresponsive to treatment.