Lung abscess: the non-conservative management: a narrative review.

Background and Objective: Systemic antibiotics are the best treatment options for lung abscesses. However, up to 37% of lung abscesses do not respond to antibiotics and may require additional interventions. Percutaneous transthoracic tube drainage (PTTD), endoscopic catheter drainage (ECD) and surgical resection are additional options available when first line therapy with systemic antibiotics are unsuccessful. In this narrative review, we summarize all available interventional procedures, techniques, complications, safety, and contraindications. Methods: A literature search was performed using Medline/PubMed from January 1980 to October 2023. Key words: "lung abscess", "pulmonary abscess", "endoscopic drainage", "percutaneous drainage", "tube drainage". Pediatric patients were excluded from this study. Key Content and Findings: PTTD and ECD are fairly safe procedures. Performing PTTD or ECD without delay may shorten the duration of hospital stay. This may lower the burden on health care. Moreover, draining abscesses may relieve discomfort in the clinical symptoms associated with abscesses. The primary factor in choosing ECD over PTTD is the location of the abscess, and the presence of a bronchial airway leading to the abscess for successful ECD. ECD has lower rate of complications and mortality; and similar success rate compared to PTTD. While mortality has been reported with PTTD, ECD appears to be safer according to present data. Conclusions: PTTD and ECD are safe procedures, with low complication rates. ECD has a lower complication rate than PTTD does.

A case of squamous cell lung cancer presented as a cystic lesion and recurrent pneumothoraces.

We report a rare case of a 70-year-old male with recurrent pneumothoraces within one year treated with intermittent insertion of chest tube on each occasion. Diagnostic testing was notable for a cystic lesion in the left lung that was initially interpreted as bulla on chest x-ray and chest computed tomographic scan. Due to thickening and nodularity changes of the thin wall of the cystic lesion, the patient underwent left upper lobectomy. Pathology showed poorly differentiated squamous cell carcinoma of the cystic lesion wall. This case emphasizes the importance of monitoring pulmonary cystic lesions especially in patients with a history of smoking and emphysema.

Induction of cyclooxygenase-2 signaling by Stomatococcus mucilaginosus highlights the pathogenic potential of an oral commensal.

Stomatococcus mucilaginosus is an oral commensal that has been occasionally reported to cause severe infections in immunocompromised patients. There is no information about the pathogenic role of S. mucilaginosus in airway infections. In a cohort of 182 subjects with bronchiectasis, we found that 9% were colonized with S. mucilaginosus in their lower airways by culture growth from bronchoalveolar lavage. To address the pathogenic potential of S.mucilaginosus, we developed a murine model of S. mucilaginosus lung infection. Intratracheal injection of S. mucilaginosus in C57BL/6 mice resulted in a neutrophilic influx with production of proinflammatory cytokines, chemokines, and lipid mediators, mainly PGE2 with induction of cyclooxygenase-2 (COX-2) in the lungs. Presence of TLR2 was necessary for induction of COX-2 and production of PGE2 by S. mucilaginosus. TLR2-deficient mice showed an enhanced clearance of S. mucilaginosus compared with wild-type mice. Administration of PGE2 to TLR2(-/-) mice resulted in impaired clearance of S. mucilaginosus, suggesting a key role for COX-2-induced PGE2 production in immune response to S. mucilaginosus. Mechanistically, induction of COX-2 in macrophages was dependent on the p38-ERK/MAPK signaling pathway. Furthermore, mice treated with S. mucilaginosus and Pseudomonas aeruginosa showed an increased mortality compared with mice treated with PA103 or S. mucilaginosus alone. Inhibition of COX-2 significantly improved survival in mice infected with PA103 and S. mucilaginosus. These data provide novel insights into the bacteriology and personalized microbiome in patients with bronchiectasis and suggest a pathogenic role for S. mucilaginosus in patients with bronchiectasis.

Non-tuberculous mycobacterial disease is common in patients with non-cystic fibrosis bronchiectasis.

BACKGROUND: Non-tuberculous mycobacteria (NTM) are ubiquitous environmental organisms. Cystic fibrosis (CF) patients are susceptible to NTM, but data about NTM in patients with non-CF bronchiectasis are limited. METHODS: We conducted a retrospective, descriptive study at the University of Illinois Medical Center. All patients diagnosed with bronchiectasis (code 494) using the International Classification of Diseases, ninth revision (ICD-9), between 1999 and 2006, were identified. Clinical data including lung function, radiology studies, and presence of NTM in sputum were abstracted for those who met the study criteria. RESULTS: One hundred eighty-two patients were enrolled in the study. Patients were divided into two groups: bronchiectasis with NTM isolates (n = 68) and bronchiectasis without isolates (n =114), and compared for clinical characteristics and underlying diseases. Mycobacterium avium complex (MAC) was the most common isolate. Fifty-five patients (30%) met the American Thoracic Society criteria for diagnosis of NTM disease. Gram-negative rods were commonly co-isolated. The probability of NTM isolation was significantly higher in elderly female patients (p = 0.04). Moreover, the probability of NTM isolation was significantly higher in the female group with low body mass index (BMI) (p = 0.002). CONCLUSIONS: NTM infections are common in non-CF bronchiectasis. MAC is the most frequently isolated NTM in these patients. There is also great variability in age and sex characteristics for NTM in non-CF bronchiectasis patients. Female patients with a low BMI are a high risk group for NTM infection in non-CF bronchiectasis. Routine screening for NTM is strongly recommended in this patient population.