Clinical characteristics of apical segment lung abscess: a 10-year retrospective study

Lung abscess in the apical segment of the lung is not rare and is often underestimated in clinical practice. However, the clinical features of apical segment lung abscess (AL) have scarcely been reported. Hence, this study aimed to determine the clinical characteristics of AL and explore moderate therapeutic strategies.

This was a retrospective, single-center cohort study. We reviewed the medical records of consecutive patients who were admitted to Shanghai Pulmonary Hospital in Shanghai, China, from January 2009 to December 2018. This study collected information on patients with lung abscess, including demographics, symptoms, clinical findings, and treatment. The statistical methods used were descriptive statistics, Chi-squared test, Fisher's exact test, t-tests, and logistic regression analysis.

Of 824 patients, 431 with lung abscess were finally eligible after a review of medical records. The patients were divided into two groups: the AL group (n=68) and the non-apical segment lung abscess (NAL) group (n=363). Compared with patients in the NAL group, those in the AL group had lower rates of chronic obstructive pulmonary disease (COPD) (5.9% vs. 17.4%, P=0.02), diabetes (14.7% vs. 32.2%, P=0.004) and hypoprealbuminemia (10.3% vs. 25.3%, P=0.007). Regarding clinical symptoms, patients in the AL group exhibited lower fever (38.2% vs. 58.4%, P=0.002) and less purulent sputum (32.4% vs. 45.5%, P=0.045). Moreover, regarding radiological features, the AL group had a lower proportion of air-fluid level on chest computed tomography (CT) (7.4% vs. 16.8%, P=0.047). In addition, the study demonstrated that the AL group had a shorter duration of intravenous antibiotic treatment [8 (7-8) vs. 10 (8-12) days, P <0.001]. Surprisingly, the AL group had a high rate of surgical treatment (36.8% vs. 15.4%, P<0.001). In multivariate analysis, surgical treatment occurred more frequently in patients with AL [odds ratio (OR): 2.58, 95% confidence interval (CI): 1.40-4.77, P=0.002], lower in patients who had fever (OR: 0.55, 95% CI: 0.31-0.98, P=0.04), and imaging features of liquefaction necrosis (OR: 0.32, 95% CI: 0.15-0.69, P=0.004).

Patients with AL presented with atypical and relatively mild clinical symptoms. However, the rate of surgical treatment was significantly higher. These data should be considered when managing the AL.