Factors associated with gravity-dependent distribution on chest CT in elderly patients with community-acquired pneumonia: a retrospective observational study

Abstract

Although lung involvement in aspiration pneumonia typically has a gravity-dependent distribution on chest images, which patient’s conditions contribute to its radiological pattern has not been fully elucidated. This study was designed to determine the factors associated with the gravity-dependent distribution of community-acquired pneumonia (CAP) on chest computed tomography (CT). This retrospective study included elderly patients aged ≥ 65 years with CAP who underwent chest CT within 1 week before or after admission. The factors associated with lower lobe- and posterior-predominant distributions of ground glass opacity or airspace consolidation were determined. Of the 369 patients with CAP, 348 (94%) underwent chest CT. Multivariate analyses showed that impaired consciousness, a low Barthel index of activities of daily living, and high hemoglobin levels were associated with lower lobe-predominant distribution, while male sex and impaired consciousness were associated with posterior-predominant distribution. Cerebrovascular diseases were unrelated to these distributions. While male sex, impaired consciousness, high hemoglobin levels, low albumin levels, and the number of involved lobes were associated with in-hospital mortality, gravity-dependent distributions were not. Impaired consciousness might be the most significant predictor of aspiration pneumonia; however, the gravity-dependent distribution of this disease is unlikely to affect disease prognosis.

Aetiological agents of adult community-acquired pneumonia in Japan: systematic review and meta-analysis of published data

“…As shown in figure 1, a search was conducted based on the PRISMA recommendations, and 56 eligible papers were extracted during the study period 17–72. Forty-eight papers were in English and eight were in Japanese.…”

“…Forty-six studies17–25 28 30 31 33 34 39 40 42–54 56 57 59–72 included a total of 13 940 patients hospitalised with CAP. A meta-analysis of these studies is shown in figure 3.…”

“…PRGNB accounted for 7.1% (95% CI 5.9% to 8.3%) of all cases. When only articles that described MRSA and/or methicillin-susceptible S. aureus separately were selected, MRSA was accounted for 40.7% of cases (95% CI 29.0% to 52.4%) in 30 studies,17 30 31 33 34 36 39 40 42 44–47 51 52 54 55 57 60–63 65–68 70 72 with S. aureus as the causative pathogen in 427 cases (online supplemental figure).…”

“…In addition, to focus on the study period, 8 studies17–22 25 29 up to the year 2000 and 13 studies24 52 53 60 62–64 66–72 after 2010 were selected to compare the frequency of detection of S. pneumoniae and PRGNB. Although there was no change in S. pneumoniae , the frequency of PRGNB isolation increased from 6.3% (95% CI 2.9% to 9.7%) to 10.5% (95% CI 6.5% to 14.4%) (figure 5, online supplemental figure).…”

The clinical significance of anaerobic coverage in the antibiotic treatment of aspiration pneumonia: a systematic review and meta-analysis

“…Not all risk factors for aspiration are uniformly associated with aspiration pneumonia; rather, the degree to which they cause the disease is thought to vary. For example, in a recent study, of the common risk factors for aspiration pneumonia, impaired consciousness was the most closely associated with chest images suggestive of aspiration pneumonia [38]. Labelling patients with CAP/NHCAP with any risk factor of aspiration as 'aspiration pneumonia' may result in the concept of the disease being too broad.…”