[Prognostic lung abscess factors].

Background: Lung abscess, although curable when caught early and treated appropriately, still may recur repeatedly or require surgery. We retrospectively assessed prognostic lung abscess factors and predictive recurrence factors. We evaluated comorbidity using the Charson comorbidity index (CCI).

Methods: Subjects numbered 44 hospitalized for lung abscesses between June 2004 and May 2009 and classified as; elderly (over 65 years) or non-elderly and cured treatment failed.

Results: Mean age and the CCI of failed treatment were statistically higher than in cures at 80.8 years and 3.25 vs 64.1 years and 1.25 (p < 0.05). Abscess location, smoking habits, symptoms, white blood cell count and C-reactive protein did not differ on day 1. The causative organism, fistula presence at 65.6% vs 45.5% (p = 0.30) and lesion size at 59.8 mm vs 71.6 mm (p = 0.14) did not differ between groups, but the degree of lesion size reduction in treatment failures was lower than cures at 24.9% vs 69.1% (p < 0.05).

Conclusions: Lung abscess prognosis is thus adversely affected by age and comorbidity. In Japan, subjects having multiple comorbidities are expected to increase with aging. The degree of lesion size reduction appears to be a predictive factor in recurrence, underscoring the importance of follow-up in imaging, including chest computed tomography.