At an isolated weather station in the central United States, a technician emerges from a small brick shed grasping a balloon. It's not just any birthday party balloon, mind you, but a massive, white sphere more than 5 feet (1.5 meters) in diameter.
Most frequently, the lung abscess arises as a complication of aspiration pneumonia caused by mouth anaerobes. The patients who develop lung abscess are predisposed to aspiration and commonly have periodontal disease.
With the now commonplace use of low tidal volumes one would expect more micro-atelectasis and it seems reasonable that higher PEEP might be needed to mitigate that tendency. Archive 2008-02-01 Obstructive foreign bodies cause atelectasis, drowned lung, and eventually pulmonary abscess.