Aspiration pneumonia: a review.

The damage caused by aspiration depends on the volume, nature and pH of the aspirate and the type of pathogen involved. Aspirate with a pH below 2.5 is much more likely to be toxic than less acidic material. Anaerobic organisms are common pathogens, but aerobic bacteria frequently appear in the hospital setting. Steroids may be useful if administered within minutes of the aspiration. Lavage with large amounts of alkaline fluid has not proved helpful.