Peritoneal lavage is performed in the trauma setting to evaluate the extent of a patient's injury from blunt force trauma to the chest and abdomen. Sterile physiological saline is infused into the peritoneal cavity and then retrieved. The color and clarity of the extracted fluid provides information on the extent of internal injuries, if present. Bloody fluid indicates organ laceration and hemorrhage. Muddy brown fluid indicates a bowel perforation.
The image on this page is a Wright-stained smear from a peritoneal lavage specimen. The specimen was collected from a child who was in a motor vehicle accident. The child was not in a safety seat and her large intestine was ruptured when she hit the seat-back in front of her. The arrows indicate a variety of intra- and extracellular bacteria, and possibly small yeast forms. These organisms represent the normal intracolonic flora, which seeded the peritoneal cavity when her bowel ruptured.