Peritoneal lavage as an aid to diagnosis of peritonitis in debilitated and elderly patients.

Twenty-seven debilitated or obtunded patients were subjected to peritoneal lavage to determine the presence or absence of peritonitis. Fourteen lavages were found to be positive, revealing peritonitis in 12 patients. Two of the 14 patients refused surgery and subsequently died. Thirteen patients had negative lavages, none of whom subsequently developed any evidence of peritonitis or required surgical intervention. Peritoneal lavage is an extremely reliable procedure, both in establishing the diagnosis of peritonitis or in ruling out its presence in debilitated or obtunded, elderly patients. The procedure can be performed quickly, without prolonged preparation, and without fear of complications. In addition, there is little cost to the procedure, especially when compared to the cost of more sophisticated time-consuming tests such as x-ray studies, gallium or CT-scanning.