Is computerized tomography useful in identifying abdominal catastrophes in patients presenting with peritonitis?

Peritonitis is a significant source of morbidity and mortality in patients on peritoneal dialysis (PD). Symptoms may persist, requiring an emergency laparotomy. Although increasingly used, we find that, in PD patients, abdominal computerized tomography (CT) is ineffective in determining significant pathology. This study was undertaken to assess the diagnostic utility of CT for the identification of intra-abdominal collections in PD patients presenting with peritonitis.

A retrospective chart review was undertaken of all patients that underwent abdominal CT scanning in the context of severe PD peritonitis in the past 2 years. All of these patients had at least one CT scan preoperatively.

133 patients presented with PD peritonitis; 19 patients had a contrast CT procedure (12 females, 7 males). Average age was 59.2 years; mean duration on PD was 43.8 months. 13 of 19 patients had gram-negative bacillary peritonitis, 6 of whom had polymicrobial peritonitis; 4 patients had fungal peritonitis and 2 had Staphylococcus aureus peritonitis. 26 CT scans were done in 19 patients an average of 10 days after presentation. 21 of 26 scans revealed no collections of surgical interest. 12 laparotomies were performed, with an average delay of 10.4 days from presentation to laparotomy. Of the 12 laparotomies, 6 found a drainable collection not seen on CT. Seven of the 19 patients died (37%) and no patient was able to return to PD.

PD patients requiring emergency laparotomy following PD peritonitis have a high mortality rate. A negative abdominal CT in the setting of ongoing symptoms should not be taken as reassuring, nor should it delay proceeding to emergency laparotomy.