Utility of Abdominal Imaging in Peritoneal Dialysis Patients Presenting With Peritonitis

Abstract

Background: Peritonitis remains a major complication in peritoneal dialysis (PD). Abdominal imaging is often performed in the setting of peritonitis to evaluate for concomitant intra-abdominal processes. However, the usefulness of this procedure is unknown. Objective: The aim of this study was to assess the prevalence of abdominal imaging performed in the setting of PD peritonitis and to evaluate clinical parameters associated with abnormal imaging results to identify clinical situations in which radiographic examinations are informative. Design: This is a retrospective cohort study. Setting: The study was conducted at the Toronto General Hospital, Ontario, Canada. Patients: We studied 166 episodes of PD peritonitis in 114 patients between January 1, 2011, and June 30, 2016. Measurements: Baseline demographics, characteristics of PD peritonitis, and characteristics of abdominal imaging performed. Methods: The association between relevant clinical parameters and abnormal abdominal imaging was examined using a univariate and multivariate logistic regression model. Results: Abdominal imaging (computed tomography [CT] scan or ultrasound) was performed in 68 cases (41%). Patients were more likely to undergo imaging if they required hospitalization, were admitted to the intensive care unit (ICU), had polymicrobial or fungal organisms causing peritonitis, had relapsing/recurrent/refractory peritonitis, had an indication for hemodialysis or PD catheter removal, or presented with hypotension, tachycardia, or an elevated serum lactate. Of the imaging performed, abnormalities were found in 32 cases (47%). The most common findings were bowel obstruction, intra-abdominal collection, and biliary abnormalities. In the univariate analysis, ICU admission (43.3% vs 14.3%, P < .01) and need for temporary or permanent hemodialysis (62.5% vs 30.6%, P < .01) were associated with imaging abnormalities. Importantly, the peritonitis organism was not associated with abnormal imaging results. In a multivariate analysis, ICU admission was the only significant clinical parameter associated with imaging abnormalities with an odds ratio (OR) of 4.4 (95% confidence interval [CI]: 1.1-17.4, P = .04). Limitations: Single-center study, small sample size, and lack of detailed information on the exact indications leading to abdominal imaging. Conclusions: Abdominal imaging is commonly performed in the setting of PD peritonitis. Abnormalities are not infrequent and are present in almost half of the cases, with need for ICU admission being the most significant clinical parameter associated with abnormal findings. Therefore, abdominal imaging should be performed in carefully selected patients with PD peritonitis, especially if there is evidence of hemodynamic instability. While the finding of fungal or polymicrobial peritonitis was a driver for abdominal imaging, the presence of these organisms did not predict radiologic abnormalities.