Clinical characteristics and outcomes of "silent" and "non-silent" peritonitis in patients on peritoneal dialysis.

OBJECTIVES: We compared the clinical characteristics and outcomes of "silent" peritonitis (meaning episodes without fever and abdominal pain) and "non-silent" peritonitis in patients on peritoneal dialysis (PD).
METHODS: Our cohort study collected data about all peritonitis episodes occurring between January 2008 and April 2010. Disease severity score, demographics, and biochemistry and nutrition data were recorded at baseline. Effluent cell counts were examined at regular intervals, and the organisms cultured were examined. Treatment failure was defined as peritonitis-associated death or transfer to hemodialysis.
RESULTS: Of 248 episodes of peritonitis occurring in 161 PD patients, 20.9% led to treatment failure. Of the 248 episodes, 51 (20.6%) were not accompanied by fever and abdominal pain. Patients with these silent peritonitis episodes tended to be older (p = 0.003). The baseline values for body mass index, triglycerides, and daily energy intake were significantly lower before silent peritonitis episodes than before non-silent episodes (p = 0.01, 0.003, and 0.001 respectively). Although silent peritonitis episodes were more often culture-negative and less often caused by gram-negative organisms, and although they presented with low effluent white cell counts on days 1 and 3, the risk for treatment failure in those episodes was not lower (adjusted odds ratio: 1.33; 95% confidence interval: 0.75 to 2.36; p = 0.33).
CONCLUSIONS: Silent peritonitis is not a rare phenomenon, especially in older patients on PD. Although these episodes were more often culture-negative, silent presentation was not associated with a better outcome.