Acinetobacter peritonitis during chronic peritoneal dialysis

Among gram-negative bacilli isolated during peritonitis in chronic peritoneal dialysis (CPD), Pseudomonas species are most common but Acinetobacter species are nearly as frequent. A survey of more than 450 patient-years' experience with CPD revealed 23 episodes of Acinetobacter peritonitis (AP), making this the second most common form of gram-negative peritonitis. Concomitant break in sterile technique and exit-site/tunnel infection were infrequent. AP appeared as the first peritonitis episode in five cases and as the second in six cases, and the duration of CPD at the time of AP ranged from less than 1 to greater than 56 months. However, AP was noted to appear shortly after treatment of another peritonitis episode or shortly after CPD access placement, within 2 months in 11 cases (47%) and within 3 months in 14 cases (61%). Treatment with intraperitoneal antibiotics succeeded in 21 cases (91%) without CPD interruption or catheter removal, with tobramycin or gentamicin alone in 16 cases, and with combined aminoglycoside and penicillin or cephalosporin in six cases. In two cases intraperitoneal antibiotics alone were insufficient therapy: one case with concomitant tunnel infection and dialysate leak and one case with bacteremia while receiving corticosteroids. The time-dependent incidence of AP suggests opportunistic infection during a vulnerable period in the first 2 to 3 months following another peritonitis episode, but AP also appears amenable to intraperitoneal antibiotic therapy alone without interruption of the CPD routine in the majority of cases.