Identification of peritoneal dialysis catheter tunnel infection by scanning with Indium-111-labeled leukocytes

Diagnosis, Prevention and Treatment of Peritonitis

Recent reports related to the diagnosis, prevention and treatment of peritonitis in patients on chronic peritoneal dialysis are reviewed. The reports deal with modifications of earlier drug therapies, the use of ultraviolet light, the use of the inline filter, and the biocompatibility of antibiotics in dialysis solutions.

[Diagnosis of the infectious complications of continuous ambulatory peritoneal dialysis by 99mTc-HMPAO labelled leukocytes]

OBJECTIVE

To assess the utility of abdominal scintigraphy with 99mTc-HMPAO labelled leukocytes in the diagnosis of infectious complications of continuous ambulatory peritoneal dialysis (CAPD).

MATERIAL AND METHODS

17 patients in CAPD were evaluated (35 studies). They were divided into three groups: group control in asymptomathic patients (5), group of studies in patients with suspicion of exit site infection/catheter tunnel (18) and group of studies in patients with clinical suspicion of peritonitis (12). All patients underwent abdominal scintigraphy with 99mTc-HMPAO labelled leukocytes. The results were compared to final clinical diagnosis, assessing the exit site or dialysis liquid external aspect, material or exit site secretion culture and clinical follow up.

RESULTS

In the case studied, we obtained high sensitivity and specificity values for the exit site infection diagnosis (83 % and 75 % respectively), and a sensitivity of 100 % in the diagnosis of peritonitis as well. We detected a case of catheter tunnel infection confirmed by culture. No pathological uptake was observed in any control case.

CONCLUSIONS

Abdominal scintigraphy with 99mTc-HMPAO labelled leukocytes allows the early diagnosis of infectious complications of CAPD, and the control of treatment response, avoiding its unnecessary prolongation.

Infections in patients undergoing peritoneal dialysis

Considering experience acquired in the past years, it seems as though physicians have reached a plateau in the frequency of peritonitis. A peritonitis rate of 1 every 2 patient years may be acceptable. Further reduction of this peritonitis rate will require inordinately large efforts on all fronts. One will have to consider what are the acceptable costs and risks of peritonitis in patients on peritoneal dialysis. New developments in catheter technology, improved connections, better understanding of patient selection and training programs, improved diagnostic and therapeutic methods in the management of peritonitis, and understanding of the infectious and immune processes are eagerly awaited developments.

The use of intracatheter instillation of streptokinase in the treatment of recurrent bacterial peritonitis in continuous ambulatory peritoneal dialysis

Recurrent bacterial peritonitis resistant to therapy with antibiotics is seen in a small percentage of patients maintained on continuous ambulatory peritoneal dialysis. In these patients, removal of the Tenckhoff catheter is necessary to achieve a cure. Sequestration of bacteria within fibrin clots located on the catheter has been postulated to contribute to this resistance to standard therapy. We, therefore, examined the efficacy of intraperitoneal streptokinase in combination with antibiotic therapy in the treatment of two patients with recurrent bacterial peritonitis. After addition of streptokinase to the therapeutic regimen, no further episodes of peritonitis were observed after 6 to 8 weeks follow-up. These data suggest that intraperitoneal streptokinase may be useful as adjunctive therapy in the treatment of recurrent bacterial peritonitis.

The value of indium-labelled leucocytes in clinical practice

Following intravenous injection, autologous 111In labelled-leucocytes migrate to sites of inflammation, where they can be imaged with the gamma camera. The principle underlining the labelling technique is exposure of a population of leucocytes or purified granulocytes to a lipophilic 111In complex, such as 111In oxine or 111In tropolonate. As a result of cell activation, the in vitro manipulation to which the leucocytes are subjected modifies their biodistribution early after re-injection. Separation and labelling in plasma-enriched media, however, limits this activation and promotes early migration into inflammatory foci.