Successful use of sodium hypochlorite pack plus systemic and local antibiotic therapy for the treatment of pseudomonas infection of peritoneal dialysis catheter exit-site.

Peritoneal catheter exit-site and tunnel infections remain critical problems in patients undergoing peritoneal dialysis. Catheter-related peritonitis occurs in about 20% of patients and exit-site infections are responsible for catheter removal in more than one-fifth of the cases. For the last 2 years in the Department of Nephrology, San Bortolo Hospital, Vicenza, Italy, we have been treating exit-site infections caused by Pseudomonas with sodium hypochlorite packs as well as systemic and local antibiotic therapy. Considering the encouraging results obtained on Pseudomonas infection, we decided to utilize the same schedule for the treatment of exit-site infections caused by other germs which are generally difficult to eradicate to prevent peritonitis and catheter removal. Between 2003 and 2004, 10 patients contracted infection of the exit-site. All patients underwent a swab test because of the reddening and the purulent secretion of the exit-site. The swab resulted positive for Pseudomonas in 7 patients, Corynebacterium sp. in 2 patients, and Candida albicans in 1 patient. All patients were treated with systemic antibiotic therapy or antifungal therapy, local sodium hypochlorite 50% packs. After 15 days all patients were submitted to a swab test of the exit site. In all patients, the swab test resulted negative after 15 days and 1 month, and they could continue peritoneal dialysis. This procedure avoided peritoneal catheter removal and temporary switch to hemodialysis in all patients with exit site infection. The mechanism of action is related to the wide antimicrobial spectrum and the rapid action of sodium hypochlorite possibly creating a protective barrier on the exit-site.

Acid-base balance in peritoneal dialysis.

In patients without functioning kidneys, alkali replenishment is accomplished by the addition, via dialysis solution, of either HCO 3 - itself or a metabolic precursor of this anion, such as lactate. The body base balance in peritoneal dialysis (PD) patients is self-regulated by the feedback between plasma bicarbonate concentration and dialytic base gain. Dialytic base gain is the only source of buffer for PD patients and this gain should counteract the metabolic acid production. Dialytic base gain depends on peritoneal buffer fluxes (lactate reabsorption minus bicarbonate lost). The plasma bicarbonate level is determined by the dialytic base gain and the metabolic acid production. Bicarbonate buffered PD solution provides some advantages over the conventional lactate buffered PD solution.

The ''Ronco'' catheter for continuous flow peritoneal dialysis.

To perform CFPD, a two way access must be available in order to allow continuous inflow and outflow of the solution. This is most likely achieved with a double lumen peritoneal catheter. To design a double lumen catheter does not necessarily mean to increase the size of the tube or to increase the discomfort of the patient. However, the real challenge is to find a design in which minimal re-circulation is experienced. The two tips of the catheter must be positioned such that a maximal exposure of the peritoneal surface to the fluid is guaranteed during one single passage of the fluid from one lumen to another. Double lumen catheters with one short branch and another long of straight and of spiral shape were originally designed. Ash and coworkers have designed a catheter with a t-shape configuration in order to distantiate to the maximum the tips of the two lumens. Recently we have designed a novel catheter for CFPD equipped with a thin walled silicone diffuser used to gently diffuse the inflow dialysate into the peritoneum. The holes on the round tapered diffuser are positioned to allow dialysate to perpendicularly exit 360 degrees from the diffuser. The diffuser design and hole locations disperse the high-flow dialysate fluid at 360 degrees, reducing trauma to the peritoneal walls and allowing the dialysate to mix into the peritoneum. The dispersed fluid infused into the peritoneal cavity is then drained through the second lumen whose tip is placed into the lower Douglas cavity. The new catheter with diffuser is also equipped with a special removable hub that allows for easy creation of the subcutaneous tunnel without increasing the size of the skin exit site. The results so far achieved seems to offer advantages in terms of high flows, minimal pressure regimes and negligible recirculation.

The Vicenza ''Short'' peritoneal catheter: a twenty year experience.

Dislocation of peritoneal dialysis catheters is one of the major causes of technique failure. We evaluated 701 Vicenza catheters, implanted since 1985 in 365 males, mean age 53 +/- 16 yrs, range 24 - 87, and 336 females, mean age 51 +/- 17 yrs, range 21 - 82. The Vicenza catheter is defined "short" since it consists of a classic straight double cuff PD catheter having however an inner segment (the portion located in the peritoneal cavity) much shorter than any other type of catheter. It is implanted in the lower abdomen, just a few centimeters above the pubis. The analysis of our results obtained in a large PD population displayed good device survival at 2 and 5 years (94.3% and 91.5% respectively), a low dislocation rate (4%) and an exit-site infection rate similar to other double cuffed catheters. There was no selection of patients receiving this catheter since from 1985 we have used this catheter in every incident patient. Due to its lower implantation site this catheter demonstrates excellent wearability and good body image acceptance.

Cannulation of the internal jugular vein: comparison of the classic Seldinger technique and an ultrasound guided method.

Central venous catheterization allows immediate and easy vascular access for hemodialysis. Accidental arterial puncture is the most frequent complication of central vein cannulation and may occur in up to 8% of cases with the classic Seldinger procedure. We compared the Seldinger technique which implies manual localization of the vascular access, and an ultrasound guided technique, to assess whether the latter is an improvement on the Seldinger procedure.

Phospholipid hydroperoxide glutathione peroxidase in the normal human kidney: a possible role in protecting cell membranes.

Reactive oxygen species have been implicated in the pathogenesis of tissue injury. It is generally accepted that selenium-glutathione peroxidases form an integrated system defending the living organism against oxidative damage. Phospholipid hydroperoxide glutathione peroxidase (PHGPX) is thought to play a prominent role in preventing lipid peroxidation. Indeed, the function of PHGPX is to reduce the lipophilic substrates in membranes. In the present study, we evaluated the expression of PHGPX in normal human kidney by immunohistochemistry. The enzyme in glomeruli is mainly expressed in podocytes and parietal epithelial cells. In addition, PHGPX antigen was detected in tubule epithelial cells. Therefore, these results suggest that renal epithelial cells possess an important antioxidizing activity related to the presence of PHGPX.