Peritoneal drainage: an important element in host defence against staphylococcal peritonitis in patients on CAPD

Abstract

The growth of Staphylococcus aureus and coagulase-negative staphylococci were studied in fresh and effluent peritoneal dialysate from patients on continuous ambulatory peritoneal dialysis (CAPD). Peritoneal drainage during CAPD removes bacterial contaminants from the peritoneal cavity with an efficiency that depends upon the volume of peritoneal fluid remaining after drainage (residual volume). Combination of our data on the growth of coagulase-negative staphylococci in dialysate with a mathematical model of peritoneal drainage during CAPD shows that a residual volume of less than 800 ml (normal = approximately 400 ml) will prevent survival in the peritoneal fluid. A residual volume of less than 200 ml is required to eliminate S. aureus because of its faster rate of growth in dialysate. Previous work has shown that numbers of macrophages are too few to influence bacterial growth in the peritoneal dialysate. Coagulase-negative staphylococci adhere poorly to mesothelial cells in culture. Survival within the peritoneal cavity during CAPD probably depends on colonization of the PD catheter. Coagulase-negative staphylococcal peritonitis is likely to be localized to areas of the peritoneal membrane in close contact with the PD catheter. S. aureus is able to multiply in the peritoneal dialysate during CAPD and thereby causes generalized peritonitis.

Research Directions in Peritoneal Dialysis Infections

“…Recurrent peritonitis can sometimes be effectively man aged by temporary cessation of peritoneal di alysis, thus improving peritoneal immune ca pacity [49,50], This approach was more suc cessful with S. epidermidis than with A. au reus. These clinical results are consistent with an in vitro model in which a residual dialysate volume of <800 ml was shown to prevent sur vival of S. epidermidis in dialysate while <200 ml was required for S. aureus [51], Since the usual peritoneal residual is about 400 ml, this explains why S. epidermidis peri tonitis, unlikeS. aureus, will respond to cessa tion of peritoneal dialysis.…”

Dynamic Analysis of Peritoneal Dialysis Associated Peritonitis

“…[11][12][13][14][15][16] PDAP is unique in that phasic washing out of the infected space arises from the mechanics of the technique itself (dialysis exchanges): with each exchange, a relatively large fraction of the free intraperitoneal fluid is drained, removing with it the contained bacteria. As previously noted by Cameron et al, 17 this effect might augment clearance of intraperitoneal bacteria. Mechanical washout might decrease the intraperitoneal bacterial burden despite the potential for microbial growth during the dwell period, as illustrated in Figure 1.…”

Serial cytokine changes in peritoneal effluent and plasma during peritonitis in patients on continuous ambulatory peritoneal dialysis (CAPD)

“…The disturbance of the local defense mechanism of the peritoneal cavity may play a key role in the pathogenesis of this phenomenon. Changes in the peritoneal cavity conditions resulting from the increased volume of the peritoneal fluid after the administration of dialysis fluid, inhibit such basic defence mechanisms as diaphragmatic lymphatic uptake [1], opsonization of micro-organisms [2,3], phagocytosis and killing by peritoneal macrophages [3,4] and polymorphonuclear cells. They also influence the peritoneal cell composition and activation [5,6].…”