Specific characteristics of peritoneal leucocyte populations during sterile peritonitis associated with icodextrin CAPD fluids.

BACKGROUND: Icodextrin dialysate used for peritoneal dialysis contains an iso-molar glucose polymer solution, which provides sustained ultrafiltration over long dwell times and is considered a valuable approach to reduce intraperitoneal glucose exposure. However, several side effects have been described, including abdominal pain and allergic and hypersensitivity reactions. Also, reactions compatible with chemical peritonitis have been reported. Over the period of a few months (January 2002-May 2002), a remarkable increase in the number of continuous ambulatory peritoneal dialysis (CAPD) patients using icodextrin dialysate diagnosed with sterile peritonitis was observed in our unit. METHODS: Five of the CAPD patients using icodextrin dialysate in our unit and diagnosed with sterile peritonitis were screened for leucocyte count and leucocyte differentiation during a follow-up period of 77 +/- 23 days. In addition, expression of CD14, a receptor for lipopolysaccharide (LPS), on the peripheral and peritoneal monocyte population was analysed. These results were compared to CAPD patients suffering from bacterial peritonitis. RESULTS: The peritoneal leucocyte count of CAPD patients using icodextrin dialysate and diagnosed with sterile peritonitis did not decrease significantly before treatment with icodextrin dialysate was interrupted, whereas it currently disappeared within 2-4 days in proven bacterial peritonitis. The sterile, cloudy icodextrin effluent contained an excess of macrophages on the day of diagnosis, whereas in bacterial peritonitis essentially an increase in the granulocyte population was observed. No elevation in the eosinophil population was observed. In contrast to bacterial peritonitis, we observed no increase in CD14 expression on the peripheral and peritoneal macrophages on the day of presentation and during the follow-up period. CONCLUSIONS: Specific batches of the icodextrin CAPD fluids contain a macrophage chemotactic agent, which causes a sustained inflammatory state in the peritoneal cavity. Because no increase in the expression of the LPS receptor CD14 could be observed, the increased peritoneal leucocyte count is probably not caused by LPS or LPS-like (possibly peptidoglycan-like) contamination.     

The impact of relapsing sterile icodextrin-associated peritonitis on peritoneal dialysis outcome

BACKGROUND: The emphasis in peritoneal dialysis (PD) has shifted from a therapy with short-term goals to one of prolonging the life of the peritoneal membrane. Icodextrin (ICO), a starch-derived glucose polymer that is metabolized to maltose, is a valuable osmotic agent in the treatment of PD patients with defective ultrafiltration. However, ICO can cause sterile peritonitis. The manufacturer has recently withdrawn a series of batches of ICO solutions due to evidence of bacterial contamination (a bacterial cell wall breakdown, peptidoglycan). Some cases have been reported of culture-negative ICO-associated peritonitis which relapse on re-challenge. METHODS: We started to use ICO in chronic uremic PD patients in 1997. Ten patients out of 82 treated in our PD unit were exposed to ICO from 1997-2002. We registered 50 peritonitis episodes in this period: 34 were bacterial and 16 culture-negative. Among the 16 episodes of sterile peritonitis, 6 occurred in patients treated with ICO. Four of the 6 ICO treated patients experienced relapsing culture-negative episodes of peritonitis. We reviewed the records of the four patients. RESULTS: The first episodes of sterile ICO-associated peritonitis occurred between February-May 2002. These were clinically very mild and the only sign was abdominal discomfort and a cloudy dialysate containing a number of WBC/mm(3) ranging from 500-800. Cultures were negative. All the ICO solutions were from the batches withdrawn by the manufacturer. ICO (with new batches of solution) was re-introduced in all patients some weeks later to improve ultrafiltration. A new episode of sterile peritonitis occurred with the same characteristics as described above. Three of the four patients were re-challenged with new batches of ICO solution and again sterile peritonitis occurred. One patient was switched directly to hemodialysis (HD); the others were transferred to a program of automated PD including hypertonic glucose solutions. In 8 months all patients were switched to HD because of the failure of ultra-filtration. It is possible that the first episode of sterile peritonitis, associated with the use of an ICO batch suspected of having high peptidoglycan levels could have induced sensitization to ICO, which in turn could have been the cause of the relapse on re-challenge. CONCLUSIONS: The disappointing result of the relapsing culture-negative ICO-associated peritonitis in our patients was the unavoidable switch to HD, due to the inability of the hypertonic glucose solutions to ensure an adequate ultrafiltration. The moral of the story is that the pharmaceutical industry should market products that are more biocompatible and safer for chronic treatments such as PD.     

Use of pure bicarbonate-buffered peritoneal dialysis fluid reduces the incidence of CAPD peritonitis.

BACKGROUND: Advances in bag connection technology have reduced the incidence of peritonitis in CAPD patients but there is little information on the effect of the new peritoneal dialysis fluids. METHODS: We studied the incidence of CAPD peritonitis for about 3 years in 100 incident patients--50 patients dialysed with lactate-buffered solution, pH 5.5 and containing glucose degradation products (GDP) (lactate group), and 50 patients with pure bicarbonate-buffered solution, pH 7.4 and low GDP (bicarbonate group). Patients in both groups were similar in age, sex, length of time on CAPD, connection technology and handling of dialysis. RESULTS: In the lactate group, 74 episodes of peritonitis were recorded compared with 43 in the bicarbonate group, i.e. one episode per 21 patient-months with the lactate dialysis fluid and one episode per 36 patient-months with the bicarbonate dialysis fluid (OR 0.58, 95% CI 0.37-0.91, P = 0.017). A total of 3369 exchanges per episode of peritonitis were recorded for bicarbonate compared with 2004 exchanges per episode of peritonitis in the lactate group. The majority of organisms isolated in both groups were Gram-positive bacteria, with a predominance of the oropharyngeal and cutaneous endogenous flora. Three episodes of fungal peritonitis occurred in the lactate group and none in the bicarbonate group. CONCLUSIONS: Our results suggest that the pure bicarbonate-buffered peritoneal dialysis fluid appears to reduce the frequency of peritonitis in CAPD patients possibly in relation to greater biocompatibility and maintenance of peritoneal membrane structural integrity. Similar results can probably relate to all low-GDP solutions.     

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

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.     

Peritonitis, peritoneal inflammation and membrane permeability: a longitudinal study of dialysate and serum MCP-1 in stable patients on peritoneal dialysis

BACKGROUND: Increase in peritoneal membrane permeability (D/P) correlates with systemic and peritoneal markers of inflammation and neoangiogenesis. Monocyte chemoattractant protein-1 (MCP-1, CCL2) is a potent chemoattractant and activator of monocytes/macrophages. We measured the serum (sMCP-1) and dialysate MCP-1 (dMCP-1) concentrations of stable peritoneal dialysis (PD) patients and studied various factors affecting MCP-1 production. We also looked at the correlation of dMCP-1 concentrations with change in D/P over 12 months. METHODS: Forty-five stable prevalent and 6 new PD patients (22 CAPD, 29 APD) were studied. Median PD duration was 21 months (range 1-114). D/P was measured by standardized peritoneal equilibration test (PET). Patients with recent peritonitis within 3 months of the start of study were excluded. MCP-1 concentrations were measured in serum, overnight dialysate and post-PET dialysate, both at baseline and at 12 months by ELISA. RESULTS: On univariate analysis, post-PET dMCP-1 concentrations positively correlated with sMCP-1 (p=0.0002), duration of PD (p=0.02), dialysate volume (p=0.001), peritoneal creatinine clearance (p=0.0002) and D/P (p=0.001). There was a negative correlation with residual renal function (p=0.001). dMCP-1 concentrations were higher in patients with past peritonitis (p=0.001). On multivariate analysis, factors independently associated with dMCP-1 were sMCP-1 (p=0.003) and past peritonitis (p=0.001). Thirty patients completed this study, and D/P rose by > 0.1 in 20% patients. dMCP-1 concentrations were higher in baseline and 12-month samples in patients with change in D/P >0.1. CONCLUSIONS: We conclude that dMCP-1 concentrations are related to past peritonitis and serum MCP-1. It is difficult to interpret the relationship of dMCP-1 with change in D/P over time due to the small number of patients.     

Diabetes,Intraperitoneal Insulin,and CAPD

In patients on continuous ambulatory peritoneal dialysis (CAPD), hemoglobin A₁ was measured in order to assess the effect of the high content of glucose in the dialysate solution. In five diabetics on CAPD, insulin was added to the dialysate in an attempt to maintain continuous control of blood glucose throughout the day. Glycosylated hemoglobin was elevated in seven diabetics prior to the initiation of CAPD (12.0 ± 2.3%) as it was in six non-diabetics after several months on CAPD. (9.6 ± 0.90%). With the use of intraperitoneal insulin, satisfactory control of blood glucose could be achieved and the rate of peritonitis was not increased. However, regardless of whether blood glucose was well-controlled or not, hemoglobin A₁ as well as triglyceride values rose in diabetics on CAPD.     

Correlation between peritoneal mesothelial cell cytology and peritoneal histopathology with respect to prognosis in patients on continuous ambulatory peritoneal dialysis

BACKGROUND: Sclerosing encapsulating peritonitis (SEP) is a serious complication seen in patients on long-term continuous ambulatory peritoneal dialysis (CAPD). We have previously reported that mesothelial cells in effluent dialysate significantly increased in size as the duration of CAPD progressed. In this study, we investigated the relationship between mesothelial cytology, histopathology of the peritoneum, and clinical outcomes of 34 CAPD patients. METHODS: When peritoneal dialysis catheters were inserted (n = 7) or removed (n = 27), a peritoneal biopsy was performed and results compared with mesothelial cytology in effluent dialysate. RESULTS: A significant positive correlation was noted between the duration of CAPD and the surface area of peritoneal mesothelial cells (r = 0.721, p < 0.0001). The surface area of mesothelial cells in peritoneal sclerosis (n = 9; 584 +/- 97 microm(2)) was significantly greater than in peritoneal fibrosis (n = 14; 389 +/- 26 microm(2), p < 0.05), pathologic acute peritonitis (n = 3; 223 +/- 10 microm(2), p < 0.005), and normal peritoneum (n = 7; 247 +/- 12 microm(2), p < 0.001). The surface area in sclerosing peritonitis (n = 1; 1,200 microm(2)) was greater than that of all the others. Giant cells were found in the 1 case with sclerosing peritonitis and in 3 of 9 cases with peritoneal sclerosis, although they were found in only 1 of 14 patients with peritoneal fibrosis and in none of those with pathologic acute peritonitis or normal peritoneum. As the surface area of mesothelial cells increased to more than 400 microm(2) and giant cells appeared in the effluent, the frequency of peritoneal sclerosis and/or clinical SEP increased. CONCLUSION: An increase in the mesothelial cell surface area and the emergence of giant cells in the effluent indicate advanced peritoneal histopathology, and may be useful indicators to determine appropriate timing of discontinuation of CAPD to prevent the development of SEP.     

Growth factors in continuous ambulatory peritoneal dialysis effluent. Their relation with peritoneal transport of small solutes.

Recent studies reveal conflicting results on the change of solute transfer with time on continuous ambulatory peritoneal dialysis (CAPD) and recurrent peritonitis. Herein, we performed a cross-sectional study of 76 patients on CAPD to examine their peritoneal permeability by measuring the dialysate to serum ratio of creatinine (D/P) and the mass transfer area coefficients of creatinine (MTACCr) or glucose (MTACGlu). Transforming growth factor-beta1 (TGF-beta1), platelet-derived growth factor (PDGF), and epidermal growth factor (EGF) were measured in the dialysate by ELISA. TGF-beta1 mRNA in peritoneal macrophages were determined by a quantitative polymerase chain reaction. We failed to observe any correlation between the duration on dialysis and the peritoneal permeability in those patients with no previous peritonitis. Frequency of peritonitis episode did not affect the MTACCr, MTACGlu, or D/P. The MTACCr correlated well with MTACGlu (r = 0.78, p = 0. 001) and with D/P (r = 0.98, p < 0.0001). No inverse correlation was demonstrated between dialysate PDGF or EGF and the peritoneal permeability. A positive correlation was demonstrated between the dialysate TGF-beta1 and MTACCr, MTACGlu or D/P (r = 0.64, 0.54, and 0.64 respectively, p < 0.001). The dialysate TGF-beta1 levels in patients with low D/P (相似文献   

Treatment of peritonitis in APD: pharmacokinetic principles

Clinicians treating peritoneal dialysis (PD)-associated peritonitis should be aware that continuous ambulatory PD (CAPD) and automated PD (APD) have different effects on the pharmacokinetics of antibiotics. Results from various APD and comparative CAPD pharmacokinetic studies are reviewed. In APD patients, antibiotic half-lives were shorter during the cycler exchanges. Antibiotic peritoneal clearance was greater in patients treated with APD than those treated with CAPD regimens. Antibiotic clearance depends upon residual renal function and dialysate flow rate. To ensure that maximal antibiotic bioavailability occurs with intermittent intraperitoneal (IP) dosing, it is recommended that the antibiotic-containing dialysate must dwell at least 4 hours to ensure an adequate antibiotic depot in the body. Knowledge of antibiotic disposition in PD patients will assist clinicians in appropriate IP antibiotic dose selection and prevention of dose-related adverse effects.     

Neutral-pH peritoneal dialysis solution improves peritoneal function and decreases matrix metalloproteinase-2 (MMP-2) in patients undergoing continuous ambulatory peritoneal dialysis (CAPD)

Background Conventional lactate-buffered peritoneal dialysis (PD) solutions have several bioincompatible characteristics, including acidic pH, lactate buffer, and the presence of glucose degradation products (GDPs), and these characteristics contribute to membrane dysfunction in PD patients. The formation of GDPs can be reduced by separating the glucose component of the solution from the lactate component during sterilization. This study was carried out to evaluate the clinical effect of dual-chambered neutral-pH PD solution in patients on continuous ambulatory peritoneal dialysis (CAPD).Methods Thirteen CAPD patients using conventional PD solution were enrolled in this study. The fast peritoneal equilibration test (fast PET) was performed periodically before and after treatment with neutral PD solution. The concentration of matrix metalloproteinase-2 (MMP-2) in dialysate effluent was measured using 4-h dwelling 2.5% glucose dialysis solution. The patients were categorized into two groups, according to the value of the initial dialysate/plasma (D/P) creatinine ratio: i.e., lower transporters (group L, D/PCr < 0.65) and higher transporters (group H, D/PCr 0.65).Results The mean D/P creatinine ratio measured by fast PET, was significantly decreased (0.72 ± 0.09 to 0.60 ± 0.06; P < 0.03) after treatment with neutral PD solution in group H. The mean glucose level in 4-h dwelling dialysate effluent was elevated (824.6 ± 195.9mg/dl to 942.6 ± 147.8mg/dl; P < 0.022) in all subjects. In group H, a significant decrease of MMP-2 in the dialysate effluent was recognized from 15 months after the beginning of treatment with the neutral PD solution (141.4 ± 52.5ng/ml to 91.3 ± 15.1ng/ml; P < 0.05), with the lowest value being shown at 21 months (80.0 ± 31.8ng/ml; P < 0.03).Conclusions Neutral-pH peritoneal dialysis solution decreased the MMP-2 level in dialysate and improved peritoneal function in high-transporter patients with CAPD treatment.     

Functional Deterioration of the Peritoneum: Does It Occur in the Absence of Peritonitis?

Peritoneal function in relation to the occurrence of peritonitisand the osmolarity of the dialysate was studied in 72 CAPD patientswith a mean duration of treatment of 16.5±9.0 months(group 1). Data from 24 of these patients, who were on CAPDfor longer than 2 years (average 28.6±4.9), were subjectedto further detailed analysis (group 2). Each group consistedof two subgroups, one of patients who had experienced peritonitisand one of patients who had had no episodes of peritonitis. Results from group 1 revealed that the use of hyperosmolar bagsincreased in parallel with the duration of CAPD treatment evenin the non-peritonitis subgroup, and that peritonitis enhancedthe tendency to use hyper osmolar dialysate solutions. Thisphenomenon was also observed in the peritonitis subgroup ofgroup 2, but was not apparent in the non-peritonitis subgroupof group 2 when examined as a whole: however, individual analysisrevealed that some of them had a similar tendency to use hyperosmolardialysate, as was seen in the peritonitis subgroup. These results comfirm that the peritonitis impairs the ultrafiltrationcapability of the peritoneum. The results also suggest thatthe long-term use of hyperosmolar dialysate may be associatedwith decreased ultrafiltration, hence emphasis should be placedupon the use of hyposmolar dialysate solutions for long-termCAPD.     

Impact of new dialysis solutions on peritonitis rates

Peritonitis remains a major cause of morbidity among patients on peritoneal dialysis (PD), yet there is little information about the effect of new biocompatible dialysis solutions on peritonitis rates and treatment. In our unit, information on each peritonitis episode is prospectively collected. Since 2003, bicarbonate/lactate dialysate has been gradually introduced for new patients and for patients experiencing abdominal pain with conventional lactate solutions. From 2002 to 2005, data from 121 episodes of peritonitis (71 automated PD and 50 continuous ambulatory PD) were analyzed; 107 episodes occurred in patients using standard lactate dialysate and 14 episodes in patients using bicarbonate/lactate solution. Patients using bicarbonate/lactate had a significantly lower peritonitis rate of 1 per 52.5 patient-months compared to those using standard lactate dialysate (1 per 26.9 patient-months) (P=0.0179). Response to treatment, however, was not affected by the type of dialysate; cure rates (71.4 and 69.1%, respectively) and recurrence rates (21.4 and 15.8%, respectively) were not significantly different. Catheter removal was required in three (21.4%) patients using bicarbonate/lactate and 23 (22.4%) patients using lactate solution. Use of biocompatible dialysate appears to reduce the peritonitis rate by 50%, although this has to be confirmed in a randomized study. The type of dialysate, on the other hand, does not affect response to treatment.     

Creatinine determination in peritoneal dialysis: what method should be used?

The accuracy of methods for measurement of creatinine in plasma,urine and dialysate is of great importance in continuous ambulatoryperitoneal dia lysis (CAPD) patients, to assess the adequacyof CAPD (creatinine clearance) and to monitor the nutritionalstatus (creatinine kinetic lean body mass). The methods mostwidely employed for creatinine determination are Jaffe's reactionand the enzymatic method, however these techniques may sufferfrom glucose interference, particularly for dialysate. We comparedcreatinine values obtained by Jaffe's reaction, the enzymaticmethod and high pressure liquid chromatography (HPLC) for threecreatinine calibration curves prepared in three dialysis solutionswith various concentrations of glucose and for plasma, urineand dialysate of 40 CAPD patients. High values of interceptof creatin inc calibration curves were observed only with Jaffe'sreaction and the enzymatic method in dialysis solutions. Inplasma, urine and dialysate, creatinine values obtained by HPLCwere always found to be lower than those measured by the othertwo methods. Concerning creatinine measurement in plasma andurine, Jaffe's reaction and the enzymatic method appeared equivalent.However it must be noted that, in dialysates, the enzymaticmethod may have glucose interference, and the use of a correctingfactor for glucose with Jaffe's reaction is convenient. NeverthelessHPLC remains a method of reference. It is concluded that, forthe CAPD patient, follow-up by creatinine kinetic lean bodymass or creatinine clearance is pos sible provided that thesame creatinine assay method is used in all biological fluids.     

Effect of dialysate glucose load on plasma glucose and glucoregulatory hormones in CAPD patients

The effect of a dialysate exchange with both 1.5 and 4.25% glucose solutions on plasma levels of glucose, insulin, gastric inhibitory polypeptide (GIP), and glucagon has been investigated in 5 continuous ambulatory peritoneal dialysis (CAPD) patients. Only in the case of the 4.25% solution did plasma glucose levels rise above 100 mg/dl. 4 of the 5 patients responded to this change with a marked insulin secretion. Employing the 1.5% solution, plasma glucose remained stable and only a slight insulin stimulation was observed in 2 patients. It is concluded that provided the 4.25% dialysates are used only occasionally, there will be no continuous stimulation of the pancreatic beta-cells due to absorption of glucose from the dialysate alone during CAPD treatment. GIP levels are highly elevated in CAPD patients. A dialysate exchange with either a 1.5 or a 4.25% glucose solution had no effect on this gastrointestinal hormone. Hyperglucagonemia was also observed in this collective. An initial suppression of glucagon levels occurred in 4 of the patients after a 4.25% dialysate exchange. The 5th patient demonstrated an initial rise followed by a later decrease in glucagon, a response similar to that reported in adult onset diabetes after an oral glucose tolerance test.     

The value of low-dose intraperitoneal immunoglobulin administration in the treatment of peritoneal dialysis-related peritonitis

BACKGROUND: Peritonitis is a major complication of continuous ambulatory peritoneal dialysis (CAPD). The value of immunomodulatory therapeutic approaches and, especially, methods aimed at augmenting opsonization in the treatment of peritoneal dialysis (PD)-related peritonitis is unclear. In this study, the effect of intraperitoneal (IP) immunoglobulin (Ig) usage, as an approach for strengthening opsonization, was evaluated in CAPD peritonitis. METHODS: The study included 24 patients with CAPD peritonitis. The patients were divided into two groups, A and B, each consisting of 12 patients. There were no significant differences between the groups in terms of age, gender, CAPD duration, and peritonitis rate. Empiric antibiotic treatment was a 2-week IP ampicillin+sulbactam/netilmycin combination. Group B was additionally given low-dose IP IgG (2 mL = 320 mg) with every exchange. The dialysate leucocyte counts were obtained in both groups until the number was <100 cells/microL to monitor the response to peritonitis treatment. RESULTS: In group A, the number of exchanges done until the dialysate leucocyte counts decreased to <100/mL was 13.9 +/- 1.4 and for group B 6.6 +/- 0.4 (p<0.001). The reduction in neutrophils was significantly faster in group B compared to group A (p<0.001). The number of exchanges until abdominal pain completely disappeared was 12.5 +/- 1.7 in group A and 5.6 +/- 0.7 in group B (p<0.001). CONCLUSIONS: The results of this study show that low-dose, continuous IP IgG administration in the treatment of PD-related peritonitis is safe and effective in shortening the treatment time.     

Down-regulation of CD43 molecule expression on intraperitoneal neutrophils in CAPD patients with peritonitis

To assess the release of proteases from neutrophils infiltrated into the peritoneal cavity in continuous ambulatory peritoneal dialysis (CAPD), we investigated the regulation of CD43, LAM-1 and Mac-1 expression on the neutrophil plasma membrane using FACS analysis in CAPD patients with peritonitis. Five CAPD patients with peritonitis and five CAPD patients without peritonitis were studied. CD43 expression was immunohistochemically determined in both groups of patients using flow cytometry, and comparisons were made between the two groups. Down-regulation of CD43 and LAM-1, and up-regulation of Mac-1 were demonstrated on neutrophils obtained from CAPD dialysate of peritonitis patients after 1-h dwell time. Further up-regulation of Mac-1 developed until a dwell time of 4 h. Immunoblot analysis for neutrophil lysate from dialysate showed the presence of the asialo form of CD43 molecules and their fragments, which may be produced by cleavage of the CD43 molecule at extracellular sites. The intraperitoneal neutrophils in dialysate from CAPD patients with peritonitis are continuously activated during dwell time, and proteases may be released from neutrophils into dialysate after only a short dwell time.     

Peritonitis, dialysate infusion and lung function in continuous ambulatory peritoneal dialysis (CAPD)

Pulmonary function tests were done in seven CAPD patients with acute peritonitis on the day of admission to the hospital and after recovery. Subsequently, the effect of dialysate infusion alone on lung function was studied in 19 patients initiated on CAPD and nine of these patients were restudied 7.6 +/- 4.1 months later. Peritonitis was associated with a 30% reduction in vital capacity and a significant fall in arterial oxygen tension (7 to 11 mmHg) (p less than 0.01). Dialysate infusion alone decreased functional residual capacity (FRC) and produced small changes in PaO2 which were more pronounced in the supine position. The decrease in PaO2 observed in changing from sitting prior to dialysate infusion, to supine after dialysate infusion was due to the development of airways closure at resting lung volumes. Follow-up studies in nine patients demonstrated a continued and significant fall in FRC with dialysate infusion, without however, any changes in PaO2. We conclude that peritonitis in CAPD patients is accompanied by significant changes in lung function which are probably due to a decrease in diaphragmatic mobility resulting in atelectasis and underventilation of dependent lung zones. In CAPD patients without peritonitis, dialysate infusion in the supine position produces significant changes in PaO2, but with time, compensatory mechanisms develop to abolish the changes in PaO2.     

Dialysate leaks in peritoneal dialysis

Dialysate leakage represents a major noninfectious complication of peritoneal dialysis (PD). An exit-site leak refers to the appearance of any moisture around the PD catheter identified as dialysate; however, the spectrum of dialysate leaks also includes any dialysate loss from the peritoneal cavity other than via the lumen of the catheter. The incidence of dialysate leakage is somewhat more than 5% in continuous ambulatory peritoneal dialysis (CAPD) patients, but this percentage probably underestimates the number of early leaks. The incidence of hydrothorax or pleural leak as a complication of PD remains unclear. Factors identified as potentially related to dialysate leakage are those related to the technique of PD catheter insertion, the way PD is initiated, and weakness of the abdominal wall. The pediatric literature tends to favor Tenckhoff catheters over other catheters as being superior with respect to dialysate leakage, but no consensus on catheter choice exists for adults in this regard. An association has been found between early leaks (< or =30 days) and immediate CAPD initiation and perhaps median catheter insertion. Risk factors contributing to abdominal weakness appear to predispose mostly to late leaks; one or more of them can generally be identified in the majority of patients. Early leakage most often manifests as a pericatheter leak. Late leaks may present more subtly with subcutaneous swelling and edema, weight gain, peripheral or genital edema, and apparent ultrafiltration failure. Dyspnea is the first clinical clue to the diagnosis of a pleural leak. Late leaks tend to develop during the first year of CAPD. The most widely used approach to determine the exact site of the leakage is with computed tomography after infusion of 2 L of dialysis fluid containing radiocontrast material. Treatments for dialysate leaks include surgical repair, temporary transfer to hemodialysis, lower dialysate volumes, and PD with a cycler. Recent recommendation propose a standard approach to the treatment of early and late dialysate leaks: 1-2 weeks of rest from CAPD, and surgery if recurrence. Surgical repair has been strongly suggested for leakage causing genital swelling. Delaying CAPD for 14 days after catheter insertion may prevent early leakage. Initiating CAPD with low dialysate volume has also been recommended as a good practice measure. Although peritonitis and exit-site infections are the most frequent causes of technical failure in peritoneal dialysis (PD), dialysate leaks represent one of the major noninfectious complications of PD. In some instances, dialysate leakage may lead to discontinuation of the technique (1). Despite its importance, the incidence, risk factors, management, and outcome of dialysate leakage are poorly characterized in the literature. We will review the limited available information on this topic in the next few sections.     

Treatment of gram-positive peritonitis with two intraperitoneal doses of vancomycin in continuous ambulatory peritoneal dialysis patients

Eight patients with end-stage renal failure on continuous ambulatory peritoneal dialysis (CAPD), who developed peritonitis, received an intraperitoneal dose of vancomycin (30 mg/kg body weight) with 6 h of peritoneal dwell and then resumed their routine CAPD schedule. Vancomycin concentration in serum, peritoneal dialysate (PD) from an overnight dwell and 1, 2 and 3 h after a new exchange was measured at 48 h (in 5 patients) and 7 days (in 6 patients). Except for an occasional 1-hour peritoneal fluid sample on the 7th day, all samples had satisfactory vancomycin levels. Five of the 8 patients who had gram-positive peritonitis and 1 with 'sterile' peritonitis received another similar intraperitoneal dose of vancomycin at the 7th day. All of these patients had good therapeutic response with a negative PD culture 3 weeks after the cessation of therapy and no relapse of infection in at least 1 month of follow-up. We conclude that 2 intraperitoneal doses of vancomycin (30 mg/kg body weight) given 1 week apart with 6 h of intraperitoneal dwell is an effective and adequate treatment for gram-positive and 'sterile' peritonitis in CAPD patients.