Continuous Ambulatory Peritoneal Dialysis Fluid Research Articles

Microbial Profile, Peritoneal Fluid White Blood Cell Count, and Outcome of Peritoneal Dialysis-Related Peritonitis at Indonesian Tertiary Hospital.

Peritonitis caused by peritoneal dialysis (PD) remains a common complication of continuous ambulatory PD (CAPD). The purpose of this study is to determine the microbial profile in CAPD-related peritonitis, the optimal cutoff of white blood cell (WBC) count, and the percentage of polymorphonuclear (PMN) in CAPD fluid in the prediction of CAPD-related peritonitis, together with the outcome of CAPD-related peritonitis at an Indonesian tertiary hospital. This is a retrospective cohort study of CAPD-related peritonitis patients at Indonesian tertiary hospitals from November 2020 to October 2022. Patients with suspected CAPD-related peritonitis who were tested for CAPD fluid culture and WBC count in CAPD fluid were eligible for this study. Patient's diagnosis and outcome obtained from medical records. Differences in clinical outcomes by category of microorganisms were analyzed with Fisher exact test. The Mann-Whitney test and receiver operating characteristic curve were used to determine optimal WBC and PMN cutoff. This study included 58 patients and 102 episodes of CAPD-related peritonitis. CAPD-related peritonitis was caused by 29.4% Gram-negative bacteria, 21.5% Gram-positive bacteria, 7.8% fungi, and 6.9% polymicrobial bacteria. CAPD fluid WBC count >79 cells/μL and PMN percentage >50% had a sensitivity of 76.4% and a specificity of 92.9% in predicting CAPD-related peritonitis. There was a significant difference in outcome between Gram-negative and Gram-positive bacterial peritonitis. It is critical to understand the microbial profile in CAPD-related peritonitis. Lower WBC count cutoff points in CAPD fluids may improve sensitivity in predicting CAPD-related peritonitis.

Clinical profile and microbiological spectrum of patients with continuous ambulatory peritoneal dialysis-associated peritonitis at a tertiary care center

BackgroundWe present risk factors, clinical profile, and microbiological spectrum of patients with continuous ambulatory peritoneal dialysis (CAPD)-associated peritonitis who were managed at our center. MethodsAll consecutive patients with CAPD-associated peritonitis who presented to our center between July 2018 and December 2019 were included in the study. Risk factors, microbiological spectrum, clinical profile, and outcome of patients were studied. ResultsEighty-five patients with CAPD-associated peritonitis and 50 patients who never had peritonitis during the study period were included. Diabetes Mellitus (OR 0.058, 95% CI0.007–0.493, p < 0.05), residence in rural area (OR 3.376, 95% CI 1.084–10.516, p < 0.05), duration of peritoneal dialysis (OR 0.935, 95% CI 0.886–0.987, p < 0.05), mean serum hemoglobin (OR 1.674, 95% CI 1.119–2.502, p < 0.05) and serum albumin (OR 0.148, 95% CI 0.066–0.333, p < 0.05) were associated with higher risk of peritonitis in CAPD patients. Eight-three patients (98.8%) had turbid CAPD fluid and 52 (61.2%) had fever at the time of presentation to the hospital. The mean CAPD fluid TLC on day 1, 3, and 5 were 2034.3 ± 3330.1 cells/cumm, 1049.0 ± 1210.9 cells/cumm, and 605.2 ± 950.5 cells/cumm, respectively. The organisms isolated were two Escherichia coli (2.4%), one Staphylococcus aureus (1.2%), one Klebsiella (1.2%), two Acinetobacter (2.4%), 10 Fungal organisms (11.7%), and in two (2.4%) cases, Mycobacterium tuberculosis (MTB) was detected by polymerase chain reaction (PCR) of CAPD fluid. Thirty-seven (43.5%) patients had a complete cure and 48 (56.5%) patients were refractory to treatment; hence catheter was removed in them (catheter loss). Six (7.0%) patients died during the study period. ConclusionCAPD-associated peritonitis is an important risk factor for technique failure. The majority of episodes are culture-negative, and PCR can help in detecting fungal and tubercular peritonitis early in the course.

POS-629 PERITONEAL MEMBRANE HISTOPATHOLOGIC CHANGES CAUSED BY PERITONITIS IN CONTINUOUS AMBULATORY PERITONEAL DIALYSIS PATIENTS: TWO CASE REPORTS

Long-term Peritoneal Dialysis (PD) causes morphologic and functional changes in the peritoneal membrane (PM) which is defined as peritoneal fibrosis, a known cause of loss of peritoneal ultrafiltration capacity. Inflammation, angiogenesis , and bioincompatible of peritoneal dialysis solution are a key event during the pathogenesis. Peritonitis remains a major problem in Peritoneal Dialysis. Excessive peritoneal inflammatory responses lead to mesothelial cell exfoliation and thickening of the submesothelial, resulting in peritoneal fibrosis and sclerosis. We report two cases of the patient in Continuous Ambulatory Peritoneal Dialysis (CAPD), focus on PM histopathologic changes. Case 1. A male, 47 years old, suffered from repeated peritonitis. After fourth episode of infection, the catheter was malfunction and removed. He was done on CAPD for 7 years with glucose base solution. Histopathologically, peritoneal membrane showed diffuse fibrosis and hyalinization, without mesothelial cell lining nor inflammatory cell infiltrate. He was transferred to hemodialysis. Case 2. A 28 years old male, came with chief complaint of fever, abdominal pain, and cloudy effluent in CAPD fluid. On third episode of peritonitis, Empirical treatment with cefotaxime intraperitoneal was done , however CAPD catheter was malfunctioned and removed. He was done on CAPD for 6 years with glucose base solution. The peritoneal membrane histopathology showed diffuse fibrosis and hyalinization, involving vessels, foci of lymphoplasmacytic cells infiltration, without mesothelial cell. He was transferred to hemodialysis. The success of PD was dependent on the structural and functional integrity of the PM. The mesothelium lines the PM and is the first line of defense against chemical / bacterial insult. Peritonitis remains a major complication of PD and cause of ultrafiltration/technique failure, morbidity and mortality. The mortality risk of PD-related peritonitis was 16-18%. Bioincompatible PD solution is also associated with production of proinflammatory and profibrotic cytokines. High peritoneal glucose exposure is associated with increased incidence of relapsing/recurrent peritonitis and conduct proinflammatory and profibrotic reactions in the peritoneal cavity leading to fibrosis and malfunction after 6-7 years. Peritoneal fibrosis was detected in 50% and 80% of PD patients within one and two years on PD. Pathological alterations in the vasculature of peritoneal include hyalinization of the blood vessels, vasculopathy, and submesothelial thickening.Figure 2Case 2.View Large Image Figure ViewerDownload Hi-res image Download (PPT) Peritonitis episode altered peritoneal structure and functional. Neglected infection and repeated infection led to PD catheter removal. Glucose based solution may a contributing factor for membrane failure due to inflammation and fibrosis after 6-7 years.

Atherosclerotic vascular disease is more prevalent among black ESKD patients on long-term\xa0CAPD in South Africa

BackgroundOccurrence of cardiovascular disease (CVD) in the setting of chronic kidney disease (CKD) can be described as a “cruel alliance”, with CVD responsible for about half of all deaths among CKD patients. Chronic kidney disease patients are more likely to die from CVD than progress to end stage kidney disease (ESKD). Dyslipidaemia, a known traditional risk factor for CVD, is highly prevalent among CKD patients and with an even higher frequency among ESKD patients on dialytic therapies. Prolonged exposure of continuous ambulatory peritoneal dialysis (CAPD) patients to high glucose concentrations in CAPD fluid have been associated with increased risk of cardiovascular events. In this study, we investigated the relationship of atherosclerotic vascular disease (AsVD) to clinical and echocardiographic parameters among black South Africans with CKD (stage 3) and ESKD on CAPD and haemodialysis (HD).MethodsThis was a cross-sectional study of 40 adult (18–65 years) non-diabetic CKD patients (kidney disease outcome quality initiative [KDOQI] stage 3), 40 ESKD patients on CAPD, 40 ESKD patients on HD and 41 age and sex-matched healthy controls. An interviewer-administered questionnaire was used to obtain information on participants’ sociodemographic and cardiovascular risk factors. Anthropometric parameters were measured. Serum blood samples were analysed for creatinine, albumin and lipid profile; lipoprotein ratios, Framingham’s risk score and the 10-year risk of developing coronary heart disease (CHD) were calculated. Echocardiography was performed on all patients and carotid intima media thickness (CIMT) was measured in both right and left carotid arteries at 1 cm proximal to the carotid bulb. Spearman’s rank correlation and binary logistic regression were conducted to determine the relationship of AsVD to clinical and echocardiographic parameters.ResultsAtherosclerotic vascular disease was most prevalent among ESKD patients on CAPD (70%, n = 28/40). Chronic kidney disease and HD patients exhibited a similar prevalence (47.5%, n = 19/40), while the prevalence in controls was 17.1% (n = 7/41). Presence of AsVD was associated with significantly older age, higher waist hip ratio (WHR), left ventricular mass index (LVMI) and Framingham’s 10-year risk of developing CHD. Significant differences in clinical and echocardiographic parameters were observed when the study groups were compared. Age and LVH independently predicted AsVD.ConclusionAtherosclerotic vascular disease was more prevalent among CAPD patients compared to pre-dialysis CKD and HD patients. Among all lipoprotein ratios assessed, non-HDL-C showed the most consistent significant difference between the groups. Age (> 40 years) and presence of LVH were independent predictors of AsVD.

Current state of continuous ambulatory peritoneal dialysis in Egypt.

Patients with end-stage renal disease (ESRD) continue to increase in number worldwide, especially in developing countries. Although continuous ambulatory peritoneal dialysis (CAPD) has comparable survival advantages as hemodialysis (HD), it is greatly underutilized in many regions worldwide. The prevalence of use of CAPD in Egypt is 0.29/million population in 2017. The aim of this study is to describe the current state and practice of CAPD in Egypt and included 22 adult patients who were treated by CAPD. All the study patients were switched to CAPD after treatment with HD failed due to vascular access problems. Patients were mainly female (68.2 %) with the mean age of 49.77 ± 11.41 years. The average duration on CAPD was 1.76 ± 1.30 years. Hypertension was the main cause of end-stage renal disease (ESRD) constituting 36.4%, followed by diabetes (27.3 %), and toxic nephropathy (4.5%). Of importance is that about 31.8% of patients had ESRD of unknown etiology. The mean weekly Kt/V urea of patients on PD was 1.92 ± 0.18. The mean hemoglobin, serum calcium, phosphorus, parathormone, and albumin levels were 10.27 ± 1.98 g/dL, 8.36 ± 1.19 mg/dL, 5.70 ± 1.35 mg/dL, 541.18 ± 230.12 pg/mL, and 2.98 ± 0.73 g/dL, respectively. There was no significant difference between diabetic and nondiabetic CAPD patients regarding demographic and laboratory data. Our data indicate that there is continuing underutilization of CAPD in Egypt which may be related to nonavailability of CAPD fluid, patient factors (education and motivation), gradual decline of the efficiency of health-care professionals, and lack of a national program to start PD as the first modality for renal replacement therapy. It is advised to start an organized program to make CAPD widespread and encourage local production of PD fluids to reduce the cost of CAPD.

Evaluation of continuous ambulatory peritoneal dialysis fluid C-reactive protein in patients with peritonitis.

Severe peritonitis causing death is one of the most devastating complications of peritoneal dialysis (PD). Since the predictive value of C-reactive protein (CRP) in PD fluid has not been assessed, the objective of the present study is to evaluate its predictive value and clinical correlation in patients on PD with peritonitis. One hundred and twenty patients on continuous ambulatory PD (CAPD) were enrolled and their serum and fluid CRP (Fl. CRP) were evaluated at the start of CAPD. All patients who developed peritonitis were further evaluated for serum and fluid CRP. The patients were categorized into four groups, namely: normal patients (control group), patients with peritonitis, patients with peritonitis leading to catheter removal, and death due to peritonitis. Sixty-five patients developed peritonitis of whom, catheter removal was performed in eight patients. Five patients died due to peritonitis-related complications. Fl. CRP showed a significant difference among the three groups, unlike S. CRP. Estimation of CRP in the peritoneal fluid may be a useful marker to monitor the onset of peritonitis.

Evaluation of different culture methods for the diagnosis of peritonitis in patients on continuous ambulatory peritoneal dialysis

A total of 170 continuous ambulatory peritoneal dialysis (CAPD) fluids were processed by various culture methods, including direct inoculation of the centrifuged sediment, inoculation into automated blood culture bottles, water lysis, Tween-80 incorporated blood agar, and Triton-X treatment of the specimen. Of 170 CAPD fluids, 127 showed the growth of bacteria/fungi. Sixty-three fluids showed growth by all methods, the water lysis alone detected 24 additional positive cultures, while Tween-80 blood agar and Triton-X yielded 30 additional positive cultures. A combination of water lysis, Tween-80 blood agar and Triton-X treatment of the CAPD fluid is recommended for diagnosis of CAPD peritonitis in resource-limited settings.

Validation of the body fluid module on the new Sysmex XN-1000 for counting blood cells in cerebrospinal fluid and other body fluids

We evaluated the body fluid (BF) module on the new Sysmex XN-1000 for counting blood cells. One hundred and eighty-seven BF samples [73 cerebrospinal fluid (CSF), 48 continuous ambulatory peritoneal dialysis (CAPD), 46 ascites, and 20 pleural fluid] were used for method comparison between the XN-1000 and manual microscopy (Fuchs-Rosenthal chamber and stained cytospin slides) for counting red blood cells (RBCs) and white blood cells (WBCs) (differential). Good agreement was found for counting WBCs (y=1.06x+0.09, n=67, R2=0.96) and mononuclear cells (MNs) (y=1.04x-0.01, n=40, R2=0.93) in CSF. However, the XN-1000 systematically counted more polymorphonuclear cells (PMNs) (y=1.48x+0.18, n=40, R2=0.99) compared to manual microscopy. Excellent correlation for RBCs >1×109/L (y=0.99x+116.56, n=26, R2=0.99) in CSF was found. For other fluids (CAPD, ascites and pleural fluid) excellent agreement was found for counting WBCs (y=1.06x+0.26, n=109, R2=0.98), MNs (y=1.06x-0.41, n=93, R2=0.96), PMNs (y=1.06x+0.81, n=93, R2=0.98) and RBCs (y=1.04x+110.04, n=43, R2=0.98). By using BF XN-check, the lower limit of quantitation (LLoQ) for WBC was defined at 5×106/L. Linearity was excellent for both the WBCs (R2=0.99) and RBCs (R2=0.99) and carry-over never exceeded 0.05%. The BF module on the XN-1000 is a suitable tool for fast and accurate quantification of WBC (differential) and RBC counts in CSF and other BFs in a diagnostic setting.

Use of the Cell-Dyn Sapphire Hematology Analyzer for Automated Counting of Blood Cells in Body Fluids

The enumeration and identification of blood cells in body fluids offers important information for the diagnosis and treatment of various medical conditions. Manual microscopic methods (hemacytometer total cell count and cytocentrifuged differential count) have inherent analytic and economic disadvantages but are still considered the "gold standard" methods. We evaluated the analytic and clinical performance of the Cell-Dyn Sapphire hematology analyzer (Abbott Diagnostics Division, Santa Clara, CA) for automated blood cell counting and leukocyte differential counting in cerebrospinal fluid, serous fluid (peritoneal and pleural fluid), and continuous ambulatory peritoneal dialysis fluid, and we compared the performance with the respective manual methods. In the present article, we describe its applicability for the distinct body fluids, and we highlight limitations and caveats.

Microbubble-enriched lavage fluid for treatment of experimental peritonitis

Relaparotomies and closed postoperative peritoneal lavage (CPPL) are performed to treat persistent peritonitis. This experimental animal study compared open abdominal lavage with CPPL, and evaluated the potential of microbubble-enriched lavage fluids to improve the efficiency of CPPL and reduce clinical morbidity, mortality and cost. Fluorescent polystyrene spheres were injected intraperitoneally into 22 male Wistar rats to simulate localized peritonitis. After 18 h the rats received open abdominal lavage and CPPL, with and without microbubbles. Microbubbles were obtained by adding ultrasound contrast agents to continuous ambulatory peritoneal dialysis fluid. Open abdominal lavage was 3.5 times more effective in particle removal than CPPL, owing to better fluid dynamics. The introduction of air-liquid interfaces in the form of microbubbles made CPPL up to 2.4 times more effective than lavage without bubbles. Best detachment results were obtained when microbubbles with a flexible surfactant shell and longer blood elimination half-life were used. Open abdominal and CPPL lavage techniques are not efficient beyond a certain duration and volume as they do not cause bacterial detachment from the peritoneal membrane. Using surface tension forces from microbubbles significantly enhanced polystyrene particle detachment. These findings may have great consequences for the treatment of patients with peritonitis.

Peritoneal-mediastinal leakage complication of peritoneal dialysis

The authors report a case of mediastinal fluid collection resulting from peritoneal-mediastinal communication after continuous ambulatory peritoneal dialysis (CAPD). To the best of the authors’ knowledge, this is the first reported case in the medical literature. A dry cough developed in the patient who had been receiving CAPD for 4 years. A mediastinal mass owing to peritoneal leakage of dialysate to the mediastinum was confirmed by a computed tomography scan taken 4 hours after the intraperitoneal infusion of contrast-mixed dialysate. The leakage persisted for 12 weeks after the discontinuation of CAPD fluid instillation.

Total metal concentrations in serum of dialysis patients and fractionation of Cu, Rb, Al, Fe and Zn in spent continuous ambulatory peritoneal dialysis fluids

Total metal concentrations were determined in the serum of 12 continuous ambulatory peritoneal dialysis (CAPD) patients and in fresh and spent CAPD fluids by electrothermal and flame atomic absorption spectrometry (ETAAS, FAAS). Concentrations of Cu in serum of CAPD patients ranged from 720 to 1780 ng cm −3, Rb from 128 to 346 ng cm −3, Al from 10 to 72 ng cm −3, Fe from 800 to 2300 ng cm −3 and Zn from 659 to 1310 ng cm −3. The accuracy of the analytical procedure was checked by the analysis of the reference material Seronom™, Trace Elements in Serum. Good agreement between the certified and determined values was obtained for Al, Cu, Fe and Zn. The data on the total metal concentrations in CAPD fluids indicated that during CAPD fluid exchange the losses of Cu from 5.0 to 35 ng cm −3, of Rb from 50 to 110 ng cm −3 and of Al from 3.0 to 14.0 ng cm −3 occurred through the peritoneal membrane. Although fresh CAPD fluids contained traces of Fe (3.0–5.0 ng cm −3), the transfer of this element took place through the peritoneal membrane into spent CAPD fluid (13.0–38.0 ng cm −3). Zn concentrations were in general lower in spent (20.0–80 ng cm −3) than in fresh CAPD fluids (∼100 ng cm −3). To follow the mechanisms of the transfer of trace elements through the peritoneal membrane of CAPD patients, fractionation of metals was carried out in spent CAPD fluids by size exclusion chromatography with UV and AAS detection, applying Superdex HR 10/30 column. The chromatographic run was followed at 278 nm and separated metal species also determined ‘off line’ in 1 cm 3 fractions by ETAAS or FAAS. From the UV chromatograms and AAS analysis of trace elements in the separated fractions it was demonstrated that Cu, Al, Fe and Zn were bound to proteins and only partially to low molecular weight (LMW) species, while Rb was associated exclusively with LMW species. For characterisation of the high molecular weight (HMW) binding proteins, fractions containing trace elements were subjected to SDS-PAGE electrophoresis. Al and Fe were presumably bound to transferrin, but due to its low concentration in spent CAPD fluids, it was not possible to confirm its presence in the separated fractions. About 10% of Al and 15% of Fe corresponded to LMW species. A fraction of HMW proteins of Cu in spent CAPD fluids was most probably bound to albumin and Zn to albumin and globulins. About 50% of Cu and Zn existed in LMW proteins, while Zn was also found partially in ionic form.

Assessment of the FAN anaerobic bottle for culture of continuous ambulatory peritoneal dialysis fluid using the BacT/Alert system

The purpose of this study was to determine if the newly available FAN anaerobic bottle (FANAN) alone would be comparable to the combination of the FAN aerobic (FANAE) plus the standard BacT/Alert anaerobic (REGAN) bottles for culture of continuous ambulatory peritoneal dialysis (CAPD) fluid from patients with CAPD peritonitis. CAPD fluid (10 mL) was injected into each bottle, which was then monitored by the BacT/Alert instrument by using a 7-day protocol. Aerobic and anaerobic terminal subculture were performed on all bottles before they were classified as being culture negative. There were 181 effluents received that were suitable for analysis. Growth was detected in 76 (42%) effluents by at least one method. FANAE was the single best medium detecting 84/96 (88%) of all organisms whereas the FANAN and REGAN each detected 69/96 (72%). The combination of FANAE and REGAN bottles detected 92/96 (96%) isolates, which was significantly better than the FANAN or FANAE alone for isolate recovery ( p < 0.001). The isolates that were missed by the FANAN but that were recovered by either FANAE or REGAN were all facultative anaerobes commonly detected in CAPD fluids. Terminal subculture revealed otherwise undetected pathogens in 3.9% of positive effluents, usually Pseudomonas aeruginosa. Based on our data, FANAE was the single best bottle for detection of CAPD peritonitis and, in combination with an anaerobic bottle, detected growth from the most effluents. FANAN alone could not substitute for the FANAE/REGAN combination. Although terminal subculture remains controversial, we recommend routine aerobic subculture to ensure that no P. aeruginosa isolates are missed.

Problems related to determination of trace elements in spent continuous ambulatory peritoneal dialysis fluids by electrothermal atomic absorption spectrometry

Critical parameters which influence the direct determination of trace elements in spent continuous ambulatory peritoneal dialysis (CAPD) fluids by electrothermal atomic absorption spectrometry (ETAAS) were investigated. Samples were collected after CAPD fluid exchange in 5.0 ml polyethylene cups and stored at −20°C. Daily spent CAPD fluids were frozen immediately, while nightly spent CAPD fluids were frozen 2–3 h after the morning exchange. Before analysis samples were equilibrated to room temperature and analysed within 8 h. It was found experimentally that some samples which were not frozen immediately leaked out of the pyrolytically coated graphite tube before the drying step. In order to keep the sample in the graphite tube and to obtain reproducible measurements of copper, aluminium and iron, samples were diluted before analysis 1+1 with 32% v/v nitric acid. The standard addition method was used in the calibration procedure. The results of direct ETAAS determinations for copper agreed well (±5–10%) with those obtained after acid digestion of CAPD fluids in Parr bomb. The procedure for direct determination of all three elements was validated with spiked samples.

Adsorption of α-1-microglobulin from biological fluids onto polymer surfaces

A recent study in our laboratory has identified the potential role of urine-derived α-1-microglobulin (α-1-m) in mediating Pseudomonas aeruginosa adhesion to polystyrene, while other workers have suggested a possible role of the protein in the immunological response. Due to the ubiquitous presence of α-1-m in body fluids, the adsorption of the protein from serum, cerebrospinal fluid, urine and used continuous ambulatory peritoneal dialysis fluid onto polystyrene was investigated. The treated surfaces were sequentially immersed in water and increasingly concentrated isopropanol-water solutions in order to selectively desorb bound proteins on the basis of their binding strength. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis of the wash supernatants showed different protein desorption profiles for each biological fluid, despite the qualitative similarity between the protein composition of the fluids, and highlighted the uptake of α-1-m from each fluid to the surface. In the case of urine, the analysis was extended to commercial polyurethane and silicone stents. The ease of desorption of urine-derived α-1-m could be correlated with surface hydrophobicity of the stent biomaterial.

High serum D-lactate in patients on continuous ambulatory peritoneal dialysis.

As abnormally high serum D-lactate levels may cause neurological impairment, we determined whether patients undergoing continuous ambulatory peritoneal dialysis (CAPD) with lactate-containing fluids have increased serum D-lactate concentrations. D- and L-lactate concentrations were determined in peritoneal dialysis fluids and in serum from control subjects (n = 10), haemodialysis patients (n = 10), and CAPD patients (n = 30) before and after 1 h of dialysis. We found the median D-lactate concentration in Dianeal CAPD fluid to be 26 mM (range 19-27), whereas it was less than 0.5 mM in DPCA2 fluid. Control, haemodialysis, and CAPD (DPCA2) patient median serum D-lactate concentrations were below 0.07 mM. However, CAPD (Dianeal) patient serum D-lactate concentrations were 4-fold higher than controls (P < 0.0001), at 0.28 mM, an hour after instillation of D-lactate-containing fluid. Three patients, whose serum D-lactate averaged 0.59 mM, were found to have D-lactate concentrations at 0.22 mM after overnight cessation of dialysis. We conclude that CAPD with D-lactate-containing fluids raises serum D-lactate to abnormal levels.

Segmental bioelectrical impedance in patients with chronic renal failure

We studied changes in hydration by whole body and segmental (arm, leg and trunk)bioelectrical impedance analysis (BIN in patients with chronic renal failure (CRF) undergoing haemodialysis and continuous ambulatory peritoneal dialysis (CAPD). Mean (SD) fluid removal by haemodialysis of 1.38 (0.81) kg was overestimated by whole body BIA at 1.83 (1.13) I, P < 0.005. Peritoneal fluid drained from the CAPD patients of 1.88 (0.36) kg was underestimated by whole body BIA at 0.59 (0.35) I, P < 0.0001. Resistance and reactance significantly increased for the whole body and all segments (except trunk reactance) after haemodialysis. Drainage of CAPD fluid resulted in smaller increases in trunk resistance and whole body resistance. The increase in trunk resistance was less in CAPD than haemodialysis patients, even though the volume of fluid drained from the peritoneum in CAPD patients exceeded that removed from the whole body during haemodialysis. We conclude that whole body BIA does not estimate changes in body fluid with sufficient accuracy to be of use in clinical practice. Segmental impedance may be a potentially useful method for investigation of regional changes in body fluid, though is insensitive to changes within the peritoneal cavity.

Cost and time savings following introduction of rejection criteria for clinical specimens.

We have evaluated the yield of several tests and have instituted specimen rejection criteria to reduce costs and save time. For a 12-month period, we recorded the reduction of these tests and calculated the resultant cost and time savings. Seven changes were analyzed: not performing fungal or mycobacterial (acid-fast bacillus) cultures on cerebrospinal fluid (CSF) specimens from patients without known immunosuppression when chemistry and cell count are normal; not performing routine stool culture or ovum and parasite examination on specimens from patients in the hospital for > 3 days; not culturing endotracheal suction aspirates when no organisms or > 10 squamous epithelial cells are present; discontinuing broth cultures on all specimens except for tissue, continuous ambulatory peritoneal dialysis fluid, and CSF from patients with shunts; and eliminating bacterial antigen tests. For each test, the number not performed (n), reagent savings, and technologist time saved, respectively, were as follows: CSF fungal culture, 267, $999, and 67 h; CSF acid-fast bacillus culture, 275, $1,662, and 124 h; stool cultures, 320, $2,991, and 98 h; ovum and parasite examinations, 216, $525, and 108 h; endotracheal suction aspirate cultures, 1,505, $4,447, and 306 h; broth cultures, 5,218, $4,931, and 80 h; and bacterial antigen tests, 2,598, $2,293, and 299 h. Overall, 5,181 tests were rejected and 5,218 broth cultures were omitted. Achievable savings were $28,000 in reagent costs and 1,082 h of technologist time. In conclusion, rejecting specimens of proven low yield saves reagent costs and, more importantly, saves technologist time. This time can be spent on specimens having greater diagnostic utility.

Quantification of beta 2-microglobulin and albumin in plasma and peritoneal dialysis fluid by a noncompetitive immunoenzymometric assay

An enzyme-linked immunosorbent assay (ELISA) was developed for measuring beta 2-microglobulin (beta 2m) and albumin in continuous ambulatory peritoneal dialysis (CAPD) fluid. Plasma concentrations of beta 2m were twofold greater in hemodialysis patients (41.3 +/- 13.3 mg/L) than in CAPD patients (23.6 +/- 5.5 mg/L) matched for duration of treatment. Measurement of beta 2m in CAPD fluid showed a substantial loss of this protein, approximately 31% of total body beta 2m, compared with a 5% loss of a protein of middle molecular mass (albumin). Because of the molecular sieving effects of the peritoneal membrane, peritoneal clearance of beta 2m was sixfold greater than that of albumin. Whether beta 2m losses prevent or delay the incidence of dialysis-induced amyloidosis in these patients remains to be established.

Wearable Artificial Kidneys for Continuous Dialysis

Since 1971, the author has been actively promoting and working on a wearable artificial kidney for continuous dialysis. Such a kidney could allow the patient to have a more normal life style, eliminate treatment scheduling, and provide stable chemistries. Two partially successful wearable kidneys based upon hemofiltration have been devised. One required the patient to drink a liter of dialysate every hour to replace ultrafiltrate loss, and the other regenerated the ultrafiltrate with a REDY sorbent cartridge. Although the patients underwent anticoagulation, their hemofilters clotted in fewer than 5 days. In addition, there was a serious risk of bleeding in the event of accidental injuries. Use of a peritoneal access eliminates these blood related problems. Continuous ambulatory peritoneal dialysis (CAPD) is a successful continuously wearable kidney, but the bag changes are a chore. This drawback often produces technique failure, resulting in the patient shifting to hemodialysis. Regeneration of peritoneal dialysis has been performed successfully in intermittent peritoneal dialysis, but the higher concentration of protein in spent CAPD fluid interfered with performance of the sorbent cartridge. The author demonstrated that removing the protein by filtration through a hemofilter before regeneration resolves this problem, permitting development of a viable wearable kidney.