Technical survival of CAPD catheters: comparison between percutaneous and conventional surgical placement techniques.

BACKGROUND: Percutaneous peritoneal dialysis catheter (PDC) placement is a well-tolerated, rapidly performed bedside procedure that allows a rapid initiation of CAPD. We compared the technical survival of PDCs while comparing the mode of insertion. METHODS: We retrospectively reviewed 215 PDCs inserted over a 60-month period in 191 patients on CAPD therapy. Of these, 133 were placed percutaneously by nephrology staff (group P) and 82 were placed using conventional surgical techniques by surgical staff (group S). The total experience accumulated was 4000 patient-months: 2260 patient-months in group P and 1740 patient-months in group S. RESULTS: The incidence of complications in PDCs did not differ between the groups (1 episode/33 patient-months in group P and 1 episode/29 patient-months in group S). Two episodes of early leakage and 9 episodes of late leakage were observed in group P compared with one early leakage and 4 episodes of late leakage in group S. Of the mechanical complications in group P, 8.86% were due to catheter malfunction, including catheter tip migration and obstruction, compared with 12.63% in group S. The incidence of catheter infections was 1 episode/73 patient-months in group P and 1 episode/62 patient-months in group S. Significantly more catheters were removed in group S compared with group P (40% vs 16%, P<0.001). One-year and 2-year technical survivals were 90% and 82% in group P, and 73% and 60% in group S (P=0.0032), respectively. CONCLUSIONS: Percutaneous bedside placement of PDCs by nephrologists provides a safe and reliable access for peritoneal dialysis.     

Ten years experience of CAPD in diabetics: comparison of results with non-diabetics

CAPD outcomes were compared between a group of 301 diabeticpatients (mean age±SD, 58.9±12.7 years, 55.8%males) and a group of 1689 non-diabetic patients (mean age±SD57.8±14.8 years, 55.9% males) treated in 30 centres participatingin the Italian Cooperative Peritoneal Dialysis Study Group from1980 to 1989, with follow-up observation periods of 444 years(mean±SD, 1.48± 1.24) and of 3502 years (mean±SD,2.07± 1.91) respectively. CAPD was the first modality for 87.2% of diabetics and 78.1%of non-diabetics (P<<0.001). The percentage of patientswho needed a partner for CAPD was 45.9% in diabetics and 30.2%in non-diabetics (P<0.00l). In diabetics compared with non-diabetics, cardiovas cular diseasesand cachexia were nearly twice and infections other than peritonitismore than three times as frequent in causing death. In diabetics,survival was significantly worse (P<0.0001) and the relativerisk of death 2.13 times higher (P<0.001). The technique survival and the relative risk of drop out werenot significantly different in the two groups. Clinical problemswere the most important cause of drop-out among diabetics. Theprobability and relative risk of drop-out due to peritonitis,as well as of the first peritonitis episode, were not significantlydifferent between the two groups and between diabetics usingor not using intraperitoneal insulin. Days per patient year of hospitalization, excluding the first,were 18.4 in diabetics and 14.3 in non diabetics. CAPD-relatedproblems caused hospitalization in a similar way in the twogroups. In conclusion, compared to non-diabetics on CAPD, diabeticson the same treatment showed more clinical problems that accountfor a higher need of partner, death, and hospitalization andare the first reason for technique failure; on the other hand,problems closely related to the CAPD technique seem to occurwith the same frequency in the two groups.     

Bidirectional peritoneal transport of albumin in continuous ambulatory peritoneal dialysis

The present study was undertaken in order to assess bidirectionalperitoneal kinetics of albumin after simultaneous i.v. and i.p.injection of radioiodinated albumin tracers (¹²⁵I-RISA and ¹³¹I-RISA)in eight clinically stable uraemic patients undergoing continuousambulatory peritoneal dialysis (CAPD). The plasma volume, intravascularalbumin mass (IVM), and overall extravasation rate of albuminwere not significantly different from that found in healthycontrols. Albumin flux from the plasma into the peritoneal cavitywas 3.71 ± 0.82 (SD) µmol/h, which was only 3%of the overall extravasation rate (137 ± 52 µmol/h).Albumin flux from the peritoneal cavity into the plasma wassubstantially lower (0.22 ± 0.07 µmol/h, P<0.01).The net peritoneal accumulation of the albumin from plasma over4 h was 14 ± 3.2 µmol, which was significantlylower than the intraperitoneal albumin mass at the end of thedialysis (54 ± 19 µmol, P<0.01). This indicatesthat only about 25% of the albumin loss during CAPD occurs directlyfrom the plasma. The initial osmotic net filtration was 508± 302 ml. The volume flow equivalent to the albumin fluxwas 6.3 ± 1.5ml/h into the peritoneal cavity and 7.8± 1.9ml/h back into the plasma. Although minor, as comparedto the osmotic net filtration (508 ml), the albumin flux equivalentvolume (31.2 ml) exceeded the steady state filtration (25.2ml) significantly (P<0.01) during the 4 h investigation. In conclusion, albumin flux into the peritoneal cavity is smallcompared to the overall extravasation rate, but our resultssuggest that CAPD loss of albumin predominantly occurs fromthe subperitoneal interstitial space and only to a minor degreedirectly from the plasma. Albumin flux equivalent volume flowis relatively small and most probably represents peritoneallymph drainage.     

Clinical evaluation of an optimized 1.1% amino-acid solution for peritoneal dialysis

A significant percentage of dialysed patients have inadequateprotein intake. One strategy for treating the protein malnutritionin peritoneal dialysis patients is to replace glucose in thedialysis solution by amino acids. A new peritoneal dialysissolution containing 1.1% amino acids in a formulation optimizedfor renal patients and with a lactate concentration of 40 mmol/lhas been evaluated. Fifteen CAPD patients completed a non-randomizedprospective 3-month study. Each patient received 2 litres ofthe optimised 1.1% amino acid solution for the second exchangeof the day with a dwell time of 5–6 h. Indicators of efficacywere serum albumin and transferrin. After 3 months of intraperitonealamino acids, serum albumin levels significantly increased from32.7±2.3 to 35.1±2.2 g/l (mean±SD; p>0.01).This occurred in parallel with a significant increase in transferrinlevels from 2.21±0.26 to 2.39±0.27 g/l (P>0.05).As expected, urea rose from 23.7±6.8 to 29.9±9.4mmol/l. Interestingly bicarbonate did not change (25.5±4.2versus 25.2±3.3 mmol/l). These results suggest that theoptimized formulation is effective in improving nutritionalparameters in CAPD patients while avoiding unwanted side-effectssuch as acidosis.     

Survey of Blood Lead and Plasma Aluminium Concentrations in Patients of a Renal Unit

Blood lead and plasma aluminium concentrations have been measuredin patients with end-stage chronic renal failure treated byhaemodialysis (HD) or by continuous ambulatory peritoneal dialysis(CAPD) and in a control group of non-dialysed patients withchronic renal failure (CRF). Data on a group of subjects withnormal renal function is included for comparison. We have foundsignificantly increased mean blood lead and plasma aluminiumconcentrations in all patients with chronic renal failure comparedto a group with normal renal function. All blood lead concentrations were within the accepted safeexposure range of less than 1.8 µmol/l (380 µg/l)).There were significant differences among the patient groups:home HD, 0.60±0.25 µmol/l (124±52 µg/l);hospital HD, 0.39±0.31 µmol/l (81±64 µg/l);CAPD, 0.32±0.17 µmol/l (66±35 µg/l);CRF, 0.38±0.20 µmol/l (79±41 µg/l);normal, 0.24±0.11 µmol/l (50±23 µg/l).Correction of the blood lead results for haemoglobin accentuatesthese differences (i.e. hospital HD, 4.61±3.25 nmol/g(0.96±0.67 µg/g); CRF, 3.05±1.46 nmol/g(0.63±0.30 µg/g); normal, 1.65±0.70 nmol/g(0.34±0.14 µg/g). Plasma aluminium concentrations show a similar pattern: homeHD, 1.09±0.70 µmol/l (29.4±18.9 µg/l);hospital HD, 0.81±0.58 µmol/l (21.9±15.7µg/l); CAPD, 0.34±0.34 µmol/l (9.2±9.2µg/l); CRF, 0.18±0.09 µmol/l (4.9±2.4µg/l); normal, 0.09±0.07 µmol/1 (2.4±1.9µg/l). The duration of dialysis treatment is an important determinantof metal accumulation: there is a significant positive correlationbetween the duration of dialysis treatment and both blood lead:haemoglobinratio (r=0.48, P<0.01) and plasma aluminium (r=0.61, P<0.01)concentrations. There is also a significant negative correlation(r= –0.59, P<0.01) between urine volume and plasmaaluminium for haemodialysis patients, but not for peritonealdialysis patients. Urine volume shows no relationship to bloodlead. Age has no effect on lead accumulation in any of the patientgroups, but there is a significant correlation of age to bloodlead in the normal renal function group (r=0.47, P<0.01).The effect of sex and hypertension on metal concentrations isalso discussed. It is considered probable that the dialysate is a major factorcontributing to the accumulation of both elements. The possiblelong-term clinical significance of these findings remains tobe determined.     

Should CAPD be the first choice for dialysis in Romania? Audit of the Iasi 'C. I. Parhon' Dialysis Center: 1995-2000.

Peritoneal dialysis was first introduced in Romania in 1995.We are reporting data on patient and technique outcomes, basedon the 5-year experience of one of the first two Romanian continuousambulatory peritoneal dialysis (CAPD) centres. During this period,Romania had the highest rate of increase in renal replacementtherapy (RRT) and CAPD (28 times over baseline) in Europe: CAPDincrease in Romania vs Eastern Europe was 6.7 compared to asimilarly defined ratio of 5.6 for haemodialysis (HD). Between 1995 and 2000, at the ‘C. I. Parhon’ Hospitalin Iasi, 259 patients were started on HD and 102 on CAPD. The90 CAPD patients we followed were treated for a total of 1896months. 86.7% of the patients were alive on 31 July 2000—67.8%continuing on CAPD, 15.6% on HD and 3.3% transplanted. The 61patients still on PD on that date, represented 11.1% of theactual Romanian CAPD population and 31% of our RRT population(compared to 13.7% nationwide). The gross mortality rate was comparable to the mean calculatedfor the HD population nationwide. Mean survival of the CAPDpatients was 45.4±2.6 months (95% CI=40.4–50.4months). One-year and 5-year patient survival rates were 97.5%and 52.7% respectively, superior and similar to mean figuresnationwide. Mean technique survival was 36.6±0.6 months(95% CI=31.5–41.6 months). One- and 5-year technique survivalrates were 83.1% and 34.3% respectively. Technique failure wasmainly due to dialysis inefficiency: 50% of cases. Mean weeklyKt/V for the 5-year period was 1.92±0.21 while mean weeklycreatinine clearance was 61.2±12.4 ml/1.73 m²/week. Eighty-four episodes of peritonitis were recorded in 46 patients(0.25 episodes/patient/year); mean duration to peritonitis was23 months (95% CI=18.2–27.5). Malnutrition was noted (SGAscore) in 25.5% of the cases. Blood pressure (assessed by 24-hABPM) was adequately controlled in 83.3% of the patients. Leftventricular hypertrophy was ubiquitous (77.7%), but left ventriculardilatation and systolic dysfunction (fractioning shorteningindex <25%) were rare—4.4% and 3.3% respectively (similarin prevalence to the Iasi HD population). No statistically significantchanges in echocardiographic parameters were recorded betweenthe first and subsequent years on CAPD treatment. Peritoneal dialysis had a rapid increase in the last 5 yearsin Romania and particularly in the region of Moldova. Outcomesand complication rates are equal or superior to nationwide HDdata and comparable to distinguished centres of CAPD in economicallydeveloped countries. We conclude that, provided that optimalmedical practice is available, CAPD should be the RRT of choicein Romania, and that it represents the only solution to thecountry's limited dialysis resources.     

Increased erythropoietin requirements in patients with failed renal transplants returning to a dialysis programme

The response to erythropoietin (Epo) is dose dependent but,for various poorly understood reasons, variable. In a cross-sectionalstudy we determined the Epo requirement of 60 patients in adialysis population to identify those patients requiring a highdose of Epo, and ascertained the reasons for higher requirements,paying particular attention to the effect of previous transplantation.All 289 patients attending a single centre were surveyed. Ofthese, 164 were receiving renal replacement therapy by continuousambulatory peritoneal dialysis (CAPD) and 125 were on haemodia-lysis(HD). Patients on HD needed more Epo than those on CAPD (129.0±14.9U/kg/week versus 86.9±10.7 U/kg/week, P<0.05). However,this difference was accounted for by a subgroup of patientswho had a previously failed transplant. The Epo requirementin those patients on HD with a failed transplant was significantlygreater than those on HD who had never been transplanted (164.0±24.5 U/kg/week versus 96.6 ± 11.9 U/kg/week, P<0.05).The seven patients who retain their transplanted kidney hadthe highest Epo requirement of all (213.4±46.6 U/kg/week).These studies have shown that previous transplantation is asignificant determinant of Epo requirement upon return to dialysis.They also show that it is necessary to ‘correct’for the effect of previous transplantation when investigatinggenerally accepted determinants of Epo need. Interpretationof previously published studies needs to take account of this.     

Acquired Cystic Disease of the Kidney in Patients with End-Stage Chronic Renal Failure: A Study of Prevalence and Aetiology

Renal ultrasound scanning was performed in 100 patients withend-stage renal failure treated by both haemodialysis and continuousambulatory peritoneal dialysis (CAPD). Each kidney was assessedfor the presence of acquired cystic disease and solid lesions.The appearances were divided into five grades from grade 0 (nocysts detected) to grade 4 (>15 cysts per kidney). Otherintra-abdominal organs were also scanned for the presence ofcysts. The findings were then correlated with possible aetiologicalfactors, including the type of dialysis used. Sixty-three percent of all the patients had acquired cysticdisease of the kidney (ACDK). No solid lesions were found andno cysts were detectable in other organs. The presence and gradeof ACDK did not correlate with the age or sex of the patient,the nature of the underlying renal disease, or the durationof chronic renal failure. There was a significant correlationbetween the grade of ACDK and the duration of both haemodialysis(P<0.001) and CAPD (P<0.01). The presence of residualrenal function did not influence the development of cysts. ACDKhad no effect on haemoglobin or other laboratory parametersmeasured.     

Increased renal allograft thrombosis in CAPD patients

In a retrospective analysis of 202 renal transplant proceduresin the years 1989–1992 we identified an excess of graftslost from primary renovascular thrombosis in patients receivingcontinuous ambulatory peritoneal dialysis (CAPD) compared tohaemodialysis (HD) patients (9 CAPD versus 0 HD, Chi-squared=9.63;P<0.01). All graft losses from thrombosis occurred within16 days of surgery. Possible predisposing causes were identifiedin three patients. Donor age was greater in CAPD patients losingtheir kidneys from thrombosis compared to the overall CAPD group[means (SD) years, 43.0(12.9) versus 29.1(15.8); P=0.01] whereasno significant difference in haematocrit, platelet count, antibodystatus, cyclosporin use, perioperative hypotension, primarydiagnosis, smoking, or diabetes mellitus was found. Data fromthe EDTA registry for 1990–91 show that graft loss fromprimary renovascular thrombosis in UK-treated patients was reportedin 7.1% of CAPD recipients compared with 1.8% in haemodialysis.We suggest that CAPD patients are at greater risk of graft lossfrom renovascular thrombosis than HD patients and may requiremore intensive fluid and anticoagulant treatment in the perioperativeperiod.     

Nocturnal intermittent peritoneal dialysis

Automated methods of peritoneal dialysis have developed as alternativemethods of treatment to CAPD. We review our experience of 47patients treated with nocturnal intermittent peritoneal dialysis(NIPD). Patients receive a nocturnal exchange of 15–25litres of dialysate with the peritoneum left dry during theday. If biochemical control is inadequate, 1 litre of dialysateis left in during the day. Indications for NIPD included socialreasons and CAPD failure due to poor ultrafiltration or problemsrelated to raised intraabdominal pressure. Some features ofbiochemical control were less good with NIPD compared with CAPDwith higher phosphate (2.18 mmol/l versus 1.83 mmol/l, P<0.001);creatinine (1256 iimol/l versus 1085 pmol/1, P.<0.00l); andpotassium (4.92 mmol/l versus 4.64 mmol/l, P=0.056) in patientschanging between CAPD and NIPD. Overall peritonitis rate onNIPD was one episode per 47.1 months compared with a rate ofone episode per 17.5 months for patients commencing CAPD overthe same period. Conversion from CAPD to NIPD was successfulin all six cases for problems related to raised intra-abdominalpressure on CAPD and in six of nine patients transferred dueto poor ultrafiltration. NIPD is a useful form of treatmentand we believe that the increased cost is offset by the reducedperitonitis rate.     

Reduced peritoneal protein selectivity may indicate peritoneal fibrosis in CAPD patients

Background. We investigated peritoneal protein selectivity to evaluate whether it may indicate changes in peritoneal pores and be related to the morphological changes in the peritoneal membrane during the course of continuous ambulatory peritoneal dialysis (CAPD) therapy. Methods. Seventeen patients on CAPD (11 men, 6 women; average age, 48.4 ± 2.8 years [mean ± SE]) were studied. The duration of CAPD ranged from 1 to 42 months (21.7 ± 3.8 months [mean ± SE]). Urea nitrogen, creatinine, transferrin, and IgG in both serum and CAPD waste fluid were measured, and dialysate/plasma (D/P) ratios for these substances were determined. To evaluate changes in the large pores, in the peritoneal membrane, the peritoneal selectivity index (PSI) was calculated in the same manner as the urinary protein selectivity index is determined; namely, as the ratio of IgG clearance to transferrin clearance into CAPD waste fluid. Results. There was no significant correlation among the D/P ratios for urea nitrogen, creatinine, transferrin, IgG, and the duration of CAPD therapy. However, the PSI showed low-grade selectivity in patients on relatively shorter periods of CAPD therapy, and high-grade selectivity in patients with longer periods of CAPD therapy. There was a significant inverse correlation between the PSI (Y) and the duration of CAPD therapy (X) (Y = −0.007X + 0.75; r = 0.75, P < 0.05). We performed a prospective study after 12 months, and 8 patients were available to measure PSI again, and almost all patients showed a decrease in the PSI (−22.8 ± 0.8%; P < 0.02). In addition, we carried out morphological evaluation of the peritoneum in 13 patients who stopped CAPD. There was a significant difference in PSI value between those with and without peritoneal fibrotic change, while there was no significant difference in PSI values for those with and without mesothelial damage or with and without arteriolar sclerosis. Conclusions. From these results, we hypothesize that reduction in the PSI may reflect the shrinkage of large peritoneal pores and the presence of peritoneal fibrotic change in CAPD patients. Received: January 9, 2001 / Accepted: July 30, 2001     

Clinical significance of exit-site infections due to Xanthomonas in CAPD patients: a comparison with Pseudomonas infection

We have assessed the clinical significance of exit-site infectionssecondary to Xanthomonas maltophilia in continuous ambulatoryperitoneal dialysis (CAPD) patients, and compared them withepisodes due to Pseudomonas. The study was a retrospective surveyof all episodes of Xanthomonas and Pseudomonas-related exit-siteinfections (ESI) in all patients treated in our unit between1984 and 1992. Thirteen episodes of Xanthomonas-related ESIwere observed in eight patients and 17 episodes of Pseudomonas-relatedESI were seen in 15 patients. Xanthomonas-related ESI was frequently associated with othermicroorganisms, while Pseudomonas related ESI was not (66% versus5%, P<0.02). Only one episode of Xanthomonas-related ESIresulted in peritonitis and subsequent catheter removal, after15 months of resistant colonization. Another case was consideredto be chronic and indolent, as the Xanthomonas-related ESI continuedafter 23 months of local treatment. The other 11 episodes wereresolved either without treatment or with an antibiotic creamafter 7–120 days. However, all but two episodes of Pseudomonas-relatedESI required intravenous antibiotics (usually ceftazidime);seven patients developed peritonitis, and 11 required surgicalcatheter manipulation (five external cuff extrusion, and sixcatheter removal) (1/13 Xanthomonas-related versus 11/17 Pseudomonas-relatedESI, P<0.03) Most Xanthomonas-related ESI do not lead to peritonitis, andconstitute a mild condition, easily treatable without parenteralantibiotics or catheter replacement. The appearance of otherassociated organisms and the favourable evolution with localtreatment suggest a saprophytic behaviour for Xanthomonas inour CAPD patients. On the contrary, Pseudomonas-related ESIis usually severe, requires parenteral antibiotics, frequentlyleads to peritonitis, and requires catheter replacement.     

Serum lipoprotein (a) concentrations in patients undergoing continuous ambulatory peritoneal dialysis

Lipoprotein (a) is a subspecies of low-density lipoprotein whichpossesses as part of its protein moiety a mutant form of plasminogentermed apolipo-protein (a), and which may be closely relatedto the risk of ischaemic heart disease and cerebral infarction.We have investigated the serum concentrations of lipoprotein(a) and other lipoproteins in 24 male patients on CAPD and comparedthem to healthy men (n= 100) and to age-matched healthy controls(n=38). The most striking finding was a substantial elevationof serum lipoprotein (a) in CAPD patients in whom it was 46.9(2.2–168) mg/dl (median and range) compared to 9.0 (<0.6–87.4)mg/dl in healthy control group and 6.7 (< 0.6–84.2)mg/dl in age-matched controls (both P<0.001). Patients, whencompared to healthy men, also had significantly increased serumtriglycerides (median and range, 1.94 (0.55–8.00) versus1.24 (0.36–4.40) mmol/1; P< 0.001), very-low-densitylipoprotein cholesterol (median and range, 0.98 (0.10–3.71)versus 0.46 (0.10–1.17) mmol/l; P<0.001), and lower-high-densitylipoprotein cholesterol (mean±1 sd, 1.26±0.29versus 1.35±0.31 mmol/l). Of these, however, only thedifference in very-low-density lipoprotein cholesterol remainedstatistically significant (P< 0.001) in comparison to age-matchedcontrols. The marked elevation of serum lipoprotein (a) in patientson CAPD may be due to increased hepatic synthesis as a consequenceof the substantial amounts of plasma proteins lost in the dialysate.Elevated serum lipoprotein (a) concentrations in CAPD patientsmay contribute to their risk of coronary artery disease.     

Oxalate elimination via hemodialysis or peritoneal dialysis in children with chronic renal failure

. Oxalate elimination and oxalate dialysance via hemodialysis (HD) or peritoneal dialysis (CAPD) has not been studied in detail in pediatric patients. We studied plasma oxalate, oxalate elimination, and oxalate dialysance in 15 infants and children undergoing CAPD (9 female, 6 male, aged 9 months to 18 years) and in 10 children on HD (4 female, 6 male, aged 7 – 18 years). Two children in each group had primary hyperoxaluria (PH). The mean duration of dialysis prior to examination was 12±11 months in CAPD and 31±23 months in HD patients. Bicarbonate HD was performed 5 h three times a week, CAPD consisted of five daily exchanges in 5 patients and four changes in the remaining 10 children (dwell volume 40 ml/kg body weight, 2.3 g/l glucose). Although oxalate dialysance was significantly higher in HD (mean 115.6 ml/min per 1.73 m² in HD versus 7.14 ml/min in CAPD), mean oxalate elimination per week was not different between both renal replacement therapies (3,478 μmol/1.73 m² surface area/week in CAPD versus 3,915 μmol/1.73 m² per week in HD). Oxalate elimination in patients with PH was between 6,650 and 9,900 μmol/week. Plasma oxalate remained elevated in both procedures [28 – 84 μmol/l in CAPD (92/148 in PH) and 33 – 101 μmol/l in HD (70/93 in PH)]. Oxalate elimination can be increased by a more frequent hemodialysis regimen. Received May 24, 1995; received in revised form and accepted October 31, 1995     

Treatment of resistant peritonitis in continuous ambulatory peritoneal dialysis with intraperitoneal urokinase: a double-blind clinical trial

Resistant peritonitis in continuous ambulatory peritoneal dialysis(CAPD) is an indication for catheter removal, followed by interimhaemodialysis and subsequent catheter replacement. This involvestwo surgical procedures using general anaesthetic and the availabilityof adequate hospital haemodialysis facilities. Urokinase isan alternative therapy but evidence of its effect is anecdotaland it has not been studied in a double-blind manner. Patients with resistant peritonitis (either no resolution ofperitonitis within 4 days of appropriate antibiotic therapyor a third episode of peritonitis within 6 months) were randomizedto receive intraperi toneal urokinase or placebo (saline) followedby 14 days of antibiotics in this double-blind prospective study.Treatment success was resolution of peritonitis within 4 daysof giving urokinase/placebo (persistent infection) and no recurrencewith the same organism for 6 months (recurrent infection). Twelvepatients received urokinase and 12 placebo. Treatment was successfulin 8/12 in the urokinase group and 1/12 in the placebo group(Fisher's exact test; P=0.0047). Urokinase was successful in 8/12 patients with resist ant peritonitisand significantly better than placebo. Urokinase is an effectiveand simple treatment that may avoid the need for catheter removaland interim haemodialysis in patients with resistant CAPD peritonitis.     

Does diurnal variation in blood pressure exist in CAPD patients?

The existence of diurnal variation in CAPD remains controversial.We therefore attempted to delineate the blood-pressure (BP)pattern in CAPD patients by ambulatory blood-pressure monitoring(ABPM). Initially ABPM was performed in 31 patients (21 M, 10F), mean age 65.4 years (26–87) using the Spacelabs model90207. The maximal normal BP preset on the recorder was 140/90mmHg. Daytime and night-time readings, recorded every 30 min,were defined as those from 0600 to 2100 and 2100 to 0600 hoursrespectively. Mean duration of dialysis was 15.2 months (3–76). There were 14 hypertensive patients, defined as a basal BP >140/90 mmHg, or those on antihypertens-ive medications. Takingthe group as a whole a significant difference between day andnight-time readings was found as regards minimal systolic BP(118 versus 107.6 mmHg), maximal systolic BP (181.6 versus 171.2mmHg), mean diastolic BP (83.9 versus 79.6 mmHg), and maximaldiastolic BP (121.7 versus 104.5 mmHg), P<0.05. Diurnal variation,defined in the initial study as a 10% decrease of MAP occurringduring any consecutive 4-h period, was present in 21 patients.In three the diurnal variation manifested as a paradoxical reductionof BP during the day. The only significant difference betweenthose with diurnal variation and those without was the durationof dialysis, being 19.2 ±19.9 versus 13.3 ±17.3months respectively, (P<0.05). In a second study 18 hypertensive CAPD patients were subjectedto ABPM. Nine of them had participated in the first study. Thesepatients were specifically asked to detail their periods ofsleep and arousal. Diurnal variation was here defined as a 10%decrease of MAP occurring 2 h after the onset of sleep. Diurnalvariation was found to exist in 10 patients (55%). Comparingthe day to night-time readings in this group, no significantdifferences were found in mean systolic and MAP. When, however,the arousal versus sleep period readings were compared, a significantdifference was observed in mean diastolic BP (83±14 versus77±17mmHg, P<0.01), and in the MAP (104 ± 18versus 98±20.5 mmHg, P<0.01). The mean systolic BPjust failed to reach statistical significance (141±26versus 137±30 mmHg) due probably to the small samplesize. We conclude that diurnal variation exists in the majority ofCAPD patients. Our findings support the concept that the setpoint model of diurnal variation, in which the major determinantis activity or arousal is the operative one in these patients.Due to disordered sleep patterns in patients on CAPD, diurnalvariation might thus be better elicited when taking into accounta decrease of MAP occurring during any consecutive 4-h period.     

Antibacterial peritoneal defence in automated peritoneal dialysis: Advantages of tidal over continuous cyclic peritoneal dialysis?

In tidal peritoneal dialysis (TPD) only a part of the infuseddialysate is drained with each exchange, leaving a residualvolume on top of which fresh fluid is cycled. As the persistentpresence of a buffered intraperitoneal reserve volume mightfavour peritoneal macrophage (PMO) function, PMO obtained fromeight patients during a 3-h continuous cyclic peritoneal dialysis(CCPD) or TPD session were studied in a randomized cross-overtrial. PMO were studied for uptake of E. coli (complement-dependent)and S. epidermidis (antibody-dependent), as well as for theirkilling capacity and peak chemiluminescence response. In addition,dialysate was sampled during both treatment sessions and studiedfor pH, osmolality, and effect on the viability of donor phagocytesand mesothelial cells. TPD-derived PMO were significantly better able to phagocytoseE. coli than CCPD-PMO (48 ±8 versus 33±6% uptake,P<0.05), whereas the other tested functional capacities revealedno significant difference between TPD- and CCPD-PMO. DuringTPD dialysate pH ranged from 6 to 7 as compared to a pH rangefrom 5 to 7 in CCPD. The presence of a residual dialysate volumeresulted in less wash-out of cells and opsonins early in thetreatment, and to some extent blunted the noxious effects offresh dialysis solutions. Overall, however, tidal PD appearedto have no advantage over CCPD regarding preservation of peritonealdefences.     

Ultrasonographic detection of thickened joint capsules and tendons as marker of dialysis-related amyloidosis: a cross-sectional and longitudinal study

Dialysis-related amyloidosis is characterized by a ß₂-microglobulin(ß₂M) infiltration of joint synovia, tendons and capsules.We report a cross-sectional ultrasonographic evaluation of supraspinatustendon and femoral neck capsule thickness in 49 patients onlong-term haemodialysis. Ultrasonographic evaluation was repeated21±4 (SD) months later in 16 patients. Normal valuesfor the supraspinatus tendon and femoral neck capsule were definedin a group of control subjects without history or signs of jointdisease. Among the 49 patients, aged 21–86 (median 59) years, dialysedfor 1–228 (median 97) months, 33 had at least one abnormaljoint. The prevalence of patients with at least one and at leasttwo abnormal joints, the number of abnormal joints per patient,and the thickness of the supraspinatus tendon and femoral neckcapsule increased significantly with dialysis duration (P<0.001 for all parameters considered). By multiple linear regressionanalysis, mean thickness of the supraspinatus tendon was positivelyrelated to both dialysis duration (P< 0.0001) and age (P= 0.036) independently. All (n=11) patients with radiological and/or histological evidenceof dialysis-related amyloidosis at the time of ultrasonographyhad thickened supraspinatus tendon and/or femoral neck capsule;which were also thickened in an additional 22 patients withoutradiological evidence of dialysis-related amyloidosis. Threedied within 5–10 months of the ultrasonographic investigation: post-mortem examination of the periarticular tissue confirmedthat the detected thickening was due in all three to ß₂Mamyloid infiltration. Sixteen patients underwent a second ultrasonographic evaluation21±4 months later. In nine patients on dialysis for <60months at the time of the first evaluation, mean femoral neckcapsule thickness increased significantly (7.0±0.8 to8.2±2.3mm, P = 0.017) whereas mean supraspinatus tendonthickness increment was not significant (6.6±0.4 to 7±0.8mm, P=0.23). In the seven other subjects dialysed for <60months, neither the supraspinatus tendon nor femoral neck capsulethickness changed. We suggest that ultrasonographic measurement of supraspinatustendon and femoral neck capsule thickness is a useful, non-invasivetool to detect and monitor dialysis-related amyloidosis.     

Comparison of peritonitis rates and patient survival in automated and continuous ambulatory peritoneal dialysis: a 10-year single center experience

Peritonitis is a common complication in patients undergoing continuous ambulatory peritoneal dialysis (CAPD) and automated peritoneal dialysis (APD). In this retrospective study, peritonitis rates and patient survival of 180 patients on CAPD and 128 patients on APD were compared in the period from January 2005 to December 2014 at Al-Nafisi Center in Kuwait. All patients had prophylactic topical mupirocin at catheter exit site. Patients on CAPD had twin bag system with Y transfer set. The peritonitis rates were 1 in 29 months in CAPD and 1 in 38 months in APD (p?<?0.05). Percentage of peritonitis free patients over 10-year period in CAPD and APD were 49 and 60%, respectively (p?<?0.05). Time to develop peritonitis was 10.25?±?3.1 months in CAPD compared to 16.1?±?4 months in APD (p?<?0.001). Relapse and recurrence rates were similar in both groups. Median patient survival in CAPD and APD groups with peritonitis was 13.1?±?1 and 14?±?1.4 months respectively (p?=?0.3) whereas in peritonitis free patients it was 15?±?1.4 months in CAPD and 23?±?3.1 months in APD (p?=?0.025). APD had lower incidence rate of peritonitis than CAPD. Patient survival was better in APD than CAPD in peritonitis free patients but was similar in patients who had peritonitis.     

Effects of haemodialysis and continuous ambulatory peritoneal dialysis on the plasma clearance of an albumin-bound furan dicarboxylic acid

Organic acids that are strongly bound to albumin are not removedby dialysis and the plasma concentrations of one such substance,a furan dicarboxylic acid (3-carboxy-4-methyl-5-propyl-2-furan-propanoicacid; 5-propyl FPA) have been measured by HPLC in healthy subjects(n=21), patients on regular haemodialysis (n=30), and patientstreated by continuous ambulatory peritoneal dialysis (n=21).The mean (±SD) concentrations of 5-propyl FPA were significantlyhigher in haemodialysis (95±44 µM) compared toCAPD patients (28±19 µM)) and both were higherthan in healthy individuals (14±7 µM). Haemoglobinconcentrations in CAPD patients were significantly higher thanin those on haemodialysis while these patients had significantlyhigher albumin concentrations than CAPD patients. The concentrationof 5-propyl FPA was positively correlated with the durationof dialysis for haemodialysis patients but not for CAPD patients.The lower concentrations of 5-propyl FPA in CAPD patients mayat least partly explain the higher haemoglobin levels foundin these patients.