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D G Oreopoulos

Publications and source records attributed to D G Oreopoulos.

At least 19 recordsLinked to original sources

N-acetylglucosamine reduces inflammatory response during acute peritonitis in uremic rats.

BACKGROUND: Peritoneal dialysis (PD) induces intraperitoneal inflammation and that process may be uremia. The goal of this study is to evaluate the effect of uremia on the kinetics of peritonitis and furthermore test the anti-inflammatory potential of N-acetylglucosamine (NAG) in a uremic environment. METHODS: Experiments were performed on healthy Wistar rats and on animals with impaired renal function. Acute PD was performed in all animals with dialysis fluid containing either glucose (GLU) or NAG as osmotic solutes. Peritonitis was induced by addition of lipopolysaccharide from Escherichia coli (LPS) to the dialysis fluid. Transperitoneal transport of water and solutes as well as intraperitoneal and systemic inflammation were evaluated. RESULTS: Uremia reduces peritoneal permeability to total protein during peritonitis (-33% vs. control, p < 0.001) and increases net ultrafiltration (+2.5 +/- 2.2 vs. -2.7 +/- 3.2 ml in control, p < 0.001). In uremic rats with peritonitis, reduced dialysate levels of the following inflammatory mediators were detected as compared to healthy animals: MCP-1 (-15%, p < 0.01); IL-1beta (-53%, p < 0.001), and elastase (-28%, p < 0.02). In the serum of uremic rats, the increase in TNFalpha and MCP-1 concentrations was smaller than in control rats: -44% (p < 0.02) and -39% (p < 0.001), respectively. NAG used as an osmotic solute in rats with preserved renal function decreases intraperitoneal and systemic inflammation during acute peritonitis. Drained dialysate volume was increased in the NAG group by 32% (p < 0.001) and transperitoneal loss of protein was reduced by 21% (p < 0.002). When NAG was used as the osmotic solute instead of GLU, intraperitoneal inflammation in uremic animals was further reduced: TNFalpha (-40%, p < 0.05); IL-1beta (-49%, p < 0.005); MCP-1 (-21%, p < 0.005). The presence of NAG also reduced the increased blood level of IL-1beta (-47%,p < 0.02) and MCP-1 (-36%, p < 0.02). CONCLUSIONS: Intensity of acute peritonitis is reduced during uremia. NAG exerts a systemic and peritoneal anti-inflammatory action under conditions of uremia that confirms the potential use of this compound as an osmotic agent in the PD fluids that also decreases inflammation.

Acetylglucosamine↗

Difference in estimated GFR with two different formulas in elderly individuals.

The aim of this study was to characterize the differences between the prediction of GFR with Cockcroft-Gault formula (CG=(140-age)/(72 x PCr (mg/ml), for females multiplied by 0.85) and the new formula based on the multicenter trial of the Modification of Diet in Renal Diseases (MDRD=186 x P (Cr) (-1.154) x age(-0.203); 0.742 if patient is female) in elderly subjects. The study involved 100 individuals aged 65-111 years (mean age 88.3+/-14.7; 79 females and 21 males). In all subjects GFR was estimated according to both formulas mentioned above and expressed in ml/min/1.73 m2. Thereafter we calculated the difference between MDRD and CG (MDRD-CG) and analyzed its determinants in every subject. Mean GFR, obtained with MDRD was 76.0+/-24.0, whereas according to CG 67.9+/-18.6 (p < 0.0001). However, the mean MDRD-CG was up to 30.0+/-26.6 which means that MDRD results were much higher in comparison with CG. Using the multiple linear regression analysis we showed that MDRD-CG strongly depend on age (p < 0.0001), BMI (p < 0.0001) and serum creatinine concentration (p<0.0001). However, the gender has not effect on MDRD-CG value. The values of MDRD-CG strongly and positively correlated with age (r=0.7027, p < 0.0001) and negatively both with body mass index (r=-0.7171, p < 0.0001) and serum creatinine (r=-0.5590, p < 0.0001). In summary, our results show that the difference between MDRD and CG strongly depends on age, BMI and Scr. Investigators should be aware of these differences and take it into account in elderly.

Age Factors↗

Time to reconsider saline as the ideal rinsing solution during abdominal surgery.

BACKGROUND: Peritoneal mesothelial cells lining the peritoneal cavity play a primary role in prevention of formation of peritoneal adhesions, which depends mainly on their fibrinolytic activity. During surgical procedures, the abdominal cavity is in most cases rinsed with normal saline solution, which may modify the fibrinolytic activity of the peritoneal mesothelium and predispose to formation of adhesions. The goal of our experiments was to evaluate how normal saline and other solutions affect the fibrinolytic properties of the peritoneal mesothelial cells. MATERIAL AND METHODS: Experiments were performed on in vitro cultures of human peritoneal mesothelial cells. Mesothelial monolayers were exposed during 6 hours to the following solutions: culture medium (control), .9% NaCl, Hanks solution, Earles solution, new peritoneal dialysis fluid with low glucose degradation products (GDP) concentration (PDF), and peritoneal dialysis fluid with high concentration of GDP (PDF-GDP). Afterwards, morphology of the cells as well as leakage of lactate dehydrogenase (LDH) from their cytosol were evaluated. During the next 24 hours when the cells were cultured in standard medium synthesis of interleukin-6 (IL-6), tissue plasminogen activator (t-PA) and plasminogen activator inhibitor-1 (PAI-1) were studied. RESULTS: Mesothelial monolayers exposed to .9% NaCl or to PDF-GDP showed destruction of their morphology after 6 hours incubation and in case of PDF-GDP release of LDH from the cytosol was increased by 275% versus the control (P<.05). During subsequent culture of all cells in standard medium, the release of IL-6 was decreased in cases of cells pretreated with .9% NaCl (-58%, P<.05) or PDF-GDP (-93%, P<.001). The release of t-PA was also reduced from cells pretreated with .9% NaCl (-71%, P<.01) or with PDF-GDP (-74%, P<.01) but increased after exposure of these cells to PDF (+35%, P<.05). Statistically significant decrease of PAI-1 synthesis was observed in cells preexposed to .9% NaCl (-69%, P<.01) or to PDF-GDP (-82%, P<.05). When changes in the PAI-1/t-PA ratio were calculated, a strong tendency for increase of that value was seen in cells pretreated with .9% NaCl or Earles salts solution but not with PDF. However, in cases of Hanks solution, a significant increase in the PAI-1/t-PA ratio was observed (+104%, P<.01). CONCLUSION: Exposure of the peritoneal mesothelial cells to .9% NaCl, Hanks, Earles salts solution, or PDF-GDP results either in reduction of their viability or in loss of their fibrinolytic activity. Peritoneal dialysis fluid with a low content of glucose degradation products appears to be the optimal solution causing the least damage to mesothelial cells and therefore may be the ideal solution for rinsing the abdominal cavity with low risk of inducing deterioration of the mesothelial cells fibrinolytic activity and formation of adhesions. We postulate therefore that such hypertonic peritoneal dialysis fluids should be used not only during peritoneal dialysis but also for rinsing the abdominal cavity during any surgical procedures.

Cell Culture Techniques↗

The Toronto Western Hospital catheter: one center's experience and review of the literature.

BACKGROUND: We report our center's experience with the Toronto Western Hospital (TWH) catheter, and discuss our catheter survival and complication rates. METHODS: Retrospective chart review of patients receiving peritoneal dialysis therapy via a TWH catheter. Catheter complication rates of peritonitis, exit site infection, obstruction, leak, and malfunction were assessed. A catheter was considered failed if removed because of exit site infection, obstruction, or malfunction. All other catheters, even if removed for other reasons, were considered censured. Survival was defined as the period from insertion to failure or censure date, and reported using Kaplan Meier analysis. RESULTS: 192 patients with a total of 208 TWH catheters (4,845.3 catheter months) were analyzed. Our overall 1- and 3-year catheter survival rates were identical at 0.9182. Our catheter complication rates (expressed as number of catheter months per event) were 31.3 for peritonitis, 42.9 for exit site infection, 72.3 for obstruction, 538.4 for malfunction, and 969.1 for catheter leak. Our findings were similar to those reported in the literature for TWH and other peritoneal catheters.

Catheters, Indwelling↗

Severe vitamin D deficiency in chronic renal failure patients on peritoneal dialysis.

UNLABELLED: The aim of this study was to evaluate the prevalence of vitamin D deficiency in chronic renal failure (CRF) patients on peritoneal dialysis (PD) and to correlate the findings with various demographic and renal osteodystrophy markers. METHOD: This cross-sectional, multicenter study was carried out in 273 PD patients with a mean age of 61.7 +/- 10.9 years and mean duration of PD 3.3 +/- 2.2 years. It included 123 female and 150 male patients from 20 centers in Greece and Turkey, countries that are on the same latitude, namely, 36-42 degrees north. We measured 25(OH)D3 and 1.25(OH)2D3 levels and some other clinical and laboratory indices of bone mineral metabolism. RESULTS: Of these 273 patients 92% (251 patients) had vitamin D deficiency i.e. serum 25(OH)D3 levels less than 15 ng/ml, 119 (43.6%) had severe vitamin D deficiency i.e., serum 25(OH)D3 levels, less than 5 ng/ml, 132 (48.4%) had moderate vitamin D deficiency i.e., serum 25(OH)D3 levels, 5-15 ng/ml, 12 (4.4%) vitamin D insufficiency i.e., serum 25(OH)D3 levels 15 - 30 ng/ml and only 10 (3.6%) had adequate vitamin D stores. We found no correlation between 25(OH)D3 levels and PTH, serum albumin, bone alkaline phosphatase, P, and Ca x P. In multiple regression analyses, the independent predictors of 25(OH)D3 were age, presence of diabetes (DM-CRF), levels of serum calcium and serum 1.25(OH)2D3. CONCLUSION: We found a high prevalence (92%) of vitamin D deficiency in these 273 PD patients, nearly one half of whom had severe vitamin D deficiency. Vitamin D deficiency is more common in DM-CRF patients than in non-DM-CRF patients. Our findings suggest that these patients should be considered for vitamin D supplementation.

Adult↗

Effect of valsartan versus lisinopril on peritoneal sclerosis in rats.

BACKGROUND: Peritoneal sclerosis (PS) is one of the most serious causes of failure in long-term peritoneal dialysis. Angiotensin II is known to promote fibrosis and inflammation in various tissues. We previously showed that ACE inhibitors (ACEIs) have beneficial effects on hypertonic PD solutions (3.86% PD) induced peritoneal alterations. The aim of this study is to compare the effects of an ACEI and a receptor blocker on peritoneal alterations induced by hypertonic PD solutions in rats. METHODS: Forty-three non-uremic rats were divided into four groups: group I (Sham) rats received no treatment (n=11), group II received hypertonic (3.86%, 10 ml/day) PD solution (n = 10) and groups III and IV received hypertonic PD solution (10 ml/day) plus 640 mg/L valsartan (n=11) and 100 mg/L lisinopril in drinking water (n = 11). After four weeks, a one-hour peritoneal equilibration test (PET) was performed with 3.86% PD solution. Dialysate-to-plasma urea ratio (D/P urea), glucose reabsorption (D 1 /D 0 glucose), ultrafiltration volume (UF), dialysate protein, TGFbeta 1 and VEGF levels were determined. RESULTS: Administration of valsartan or lisinopril resulted in preserved UF (8+/-0.8 and 6.7+/-0.7 vs 4.9+/-0.8 mL), D1/D0 glucose (0.69+/-0.05 and 0.62+/-0.05 vs 0.56+/-0.04) and peritoneal thickness (19.4+/-2.9 and 28.5+/-5.2 vs 53+/-3 microm), respectively. Both higher level of TGF beta 1 (206+/-40 vs 474+/-120 pg/mL, p<0.05), and VEGF in dialysate effluent (4+/-0.4 vs 7.9+/-3 pg/mL, p>0.05), was determined in the dextrose group. Both cytokines are partially inhibited by valsartan or lisinopril (p >0.05) CONCLUSION: Exposure to hypertonic glucose solution resulted in alterations in peritoneal transport manifested by a rapid dissipation of the glucose gradient and resultant impaired UF response. Administration of valsartan or lisinopril led to attenuation of these alterations. We suggest that the equal protection of the peritoneal membrane from the effects of hypertonic glucose was achieved by receptor blockers and ACE inhibitors.

Angiotensin II Type 1 Receptor Blockers↗

Atorvastatin improves peritoneal sclerosis induced by hypertonic PD solution in rats.

BACKGROUND: Peritoneal sclerosis is a complication of peritoneal dialysis and results in ultrafiltration failure. It is related to chronic peritoneal injury due to dialysis solution content and recurrent peritonitis. Statins have anti-inflammatory properties which may be of value in modulating responses to injury. We evaluated the capacity of atorvastatin to modify peritoneal alterations secondary to hypertonic glucose. METHODS: Thirty-two non-uremic rats were divided into three groups: group I (Sham) rats received no treatment (n=11), group II received hypertonic (3.86%, 10 ml/day) PD solution (n=10) and group III received hypertonic PD solution (10 ml/day) plus 80 mg/L atorvastatin in drinking water (n=11). After four weeks, a one-hour peritoneal equilibration test (PET) was performed with 3.86% PD solution. Dialysate-to-plasma urea ratio (D/P urea), glucose reabsorption (D 1 /D 0 glucose), ultrafiltration volume (UF), dialysate protein, TGF-beta 1 and VEGF levels were determined. RESULTS: Administration of atorvastatin resulted in preserved UF (4.9+/-0.8 vs 7.5+/-0.6 mL, p <0.01), protein loss (2.2+/-0.2 vs 2.1+/-0.1 g/L, p >0.05), and peritoneal thickness (53+/-3 vs 26+/-4 microm, p <0.01). D 1 /D 0 glucose was significantly reduced in the dextrose group (0.70+/-0.02 vs 0.56+/-0.04, p <0.01). Both higher levels of TGF-ss 1 (206+/-40 vs 474+/-120 pg/mL, p<0.05), and VEGF in dialysate effluent (4+/-0.4 vs 7.9+/-3 pg/mL, p>0.05), was determined in the dextrose group. CONCLUSION: Exposure to hypertonic glucose solution resulted in alterations in peritoneal transport manifested by a rapid dissipation of the glucose gradient and resultant impaired UF response. Administration of atorvastatin led to prevention of these alterations. We suggest that the anti-inflammatory properties of statins are useful in providing protection of the peritoneal membrane from the effects of hypertonic glucose.

Animals↗

Predictive factors of low HCO3- levels in peritoneal dialysis patients.

BACKGROUND: Metabolic acidosis is a major metabolic abnormality in end-stage renal disease (ESRD) and alkali is provided with dialysis treatment to patients on chronic peritoneal dialysis (CPD) to keep their acid-base balance within normal serum HCO3- levels. METHODS AND RESULTS: We examined the levels of venous serum HCO3- in 163 patients on CPD and the predictive factors for HCO3- levels low enough to indicate metabolic acidosis. The mean value for HCO3- was 26+/-2.4 mmol/l and for anion gap was 13.1+/-3.1 mEq/l. A serum bicarbonate concentration of less than 24 mmol/l, compatible with metabolic acidosis, was observed in 13.5% of the patients. In a multivariate analysis HCO3- levels were directly correlated with older age and use of CaCO3- as phosphate binders, and inversely associated with serum potassium, the use of sevelamer and low lactate dialysis solutions. Higher serum urea levels, the use of low lactate solutions and sevelamer instead of CaCO3 were significantly predictive factors for HCO3- levels < 24 mmol/l. CONCLUSIONS: Venous HCO3- and anion gap values were within the normal ranges in stable CPD patients. In 13.5% of them, however, chronic metabolic acidosis was observed based on venous HCO3- levels < 24 mmol/l. Dietary protein intake, the use of sevelamer and low (35 mmol/l) concentration of lactate in dialysis solutions are important predictive factors for chronic metabolic acidosis in these patients.

Acidosis↗

Renal cell carcinoma in peritoneal dialysis patients.

Renal cell carcinoma is a rare but serious complication in ESRD patients. In these patients the incidence of renal cell carcinoma (RCC) is 20-40 times higher than in the general population. We performed a retrospective study to measure the incidence rate, prevalence, characteristics and survival among our peritoneal dialysis (PD) patients diagnosed with renal cell carcinoma. The study was carried out among 607 patients who were on the PD program from January 1997 to June 2002. RCC was detected in eight patients (four males and four females) with mean age of 52.1 +/- 10.6 years. Among these eight patients four were new cases that were diagnosed before the patients were started on dialysis (three in native kidneys and one in a transplanted kidney). In the other four patients the RCC was diagnosed after they had been on dialysis for 33-204 months (mean 60.75 +/- 50.48). We found an incidence rate of 1.3 per 1000 patients per year and a prevalence of 1.3%. Six of the eight patients had renal cysts. Tumor size was less than 7 cm in seven patients and in the other patient it was 8.5 cm. Seven of eight patients were alive at the time of study with a survival time ranging from 3-138 months (mean 122.25 +/- 88.2) months. In one patient, the RCC metastasised to the scalp, and, in two other patients, the tumors subsequently involved the second kidney. A cardiovascular complication was the cause of one death. Two patients received a renal transplant 36 and 66 months after diagnosis. We conclude that despite the low rate of metastases and mortality in our study, regular ultrasonography should be added to the follow-up of PD patients. Renal transplantation can be considered in these ESRD patients with RCC; however, close follow-up for metastases is recommended.

Adult↗

Peritoneal catheter exit-site infections: predisposing factors, prevention and treatment.

Catheter-related infections, exit-site-tunnel infections and peritonitis remain the Achilles heel of peritoneal dialysis. Although the overall incidence of peritoneal-dialysis-related infectious complications has been reduced since the introduction of the Y-set and double bag system, approximately one-fifth of peritonitis episodes are associated with catheter exit-site and tunnel infections. Since its development in 1968, the Tenckhoff catheter has become one of the most widely used peritoneal catheters, and many have proposed that a number of modifications have made it a better choice. Controversies concerning the effect on exit-site infections of catheter(s) with one or two cuffs, with straight, coiled, Swan-Neck, or other modifications led to the randomized controlled studies that are reviewed in this paper. Several studies have confirmed that mupirocin, applied at the exit-site as part of regular exit-site care, reduces the risk of S. aureus exit-site and tunnel infections. Recently, the emergence on a world-wide basis of mupirocin-resistant S. aureus (MuRSA) in peritoneal dialysis patients has brought this prophylactic strategy into question. However the low frequency of resistant organisms after four years of mupirocin prophylaxis suggests that we can continue its use with annual surveillance. Once established, exit-site infections may respond to appropriate treatment, but if not the only option may be catheter removal and replacement. Although peritonitis risk has decreased over the past decade, mainly due to improvements in connection technology, exit-site and tunnel infections have not. An exit-site infection that does not respond to treatment may lead to tunnel infection and to persistent peritonitis, which may require catheter removal and occasionally discontinuation of the peritoneal dialysis. Therefore it is important to be familiar with these factors that predispose to exit-site infection and to know how to prevent and to treat such infections. This review will discuss factors that predispose to catheter-related exit-site infections, techniques of exit-site care, and ways to prevent exit-site infection, with emphasis on S. aureus infections and their treatment.

Antibiotic Prophylaxis↗

Infections in patients undergoing peritoneal dialysis.

Considering experience acquired in the past years, it seems as though physicians have reached a plateau in the frequency of peritonitis. A peritonitis rate of 1 every 2 patient years may be acceptable. Further reduction of this peritonitis rate will require inordinately large efforts on all fronts. One will have to consider what are the acceptable costs and risks of peritonitis in patients on peritoneal dialysis. New developments in catheter technology, improved connections, better understanding of patient selection and training programs, improved diagnostic and therapeutic methods in the management of peritonitis, and understanding of the infectious and immune processes are eagerly awaited developments.

Anti-Bacterial Agents↗

The relation between nutrition indices and age in patients on continuous ambulatory peritoneal dialysis receiving similar small solute clearances.

OBJECTIVE: To analyze the effect of age on nutrition indices in subjects on the same continuous ambulatory peritoneal dialysis (CAPD) schedule. METHODS: We analyzed 613 sets of clearance values and nutrition indices in 302 CAPD patients. Small solute clearances included urea clearance (Kt/Vurea) and creatinine clearance (Ccr). Nutrition indices included body mass index (BMI), serum albumin, urea and creatinine, 24-h urea nitrogen and creatinine excretion in urine plus dialysate, protein nitrogen appearance (PNA), PNA normalized by standard weight (nPNA), lean body mass (LBM) computed by creatinine kinetics, and LBM/Weight. CAPD subjects were classified in 4 age quartiles (Q): Group Q1, age 33.7 +/- 7.6 years, N = 149; group Q2, age 49.5 +/- 3.8 years, N = 158; group Q3, age 61.5 +/- 2.6 years, N = 154; and group Q4, age 72.1 +/- 5.4 years, N = 152. Group comparison was done by one-way ANOVA or chi-square. Predictors of low nutritional parameters were identified by logistic regression. Selected variables were compared by linear regression. RESULTS: Mean Kt/Vurea and Ccr were above the current adequacy standards and did not differ between the age quartiles. In contrast, older quartiles had, in general, lower nutrition indices than younger quartiles. However, the youngest quartile had the lowest BMI. By logistic regression, young age was a predictor of low BMI, while advanced age was a predictor of low creatinine and urea nitrogen excretion, low nPNA, and low LBM/Weight. The regressions of nPNA on Kt/Vurea differed between the age quartiles. By these regressions, the youngest quartile had higher nPNA values for the same Kt/Vurea than the oldest quartile in the clinically relevant range of Kt/Vurea and nPNA values. CONCLUSIONS: Nutrition indices are worse in older than in younger CAPD patients with the same small solute clearances. Nutrition of CAPD patients is adversely affected by age and requires special attention in the older age group.

Adult↗

Plasma glutathione peroxidase activity in the elderly.

Schiavon et al. (1994) have reported that the measurement of plasma glutathione peroxidase activity (PGP) could provide an index of renal function. Its activity, which was depressed in patients with impaired renal function, correlated positively with creatinine clearance and negatively with serum creatinine. To evaluate the hypothesis that the plasma PGP activity may be used to assess renal function in elderly, we measured the plasma PGP and creatinine clearance (ClCr) in 65 active, community-dwelling elderly (range: 65-93 years; 47 women and 18 men). We did not include persons with advanced renal failure in our study. PGP did not correlate with PCr and it was similar among patients with normal and with increased PCr (127.0 +/- 30.7 U/l and 119.7 +/- 21.6 U/l, respectively). A positive correlation was found between PGP and ClCr (r = 0.30; p < 0.01). Plasma PGP activity was lower in patients with a ClCr lower than 70 ml/min/1.73 m2 than in those who had a higher ClCr (113.0 +/- 25.8 U/l and 131.2 +/- 26.7 U/l, p < 0.01). However, no correlation was found between ClCr and PGP in subjects with lower ClCr. PGP did not correlate with age but there was a correlation between ClCr and age (r = -0.24, p < 0.05). Our results suggest that plasma PGP activity is decreased in the patients with impaired renal function but this decrease does not correlate with age-dependent decline of kidney function.

Aged↗

Chronic peritoneal dialysis in octogenarians.

BACKGROUND: During the past few decades the pattern of end-stage renal failure disease has changed with increasing number of elderly patients admitted for dialysis. In spite of their increasing number, little is known about the optimal mode of therapy of the 'old old' (those >or=80 years) patients. METHODS: In this retrospective study, we analysed the results of treatment of 31 non-institutionalized 'old old' patients at Toronto Western Hospital (17) and Scarborough General Hospital (14) and seven institutionalized patients in chronic care, Riverdale Hospital. The patients were on CAPD with Twin-bag Baxter (28) or Home Choice, Baxter or Fresenius CCPD system (10). Patients were screened at the CAPD clinic when routine blood investigations were done. Patient and technique survival, initial and final laboratory data (last visit or before death) and complications related/unrelated to dialysis method are presented. RESULTS: Multiple comorbid conditions were present at the start of the treatment and new added during treatment; very few were dialysis-related. The majority of non-institutionalized patients required assistance of home-care nurse to perform dialysis. Peritonitis (1/28.6 patient months) and exit-site infection rate (1/75.1 patient months) were low and responded to treatment. Incidence of peritonitis was higher among institutionalized debilitated patients (1/5.3 patient months). Incidence of hospitalization was 1/14.7 patient months and patients spent in hospital 7.5 days/patient year. Forty-seven per cent of patients survived 24 months; 39% survived 30 months. Technique survival was 91.5% at 12 months and 81.4% at 30 months. Poor appetite and malnutrition were frequent among very old patients. Patients and their families were motivated for treatment and discontinuation of dialysis was not higher than described elsewhere in literature. CONCLUSIONS: This study has demonstrated that chronic peritoneal dialysis could be recommended as a safe and suitable modality of treatment of end-stage renal failure in old old patients.

Aged↗

Long-term blood pressure control in a cohort of peritoneal dialysis patients and its association with residual renal function.

BACKGROUND: Hypertension is the prime contributor for cardiovascular mortality in the dialysis population. Peritoneal dialysis (PD) has been thought to improve blood pressure (BP) control in the short term, but the long-term benefits are not conclusively proven. We aimed to evaluate the degree of BP control in PD patients in the long term and analyse the factors associated with poor control. METHODS: Data of all patients who were initiated on PD at one centre between July 1994 and July 1998 and completed at least 1 year of PD were analysed retrospectively at initiation of PD, at 6 months, and annually thereafter until 5 years or until discontinuation of therapy. Hypertension was defined as per WHO/ISH criteria. A 'Blood Pressure Control Index' was empirically defined to account for the effect of antihypertensives on measured BP. Factors associated with poor BP control were analysed. RESULTS: Out of 207 patients (age 57.0+/-16.0 years, 103 male, 104 female) 91.3% were hypertensive at the start of PD. About 33.8% had diabetic nephropathy. Systolic and mean arterial pressure index improved in early phase reaching a nadir between 6 months and 1 year followed by steady progressive worsening through out the rest of follow up. On multiple linear regression analysis age (P<0.001), duration of hypertension prior to dialysis (P<0.001), and declining residual renal function, expressed as both average of urea and creatinine clearance (P=0.002) and residual urine output (P<0.001) were independently associated with poor BP control. Diabetes (P=0.836), peritoneal transport (D/P 4 of creatinine at start) (P=0.218), peripheral oedema (P=0.479) and dose of erythropoetin (P=0.488) were not associated. CONCLUSIONS: Initiation of PD results in early improvement of hypertension in end-stage renal disease (ESRD). BP control thereafter deteriorates steadily with time and this is associated with age, duration of hypertension, and declining residual renal function. This suggests that hypertension in ESRD patients is a progressive disease primarily related to falling glomerular filtration rate, the preservation of which might improve BP control and possibly modify cardiovascular risk.

Adult↗

Multidirectional approach to study peritoneal dialysis fluid biocompatibility in a chronic peritoneal dialysis model in the rat.

BACKGROUND: Peritoneal dialysis causes the functional and morphological changes in the peritoneum that result from the bioincompatibility of dialysis solutions. We present a model of chronic peritoneal dialysis in the rat that can be used for testing the biocompatibility of dialysis fluids. Methods and Results. Long-term exposure of the peritoneum to dialysis solutions can be performed in rats with implanted peritoneal catheters. Sampling of the dialysate allows the evaluation of intraperitoneal inflammation by examining cell differential and dialysate cytokine levels. Peritoneal permeability can be evaluated at designed time intervals with the peritoneal equilibration test (PET). At the end of dialysis, peritoneal histology is studied with light and electron microscopy. CONCLUSIONS: Such a multidirectional approach is an effective way to test biocompatibility of dialysis solutions.

Animals↗