PubMed Health⌕ Search

Biomedical subjects

Dimitrios G Oreopoulos

Publications and source records attributed to Dimitrios G Oreopoulos.

46 records · Page 3Linked to original sources
PubMedDate not supplied

Effects of intraperitoneal hyaluronan on peritoneal fluid and solute transport in peritoneal dialysis patients.

BACKGROUND: Hyaluronan (HA) is a glycosaminoglycan found in connective tissues and tissue spaces, including the peritoneal cavity. In vivo studies in a rat model of peritoneal dialysis (PD) have shown that addition of HA to PD solution during an intraperitoneal dwell can alter peritoneal fluid transport and protect the peritoneal membrane from the effects of inflammation and repeated infusions of dialysis solution. The current study sought to evaluate the safety of intraperitoneal HA and its effect on peritoneal fluid and solute transport when administered during a dialysis dwell in humans. METHODS: 13 PD patients were enrolled in a prospective, randomized crossover study involving three dialysis treatments using the following PD solutions: (1) a commercially available PD solution (Dianeal PD-4, 1.36% glucose; Baxter Healthcare Corporation, Alliston, Ontario, Canada); (2) Dianeal PD-4 containing 0.1 g/L HA, and (3) Dianeal PD-4 containing 0.5 g/L HA. Each 6-hour dialysis exchange was separated from the other exchanges by a 2-week washout period. Radioiodinated human serum albumin (RISA) was administered with the dialysis solution to evaluate intraperitoneal volume, net ultrafiltration (UF), and fluid reabsorption. Peritoneal clearances, dialysate/plasma ratios (D/P), and mass transfer area coefficients (MTACs) were determined for sodium, urea, creatinine, albumin, and glucose. Safety was evaluated by monitoring adverse events and changes in serum chemistries. Ten patients completed all three dialysis exchanges and two additional patients completed at least one treatment exchange. RESULTS: There were no reported adverse events related to HA administration and no significant changes in serum chemistries. There were no significant differences in net UF or peritoneal volume profiles among the three treatments. Mean net UF calculated using residual volumes, estimated by RISA dilution, tended to be slightly higher during treatment with solution containing 0.1 g/L HA and 0.5 g/L HA [74 +/- 86 (SE) and 41 +/- 99 mL, respectively] compared to control treatment (-58 +/- 129 mL). Although not statistically significant, there was a trend toward decreased fluid reabsorption during treatment with HA. Solute clearances, D/P ratios, and MTACs were similar for the three treatments. Serum levels of HA were also unaffected by the two treatment solutions. CONCLUSIONS: These data support the acute safety of HA when administered intraperitoneally with the dialysis solution to PD patients. Due to the small sample size and variability in net UF and fluid reabsorption, statistically significant differences were not demonstrated for these parameters. However, a trend toward decreased fluid reabsorption was observed, suggesting that HA may act by a mechanism similar to that observed in animal studies. Further studies are necessary to evaluate whether the beneficial effects of HA observed in animal studies can be shown in humans.

Adjuvants, Immunologic↗
PubMedDate not supplied

Chiropody may prevent amputations in diabetic patients on peritoneal dialysis.

BACKGROUND: A multidisciplinary approach has been shown to be of benefit in the prevention of lower limb ulceration and amputation in patients with diabetes, but there is less information on the role of such an approach in patients receiving dialysis treatment. OBJECTIVE: The purpose of the present study was to determine whether the institution of a chiropody program would result in fewer amputations in diabetic patients on peritoneal dialysis (PD). DESIGN: Retrospective chart review. SETTING: The PD program at a tertiary-care hospital. PATIENTS: Patients with diabetes that were enrolled in the PD program between January 1997 and December 1999, inclusive, that were offered the opportunity to see a chiropodist, and that agreed to be seen. A total of 132 patients were included. INTERVENTION: Education about foot care, assessment, and, in some instances, treatment by a chiropodist. RESULTS: Patients with an amputation were more likely to be male (p < 0.01) and have peripheral vascular disease (p < 0.001) compared to those without an amputation. They also had a lower average mean arterial pressure (p < 0.05), lower weekly creatinine clearance (p < 0.01), higher mean erythropoietin dose (p < 0.05), and longer duration of end-stage renal disease (p < 0.001). Factors that were predictive of shorter time to death or amputation were older age [hazard ratio (HR) = 1.03, p < 0.05], peripheral vascular disease (HR = 2.66, p< 0.01), and cerebrovascular disease (HR = 2.70, p< 0.01). Being seen by a chiropodist was protective (HR = 0.39, p < 0.01). CONCLUSION: The current study suggests that a chiropody program may help to prevent amputation in patients with diabetes on PD.

Adult↗
PubMedDate not supplied

Peritoneal dialysis in acute renal failure.

Given the discussion so far, it might be apparent that factors beyond efficacy have dictated the decline in the use of PD for ARF. The importance of these factors should not be underestimated. They might be related to the perceived "labor intensive" aspect of PD, fear of a malfunctioning catheter (which in some instances may be real), insufficient exposure to PD during nephrology training, and, last, the comfort offered by the technology used for HD. Such psychological barriers are difficult to overcome, much more so than technical barriers (which can be and have been overcome). Only a concentrated effort by the PD community in educating the general nephrologist concerning the feasibility of PD in ARF, better clinical trials that harness the full potential of PD, and careful patient selection for the use of PD will bring PD back to the mainstream in the treatment of ARF.

Acute Kidney Injury↗
PubMedDate not supplied

What is the optimal dwell time for maximizing ultrafiltration with icodextrin exchange in automated peritoneal dialysis patients?

BACKGROUND: Icodextrin is increasingly being used in automated peritoneal dialysis (APD) for the long dwell exchange to maintain adequate ultrafiltration (UF). However, the UF reported in the literature varies with different dwell times: from 200 to 500 mL with 12 - 15 hour dwells. In order to maximize UF, it is important to know the relationship between dwell time and UF when using icodextrin in APD patients. With this knowledge, decisions can be made with respect to dwell period, and adjustments to the dialysis prescription can be made accordingly. METHODS: We prospectively studied this relationship in 36 patients from Canada and Turkey. All patients did the icodextrin day exchange manually after disconnecting themselves from overnight cycler dialysis. Dwell period was increased by 1 hour every week, from 10 to 14 hours. Ultrafiltration was noted for each icodextrin exchange. Mean UF for each week (i.e., dwell period) was compared by repeated measures ANOVA. RESULTS: We found no difference in mean UF with increasing dwelt time: 351.73 +/- 250.59 mL at 10 hours versus 371.75 +/- 258.25 mL at 14 hours (p = 0.83). We also compared mean UF between different subgroups and found that males (p = 0.02 vs females) and high transporters (p = 0.04 vs low) had higher mean UF. Further analysis of maximal UF showed no correlation to age, sex, diabetic status, transport category, creatinine clearance, Kt/V, duration on peritoneal dialysis, or duration of icodextrin use. CONCLUSION: Icodextrin-related UF in APD patients is not related to demographic factors and does not increase significantly beyond 10 hours.

Adult↗
PubMedDate not supplied

Relationship between serum magnesium, parathyroid hormone, and vascular calcification in patients on dialysis: a literature review.

Secondary hyperparathyroidism is present in most patients with end-stage renal disease and has been linked to uremic bone disease, vascular calcification, and mortality. Current literature suggests an association between hypomagnesemia and cardiovascular disease in the general population. We reviewed all published studies on the relationship between serum magnesium and parathyroid hormone and the relationship between serum Mg and vascular calcification in dialysis patients. Of these, 10 of 12 studies of patients on hemodialysis and 4 of 5 studies of patients on peritoneal dialysis showed a significantinverse relationship between serum Mg and serum intact parathyroid hormone. Hyperparathyroidism develops in peritoneal dialysis patients dialyzed with a solution containing normal calcium (1.25 mmol/L) and low Mg (0.25 mmol/L), even though serum calcium is maintained at a normal level. Four of the hemodialysis studies and one of the peritoneal dialysis studies indicated that there is an inverse relationship between serum Mg and vascular calcification in these patients. Potential benefits have been attributed to magnesium carbonate as a phosphate binder and it may possibly be an effective, less toxic, less expensive phosphate binder. We believe that the role of Mg in secondary hyperparathyroidism and vascular calcification merits further investigation.

Calcinosis↗
PubMedDate not supplied

Correlation between fractional reabsorption of sodium and erythropoietin dose in peritoneal dialysis patients.

BACKGROUND: Erythropoietin (EPO) deficiency of chronic renal failure (CRF) may be a functional consequence of decreased glomerular filtration rate and fractional reabsorption of sodium (FR(Na)). Decreased FR(Na) reduces renal oxygen consumption and increases tissue oxygen pressure, resulting in less EPO production. We hypothesized that, in CRF patients, there is a positive relationship between EPO production and FR(Na) and that, in such patients receiving EPO, a negative correlation is expected between FR(Na) and EPO dose. METHODS: Creatinine clearance, FR(Na), serum iron, transferrin, transferrin saturation, ferritin, and intact parathyroid hormone (iPTH) levels were measured in 91 peritoneal dialysis patients. The correlation between EPO dose and FR(Na) was studied. RESULTS: Mean EPO dose was 7076 +/- 4821 units/week and mean FR(Na) was 93.40% +/- 6.14%. A negative correlation was found between EPO dose and FR(Na) (r = -0.28, p < 0.01), and a positive correlation was found between both ferritin and iPTH and EPO dose (r = 0.39, p < 0.001 and r = 0.35, p < 0.002 respectively). After adjusting for the effect of creatinine clearance, ferritin, and iPTH, there was still a significant correlation between EPO dose and FR(Na) (p < 0.05). CONCLUSION: In CRF patients there is a negative correlation between FR(Na) and EPO dose, which supports the hypothesis that EPO deficiency may be related to the decreased renal oxygen-consuming work of sodium reabsorption.

Adult↗