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Biomedical subjects

D Oreopoulos

Publications and source records attributed to D Oreopoulos.

At least 19 recordsLinked to original sources
PubMed2006

Reverse epidemiology in peritoneal dialysis patients: the Canadian experience and review of the literature.

High Body Mass Index (BMI) has been associated with improved survival of End-Stage Renal Disease (ESRD) patients on chronic hemodialysis (HD); however, studies on the relationship of BMI with survival in Peritoneal Dialysis (PD) patients have yielded conflicting results. The purpose of this study was to evaluate the impact of BMI on survival of Canadian ESRD patients on PD, correcting for their age, sex, race, diabetes mellitus, and arterial hypertension. In an intent to treat study, we reviewed data of the Canadian Organ Replacement Register (CORR), of incident patients, starting PD between 1994 and 1998 and followed up from their initial PD treatment to the end of 2003. Patients were censored at loss to follow up, transplantation, and the end of the observation period. Cox regression (multivariate) analysis was performed and adjustments were made for age, gender, race, primary renal disease and BMI. During these years, 4054 patients commenced PD, 1742 (43%) of them were females and 1471 (36.3%) were diabetics. The majority were Caucasians (n=3058, 75.4%); 120 (3%) belonged to the First Nations, 137 (3.4%) were black, and the rest (739 pts-18.2%) belonged to various other ethnicities. Based on quartiles of the BMI distribution, 1130 patients (28%) had a BMI < 18.5 kg/m(2); 1163 (28.7%), 18.5-24.9 kg/m(2); 1214 (30%), 25-29.9 kg/m(2); 547 (13.5%) > 30 kg/m(2). Intent to treat Cox regression analysis showed that being underweight was a strong risk factor for death. Specifically, a BMI less than 18.5 was associated with a death hazard ratio (HR) 1.3, (CI: 1.1-1.6). On the contrary, BMI > 30 was not associated with worse survival than those with normal BMI (HR = 1.009, CI = 0.89-1.14). High-BMI patients should not be discouraged from PD just because of their size.

Adolescent↗
PubMed2003

Anaphylaxis from topical bovine thrombin (Thrombostat) during haemodialysis and evaluation of sensitization among a dialysis population.

BACKGROUND: Topical bovine thrombin (TBT) is used as a topical haemostatic agent in haemodialysis (HD) units and for surgical procedures. It has caused allergic reactions during surgical procedures, but no previous cases have been reported with dialysis usage. OBJECTIVE: A case is reported of anaphylaxis due to TBT in an HD patient. This led to a determination of whether HD patients exposed to TBT develop specific IgE and IgG antibodies to TBT and an assessment of the frequency of allergic symptoms in HD patients as compared with peritoneal dialysis (PD) patients. METHODS: A cross-sectional study of 100 HD and 52 PD patients was performed using a questionnaire to determine allergic symptoms. An ELISA assay was developed to determine TBT-specific IgE and IgG serum antibodies among HD patients. HD patients without TBT exposure and age- and gender-matched blood donors served as controls. RESULTS: Allergic symptoms temporally related to dialysis reported by a questionnaire were significantly more frequent for HD patients than for PD patients: rhinoconjuctivitis 11% vs. 2%, asthma symptoms 20% vs. 6%, urticaria 23% vs. 8% (P values <0.05). Positive TBT-specific IgE and IgG antibodies were more frequent among 65 exposed HD patients (28% for IgE and 26% for IgG) than for controls (4% and 9%), P<0.05. CONCLUSIONS: Results indicate the potential for sensitization and clinical allergic responses to beef thrombin when used for haemostasis in HD and suggest that other haemostatic methods should be considered.

Adult↗
PubMed2003

Structural changes in silicon rubber peritoneal dialysis catheters in patients using mupirocin at the exit site.

Structural damage to polyurethane PD (peritoneal dialysis) catheters in patients using mupirocin ointment is widely appreciated, but damage to silicon rubber PD catheters is less well described. Ten catheters (6.6%) out of 152 were found to have structural alterations such as opacification, ballooning, thinning, and rupture. The duration of PD in these 10 patients ranged from 23 months to 80 months (mean duration 51.1 months). The frequency of mupirocin application varied from daily (2 cases) to 2-3 times per week (7 cases). In eight catheters opacification occurred at the exit site whereas one catheter showed opacification midway between the exit site and the titanium adaptor. One catheter showed opacification, ballooning, and thinning at the exit site ruptured in the form of two slit-like openings. In conclusion, various structural changes such as opacification, ballooning or thinning were seen in 6.6% of silicon rubber PD catheters in patients using mupirocin at the exit site. Although the mechanism remains elusive, mupirocin or the antiseptic solution alone or in combination may be contributory. We believe that this is an under-reported complication and encourage other health care givers to incorporate a search for such changes during clinic visits.

Adult↗
PubMed2003

Negative impact of Crohn's disease on bone mineral mass.

Prolonged chronic inflammation and corticosteroid therapy increase the risk of osteoporosis in patients with Crohn's disease. It has been estimated that 30% of these patients, who take steroids for prolonged periods, will suffer a vertebral fracture. Patients with Crohn's disease are difficult to wean from corticosteroids and therefore are at risk of developing bone complications. The purpose of this cross-sectional study was to examine the relationship between cumulative steroid dose, duration of the disease and the development of osteopenia in patients with Crohn's disease. We studied 28 patients (17 men, 11 women) with Crohn's disease: eight had one or more bowel resections and all the women were premenopausal. Serum calcium, phosphate, total alkaline phosphatase, immunoreactive parathyroid hormone (iPTH), 25(OH)Vitamin D(3) and 1,25 (OH)(2) Vitamin D(3) were measured by autoanalyser methods or radioimmunoassay. Bone mineral density (BMD) was studied using dual energy X-ray bone absorptiometry of the lumbar spine (L2-L4) and the femoral neck. Of these 28 patients, 27 received an average of 17.3 +/- 21.7 g (range 1 to 80) g of prednisone over a period of 4 to 216 months. Fourteen out of the 28 patients had mildly diminished bone density (z-score >-2.5 SD and < -1 SD) of the spine and 15/28 of the hip. We found a greater decrease in bone density (z-score < -2.5 SD) in 2 out of 28 patients at the spine and in 5 out of 28 at the femoral neck. Those in whom the duration of the disease was less than two years (12 patients) had significantly higher vertebral z-scores (-0.096 +/-0.91) than those who had the disease for over two years (-1.31 +/- 2.37), (p<0.05). We found no significant correlation between lumbar spine and femoral neck z-scores and cumulative steroid therapy. Six out of 28 patients (four women and two men), of mean age 47.2+/-11.7, had one vertebral fracture. The mean cumulative dose of steroids (prednisone or budesonide) in patients with vertebral fractures was higher but not significantly different from that in patients without fractures -20.1+/-18.2 versus 14.1+/-11.2 g of prednisone, respectively (p>0.05). No correlation was found between various serum hormones and other biochemical parameters of bone turnover or bone density. We conclude that a large proportion of patients with Crohn's disease have reduced bone mineral density (58% at the spine and 75% at the femoral neck). The pathogenesis of bone loss is probably multifactorial. Although steroid therapy might be an important contributory factor, we were unable to find a significant correlation between it and bone loss. On the contrary, we observed that the duration of the disease makes a significant contribution to bone loss.

Journal Article↗
PubMed2001

Hyaluronan modifies inflammatory response and peritoneal permeability during peritonitis in rats.

The effect of high-molecular-weight hyaluronan (HA) on peritoneal and systemic inflammation and peritoneal permeability to water and solutes was studied during endotoxin-induced peritonitis in rats. Acute peritonitis was induced by adding lipopolysaccharide (LPS) to the dialysis fluid (Dianeal 3.86; Baxter Healthcare, Ireland, Castlebar). HA was added to the dialysis solution in a concentration of 10 mg/dL. During 4- and 8-hour dwells of the dialysis fluid, we studied the intensity of peritoneal (dialysate) and systemic (blood) inflammation (dialysate cell count and differential, cytokine and HA levels), as well as the transperitoneal transport of solutes and water. In rats, the addition of LPS to the dialysis fluid induced changes in inflammatory reaction and transperitoneal transport similar to those seen in continuous ambulatory peritoneal dialysis patients with peritonitis. During peritonitis, the addition of HA to the dialysis fluid reduced the loss of ultrafiltration, which resulted in a greater peritoneal creatinine clearance during the 8 hours of dwell (29.9 +/- 6.7 mL/8 h in the HA-LPS group versus 19.7 +/- 7.8 mL/8 h in the LPS group; P < 0.05). Dialysate interferon-gamma (INF-gamma) levels during peritonitis were greater in HA-treated animals (536.8 +/- 296.6 pg/mL in the HA-LPS group versus 169.8 +/- 137.8 pg/mL in the LPS group; P < 0.05). Dialysate elastase activity increased during peritonitis (44.4 +/- 9.3 versus 14.2 +/- 4.1 U/mL in peritonitis-free rats); during peritonitis, the increase in dialysate elastase activity was less pronounced in the rats that had HA in the dialysate (27.3 +/- 4.1 U/mL versus the LPS group; P: < 0.01). We conclude that HA added to the dialysis fluid reduces loss of ultrafiltration during peritonitis in rats. In the presence of HA dialysate, INF-gamma levels during peritonitis increased, whereas elastase activity decreased; these changes might improve the peritoneal immune reaction during peritonitis and at the same time prevent peritoneal membrane injury.

Acute Disease↗
PubMed2001

Peritoneal dialysis in diabetic patients.

Diabetes mellitus is the fastest growing cause of end-stage renal disease (ESRD) and has become the leading cause of such ESRD worldwide. In the United States, between 1984 and 1997, the proportion of new patients starting renal replacement therapies whose ESRD was caused by diabetes increased from 27% to 44.4%. Canada saw an increase from 16.5% in 1984 to 28.9% in 1997, and many European countries had similar increases. Among the modes of renal replacement, many clinicians have favored continuous ambulatory peritoneal dialysis (CAPD) for the treatment of diabetic ESRD for several reasons. Many studies have compared clinical outcomes in diabetic patients undergoing CAPD, and nondiabetic patients undergoing CAPD, or diabetic patients undergoing peritoneal dialysis (PD) and those undergoing hemodialysis (HD). However, only a small number of diabetic dialysis patients have been followed up for more than 5 years, largely because of the presence of several comorbid conditions at the start of dialysis and the coexistence of far-advanced target-organ damage at dialysis initiation and its progression during the course of dialysis. Diabetic patients undergoing PD and HD probably have similar survival, and those undergoing CAPD have lower survival and technique success rates than nondiabetic patients of comparable age. This article reviews the literature and our experience with diabetic patients undergoing PD and compares clinical outcomes in diabetic patients undergoing PD and HD.

Diabetic Nephropathies↗
PubMed2001

The case for oral treatment of peritonitis in continuous ambulatory peritoneal dialysis.

Among several regimes used in the oral treatment of continuous ambulatory peritoneal dialysis (CAPD)--related peritonitis, ciprofloxacin and ofloxacin showed the higher treatment efficacy, with an overall cure rate of 80% over a treatment duration of 10-16 days. The antimicrobial activity of these agents against gram-positive episodes was equal to or even higher than that against other peritonitis episodes, and the effectiveness of oral ciprofloxacin can be further increased either by an additional intraperitoneal dose for the first 1-5 days, or by a simultaneous intraperitoneal dose of vancomycin in the first 24 hours. Clinical resistance to the new quinolones has been uncommon. The possibly increasing resistance to ciprofloxacin is a consequence of suboptimal dosing, with the resulting low local concentrations of the antibiotic. Oral treatment with quinolones provides a good therapeutic alternative to more widely used antibiotics for initial treatment of peritonitis episodes. However, more extensive data from comparative randomized studies with agents administered orally and intraperitoneally would be able to clearly elucidate the overall safety and success of oral treatment of PD-related peritonitis with quinolones or any new agent.

Administration, Oral↗
PubMed2001

Long-term survival with peritoneal dialysis in ESRD due to diabetes.

Several clinical studies have evaluated the factors that affect survival rates and compared outcomes between CAPD and HD in diabetic patients. However, only a small number of diabetic PD patients have been followed for over 5 years, largely because of coexisting, far-advanced, target organ damage at the initiation of dialysis and its progression during the course of dialysis, the presence of various comorbid conditions at the start of dialysis and finally, the limitations of long-term PD. Among the various modes of renal replacement, many clinicians have favored continuous ambulatory peritoneal dialysis (CAPD) for the management of diabetic patients for several reasons. However, survival of diabetic patients undergoing peritoneal dialysis (PD) and hemodialysis (HD) is probably similar, while diabetics on CAPD have a lower actuarial survival and technique success rates than non-diabetic patients of comparable age. This paper reviews the literature and our experience concerning the long-term survival on peritoneal dialysis of diabetic patients with ESRD.

Adult↗
PubMed2000

Long-term survival on peritoneal dialysis in end-stage renal disease owing to diabetes.

Only a small number of peritoneal dialysis (PD) patients with diabetes have been followed for more than 5 years. Lack of extended follow-up for these patients is largely due to coexisting, far-advanced damage to target organs at initiation of dialysis, with progression of that damage during the course of dialysis; the presence of various comorbid conditions at the start of dialysis; and limits to long-term PD technique. Among renal replacement modalities, continuous ambulatory peritoneal dialysis (CAPD) has been favored by many clinicians for the treatment of diabetic patients owing to reasons inherent in the therapy. Reported survival rates of diabetic patients on CAPD vary from 17%-72% for the fourth year (mean value: 39%) and from 19%-63% for the fifth year (mean value: 35%). Diabetic patients have actuarial rates of patient survival and technique survival that are lower than those for non diabetic patients of comparable age on CAPD. Patient survival for diabetic patients undergoing PD is similar to that for diabetic patients on hemodialysis. Because the peritoneal membrane maintains its ability to adequately purify blood for a long time, CAPD remains a viable form of long-term renal replacement therapy for diabetic patients with end-stage renal disease.

Diabetic Nephropathies↗
PubMed2000

Prevalence and causes of cough in chronic dialysis patients: a comparison between hemodialysis and peritoneal dialysis patients.

Peritoneal dialysis (PD) and hemodialysis (HD) are both common forms of dialysis for patients with end-stage renal disease. A few case reports have suggested that cough is associated with PD. From 1991 to 1998, 17 patients being treated with PD at the Toronto Western Hospital demonstrated persistent cough severe enough for referral to a respirologist. Causes of cough, often more than one cause per patient, included asthma, post-nasal drip, gastroesophageal reflux disease (GERD), chronic obstructive pulmonary disease, congestive heart failure, allergic rhinitis, pleural effusion, and respiratory infection. The aim of this cross-sectional study was to establish the prevalence of cough among PD patients, to determine if PD patients more commonly have a dry persistent cough than do HD patients, and, if the latter case is true, the possible reasons for it. A detailed survey of 92 PD patients and 91 HD patients was conducted in 1998 and 1999 at the University Health Network. Survey questions inquired about patient respiratory symptoms since onset of dialysis. Charts were reviewed to obtain information on use of medications possibly relevant to cough. In the PD and HD groups, 52% and 23% were females (p = 0.001), and the mean ages were 59.1 and 60.1 years, respectively. Angiotensin converting enzyme (ACE) inhibitors had been taken by 65% (PD) and 55% (HD) of patients, and beta-blocking medications by 43% (PD) and 51% (HD). Since initiation of dialysis--mean 2.7 years (PD) and 3.7 years (HD)--22% of PD patients reported persistent cough versus 7% of HD patients (p = 0.003). Although no significant association was seen between cough and self-reported heartburn in HD patients (p = 0.439), a significant association between cough and self-reported heartburn was seen in PD patients: 67% of PD patients with persistent cough reported heartburn versus 29% of those without cough (p = 0.008). The findings suggest that GERD and associated cough are more common in PD patients than in HD patients, perhaps owing to increases in intra-abdominal pressure from the peritoneal dialysate.

Cough↗
PubMed1999

Evaluation of the effect of uremia on peritoneal permeability in an experimental model of continuous ambulatory peritoneal dialysis in anephric rats.

Anephric rats were maintained on continuous ambulatory peritoneal dialysis (CAPD). Peritoneal permeability was assessed during a standard 4-hour peritoneal equilibration test (PET) performed with Dianeal 3.86% (Baxter Healthcare, Deerfield, Illinois, U.S.A.). The effect of uremia on peritoneal permeability was evaluated in an experimental protocol in which each animal served as its own control. In each rat, PET1 (control) was performed before removal of kidneys and PET2 (uremia) was performed four days after removal of kidneys. Net ultrafiltration during a 4-hour exchange with Dianeal 3.86% was higher during PET1 (3.8 +/- 2.3 mL) than during PET2 (-1.3 +/- 3.3 mL), p < 0.05. Peritoneal permeability to urea and glucose was similar in both series. Transperitoneal equilibration of creatinine concentration was faster in uremic animals: D/P at 4 hours was 0.94 +/- 0.06 during PET2 versus 0.77 +/- 0.08 during PET1, p < 0.001. The opposite difference was seen for total protein: D/Px 1000 after a 4-hour dwell was 51.4 +/- 19.8 during PET2 versus 70.3 +/- 12.9 during PET1, p < 0.05. Our results show that uremia modifies the permeability of the peritoneum to both water and solutes.

Animals↗
PubMed1999

Bioelectrical impedance analysis in the evaluation of the nutritional status of continuous ambulatory peritoneal dialysis patients.

The authors evaluated the nutritional status of 47 continuous ambulatory peritoneal dialysis (CAPD) patients, 26 men (age 58.9 +/- 14.6 years, duration on CAPD 27.3 +/- 18.3 months) and 21 women (age 56.2 +/- 14.9 years, duration on CAPD 34.5 +/- 23.4 months), using subjective global assessment (SGA), an established method for the nutritional assessment of dialysis patients, and bioelectrical impedance analysis (BIA: body cell mass, fat mass, and phase angle). Of the studied patients, 19 were diabetic (age 59.7 +/- 13.8 years, duration on CAPD 29.2 +/- 19.7 months) and 28 were non diabetic (age 53.9 +/- 14.3 years, duration on CAPD 31.5 +/- 21.8 months. According to SGA, 24 patients were scored as well nourished (Group I), 18 as mildly malnourished (Group II), and 5 as moderately malnourished (Group III). No patient scored as severely malnourished (Group IV). Analysis of the main nutritional parameters for the subgroups revealed a proportional decrease in phase angle, with a statistically significant correlation (p < 0.009) between phase angle and SGA. No significant difference was seen in serum albumin levels between patients in Group I and Group II, but the mean level was significantly lower in patients in Group III compared to Group I. The nutritional and biochemical data in diabetic patients and non diabetic patients were not significantly different. BIA phase angle seems to be a simple and reliable method for the routine assessment of nutritional status in CAPD patients.

Diabetes Complications↗
PubMed1994

Immunological quantification of advanced glycosylation end-products in the serum of patients on hemodialysis or CAPD.

We have developed an immunological procedure for measuring advanced glycosylation end-products (AGEs) in serum. Using this method, we measured AGEs in healthy volunteers, patients with diabetes, renal failure without treatment and in patients with renal failure, treated with hemodialysis (HD) or continuous ambulatory peritoneal dialysis (CAPD). We found that AGEs were moderately elevated in diabetics without renal failure and highly elevated in CAPD and HD patients irrespective of their glycemic status. AGE levels correlated significantly with creatinine levels but not with levels of glucose or patient age or sex. AGE levels were reduced significantly post-hemodialysis. Preliminary experiments have shown that circulating AGEs have a molecular weight of approximately 1.5 to 2.0 kDa. More studies are needed to establish if AGE measurements in serum are prognostic indicators of the complications of either diabetes or renal failure.

Adult↗