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Biomedical subjects

R Gokal

Publications and source records attributed to R Gokal.

At least 37 records · Page 2Linked to original sources

Bone loss in long-term renal transplantation: histopathology and densitometry analysis.

BACKGROUND: There is little information of the spectrum and factors implicated in the bone loss in long-term renal transplantation, and virtually no data using both histomorphometric and densitometric analysis. METHODS: Twenty-three males and 22 females (13 postmenopausal) were studied with a bone biopsy and densitometry. Sixteen patients were on cyclosporine A monotherapy, 20 on azathioprine + prednisolone, and 9 on cyclosporine A + prednisolone or triple therapy. The mean time after transplantation was 127 +/- 70 months. RESULTS: No group had a significant decrease in bone mineral density (BMD) of the axial skeleton compared with an age- and sex-matched normal population. Compared with sex-matched young controls, osteopenia was observed in all groups at the femoral neck (except premenopausal women and triple therapy) and in the triple-therapy group at the L1-L4 spine region. At the distal radius, osteopenia was found in all the groups. Histopathological diagnosis was mixed uremic osteodystrophy in 46.5%, adynamic bone in 23.2%, hyperparathyroid disease in 13.9%, and normal bone in 16.3%. The diagnosis was not different according to immunosuppressive therapy, but men tended to show more mixed uremic bone disease. There was no significant difference in BMD between histopathological subtypes. In general, patients showed slight osteoclast function increase, osteoblast function decrease, and marked retardation of dynamic parameters. The cyclosporine A monotherapy group had a significantly lower appositional rate than azathioprine + prednisolone. Men had a significantly lower bone volume than women, and premenopausal women had a significantly lower mineralizing surface than postmenopausal women and men. In the multivariate analysis, male gender, time after transplantation, old age, and time on dialysis prior to transplantation were significant predictive factors for a negative effect on bone mass. CONCLUSIONS: Long-term renal transplant-patients showed reduced BMD in both trabecular and cortical bone. This reduction in BMD was not as severe as in short-term reports and was associated with osteoclast stimulation, osteoblast suppression, and retardation of mineral apposition and bone formation rates. Bone mass loss was not different between the immunosuppression therapy groups. Male gender and age were the strongest predictive factors for low bone mass.

Absorptiometry, Photon↗

Outcomes in peritoneal dialysis and haemodialysis--a comparative assessment of survival and quality of life.

Ever since the introduction of peritoneal dialysis (PD) as a therapy for managing patients with end-stage renal disease, there has been considerable debate about how it compares with outcomes on haemodialysis (HD) especially in terms of survival and quality of life. Whilst earlier results in the 1980s were certainly not comparable, data now emerging show that survival on PD is equivalent to that on HD. Recent registry data from the Canadian Organ Replacement Register show that survival of patients on PD is equivalent to that on HD and may well be better in the first few years of therapy. There have been numerous quality of life studies in patients on PD and HD. Health-related quality of life has been assessed using health profile measurements (both generic and disease-specific instruments) or preference-based measurements. The former approach has been used to analyse 14 different comparative studies. These studies suggest that patients on home HD and CAPD show better quality of life than patients on centre HD. Only a few studies found statistical differences between groups, and only in seven studies were results adjusted for patient differences. There is a need for longitudinal studies with more accurate information on health. Similar data are available for preference-based measurements and studies. Overall, the analysis suggests that PD and HD are equivalent therapies. On this basis, it is hard to explain the wide variation seen in the use of the two therapies.

Humans↗

The repositioning of migrated Tenckhoff continuous ambulatory peritoneal dialysis catheters under fluoroscopic control.

We describe a non-invasive, simple technique which, under fluoroscopic control, repositions migrated Tenckhoff CAPD catheters back into the pelvis. 18 patients, who had a total of 23 manipulations, were studied retrospectively over 2 1/2 years. Technical success (successful repositioning of the catheter at screening) and clinical success (continued effective CAPD for at least 6 months thereafter) were obtained in 84% and 45% of patients respectively. The results showed this technique to be effective in restoring the correct catheter position in CAPD patients whose catheters have migrated. Clinical success was more likely to be achieved in patients who had fewer risk factors for the development of peritoneal adhesions. The use of custom-made stainless steel wires eased manipulations and significantly reduced the radiation dose to patient and operator from the procedure.

Adult↗

Neuropathy and quality of life in diabetic continuous ambulatory peritoneal dialysis patients.

Diabetes mellitus is the commonest cause of end-stage renal failure and is associated with considerable morbidity. Neuropathy is one of the most serious complications of diabetes, linked to the incidence of nephropathy and retinopathy. The prevalence of neuropathy increases with age and duration of diabetes. Peripheral sensorimotor neuropathy is the main manifestation of neurological damage in diabetes, while autonomic neuropathy, a devastating complication, is also present in a large number of patients with long-term diabetes. Clinical features of autonomic neuropathy are mainly cardiovascular disorders and abnormal visceral function. One of the most important sequelae of neuropathy is the development of the insensitive foot at risk of ulceration, deformation, Charcot neuroarthropathy, and amputation. Prevention, education, and identification of the at-risk patient are the key elements in managing these severe complications. Dialysis, and mainly peritoneal dialysis, still remains the main renal replacement therapy for end-stage renal disease (ESRD) diabetic patients. It is obvious from many studies that diabetes and its complications are major risk factors associated with poorer survival rates, increased morbidity, and decreased quality of life. Few, if any, data are available specifically evaluating quality of life in continuous ambulatory peritoneal dialysis (CAPD) diabetic patients. Fewer data are available estimating the impact of neuropathy on the quality of life of such patients. Specific studies must be carried out to further investigate quality-of-life issues and neuropathy in this vulnerable group of patients.

Autonomic Nervous System Diseases↗

Taking peritoneal dialysis beyond the year 2000.

Over the past 25 years, peritoneal dialysis (PD) has steadily improved so that now its outcomes, in the form of patient survival, are equivalent to, and at times better than, those for hemodialysis. We now have a better understanding of the pathophysiology of peritoneal membrane function and damage and the importance of appropriate prescription to meet agreed-upon targets of solute and fluid removal. In the next millennium, greater emphasis will be put on prescription setting and subsequent monitoring. This will entail an increase in automated PD, especially for lifestyle reasons as well as for patients with a hyperpermeable peritoneal membrane. To improve outcomes, dialysis should be started earlier than is currently the case. It is easy to do this with PD, where an incremental approach is made easier by the introduction of icodextrin for long-dwell PD. In the future, solutions will be tailored to be more biocompatible and to provide improved nutrition and better cardiovascular outcomes. Finally, economic considerations favor PD, which is cheaper than in-centre hemodialysis. Thus, for many, PD has become a first-choice therapy, and with further improvements this trend will continue.

Cost-Benefit Analysis↗

Peritoneal dialysis immediately post transplantation.

Many peritoneal dialysis (PD) patients undergo successful renal transplantation. The outcome is similar to that for transplanted hemodialysis (HD) patients. For delayed graft function, dialysis is necessary in the immediate post-transplant period. PD can be undertaken, with a small risk of peritonitis and other PD-related complications. Delayed graft function is less prevalent in patients who were on PD before transplantation than in those who were on HD. The dialysis modality may have an impact on graft survival. The graft thrombosis rate is unaffected by the prior mode of dialysis. Catheter-related problems are infrequent, but there must be a low threshold for catheter removal for any sign of non response to therapy for peritonitis or for exit-site and tunnel infections. PD can be undertaken successfully in the immediate post-transplant period.

Catheters, Indwelling↗

Does peripheral neuropathy invariably accompany nephropathy in type 1 diabetes mellitus?

In patients with Type 1 diabetes mellitus complicated by diabetic nephropathy and retinopathy, it is usually believed that significant neuropathy is almost universal, but few studies have directly addressed this. This study assessed neuropathy in 91 such subjects, using vibration perception thresholds (VPT) and the neuropathy disability score (NDS). A total of 34% of subjects had no neuropathy on age adjusted VPT (z score) and 26% had no neuropathy on NDS. The severity of neuropathy as measured by VPT z score was related to increasing glycated haemoglobin (P = 0.02) and male sex (P = 0.03), and NDS was independently associated with age (P < 0.0001) and HbA1c (P = 0.003). These factors together accounted for only 12 and 31% of the total variance in VPT z score and NDS, respectively. In conclusion, the study has shown that a significant proportion of patients with diabetic nephropathy are free of neuropathy, but the full explanation for their protection from neuropathy is unclear.

Adult↗

Icodextrin provides long dwell peritoneal dialysis and maintenance of intraperitoneal volume.

Icodextrin 7.5% is an isosmolar solution for once-daily use in peritoneal dialysis for patients with end-stage renal failure (ESRF). It produces substantial ultrafiltration (UF), performing best over longer dwells of 8-12 h in continuous ambulatory peritoneal dialysis (CAPD) patients, and up to 16 h in automated peritoneal dialysis (APD) patients. Subsequent use in other clinical areas (ultrafiltration failure) and normal postmarketing clinical experience has established its tolerability and safety profiles; a small number of patients, including those with diabetes, have now received icodextrin for up to 6 years. Icodextrin's ability to maintain intraperitoneal volume over many hours has led to its undergoing development as an intraperitoneal drug delivery system for targeted regional delivery of anticancer drugs and lymphatic delivery of anti-HIV treatment. Isosmolar icodextrin 7.5% solution represents the first major advance in the treatment of ESRF by peritoneal dialysis since the development of CAPD using glucose-based solutions 20 years ago.

Dialysis Solutions↗

A controlled trial of two bicarbonate-containing dialysis fluids for CAPD--final report.

BACKGROUND: The combination of a low pH and a high concentration of lactate which is present in most dialysis fluids is found to be cytotoxic in vitro. For these reasons it would seem logical to use a bicarbonate-containing solution and thus automatically provide a solution with a neutral pH. METHODS: A parallel, randomized, open-label, prospective 2-month trial with an optional 4 month extension was undertaken to compare two novel bicarbonate-based solutions; one containing 38 mmol/l of bicarbonate (B), and one containing a mixture of 25 mmol/l bicarbonate and 15 mmol/l of lactate (B/L), with a control solution (C) containing 40 mmol/l lactate. RESULTS: Three groups of 19 (C), 20 (B), and 20 (B/L) patients were recruited and data from approximately 55 patient months were accumulated in each group. The data show that both bicarbonate-based solutions maintain acid-base levels within the normal range, that there were no changes in any of the other blood biochemistry parameters measured in the peritoneal equilibration test or with regard to adequacy of dialysis, and that furthermore, both solutions were well tolerated. CONCLUSIONS: This study showed that either the bicarbonate or bicarbonate/lactate solutions could be utilized efficaciously in patients undergoing CAPD.

Acid-Base Equilibrium↗

Bicarbonate and bicarbonate/lactate peritoneal dialysis solutions for the treatment of infusion pain.

A randomized, double-blind, cross-over study was undertaken to determine the effects of novel bicarbonate (38 mM) and bicarbonate (25 mM)/lactate (15 mM) containing peritoneal dialysis (PD) solutions on infusion pain in patients who experienced inflow pain with conventional lactate (40 mM) solution. Pain was assessed using a verbal rating scale and the validated McGill Pain Questionnaire (MPQ). Eighteen patients were recruited to the study. Both novel solutions resulted in highly statistically significant reductions in inflow pain compared to the control lactate solution, as assessed with both the verbal rating scale and the MPQ. For all pain variables assessed, the bicarbonate/lactate solution was more effective than the bicarbonate solution in alleviating pain. In conclusion, both solutions reduced the infusion pain experienced with control solution, but the bicarbonate/lactate solution appears to be the most effective. In contrast to the most widespread current treatment, which is the manual injection of sodium bicarbonate, the bicarbonate/lactate solution does not have the associated increased risk of peritonitis.

Bicarbonates↗

Impact of increasing dialysis volume on adequacy targets: a prospective study.

Failure to achieve target values for both urea (Kt/V) and creatinine clearance has been associated with increased morbidity and mortality in continuous ambulatory peritoneal dialysis patients. The conventional continuous ambulatory peritoneal dialysis regimen, which uses four 2-L exchanges per day, has resulted in up to 40% of such patients failing to achieve proposed targets for weekly Kt/V of 1.7 and weekly creatinine clearance (WCC) of 50 L. In a prospective study, the impact of increasing prescribed volumes by 0.5 L per exchange was evaluated on attaining urea and creatinine clearance targets over a 1-yr period. At 1 yr, 17 patients remaining on the increased dialysis prescription were compared with 18 patients remaining on an unchanged regimen. The mean increase in daily prescribed volume was 1.5 L (22%). This resulted in a significant increase in both peritoneal dialysis Kt/V (1.59 to 1.78 L = 12%) and peritoneal dialysis WCC (45.8 to 50.1 L = 10%) by 1 yr. Because of loss of renal function, there was no significant increase in total clearance at 1 yr, but this loss of renal clearance was offset by the gain in peritoneal clearance. Residual renal function fell at a similar rate in both the increased dialysis and control groups. In the latter, although peritoneal clearance remained stable over the 1-yr period, loss of renal function resulted in reductions in both total Kt/V and WCC. In conclusion, exchange volume can be increased to compensate for loss of renal function over a 1-yr period. Progressive loss of renal clearance resulted in only a modest gain in total solute clearance. It was the larger patients who tolerated the increase in exchange volumes. However, such patients (by virtue of their size) tended not to achieve target values for solute clearance, and the modest gain in peritoneal clearance was insufficient to increase the number of patients in this group achieving such targets for dialysis adequacy.

Adult↗