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Biomedical subjects

D N Churchill

Publications and source records attributed to D N Churchill.

At least 37 records · Page 2Linked to original sources
PubMed1996

Sodium and water profiling in chronic uraemia.

Haemodialysis is frequently complicated by side-effects both during and after treatment. Hypotension and muscle cramps have been attributed to depletion of intravascular volume; headache and fatigue have been attributed to rapid changes in intracellular and extracellular osmolality. An evidence-based systematic review of the English language literature was used to evaluate these hypotheses. Four studies have addressed the morbidity associated with changes in intravascular volume. These data suggest that during haemodialysis the vascular space is refilled from the interstitial space. Overhydrated patients are less likely to experience hypotension than are dehydrated patients, perhaps at the risk of congestive heart failure and hypertension. Intradialytic changes in haematocrit reflect changes in vascular volume and may be used to predict intradialytic hypotension. Eight studies have addressed the morbidity associated with changes in osmolality. In two of these studies the investigators reported clinical benefit for patients with patient-specific sodium profiles during dialysis. Four studies lacked sufficient statistical power to detect an effect of sodium profiling on patient symptoms. Two studies suggest a clinically important decrease in intradialytic symptoms during treatment with sodium-profiled dialysate. A definitive test of these hypotheses will require a randomized, blinded study of the clinical impact of sodium/ultrafiltration modelling on patient symptoms.

Blood Volume↗
PubMed1995

A controlled trial of cyclosporine in patients with progressive membranous nephropathy. Canadian Glomerulonephritis Study Group.

A controlled trial of cyclosporine in patients diagnosed with progressive membranous nephropathy (MGN) was carried out to determine whether cyclosporine (D) would be more effective than placebo (P) in reducing the rate of deterioration in renal function. Patients (N = 64) with MGN were placed on a restricted protein diet (< or = 0.9 g/kg) and followed closely for 12 months (Part 1). Patients at high risk of progression based on an absolute loss in creatinine clearance (CCr) of > or = 8 ml/min and persistent nephrotic range proteinuria (Pr) were selected and randomly assigned to either (D) (N = 9) or (P) (N = 8) for 12 months (Part 2). No differences in the two groups were noted at entry. After 12 months, the improvement in CCr slope in ml/min/month was significantly greater in the D patients (D + 2.1 vs. P + 0.5, mean difference 1.6; 95% CI 0.3 to 3.0, P < 0.02). This improvement was maintained in six of eight D (75%) over a mean follow-up period of 21 months. Daily Pr also improved with D (by month 3, D - 4.5 g/day vs. P + 0.7 g/day, P = 0.02) and was sustained in six of eight (75%) D patients. When Pr was expressed as a function of their concurrent CCr, the D versus P patients' time to halving was faster (P = 0.02) and absolute number higher (4/9 D vs 0/8 P). In the D group a trend towards worse hypertension and an increase in the number of transient rises in serum creatinine were noted.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Effect of recombinant human erythropoietin on hospitalization of hemodialysis patients.

The effect of recombinant human erythropoietin (EPO) on hospitalization of patients with end-stage renal disease (ESRD) was evaluated in a controlled clinical trial. A cohort of 67 new hemodialysis patients prescribed EPO shortly after the clinical availability of EPO were the treatment group. The control group was a cohort of 67 new hemodialysis patients matched for clinical center, age, cardiovascular disease and transfusion history. These patients had not been prescribed EPO as they had started hemodialysis prior to the clinical availability of EPO. There were 21 pairs without hospitalization and 46 pairs with at least 1 member of the pair experiencing hospitalization. Among the latter group, the median follow-up was 174 and 184 days for the EPO and control patients respectively. For all hospitalizations, those treated with EPO were hospitalized 15.3 days per year compared to 23.2 days for the control patients. The difference (EPO-control) was -7.9 days (95% CI: -21.0; 7.8) for all cause hospitalization. For hospitalizations due to cardiac, infectious disease and gastrointestinal disease, the differences were 1.6, 1.8 and 1.2 days favouring EPO treated patients. For hospitalizations related to vascular access complications, the difference was 0.9 days favoring the control group. All other causes favoured EPO treated patients by 4 days. There had been 58 hospitalizations in the EPO group compared to 97 in the control group. The mean duration of hospitalization was 8.0 days for the EPO and 9.6 for the control group. The direction and magnitude of the change in all cause hospitalization represents an improvement in morbidity and an important decrease in health resource utilization.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

Cost analysis of dialysis treatments for end-stage renal disease (ESRD).

The cost of alternative dialysis modalities for the treatment of end-stage renal disease (ESRD) was evaluated, using a societal viewpoint, in a regional nephrology program in south-western Ontario. The dialysis treatments compared were hospital hemodialysis, home hemodialysis, self-care hemodialysis, and continuous ambulatory peritoneal dialysis (CAPD). The participants were all patients treated by the same dialysis modality for the fiscal year April 1990 to March 1991. Fully allocated costs are expressed in 1993 Canadian dollars. The average costs per patient year were $88,585 for hospital hemodialysis, $55,593 for self-care hemodialysis, $44,790 for CAPD, and $32,570 for home hemodialysis. The dialysis treatment costs were $54,929 for hospital hemodialysis, $43,313 for self-care hemodialysis, $31,918 for CAPD, and $26,048 for home hemodialysis. These data quantify the magnitude of the differences between fully-allocated costs among the dialysis modalities in a regional nephrology program in Canada. The methodology used in this economic analysis can be applied to programs which differ in structure and scale. The breakdown of dialysis treatment costs into overhead, support department, personnel, supplies, and medication identifies potential areas for cost reduction strategies.

Cost Allocation↗
PubMed1994

Probability of thrombosis of vascular access among hemodialysis patients treated with recombinant human erythropoietin.

The objective was to evaluate the effect of the treatment of anemia with recombinant human erythropoietin (EPO) on thrombosis of the vascular access used for hemodialysis. The research design was a prospective cohort study comparing EPO-treated hemodialysis patients with a comparison group matched for type of vascular access, clinical center, and age. All patients commencing hemodialysis in the study centers between March 1988 and July 1991 were eligible if either a graft or fistula had been used as a first permanent vascular access. There were 64 matched fistula pairs and 38 matched graft pairs. There were more patients with a history of cardiovascular disease in the EPO group than in the comparison group for both fistulae and grafts, 34 versus 14% for the former and 37 versus 5% for the latter. There was no difference between EPO and comparison groups with respect to time to first thrombosis of fistula, 11.3 versus 10.6%, respectively, by thrombosis of grafts among those treated with EPO--33.6 versus 11.2% (P = 0.02). EPO treatment does not increase the probability of fistula thrombosis, but there is an association with an increased probability of graft thrombosis.

Actuarial Analysis↗
PubMed1993

Effect of high-flux hemodialysis on cardiac structure and function among patients with end-stage renal failure.

The effect of high flux hemodialysis on left ventricular function in ESRD patients was evaluated in a double blind, single cross-over, study comparing conventional to high flux hemodialysis. The subjects were 21 stable chronic hemodialysis patients. Ten were randomly allocated to the conventional-high flux sequence and 11 to the reverse sequence. The conventional membrane was the CD 3,500 or 4,000; the high flux membrane was the Duoflux (Althin Medical Inc., Miami Lakes, Fla.). Both were cellulose acetate and both were sterilized with ethylene oxide. The dialysate bicarbonate and sodium were held constant for the study. The ultrafiltration rates were 3.5-5.0 ml/h/mm Hg transmembrane pressure for the conventional and 15 ml/h/mm for the high flux membrane. The beta-2-microglobulin sieving coefficient was 0 for conventional and 0.27 for the high-flux membrane. The modest improvements in estimates of systolic function suggest a cardiac advantage in high-flux dialysis, the clinical impact of which requires further study.

Adult↗
PubMed1992

The natural history of asymptomatic urolithiasis.

An inception cohort of 107 patients was reviewed to establish the natural history of asymptomatic urolithiasis. With an over-all mean followup of 31.6 months, 73 patients (68.2%) remained asymptomatic and were censored at the time of the last clinical visit. A symptomatic event developed in 34 patients (31.8%). Spontaneous passage occurred in 16 patients (15.0%), endoureteral removal was done in 6 (5.6%), percutaneous nephrostolithotomy was done in 3 (2.8%) and 9 (8.4%) were referred for therapeutic lithotripsy. Cumulative 5-year probability of a symptomatic event developing was 48.5%. A linear association was identified between the development of a symptomatic event and the number of previous stones as well as the number of asymptomatic stones at identification. A significant burden of illness is associated with an expectant strategy as an approach to asymptomatic urolithiasis. Of the patients who had a symptomatic event 47% had spontaneous stone passage, while 26.5% required urological intervention and 26.5% were referred for therapeutic lithotripsy. Prophylactic extracorporeal shock wave lithotripsy, although often advocated, has associated risks and is not always a benign procedure. A randomized controlled trial is required to evaluate properly the role of prophylactic lithotripsy versus an expectant strategy.

Adult↗
PubMed1992

Canadian Hemodialysis Morbidity Study.

The objective of this study was to determine the probabilities of specific morbid events or death among patients with end-stage renal disease (ESRD) treated by hemodialysis. A prospective cohort study was performed between March 1988 and September 1989 in 18 hemodialysis centers in 13 Canadian cities, representing about one third of the hemodialysis population in Canada. The inception cohort consisted of 496 patients entering hemodialysis who had survived 1 month. The few new hemodialysis patients who received erythropoietin (EPO) in the last 3 months of the study were excluded. Survival curves were compared using the Cox proportional hazards regression model. Older age and history of cardiovascular disease were independently associated with a greater probability of death. Age and history of cardiovascular disease were also associated with a greater probability of nonfatal circulatory events (myocardial infarction, angina requiring hospitalization, or stroke), while a serum albumin level less than or equal to 30 g/L (3.0 g dL) was associated with an increased probability of pulmonary edema. The probability of surviving 12 months without receiving a blood transfusion was 47.2% for males and 27.5% for females. The incidence of non-A, non-B hepatitis, as estimated by unexplained elevations in serum aspartate aminotransferase (AST) values, was not different between patients receiving and not receiving blood transfusions. The probability of hospitalization for any cause was greater for patients with grafts for vascular access than for those with fistulae, for those with a history of cardiovascular disease, for those with a serum albumin level less than or equal to 30 g/L, and for those with renal disease due to diabetes or vascular disease. Hospitalization due to circulatory disease was more likely among those with a history of cardiovascular disease and among those with a lower serum albumin level. Hospitalization for infectious disease was more likely among those with a lower serum albumin level and less likely among those with a fistula for vascular access. Among all patients receiving hemodialysis treatment for more than 6 months, there were 14.8 hospital days per year.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1992

The quality of life in renal transplantation--a prospective study.

Methodologically sound measures of quality of life are required to judge accurately the impact of successful renal transplantation on patient well-being. The time trade-off (TTO) method is a reproducible and valid measure which we used to prospectively assess changes in the quality of life of 27 patients on maintenance dialysis who subsequently underwent renal transplantation. TTO scores approaching 0 signify a very poor quality of life, while scores approaching 1 represent perfect health. Of 98 dialysis patients who completed baseline TTO interviews, 31 consecutive patients subsequently received 28 cadaveric and 3 living related kidney transplants. Four of 31 patients did not complete a second TTO assessment, because of death in 2 patients and graft loss in 2 others. The remaining 27 patients completed a second TTO interview an average of 30.9 months following transplantation (range 1.5-52, 95% confidence interval [CI] 24.4-37.5) and formed the study cohort. At the time of study the mean serum creatinine for the cohort was 173 mumol/L (range 90-290, 95% CI 152-195 mumol/L). The employment rate rose 27% following transplantation (P = 0.10); but when males alone were analyzed, a significant increase of 38% (P = 0.048) was noted. During the dialysis period, the mean baseline TTO score was 0.41 (95% CI 0.33-0.49), confirming the observations of others. Following transplantation, the mean TTO score rose to 0.74 (95% CI 0.67-0.81), a difference that is statistically significant (P < 0.001). The mean increase in TTO score observed as a result of successful transplantation was 0.33 (95% CI 0.26-0.40). This magnitude of improvement was found in 20 of 27 patients (74%), whose TTO scores lay within or above the 95% CI (0.26-0.40) for the mean change in score of 0.33. One patient's score fell, while the remaining 6 patients had improvements in their TTO score which fell below the lower 95% CI value (0.26) for the mean change in score. We conclude that the 95% CI of 0.26-0.40 identifies a range in which clinically important improvements in quality of life will be found for the majority of patients receiving successful kidney transplants.

Adult↗
PubMed1992

Comparison of subcutaneous and intravenous recombinant human erythropoietin for anemia in hemodialysis patients with significant comorbid disease.

While recombinant human erythropoietin (rHuEPO) is an effective therapy for anemia in renal failure, most published studies concern benefits in relatively healthy hemodialysis patients. The present study compares intravenous and subcutaneous administration of rHuEPO in an unselected group of 128 hemodialysis patients who were randomized to receive rHuEPO in an initial dose of 150 U/kg/week in three divided doses by subcutaneous or intravenous injection. Following a 4-week placebo run-in period, patients received rHuEPO until their hemoglobin was stable between 105 and 125 g/l for 4 weeks and then followed for a further 24 weeks. Eighty-three patients completed the study, 45 in the subcutaneous and 38 in the intravenous group. There was no difference in mean hemoglobin at any stage between subcutaneous and intravenous patients. Mean rHuEPO dose at the time of stabilization was significantly lower in the subcutaneous group compared to the intravenous (205.9 +/- 135.4 vs. 274.1 +/- 142.4 U/kg/week; p = 0.019), mean time to hemoglobin target was 9.9 +/- 4.5 weeks for the subcutaneous group and 11.9 +/- 4.9 weeks for the intravenous group (p = 0.037). Time to stabilization was 14.9 +/- 4.7 weeks for the subcutaneous compared to 17.3 +/- 3.9 weeks for the intravenous group (p = 0.006). Diabetic patients had higher dose requirements for rHuEPO at all time points and required a longer time to reach stabilization than nondiabetics (18.6 +/- 4.6 vs. 15.6 +/- 4.3 weeks; p = 0.016). Quality of life estimated by a disease-specific Kidney Disease Questionnaire improved significantly during rHuEPO therapy in both groups. There was no significant change in dialysis prescription throughout the study.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Effect of high-flux hemodialysis on quality of life and neuropsychological function in chronic hemodialysis patients.

The objective was to evaluate the effect of high-flux hemodialysis on quality of life, intra- and interdialytic symptoms and neuropsychological function. The study was double-blind single cross-over with random allocation to order of treatment. The patients were stable adult hospital hemodialysis patients. Both the conventional and high-flux membranes were cellulose acetate, the dialysate was bicarbonate, and dialysate sodium was held constant. The high-flux membrane had an ultrafiltration rate of 15 ml/h/mm Hg transmembrane pressure, a B12 clearance of 88 ml/min and a beta 2-microglobulin clearance of 11.4 ml/min. The values of the conventional membrane were 3.5-5.0, 34-45 and negligible. Each treatment period was 4 months. Twenty-two patients completed both phases of the cross-over. The KT/V value was higher during high-flux than conventional treatment; 1.42 versus 1.27(p < 0.05). There were no differences between high-flux and conventional treatment with respect to quality of life. Symptoms during dialysis were less severe during high-flux than conventional treatment for 12/14 items. Only 3 items reached statistical significance (0.05 > p > 0.01) and none were clinically significant. Symptoms between dialyses were less severe during high-flux than conventional treatment for 18/20 items. No single item had a statistically significant improvement but 3 had clinically important improvement. Among the 23 neuropsychological variables, none demonstrated statistically significant changes.

Adolescent↗