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W T van Dorp

Publications and source records attributed to W T van Dorp.

At least 19 recordsLinked to original sources
PubMed2001

Morbidity and mortality during renal replacement therapy: dialysis versus transplantation.

AIM: Many patients with end-stage renal disease are eligible for renal transplantation. To enable a patient to choose between transplantation or to remain on dialysis comparable data on morbidity and mortality should be available. METHODS: Data were collected retrospectively from the medical records of all patients on the waiting list for renal transplantation and of transplanted patients during the period January 1, 1990, to January 1, 1997. All patients were dialyzed in the Kennemer Gasthuis and renal transplantation was performed in the Leiden University Medical Center (LUMC). Morbidity and mortality in both groups were compared. Morbidity was assessed by studying number, length and cause of hospital admissions. RESULTS: During the study period 102 patients had been on the waiting list and 54 patients had been transplanted in the LUMC. Mean length of stay on the waiting list before transplantation was 37 months. During the follow-up period 11 patients (10.8%) died on the waiting list and 6 patients (11.1%) died after renal transplantation. The mean length of stay on the waiting list of these two groups was much longer, being 55 months and 62 months, respectively. Length of hospitalization was significantly different between both patient groups during the first 6 months of treatment (13.24 days for those on the waiting list versus 40.75 days transplanted patients) and after 6 months (32.4 days for those on the waiting list versus 13.1 days transplanted patients). The number of hospital admissions did not differ significantly. Dialysis-related admissions constituted 47% of the total of admissions in the waiting list group and transplantation-related admissions were 43% in the transplanted group. CONCLUSION: In the present study we revealed no difference in overall mortality. However, mortality was influenced by length of stay on the waiting list. Morbidity was increased during the first 6 months after transplantation. Therapy modality greatly influenced the specific cause of morbidity.

Female↗
PubMed2000

Acute pancreatitis in peritoneal dialysis and haemodialysis: risk, clinical course, outcome, and possible aetiology.

BACKGROUND: It has been suggested that the incidence of acute pancreatitis in patients with end stage renal failure is increased. AIMS: To assess the risk of acute pancreatitis in patients on long term peritoneal dialysis and long term haemodialysis compared with the general population, to evaluate its clinical course and outcome, and to identify possible aetiological factors. PATIENTS: All patients who were maintained on long term peritoneal dialysis and/or haemodialysis (total dialysis time more than six weeks) from January 1989 to March 1998 in a large general hospital in The Netherlands. METHODS: Retrospective cohort study. Standardised ratios (as an approximate relative risk) between the incidence of acute pancreatitis in haemodialysis or peritoneal dialysis and the general population were calculated. Possible risk factors were identified. Patients with and without acute pancreatitis were compared. RESULTS: In 269 patients on haemodialysis (total of 614 person years), one patient developed an attack of acute pancreatitis. Patients on haemodialysis did not show an increased risk for acute pancreatitis compared with the general population (standardised ratio 11; 95% confidence interval (CI) 0.275 to 60.5). In 128 patients on peritoneal dialysis (total of 241 person years), seven patients had nine attacks of acute pancreatitis. Patients on peritoneal dialysis had a significantly and highly increased risk for acute pancreatitis (standardised ratio 249; 95% CI 114 to 473). Mortality in this series of nine attacks was 11%. No single aetiological risk factor could be identified. CONCLUSIONS: The risk of acute pancreatitis in patients on long term peritoneal dialysis is significantly and highly increased compared with the general population. The underlying causal mechanisms remain to be elucidated.

Acute Disease↗
PubMed1999

Improved cardiovascular variables during acetate free biofiltration.

BACKGROUND AND AIM: Acetate free biofiltration (AFB) provides a well-tolerated and efficient renal replacement therapy. Replacement of most of the acetate by bicarbonate in standard hemodialysis has resulted in a decrease in intradialytic hypotensive episodes. This has been attributed to a decrease in the acetate-induced impairment of myocardial contractility. The aim of the present study was to investigate whether the total absence of acetate in AFB would further enhance dialysis stability and improve cardiovascular status. PATIENTS AND METHODS: In a long-term, randomized trial we included 11 patients on AFB and 9 patients on bicarbonate hemodialysis (HD) for one year. Patients were matched for age, sex and urea reduction rate, but not for the presence of hypertension or cardiovascular history. During each dialysis session blood pressure was measured automatically and the presence of significant hypotension was recorded. Antihypertensive medication was registered every three months. Before and at the end of the study M-mode echocardiography was performed and left ventricular mass index (LVMi) was calculated. Every six months serum lipids were measured. RESULTS: At baseline, mean arterial pressure (MAP) before and after dialysis, the percentage of hypotensive dialyses, LVMi and serum lipids did not differ between AFB and HD. Pre-dialysis MAP decreased in AFB (from 112.5 to 107 mmHg) and increased in HD (from 101.7 to 105.3 mmHg; p = 0.01, HD versus AFB). Postdialysis MAP remained stable in both groups (AFB 91.6 mmHg at 0 months and 90.6 mmHg at 12 months, for HD respectively 83.9 and 86.5 mmHg, NS). The percentage of hypotensive dialyses did not differ significantly between the groups during the study. LVMi decreased in AFB from 195.4 to 162.1 gr/m2 and increased in HD patients from 153.8 to 182.5 gr/m2 (p = 0.03 HD versus AFB). The number of antihypertensive medications per patient did not differ between groups. Serum lipids remained unchanged during the trial. CONCLUSION: In conclusion, AFB provided better control of pre-dialysis MAP compared to HD, and stable postdialysis MAP. The percentage of dialysis sessions with hypotension did not differ. LVMi decreased significantly in AFB, but rose in HD.

Acetates↗
PubMed1998

Dialysis efficacy during acetate-free biofiltration.

BACKGROUND: Acetate-free biofiltration (AFB) is a haemodiafiltration technique based on continuous post-dilution infusion of a sterile isotonic bicarbonate solution. We performed a long-term randomized prospective trial to compare dialysis efficacy and metabolic control of AFB versus bicarbonate haemodialysis (HD). METHODS: The AFB group consisted of 11 and the HD group of nine patients, matched for age, sex and urea reduction rate. Biochemical parameters were obtained every 3 months for 1 year (haemoglobin, calcium, phosphate, urea, pre- and post-dialysis bicarbonate, and parathormone (PTH)) and medication was updated. Efficacy of dialysis calculated by KT/V using the dialysate sampling method was determined every 3 months. In AFB patients, the infusion rate of bicarbonate solution was adjusted individually to obtain bicarbonate values of > or = 22 mmol/l before dialysis and < or = 32 mmol/l after dialysis. In the HD group, bicarbonate was added as oral medication to match these bicarbonate concentrations. Statistical analysis was performed using ANOVA for repeated measurements. RESULTS: Pre-dialysis serum bicarbonate levels had risen to the same extent in both groups at the end of the study period (AFB from 21.8 to 26.1 mmol/l, P < 0.001, and HD from 20.8 to 24.9 mmol/l, P < 0.001). Post-dialysis bicarbonate level was higher in the AFB than in the HD group (P < 0.01). Calcium and phosphate levels remained stable in both groups. PTH increased in both groups (AFB from 10.6 to 23.7 pmol/l, and HD from 24.6 to 32.8 pmol/l), with a significant rise only in the AFB patients (P < 0.04). In AFB patients, KT/V increased from 2.73 to 3.17 per week (P < 0.04). In HD patients KT/V did not change (P < 0.38); the difference between the groups was significant at the end of the trial (P < 0.013). Finally, haemoglobin levels and erythropoietin dosage did not change in either group. No significant differences between the two groups were observed. CONCLUSIONS: Acidosis was better corrected in AFB without the need for oral supplementation of bicarbonate. However, neither serum calcium nor phosphate levels changed. The observed increase in PTH in the AFB group remains to be clarified. Dialysis efficacy, measured as KT/V, improved during AFB.

Acetates↗
PubMed1998

Colonic pseudo-obstruction due to beta2-microglobulin amyloidosis after long-term haemodialysis.

Beta2-microglobulin (A beta2M) amyloidosis is a relatively new secondary amyloidosis associated with renal failure and haemo- and peritoneal dialysis. Although beta2-microglobulin depositions are systemic, clinical manifestations are limited to articular and para-articular disease in most cases. A very limited number of patients have been reported with extra-articular manifestations including those of the gastrointestinal tract. We report on a patient who was treated with haemodialysis for 23 years and developed colonic pseudo-obstruction due to A beta2M amyloidosis.

Aged↗
PubMed1997

A randomized trial of alcohol 70% versus alcoholic iodine 2% in skin disinfection before insertion of peripheral infusion catheters.

Skin disinfection before insertion of peripheral infusion catheters is standard practice, but a comparison in effectiveness of the two most widely used disinfectants is lacking. We compared alcohol 70% and alcoholic iodine 2% in a prospective randomized trial. Data from 109 patients on a pulmonary ward were analysed. Phlebitis occurred six times in the alcohol group and 12 times in the iodine group. This relative risk reduction of 53% failed to reach significance (P = 0.18). The power of the study, however, was only 0.55, meaning a 45% chance of missing a true difference. As countless catheters are inserted each year, a small difference in phlebitis rate could save discomfort to many patients. Thus, a larger trial seems warranted. The addition of theophylline to the prednisone infusion resulted in a significantly higher phlebitis rate: 27.3 versus 9.2% (P = 0.03).

Aged↗
PubMed1997

Dosage recommendation of vancomycin during haemodialysis with highly permeable membranes.

The standard dosage of vancomycin in haemodialysis patients is usually 1 gram, once a week. The aim of our study was to investigate vancomycin clearance by two highly permeable membranes and to determine whether dosage adjustment is necessary in regular haemodialysis settings when using these type of dialyzers. 12 patients on regular haemodialysis and treated with vancomycin either prophylactically or therapeutically were prospectively randomised to either dialysis with a polyacrylonitril parallel membrane (AN-69) or a cellulose-acetate hollow fiber membrane. After administering vancomycin to the patient vancomycin plasma levels were measured at different intervals. The vancomycin clearance by the dialyzer was calculated from blood samples taken 1 hour after commencing dialysis. The data were used for pharmacokinetic computer simulation in order to develop a vancomycin dosage regimen for patients on regular haemodialysis with highly permeable membranes. The mean vancomycin dialysis clearance was 46 +/- 5 ml/min and did not differ between the two artificial kidneys. Dialysis clearance of vancomycin was independent of blood flow rate. Together with the dialyzer data a pharmacokinetic profile of each patient was calculated from the plasma samples. The average non-renal clearance was 3.3 ml/min/1.73 m2 while renal vancomycin clearance, as a fraction of creatinine clearance, was found to be 0.83 +/- 0.20. The computer calculations predicted that, irrespective of residual renal function, in most patients on regular haemodialysis and treated with these type of artificial kidneys, therapeutic and non-toxic vancomycin levels could be obtained by giving 1000 mg of vancomycin intravenously as a loading dosage and 500 mg during every subsequent dialysis.

Adult↗
PubMed1997

Cerebral involvement in two patients with Wegener's granulomatosis.

Two cases of cerebral involvement in Wegener's granulomatosis (WG) are described. The course of the disease in both patients was characterized by sudden onset and fatal outcome, despite maximum immunosuppressive therapy. Cerebral involvement is a rare complication of WG. Over the past two decades, only a small number of case-reports appeared of patients with WG who showed this complication. Since the era of cyclophosphamide therapy, it is commonly assumed that cerebral involvement in WG has no influence on patient survival. However, the two patients described here both died shortly after the occurrence of central neurological symptoms.

Aged↗
PubMed1996

Mycotic aneurysm after aortic bifurcation prosthesis.

Fever in the presence of an intravascular graft will focus the clinical investigation on an infection of this graft. This case report describes an uncommon cause of fever in a 75-year-old patient, namely a mycotic aneurysm of the aortic stump.

Aged↗
PubMed1996

Intracutaneous versus intramuscular hepatitis B vaccination in primary non-responding haemodialysis patients.

OBJECTIVE: To determine whether hepatitis B vaccination given intracutaneously (i.c.) is more effective than intramuscularly (i.m.) in primary non-responding haemodialysis patients. DESIGN: A prospective, randomized study of antibody responses to hepatitis B vaccine given i.c. or i.m., in 25 haemodialysis patients. Outcome measures were rates of seroconversion, mean and geometric mean levels of antibody achieved, and antibody levels 1 year after vaccination. RESULTS: With a dosing schedule of 10 micrograms vaccine once a week i.c. in the skin overlying the deltoideus muscle of the non-dominant arm during 12 consecutive weeks, antibody levels to hepatitis B surface antigen (anti-HBsAg) of 10 IU/1 or more were achieved in nine of 10 evaluable patients, with a geometric mean of 70 IU/1. Nine months after the end of the vaccination anti-HBsAg levels had dropped to 9 +/- 4 IU/1 (M +/- SE), with a geometric mean of 5 IU/1, in the nine remaining evaluable patients. With a dosing schedule of 40 micrograms vaccine i.m. in the deltoideus muscle of the non-dominant arm at 0, 1, and 3 months, anti-HBsAg levels of at least 10 IU/1 were achieved in eight of 14 evaluable patients, with a geometric mean of 94 IU/1. Nine months after the end of the vaccination anti-HBsAG levels had dropped to 16 +/- 7 IU/1, with a geometric mean of 9 IU/1, in the nine remaining evaluable patients. Anti-HBsAg levels at 8 and 12 weeks were higher in the i.c. than in the group receiving vaccine i.m. (at 8 weeks 134 +/- 76 vs 39 +/- 20 IU/1, P < 0.05, and at 12 weeks 188 +/- 98 vs 47 +/- 18 IU/1 P < 0.01). The half-time of anti-HBsAg is about 13 weeks, both when the averaged absolute and when the geometric mean levels are used for the estimate. CONCLUSION: intracutaneous route is a less practical but effective method of vaccination against hepatitis B in primary non-responding haemodialysis patients. The weekly 10 micrograms vaccine i.c. scheme resulted in the fastest development of protective antibody levels, within 8 weeks, which may be useful in previously non-immune persons who may be infected with hepatitis B virus (e.g. needle-stick accidents).

Drug Administration Routes↗
PubMed1995

Beneficial effects of conversion from cyclosporin to azathioprine after kidney transplantation.

Immunosuppression with cyclosporin after renal transplantation is associated with better graft survival than is azathioprine treatment. However, nephrotoxicity and other side-effects have led to regimens that change treatment to azathioprine shortly after transplantation. Conversion has beneficial effects in the short term on renal function and hypertension. We report long-term follow-up (minimum 5 years) of 128 patients who had received a first or second cadaveric kidney graft and were treated with cyclosporin and prednisone; they were randomly assigned 3 months after transplantation to groups continuing to receive cyclosporin (n = 68) or changing to azathioprine (n = 60). 8 years after transplantation, patient survival was 75.3% in the cyclosporin group and 85.9% in the azathioprine group (p = 0.14) and graft survival was 64.0% and 76.6%, respectively (p = 0.38). The frequency of cardiovascular death with a functioning graft was 8% higher in the cyclosporin group (95% CI -1 to 18). The relative risk of graft loss after conversion to azathioprine compared with graft loss after conversion to azathioprine compared with cyclosporin maintenance was 0.71 (0.37-1.38) and the relative risk of patient death was 0.57 (0.23-1.41). The cyclosporin group had poorer mean creatinine clearance (17.8 mL/min [8.1-27.5] lower than azathioprine group) and a higher proportion needed hypertensive drugs (20% [4-36] more). Gout was found in 9 cyclosporin-treated patients and 1 azathioprine-treated patient (difference 12% [3 to 20]). Elective conversion from cyclosporin to azathioprine 3 months after transplantation is safe and cost-effective.

Adult↗
PubMed1995

Mortality in patients receiving renal replacement therapy, a single center study.

We studied all patients receiving renal replacement therapy (RRT) in the Kennemer Gasthuis Dialysis Centre (Haarlem) during the period January 1st 1986 to January 1st 1991 in order to evaluate their mortality. Of the total number 205 patients, 76 had died in this period, 82 were still receiving RRT on December 31st 1991 and 47 had been transplanted. The most frequent cause of death was cardiovascular. Of the 76 patients who had died, 38 had requested cessation of dialysis. Of these, 26% had also a malignancy and 29% had irreversible brain damage (CVA, dementia). Compared to the expected mortality rate in the general population of The Netherlands, dialysis patients have a Standardized Mortality Rate (SMR) of 6.91 (95% Confidence Interval (CI) 4.72-9.54). Male patients had a SMR twice as high as females. Patients under age 50 had a SMR of 50.00 (95% CI 8.93-124.40) versus 50 and older 7.19 (95% CI 4.26-8.91). The SMR was similar for patients with and without cardiovascular comorbidity before entering RRT. A Kaplan-Meier plot showed a significant difference for not transplantable versus transplanted or transplantable patients, however SMR for these 3 groups revealed no difference. A Kaplan-Meier plot of patient survival of patients starting RRT after January 1986 (n = 114) showed a linear decrease of 20% yearly mortality. No gender difference was found. We conclude that 1. RRT is associated with high mortality, 2. SMR of young patients is higher than of the elderly and SMR of men is twice as high as SMR of women. Interestingly Kaplan-Meier survival plot did not reveal this difference.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiovascular Diseases↗
PubMed1994

Analysis of donor selection procedure in 139 living-related kidney donors and follow-up results for donors and recipients.

In 1981 an active programme was started in our centre for living-related kidney donation (LRD). The structure of this LRD programme is described in this paper. Retrospectively the results of this LRD programme were studied. Between 1981 and 1988 139 potential living donors were evaluated. Of all potential donors 47 (34%) actually donated a kidney, including 24 HLA non-identical combinations. Follow-up was obtained until 1990. An acceptable incidence of morbidity and mortality for donors and recipients was observed. A high number of potential donors was excluded during the selection procedure (66%). They were often refused for medical reasons (29%), with a high incidence of renal dysfunction (16%). No long-term adverse effects of nephrectomy regarding decreased renal function, hypertension, or proteinuria were seen. Of all actual donors 23% experienced minor complications after donation. Living-related kidney transplants showed better graft function than cadaveric grafts.

Adolescent↗
PubMed1994

Mycotic aneurysm of the suprarenal abdominal aorta.

Staphylococcus aureus is one of the main causes of bacteriaemia. Haemodialysis patients are likely to develop bacteriaemia due to S. aureus, probably because they are often carriers of S. aureus and also frequently have intravascular catheters. This case report describes a very rare complication of S. aureus sepsis in a 62-year-old haemodialysis patient, namely a suprarenal aneurysm of the abdominal aorta.

Aneurysm, Infected↗
PubMed1993

Cytomegalovirus directly enhances MHC class I and intercellular adhesion molecule-1 expression on cultured proximal tubular epithelial cells.

Clinically, there is an association between CMV infections and the occurrence of rejection after renal transplantation. Adhesion molecules such as intercellular adhesion molecules (ICAM) and MHC Ags are thought to be important in the induction and amplification of the rejection process. Therefore, we studied ICAM-1 and MHC expression after CMV infection or stimulation with cytokines. Cultured proximal tubular epithelial cells (PTEC) were stimulated with cytokines or infected with CMV. MHC class I, class II, and ICAM-1 expression were determined by radioimmunoassay. IFN-gamma induced class II and ICAM-1 expression. Small concentrations of IFN-alpha inhibited the IFN-gamma induced class II expression. CMV-infected PTEC displayed increased levels of ICAM-1 and class I expression. This enhancement is a direct effect of the virus on the infected cells and not mediated by soluble factors. Although MHC class II expression is not directly enhanced by CMV, infected PTEC display a normal increase of class II expression after stimulation with IFN-gamma.

Cell Adhesion Molecules↗