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Biomedical subjects

Jeroen P Kooman

Publications and source records attributed to Jeroen P Kooman.

At least 19 recordsLinked to original sources
PubMed2006

Impact of a quality improvement programme based on vascular access flow monitoring on costs, access occlusion and access failure.

BACKGROUND: Vascular access thrombosis is a substantial source of morbidity in chronic haemodialysis patients. Periodical access flow measurements can predict the presence of vascular access stenosis and provide an opportunity for early intervention to prevent subsequent vascular access thrombosis. By this system of quality improvement, vascular access-related costs might be reduced. The aim of this study was to analyse the cost impact of a quality improvement programme based on periodic access flow measurements. METHODS: The number and costs of vascular access interventions (summary of angiography, percutaneous transluminal angioplasty, catheter placement, hospitalization days and costs for surgery) in the period 2001-2003 (quality improvement period; QIP, 218.6 patient-years observed) were retrospectively compared with a reference period (RP, 1996-1998, 214.4 patient-years observed) during which no access flow was measured. All access flow measurements were done on a regular base and interventions were performed according to the Kidney Disease Outcome Quality Initiative. RESULTS: Surgical thrombectomy procedures were significantly less during the QIP (0.25 +/- 0.57 events/patient-year) compared with RP (0.63 +/- 1.06 events/patient-year; P = 0.000), whereas access loss was not significantly different. During the QIP, 205 radiological interventions were performed (0.88 +/- 1.16 events/patient-year), and in the RP around 48 (0.33 +/- 0.65 events/patient-year; P = 0.000). Access-related costs tended to be lower during the QIP compared with the RP. The cost reduction appeared to be limited to patients with arteriovenous graft (AVG), in which access-related costs were significantly lower during the QIP (2360.95 euro +/- 2838.17 euro patient-year) compared with the RP (4003.96 euro +/- 3810.92 euro patient-year; P = 0.012), but not in patients with arteriovenous fistula (AVF). CONCLUSION: A quality improvement programme based on periodical access flow measurement reduced the number of acute vascular access failures due to thrombotic events and also significantly reduced health care costs in patients with AVG, but not in patients with AVF. The quality improvement programme had no effect on access survival.

Aged↗
PubMed2006

The predictive value of C-reactive protein in end-stage renal disease: is it clinically significant?

Cardiovascular disease is the leading cause of death in patients with end-stage renal disease. Besides traditional risk factors, disturbances in mineral and bone metabolism and inflammation are thought to be responsible for the increased risk of death. In the last years C-reactive protein (CRP) has gained a lot of attention in the general population, especially with regard to its link with atherosclerosis. Although several studies suggest that CRP may be useful as a parameter in predicting future cardiovascular events in both the general population and in patients with end-stage renal disease, there is doubt about the clinical evidence of this assumption. A statistical association between CRP and cardiovascular disease was observed in various studies, but the predictive power of this association is markedly diminished when adjusted for other risk factors. The relative contributions of CRP as a marker, as a causative agent, or as a consequence of atherosclerotic vascular disease are unclear, both in the general population and in the dialysis population. The CRP levels are highly variable and influenced by intercurrent events in dialysis patients. In dialysis patients, it is possible to reduce the CRP levels by statins, although these agents do not reduce the cardiovascular mortality in diabetic dialysis patients.

Biomarkers↗
PubMed2006

Study on the relationship of serum fetuin-A concentration with aortic stiffness in patients on dialysis.

BACKGROUND: An increase in aortic stiffness, as reflected by an increase in pulse wave velocity (PWV) or aortic augmentation index (AI) is an important predictor of cardiovascular mortality in dialysis patients. Dysregulation of calcification inhibitors, such as fetuin-A, is involved in vascular pathology in dialysis patients and fetuin-A is inversely related to mortality in dialysis patients. In this study, the relation between serum fetuin-A concentration and parameters of aortic stiffness was investigated in patients with end-stage renal disease. METHODS: In a cross-sectional study we included 131 dialysis patients, aged 62+/-14 years (33 on peritoneal dialysis and 98 on haemodialysis), and 41 controls, aged 60+/-8 years. Time-averaged pre-dialysis values of serum albumin, Ca, P and intact parathyroid hormone were included in multiregression analysis, as were high-sensitivity C-reactive protein (hsCRP), fetuin-A, age, mean arterial pressure (MAP) and dialysis modality. PWV and AI were measured with the SphygmoCor device. RESULTS: Mean fetuin-A concentration in dialysis patients (0.63+/-0.16 g/l) did not differ from controls (0.63+/-0.11 g/l). Median hsCRP levels in dialysis patients were higher compared with controls (4.0 vs 1.9 mg/l; P<0.0001). PWV but not AI was higher in dialysis patients than in controls (9.9 vs 7.9 m/s; P<0.0001). In univariate analysis in dialysis patients, fetuin-A levels were inversely related to both PWV (r = - 0.25, P = 0.007) and AI (r = - 0.26, P = 0.006), respectively. However, after correction for age, gender, MAP and diabetes mellitus, this relation lost statistical significance. CONCLUSIONS: In a dialysis population with a relatively low level of inflammatory activity, the soluble calcification inhibitor fetuin-A could not be identified as an independent predictor of aortic stiffness as measured with PWV and AI.

Analysis of Variance↗
PubMed2006

Peritoneal sclerosis--aetiology, diagnosis, treatment and prevention.

Peritoneal selerosis (PS) is a rare, but potentially life-threatening complication in peritoneal dialysis (PD). The annual incidence increases with the duration of PD treatment and the mortality rate is high. Aetiology of PS is probably multifactorial and in most cases not exactly known. One import factor of PS is the bioincompatibility of the glucose-based PD solutions. Diagnosis is mainly based on clinical suspicion and radiological findings. Early detection is important to institute preventive strategies and development of therapeutic strategies has reduced mortality.

Humans↗
PubMed2006

Peritoneal dialysis in patients with congestive heart failure.

BACKGROUND: Peritoneal dialysis (PD) may be a useful technique in the treatment of patients with congestive heart failure, both with and without primary end-stage renal disease (ESRD). METHODS: In the treatment of patients with ESRD and congestive heart failure (CHF), PD has theoretical advantages compared with haemodialysis (HD), such as the absence of an arteriovenous fistula and the more gradual fluid removal. In cohort studies, the incidence of heart failure was less as compared with HD, however, randomized studies on this aspect are lacking. RESULTS: As an acute rescue treatment of patients with treatment refractory heart failure, functional improvement has been observed with the use of PD. However, fluid removal is less predictable compared with continuous haemofiltration therapies. CONCLUSIONS: As a long-term option for patients with treatment refractory CHF without ESRD, various case series showed improved functional performance and a reduction in hospitalization with the use of PD. However, also with the use of PD, median survival is still limited in these patients. Randomized studies are needed to establish the potential role of PD for this indication.

Heart Failure↗
PubMed2006

Is there a competition between urine volume and peritoneal ultrafiltration in peritoneal dialysis patients?

Many peritoneal dialysis patients are overhydrated. Overhydration may lead to hypertension and left ventricular hypertrophy, and may be related to inflammation and malnutrition. The presence of overhydration is not always detected by clinical examination. Especially patients with peritoneal ultrafiltration failure and/or negligible residual renal function are prone to overhydration. Treatment consists of a combination of sodium and fluid restriction, in combination with increased peritoneal ultrafiltration and loop diuretics in patients with residual diuresis. Peritoneal ultrafiltration can be enhanced by the use of hypertonic glucose solutions or icodextrin. In some, but not all, studies, residual renal function or diuresis declined with an increase in peritoneal ultrafiltration. At least in a subset of patients, underhydration might have played a role in this phenomenon. We propose to treat overhydration using both clinical criteria and objective techniques such as vena cava echography or bioimpedance measurements.

Body Water↗
PubMed2005

Diameter measurements of the forearm cephalic vein prior to vascular access creation in end-stage renal disease patients: graduated pressure cuff versus tourniquet vessel dilatation.

BACKGROUND: Preoperative assessment of forearm superficial venous diameter may predict early failure of newly created arteriovenous fistulas for haemodialysis access. However, early failure and non-maturation rates remain high (up to 30%) and reported cut-off diameters are inconsistent. We hypothesize that this inconsistency is due to differences in the methods used to achieve venous dilatation prior to diameter measurements and daily variation in superficial venous diameter. We furthermore hypothesize that the use of a cuff will lead to a better inter-observer agreement since the applied pressure can be precisely determined. The purpose of this study was to determine inter-observer agreement of superficial venous diameter measurement under venous congestion by using either a graduated pressure cuff or tourniquet and furthermore, to determine daily variations in superficial venous diameter. METHODS: Diameter measurements were performed by two observers on days 1 and 3, in 21 end-stage renal disease patients using either a cuff (60 mmHg) or tourniquet. Measurements were carried out in random order and observers were blinded for each other's results. Inter-observer agreement was expressed as interclass correlation coefficients. Variance components analysis was used to determine possible causes of disagreement. RESULTS: Using a cuff, mean venous diameter was 1.8 mm (range, 0.7-3.3 mm). When a tourniquet was used, the mean diameter was 1.8 mm (range, 0.6-3.2 mm). Interclass correlation coefficients between observers were 0.76 and 0.74 for the use of a cuff and tourniquet, respectively. Diameter measurements were revealed to be observer independent. Variations in venous diameter were determined by the patient and the interaction of patient and day. Repeated assessment of venous diameter on different days revealed a variation coefficient of 26.4% when using a cuff, and 26.5% when using a tourniquet. CONCLUSIONS: Venous diameter assessment is observer and congestion method independent. Daily variations in forearm superficial venous diameters should be taken into account when defining and using cut-off diameters prior to vascular access surgery.

Adult↗
PubMed2005

Effect of ultrafiltration on thermal variables, skin temperature, skin blood flow, and energy expenditure during ultrapure hemodialysis.

The cause of the increase in core temperature (CT) during hemodialysis (HD) is still under debate. It has been suggested that peripheral vasoconstriction as a result of hypovolemia, leading to a reduced dissipation of heat from the skin, is the main cause of this increase in CT. If so, then it would be expected that extracorporeal heat flow (Jex) needed to maintain a stable CT (isothermic; T-control = 0, no change in CT) is largely different between body temperature control HD combined with ultrafiltration (UF) and body temperature control HD without UF (isovolemic). Consequently, significant differences in DeltaCT would be expected between isovolemic HD and HD combined with UF at zero Jex (thermoneutral; E-control = 0, no supply or removal of thermal energy to and from the extracorporeal circulation). During the latter treatment, the CT is expected to increase. In this study, changes in thermal variables (CT and Jex), skin blood flow, energy expenditure, and cytokines (TNF-alpha, IL-1 receptor antagonist, and IL-6) were compared in 13 patients, each undergoing body temperature control (T-control = 0) HD without and with UF and energy-neutral (E-control = 0) HD without and with UF. CT increased equally during energy-neutral treatments, with (0.32 +/- 0.16 degrees C; P = 0.000) and without (0.27 +/- 0.29 degrees C; P = 0.006) UF. In body temperature control treatments, the relationship between Jex and UF tended to be significant (r = -0.51; P = 0.07); however, there was no significant difference in cooling requirements regardless of whether treatments were done without (-17.9 +/- 9.3W) or with UF (-17.8 +/- 13.27W). Changes in energy expenditure did not differ among the four treatment modes. There were no significant differences in pre- and postdialysis levels of cytokines within or between treatments. Although fluid removal has an effect on thermal variables, no single mechanism seems to be responsible for the increased heat accumulation during HD.

Body Temperature↗
PubMed2005

Pre-dilution on-line haemofiltration vs low-flux haemodialysis: a randomized prospective study.

BACKGROUND: Accumulation of larger molecular weight uraemic toxins molecules may have a negative effect on the cardiovascular and nutritional state of dialysis patients and influence uraemic symptomatology. Their clearance can be enhanced by the use of haemofiltration (HF). METHODS: The effects of low-flux haemodialysis (HD) (ultrapure dialysate; polyamide membranes) and pre-dilution on-line HF (1:1 blood/substitution ratio; target filtration volume: 1.2 times body weight) on cardiovascular and nutritional parameters, interdialytic levels of uraemic toxins and quality of life (QOL; Laupacis questionnaire) were assessed during 1 year follow-up. Forty patients were randomized. RESULTS: After 1 year, 27 patients were eligible for analysis (HF: 13 patients; HD: 14 patients). Left ventricular mass index did not change in the HF patients (127+/-33 --> 131+/-36 g/m(2) after 12 months) or in the HD group (135+/-34 --> 138+/-32 g/m(2)). Also, there were no changes in pulse wave velocity, and 48 h systolic and diastolic blood pressures. Lean body mass, assessed by dual-energy X-ray absorptiometry, increased in the HF group (44.8+/-8.9 --> 46.2+/-9.6 kg; P<0.05), but not in the HD group (49.4+/-9.2 --> 50.6+/-8.8 kg), although differences between groups were not significant. Insulin-like growth factor-1 levels remained stable in the HF patients, but decreased in the HD group (P<0.05 between groups). QOL for physical symptoms improved in the HF group (4.2+/-1.2 --> 5.0+/-1.1; P<0.05 within the HF group and P = 0.06 between groups), but not in the HD group (4.0+/-1.0 --> 4.4+/-1.4). beta2-microglobulin, complement factor D and homocysteine decreased significantly in the HF but not in the HD group, whereas l-ADMA, leptin and advanced glycation end-products-related fluorescence did not change. CONCLUSIONS: No changes in cardiovascular parameters were observed during pre-dilution on-line HF compared with low-flux HD. Treatment with on-line HF resulted in marked changes in the uraemic toxicity profile, an improvement in physical well-being and a small improvement in nutritional state.

Aged↗
PubMed2005

Endothelin-1 levels and conduit artery mechanical properties in end-stage renal disease.

BACKGROUND: Endothelial cell (EC) dysfunction markers are increased in end-stage renal disease (ESRD). The present study focused on the relationship between EC markers, conduit artery wall mechanics and hemodynamics in ESRD. METHODS: In 29 ESRD patients and 16 controls, brachial artery diameter, distension, and wall thickness was measured and circumferential wall stress (CWS) calculated. Shear stress was determined with a shear rate-estimating system. Furthermore, von Willebrand factor antigen (vWF) and endothelin-1 (ET-1) levels were measured. RESULTS: vWF (p = 0.002) and ET-1 (p < 0.001) were higher in ESRD patients and vWF was related to ET-1 (r = 0.70, p = 0.005). Peak (p = 0.001) and mean shear stress (p = 0.003) were significantly lower in ESRD patients, and ET-1 showed an inverse log linear relation with both (peak: r = -0.59, p = 0.016; mean: r = -0.64, p = 0.007). Also, ET-1 was log linearly related to CWS (r = 0.58, p = 0.014). CONCLUSION: These results indicate that, in ESRD, conduit artery shear stress is lower, which might be secondary to an increased peripheral vascular resistance caused by higher ET-1 levels.

Aged↗
PubMed2005

The effect of flow changes on the arterial system proximal to an arteriovenous fistula for hemodialysis.

Arterial remodeling in response to flow changes is controlled by the endothelium, sensing wall shear stress (SS) changes. The present study focuses on the remodeling capacities of the brachial (BA) and radial artery (RA) of 16 renal failure patients after arteriovenous fistula creation. Pre- and postoperatively at predetermined time-points, diameter, wall thickness and peak and mean SS were assessed. After arteriovenous fistula creation, acute increases in BA SS (p = 0.018) and lumen diameter (p = 0.028) were observed. The diameter further increased in the next year (p = 0.023), whereas BA SS remained unchanged. RA SS and diameter increased acutely (p = 0.005) and remained unaltered after 1 y. RA wall thickness tended to decrease acutely (p = 0.059) and increased steadily during 1 y (p = 0.008). BA and RA diameter acutely increased after an acute SS rise and remained augmented after 1 y. Also, the RA vessel wall thickness enlarged, indicating structural remodeling. After 1 y, however, these changes did not result in SS restoration.

Aged↗
PubMed2005

The relation between vascular access flow and different types of vascular access with systemic hemodynamics in hemodialysis patients.

Access flow (Qa) has an important effect on systemic hemodynamics in dialysis patients. A Qa : cardiac output (CO) ratio higher than 0.3 is considered a risk factor for high-output cardiac failure. However, the effect of different types of vascular access in hemodialysis patients has not yet been studied. The aim of the present study was to assess the relationship between Qa and systemic hemodynamics and to compare systemic hemodynamics between patients with elbow/upperarm access with forearm access types. Qa, CO, cardiac index (CI), central blood volume (CBV), and peripheral vascular resistance (PVR) were studied by the saline dilution technique in 58 hemodialysis patients (18 with elbow/upperarm access; 40 with forearm access types). This article found that Qa was significantly and positively related to CO and CI, and inversely related to PVR. CBV, Qa, and presence of cardiac failure were independent determinants of CI. Qa and the Qa : CO ratio were significantly higher, and PVR significantly lower, in patients with elbow/upperarm access compared to patients with forearm access types. When patients with cardiac failure were excluded, CO and CI were also significantly higher in patients with elbow/upperarm access types. Eleven percent of patients with elbow/upperarm fistula had a Qa : CO ratio above 0.3. In conclusion, Qa is strongly related to systemic hemodynamics in dialysis patients. In patients without cardiac failure, CO and CI are significantly higher in patients with elbow/upperarm access compared to patients with forearm access types. However, only a small percentage of patients with elbow/upperarm fistulae appeared to be in the risk zone for development of high-output cardiac failure.

Aged↗
PubMed2005

Similarities in skeletal muscle strength and exercise capacity between renal transplant and hemodialysis patients.

Exercise intolerance is common in hemodialysis (HD) and renal transplant (RTx) patients. Aim of the study was to assess to what extent exercise capacity and skeletal muscle strength of RTx patients differ from HD patients and healthy controls and to elucidate potential determinants of exercise capacity in RTx patients. Exercise capacity, muscle strength, lean body mass (LBM) and physical activity level (PAL) were measured by cycle-ergometry, isokinetic dynamometry, DEXA and Baecke Questionnaire, respectively, in 35 RTx, 16 HD and 21 controls. VO2peak and muscle strength of the RTx patients were significantly lower compared to controls (p<0.01), but not different compared to HD patients. In RTx patients, strength (p<0.001), PAL (p=0.001) and age (p=0.045) were significant predictors of VO2peak. Muscle strength was related to LBM (p=0.001) and age (p=0.001), whereas gender (p<0.001) and renal function (p=0.01) turned out to be significant predictors of LBM. No effects of corticosteroids were observed. Exercise capacity and muscle strength seem equally reduced in RTx and HD patients compared to controls. In RTx patients, muscle strength and PAL are highly related to exercise capacity. Renal function appears to be a significant predictor of LBM, and through the LBM, of muscle strength and exercise capacity.

Exercise Test↗
PubMed2004

Haemodynamics and electrolyte balance: a comparison between on-line pre-dilution haemofiltration and haemodialysis.

BACKGROUND: An important advantage of convective therapies is improved vascular reactivity. However, it is not well known whether the vascular response during convective therapies remains superior when compared to haemodialysis (HD) with an adjusted temperature of the dialysate. It has also been suggested that convective therapies may impair small electrolyte removal through an effect on the Donnan equilibrium. In the present study, we compared the haemodynamic response and small electrolyte removal between pre-dilution on-line haemofiltration (HF) and HD procedures. METHODS: Cardiac output (CO), central blood volume (CBV) and peripheral vascular resistance (PVR) were assessed, using the saline dilution technique, in 12 stable patients during HF and HD with two different temperatures of the dialysate [36.5 and 35.5 degrees C (HD(36.5) and HD(35.5))]. Balances for sodium, potassium, calcium and conductivity were assessed using total dialysate/filtrate collections. Target filtration volume for HF was 1.2 times body weight. The temperature of the infusate was 36.5 degrees C. RESULTS: The change (Delta) in CBV was less during HD with a dialysate temperature of 35.5 degrees C (-0.03+/-0.14 l; P<0.05) compared to HF (-0.16+/-0.05 l) and HD(36.5) (-0.11+/-0.14 l), but the other haemodynamic parameters did not differ between the studied techniques. DeltaPVR was significantly related to DeltaCBV (r = -0.46; P<0.01), whereas DeltaCBV was related to ultrafiltration rate (r = -0.34; P = 0.05). DeltaCO was related to DeltaCBV (r = 0.62; P<0.001). Solute balances did not differ between HF and HD. CONCLUSION: Using the saline dilution method, no difference in the change in CO and PVR was observed between on-line HF vs HD(36.5) and HD(35.5). Only CBV declined to a significantly lesser degree during HD(35.5), although absolute differences were small. Changes in the other haemodynamic variables appeared more dependent upon the degree and rapidity of fluid removal than upon the treatment modality. No difference in small electrolyte balance was observed between HF and HD, suggesting that ionic removal is not impaired during on-line HF.

Aged↗