Early home-based group education to support informed decision-making among patients with end-stage renal disease: a multi-centre randomized controlled trial.

BACKGROUND: The aim was to test the effectiveness of early home-based group education on knowledge and communication about renal replacement therapy (RRT). METHODS: We conducted a randomized controlled trial using a cross-over design among 80 end-stage renal disease (ESRD) patients. Between T0 and T1 (weeks 1-4) Group 1 received the intervention and Group 2 received standard care. Between T1 and T2 (weeks 5-8) Group 1 received standard care and Group 2 received the intervention. The intervention was a group education session on RRT options held in the patient's home given by social workers. Patients invited members from their social network to attend. Self-report questionnaires were used at T0, T1 and T2 to measure patients' knowledge and communication, and concepts from the Theory of Planned Behaviour such as attitude. Comparable questionnaires were completed pre-post intervention by 229 attendees. Primary RRT was registered up to 2 years post-intervention. Multilevel linear modelling was used to analyse patient data and paired t-tests for attendee data. RESULTS: Statistically significant increases in the primary targets knowledge and communication were found among patients and attendees after receiving the intervention. The intervention also had a significant effect in increasing positive attitude toward living donation and haemodialysis. Of the 80 participants, 49 underwent RRT during follow-up. Of these, 34 underwent a living donor kidney transplant, of which 22 were pre-emptive. CONCLUSIONS: Early home-based group education supports informed decision-making regarding primary RRT for ESRD patients and their social networks and may remove barriers to pre-emptive transplantation.

A psychometric analysis of the Rotterdam Renal Replacement Knowledge-Test (R3K-T) using item response theory.

Knowledge is a prerequisite for promoting well-informed decision-making. Nevertheless, there is no validated and standardized test to assess the level of knowledge among renal patients regarding kidney disease and all treatment options. Therefore, the objective of this study was to investigate the psychometric properties of such a questionnaire for use in research and practice. A 30-item list was validated in four groups: (1) 187 patients on dialysis, (2) 82 patients who were undergoing living donor kidney transplantation the following day, (3) the general population of Dutch residents (n = 515) and (4) North American residents (n = 550). The psychometric properties of the questionnaire were examined using multidimensional item response theory (MIRT). Norm references were also calculated. Five items were found to distort ability estimates (Differential item functioning; DIF). MIRT analyses were subsequently carried out for the remaining 25 items. Almost all items showed good discrimination and difficulty parameters based on the fitted model. Two stable dimensions with 21 items were retrieved for which norm references for the Dutch and North American, dialysis and transplantation groups were calculated. This study resulted in a thorough questionnaire, the Rotterdam renal replacement knowledge-test, which enables reliable testing of patient's knowledge on kidney disease and treatment options in clinic and research.

Justification for a home-based education programme for kidney patients and their social network prior to initiation of renal replacement therapy.

In this article, an ethical analysis of an educational programme on renal replacement therapy options for patients and their social network is presented. The two main spearheads of this approach are: (1) offering an educational programme on all renal replacement therapy options ahead of treatment requirement and (2) a home-based approach involving the family and friends of the patient. Arguments are offered for the ethical justification of this approach by considering the viewpoint of the various stakeholders involved. Finally, reflecting on these ethical considerations, essential conditions for carrying out such a programme are outlined. The goal is to develop an ethically justified and responsible educational programme.

Norepinephrine-induced vasoconstriction results in decreased blood volume in dialysis patients.

BACKGROUND: Hypotension during haemodialysis results from an inadequate cardiovascular response to ultrafiltration-induced hypovolaemia. It has been suggested that plasma volume could be increased as a result of systemic vasoconstriction. METHODS: We studied the effect of a norepinephrine (NOR) infusion (30 min), compared with no infusion, on relative blood volume (RBV) in six haemodialysis patients. During infusion we measured RBV, systolic blood pressure (SAP), heart rate (HR), stroke volume index (SI), total peripheral resistance (TPRI), ejection fraction (EF), inferior vena cava diameter (VCD) and core temperature. RESULTS: At the end of the NOR infusion, we observed a significant increase in TPRI (47+/-47% vs 4+/-17%; P<0.01) and SAP (27+/-12% vs 0+/-8%; P<0.01). Norepinephrine-induced vasoconstriction resulted in a significant decrease in RBV (-9+/-3% vs 0+/-1%; P<0.01). No significant changes were seen in SI (-4+/-21% vs 0+/-8%), HR (-5+/-19% vs -4+/-5%), EF (7+/-14% vs -2+/-10%), VCD or temperature. CONCLUSIONS: We conclude that norepinephrine-induced vasoconstriction results in a decrease in RBV. This indicates that improved haemodynamic stability during haemodialysis through vasoconstriction can be accompanied by a decrease in RBV and that part of the variability in blood volume may be due to changes in arterial tone. Such changes must be taken into account if RBV measurements are used to improve the haemodynamic tolerance of dialysis.

Myocardial contractility does not determine the haemodynamic response during dialysis.

BACKGROUND: LV systolic dysfunction in dialysis patients has been implicated in the genesis of dialysis hypotension. End-systolic elastance (E(es)), a relatively load-independent parameter of myocardial contractility, was assessed by testing the acute left ventricular (LV) response to nitroglycerine (NTG) in hypotension-prone (HP) and hypotension-resistant (HR) patients. METHODS: Routine measurement of ejection fraction (EF) was done before dialysis in 15 patients without significant valvular disease or symptoms of coronary heart disease. Continuous arterial pressure was measured by Finapres, with systolic blood pressure (SBP) as surrogate for LV end-systolic pressure. Simultaneously, LV area was measured using automated border detection. SBP and LV area data were combined online to create pressure-area loops in real time following intravenous NTG bolus. E(es) was determined offline by beat-to-beat analysis of consecutive pressure-area loops. RESULTS: SBP, at baseline 168 mmHg (128-188 mmHg), decreased to 127 mmHg (79-161 mmHg). End-systolic LV area, at baseline 6 cm2 (1-12 cm2), decreased to 4 cm2 (1-10 cm2). E(es) in the HP group (11 mmHg cm(-2); 7-22 mmHg cm(-2)) was not different from E(es) in the HR group (9 mmHg cm(-2); 4-16 mmHg cm(-2)). EF was 61% (45-73%). There was no correlation between E(es) and EF. CONCLUSIONS: In this population of dialysis patients without clinically manifest heart disease, the HP and HR groups had a similar E(es). Therefore, these two types of dialysis patients were not distinguished by a difference in myocardial contractility. The results of this study argue against a role for reduced myocardial contractility in the genesis of intradialytic hypotension.

Preload dependence of new Doppler techniques limits their utility for left ventricular diastolic function assessment in hemodialysis patients.

Left ventricular (LV) hypertrophy leads to diastolic dysfunction. Standard Doppler transmitral and pulmonary vein (PV) flow velocity measurements are preload dependent. New techniques such as mitral annulus velocity by Doppler tissue imaging (DTI) and LV inflow propagation velocity measured from color M-mode have been proposed as relatively preload-independent measurements of diastolic function. These parameters were studied before and after hemodialysis (HD) with ultrafiltration to test their potential advantage for LV diastolic function assessment in HD patients. Ten patients (seven with LV hypertrophy) underwent Doppler echocardiography 1 h before, 1 h after, and 1 d after HD. Early (E) and atrial (A) peak transmitral flow velocities, peak PV systolic (s) and diastolic (d) flow velocities, peak e and a mitral annulus velocities in DTI, and early diastolic LV flow propagation velocity (V(p)) were measured. In all patients, the E/A ratio after HD (0.54; 0.37 to 1.02) was lower (P < 0.01) than before HD (0.77; 0.60 to 1.34). E decreased (P < 0.01), whereas A did not. PV s/d after HD (2.15; 1.08 to 3.90) was higher (P < 0.01) than before HD (1.80; 1.25 to 2.68). Tissue e/a after HD (0.40; 0.26 to 0.96) was lower (P < 0.01) than before HD (0.56; 0.40 to 1.05). Tissue e decreased (P < 0.02), whereas a did not. V(p) after HD (30 cm/s; 16 to 47 cm/s) was lower (P < 0.01) than before HD (45 cm/s; 32 to 60 cm/s). Twenty-four hours after the initial measurements values for E/A (0.59; 0.37 to 1.23), PV s/d (1.85; 1.07 to 3.38), e/a (0.41; 0.27 to 1.06), and V(p) (28 cm/s; 23 to 33 cm/s) were similar as those taken 1 h after HD. It is concluded that, even when using the newer Doppler techniques DTI and color M-mode, pseudonormalization, which was due to volume overload before HD, resulted in underestimation of the degree of diastolic dysfunction. Therefore, the advantage of these techniques over conventional parameters for the assessment of LV diastolic function in HD patients is limited. Assessment of LV diastolic function should not be performed shortly before HD, and its time relation to HD is essential.

Hemodynamic response to lower body negative pressure in hemodialysis patients.

BACKGROUND: Hypovolemia is thought to have an important role in the pathogenesis of dialysis-related hypotension. METHODS: We studied the effect of hypovolemia simulated by lower body negative pressure (LBNP) in 11 hypotension-prone (HP) and 11 hypotension-resistant (HR) hemodialysis patients. LBNP was applied stepwise from 0 to -20 to -40 mm Hg. Systolic arterial pressure, heart rate, and central venous pressure (CVP) were recorded continuously after cannulation of the right jugular vein. Stroke volume index was measured at each step echocardiographically. At the end of each level of LBNP, blood samples were obtained to measure norepinephrine (NE), epinephrine (E), and atrial natriuretic peptide (ANP) levels. RESULTS: At baseline, CVP (12 +/- 5 and 16 +/- 7 mm Hg), heart rate (72 +/- 9 and 70 +/- 13 beats/min), cardiac index (2.3 +/- 0.6 and 2.5 +/- 0.9 L/min), NE (median, 341 pg/mL [range,198 to 789 pg/mL] and 365 pg/mL [range, 177 to 675 pg/mL] or 2.02 nmol/L [range, 1.17 to 4.66 nmol/L] and 2.16 nmol/L [range, 1.05 to 4.00 nmol/L]), E (median, 46 pg/mL [range, 18 to 339 pg/mL] and 58 pg/mL [range, 21 to 122 pg/mL] or 251 pmol/L [range, 98 to 1,951 pmol/L] and 317 pmol/L [range, 115 to 666 pmol/L]) were similar, whereas systolic arterial pressure (141 +/- 26 versus 164 +/- 22 mm Hg) and ANP (median, 441 pg/mL [range, 152 to 1,330 pg/mL] versus 804 pg/mL [range, 517 to 3,560 pg/mL] ng/L) were lower (P < 0.05) in HP patients. In response to LBNP (-40 mm Hg), CVP decreased by 6.5 +/- 4.0 mm Hg in the HP group and 4.9 +/- 4.9 mm Hg in the HR group. In HP patients, this decrease was associated with a greater decrease in SI (37% +/- 16% versus 27% +/- 16%) and systolic arterial pressure (19% +/- 21% versus 4% +/- 14%) than in HR patients. Plasma ANP levels did not change, whereas increases in NE and E levels were similar in HP and HR patients. CONCLUSION: Patients who frequently experience episodes of hypotension during dialysis also are prone to develop hypotension during LBNP, which results from reduced myocardial contractile reserve and/or inadequate sympathetic tone.

Specific effect of the infusion of glucose on blood volume during haemodialysis.

BACKGROUND: Intradialytic morbid events such as hypotension and cramps during haemodialysis are generally treated by infusion of iso- or hypertonic solutions. However, differences may exist between solutions with respect to plasma refilling and vascular reactivity. METHODS: We compared the effect of no infusion (NI) with isovolumetric infusion of isotonic saline 0.9% (IS), saline 3% (HS), isotonic glucose 5% (IG), glucose 20% (HG) and mannitol 20% (HM), in six patients during the first hour of six standardized haemodialysis sessions with ultrafiltration. Relative blood volume was monitored continuously by measurement of the intravascular amount of protein. Blood pressure was measured by an oscillometric method, while cardiac output was measured by a thoracic impedance technique. RESULTS: At baseline, no differences in serum urea, sodium, potassium, glucose and osmolarity were found between the various infusion experiments. The maximum increase in relative blood volume directly after infusion was significantly greater with HG (5.1+/-0.7%) than with all other infusions (P<0.05). Stroke volume increased (21.0+/-19.2%, P<0.05) and total peripheral resistance decreased significantly (15.4+/-16.4%, P<0.05) after HG infusions. CONCLUSIONS: Infusion of hypertonic glucose during dialysis results in a greater increase in relative blood volume (RBV) than equal volumes of other solutions. As mannitol has the same osmolarity, molecule mass and charge, the greater increase in RBV following hypertonic glucose appears to be a specific effect, possibly related to a decline in vascular tone. It is therefore uncertain whether the observed increase in plasma volume during hypertonic glucose infusions will be of clinical benefit.