Does ethnicity influence perceived quality of life of patients on dialysis and following renal transplant?

BACKGROUND: Quality of life (QoL) as perceived by patients with end-stage renal disease (ESRD) is an important measure of patient outcome. There is a high incidence of ESRD in the Indo-Asian population in the UK and a lower rate of transplantation compared with white Europeans. The aim of this study was to determine whether perceived quality of life was influenced by treatment modality and ethnicity. METHODS: Sixty Indo-Asians treated with either peritoneal dialysis (n=20), hospital haemodialysis (n=20) or with a renal transplant (n=20) for >3 months were compared with 60 age-matched white Europeans closely matched for gender, diabetes and duration of renal replacement therapy. QoL was measured using the Kidney Disease and Quality of Life questionnaire (KDQOL-SF). The KDQOL-SF measures four QoL dimensions: physical health (PH), mental health (MH), kidney disease-targeted issues (KDI) and patient satisfaction (PS). Adequacy of treatment was measured by biochemistry, 24 h urine collection and dialysis kinetics. The number of comorbid conditions was scored. Social deprivation was calculated from the patient's postal address using Townsend scoring. RESULTS: QoL was significantly lower in Indo-Asians than white Europeans for PH, MH and KDI. This was not related to treatment adequacy, which was similar in both for each modality. Indo-Asians had a worse index of social deprivation than white Europeans (P=0.008). PH and KDI were related to social deprivation (P=0.007 and P=0.005, respectively). QoL (except PS) was inversely correlated with comorbidity. Dialysis patients had higher comorbidity than transplant patients (P<0.02). Comparing only those dialysis patients considered fit for transplantation (n=51) with transplant patients, comorbidity was similar, but differences in QoL persisted. CONCLUSION: This study demonstrates a lower perceived QoL in Asians compared with white Europeans with ESRD. Analysis of QoL indicates that Asian patients in particular perceive kidney disease as a social burden, even if successfully transplanted.

Cyclosporin A in refractory idiopathic nephrotic syndrome: 5 years clinical experience.

The use of cyclosporin A (Cy A) in idiopathic nephrotic syndrome, particularly lesions of focal segmental glomerular sclerosis, is controversial. A retrospective study of 10 adult patients with nephrotic syndrome treated with Cy A was performed. Histological diagnosis was established in all patients: focal segmental glomerular sclerosis (n = 6), focal global sclerosis (n = 1), mesangial proliferative glomerulonephritis (n = 1), focal proliferative glomerulonephritis (n = 1) and minimal change disease (n = 1). All patients had previously received immunosuppressive therapy (duration of steroids 1-76 months; 35.0 +/- 12.1, mean +/- SEM). Cy A in a dose of 3-5 mg/kg/day, reduced proteinuria from 16.85 +/- 6.67 to 3.37 +/- 1.48 g/24 hours (P = 0.008), with an associated increase in serum albumin from 15.2 +/- 2.6 to 34.3 +/- 2.5 g/l (P < 0.001). In six patients steroid therapy was discontinued. Cy A was well tolerated for up to 5 years. There was no significant nephrotoxicity. In conclusion, Cy A was effective treatment of refractory idiopathic nephrotic syndrome, including those cases with focal segmental glomerular sclerosis.

Deterioration in renal function associated with angiotensin converting enzyme inhibitor therapy is not always reversible.

Fifteen patients presented between January 1986 and January 1991 with deterioration in renal function coincident with the introduction of angiotensin converting enzyme inhibitors. There was evidence of extrarenal vascular disease in 12 patients and preexisting renal impairment in 13. Four patients remained dialysis-dependent and died within 4 weeks of presentation. Five patients required short-term dialysis. Serum creatinine remained above pre-treatment values in seven patients. Conventional explanations of the decline in renal function with ACE inhibition do not account for irreversible decrements in renal function. Possible mechanisms for this observation and clinical guidelines to identify patients at risk are suggested. We conclude that these agents should be used with great care in patients in whom atherosclerotic vascular disease is likely.

Effect of recombinant human erythropoietin on erythropoiesis in homozygous sickle-cell anaemia and renal failure.

The development of end-stage renal disease (ESRD) in patients with sickle-cell anaemia results in increased transfusion dependence, increasing the risk of iron overload. Correction of anaemia with recombinant human erythropoietin (rHuEpo) in dialysis patients might also result in stimulation of haemoglobin F production, which protects against sickling, although very high doses were required to achieve this effect in non-uraemic animals. rHuEpo was administered to three transfusion-dependent patients with ESRD and homozygous sickle-cell disease (initial dose 100 U/kg twice weekly, increasing to 125 U/kg at 6 weeks, and to 150 U/kg at 9 weeks in two patients). This resulted in reticulocytosis and increased circulating erythroid blast-forming units. Total haemoglobin was predominantly HbA (i.e. transfused blood) at the start of the study, reflecting transfusion dependence, but after 3 months' treatment was between 60 and 94% HbS. No sickling crises occurred. Haemoglobin F remained at less than 3% of total haemoglobin. One patient was withdrawn at 10 weeks with CAPD peritonitis. The other two patients completed 12 weeks' treatment without transfusion but final Hb concentrations were 4.5 and 5.5 g/dl. Whether larger doses of rHuEpo will be more successful in managing such patients remains unclear. No effect on HbF production can be expected.

Plasma erythropoietin levels and acquired cystic disease of the kidney in patients receiving regular haemodialysis treatment.

Acquired cystic disease of the kidney (ACDK) in patients with end-stage renal failure can be associated with development of polycythaemia. The relationship between plasma erythropoietin levels and ACDK in 17 patients on long-term haemodialysis treatment was studied. There was a significantly higher level of plasma erythropoietin in patients with multiple renal cysts than in those patients with less than five cysts or no cysts. Haemoglobin tended to be higher in the ACDK group, but the difference was not significant. These results indicate that the development of renal cysts results in increased secretion of erythropoietin.

Baroreceptor-heart rate reflex function before and after surgical reversal of two-kidney, one-clip hypertension in the rat.

Baroreflex function was studied in conscious early phase (less than 6 weeks) two-kidney, one-clip hypertensive rats before and 24 hours after surgical reversal of hypertension by removal of the constricting renal artery clip or after pharmacological reduction of blood pressure by an infusion of hydralazine or captopril. A normotensive sham-clipped group was included. Another group of two-kidney, one-clip rats was studied 3 weeks after unclipping. Baroreflex sensitivity, as assessed by the steady-state method using a graded phenylephrine infusion, mean arterial pressure, and heart rate were measured preoperatively and at 24 hours postoperatively. Two-kidney, one-clip rats were significantly hypertensive preoperatively compared with control (mean arterial pressure, 183 +/- 4 vs. 106 +/- 2 mm Hg, p less than 0.001), heart rate was similar (420 +/- 9 vs. 401 +/- 9 beats/min, p greater than 0.05), and baroreflex sensitivity was significantly reduced (0.76 +/- 0.07 vs. 1.50 +/- 0.20 msec/mm Hg; p less than 0.001). There was a minimal change in heart rate despite the fall in mean arterial pressure in all hypertensive groups, indicating resetting of the baroreflexes. At 24 hours after the operation, baroreflex sensitivity was unchanged in all groups compared with the preoperative value. By 3 weeks, baroreflex sensitivity was significantly greater than in the hypertensive two-kidney, one-clip rats before the operation and 24 hours after they were unclipped, but not compared with normotensive sham-clipped rats. Thus, although resetting occurs within 24 hours, whatever the method of blood pressure reduction, baroreflex sensitivity remains impaired at this time.(ABSTRACT TRUNCATED AT 250 WORDS)

Vascular capacitance in rats subjected to chemical renal medullectomy.

Selective renal medullary destruction is produced in rats by a single injection of 2-bromoethylamine hydrobromide. The object of these studies was to investigate whether destruction of the renal medulla in normal rats would alter vascular capacitance. Conscious bromoethylamine-treated rats (n = 15) were compared with control saline-injected rats (n = 12). Mean circulatory filling pressure was measured during a brief circulatory arrest caused by inflation of a right atrial balloon. Blood volume was determined from plasma volume (iodine-125-labeled albumin) and hematocrit. Mean circulatory filling pressure was measured at resting blood volume and after rapid blood volume changes. Vascular compliance was derived from the mean circulatory filling pressure-blood volume curve. The bromoethylamine-treated rats were significantly hypertensive compared with control rats (mean arterial pressure 133 +/- 2 and 114 +/- 3 mm Hg, respectively, p less than 0.001) and had a significant tachycardia (475 +/- 8 and 443 +/- 10 beats/min, respectively, p = 0.02). Blood volume, plasma volume, hematocrit, and sodium excretion were no different. There was no significant difference in mean circulatory filling pressure (6.5 +/- 0.2 and 6.8 +/- 0.2 mm Hg, respectively, p = 0.4) or vascular compliance (3.64 +/- 0.20 and 3.53 +/- 0.12 ml/kg/mm Hg, respectively, p = 0.7). The position of the vascular pressure-volume curve was unchanged indicating no change in vascular capacity. This would suggest that the destruction of renal medullary vasodepressor mechanisms does not result in alterations in vascular capacitance.

Acute renal failure associated with a labetalol overdose.

A case of acute renal failure in association with a deliberate labetalol overdose is described. The possible pathogenetic mechanisms behind the deterioration in renal function are discussed. Treatment of beta-blockade overdose, with special emphasis on the place of glucagon in such poisoning, is reviewed.

Vascular capacitance and reversal of 2-kidney, 1-clip hypertension in rats.

Vascular capacitance was studied in conscious early-phase (less than 6 wk) 2-kidney, 1-clip (2K, 1C) hypertension and compared with sham-clipped control rats. Two other groups of 2K, 1C rats were studied before and 6 h after unclipping or a sham operation. Mean circulatory filling pressure (MCFP) was measured during a brief circulatory arrest caused by inflation of a right atrial balloon. Blood volume (BV) was determined from plasma volume (125I-labeled albumin) and hematocrit. MCFP was measured at resting BV and after rapid BV changes. Vascular compliance was derived from the MCFP-BV curve. Hypertensive 2K, 1C rats had an increase in hematocrit (46 +/- 1.3 vs. 42 +/- 0.4%, P less than 0.01) and no difference in BV compared with controls. MCFP was increased (8.6 +/- 1.0 vs. 7.2 +/- 0.2 mmHg, P less than 0.01) with no difference in compliance, indicating decreased unstressed vascular volume in the 2K, 1C group. After unclipping, there was a significant fall in mean arterial pressure to normal, with a fall in MCFP (8.14 +/- 0.32 to 6.78 +/- 0.11 mmHg, P less than 0.01), but there was no difference in BV or compliance compared with the 2K, 1C group, indicating an increase in unstressed vascular volume after unclipping. These studies for the first time show an important role for vascular capacitance in modulating the circulatory changes accompanying the fall in blood pressure in surgical reversal of 2K, 1C hypertension.

Seizures in haemodialysis patients treated with recombinant human erythropoietin.

Administration of recombinant erythropoietin (r-HuEPO) is an effective treatment for the anaemia of chronic renal failure, but in some patients it has been accompanied by elevated blood pressure. This study focuses on seven patients with end-stage renal failure, managed on haemodialysis, who developed probable hypertensive encephalopathy with seizures during treatment with r-HuEPO. All made a full recovery. The events were not clearly related to the haemoglobin concentrations achieved, and four patients have subsequently been restarted on r-HuEPO therapy at a reduced dose, resulting in a slower increase in haemoglobin with no recurrence of episodes of severe hypertension. Close attention needs to be paid to blood pressure in patients commencing erythropoietin therapy, and it seems prudent to aim for a gradual increase in haemoglobin concentration to allow the circulation to adapt to changes in oxygen delivery and haematocrit.

Does increasing haemoglobin concentration and haematocrit have a pressor effect in dialysis patients?

The haemodynamic consequences of differing rates of rise of haemoglobin and haematocrit in haemodialysis and CAPD patients were examined. Pre-dialysis mean arterial pressure, weight and haematological indices were recorded in 100 established haemodialysis patients prior to a 2-unit blood transfusion and repeated, pre-dialysis, within 1 week. Haemoglobin rose from 6.7 +/- 0.2 to 9.3 +/- 0.1 g/dl, weight was unchanged, and there was a small fall in mean arterial pressure. Similar indices were recorded, including the mid-arm circumference (MAC) in 100 CAPD patients 1 month after starting CAPD and at the time of maximum haemoglobin within the first year. Haemoglobin rose from 8.5 +/- 0.1 to 10.7 +/- 0.1 g/dl, weight increased slightly, but there was no change in MAC: weight ratio and there was a small fall in mean arterial pressure. In neither group was there a change in antihypertensive medication. In conclusion, increasing the haemoglobin concentration and haematocrit of dialysis patients within the range described in this study did not promote elevated blood pressure.

Renal vasodepressor mechanism: characterization by chemical medullectomy.

The features of hypertension produced in the rat by chemical medullectomy with 2-bromoethylamine hydrobromide are described. This procedure partially prevents the fall in blood pressure that occurs when the constriction is removed from the renal artery of rats with two-kidney one-clip Goldblatt hypertension. In normal rats, chemical medullectomy causes a moderate but consistent blood pressure elevation that is dose related and associated with elevation of peripheral resistance; the venous side of the circulation is normal. The hypertension is not associated with sodium retention or with activation of the renin angiotensin system. Although vasopressin levels are elevated, the rise is only modest, and blood pressure is not reduced by a vascular AVP antagonist. It is concluded that chemical medullectomy removes the source of a humoral substance that has been shown by other workers to carry out a vasodepressor role. The chemical medullectomy model therefore offers new insights into the renomedullary vasodepressor system.

Reversal of renovascular hypertension: role of the renal medulla.

The fall in blood pressure, which occurs when renovascular hypertension is corrected surgically, offers a means of elucidating the factors responsible for blood pressure control. When Goldblatt two-kidney, one-clip hypertension in the rat is reversed by unclipping the renal artery, or by removal of the ischaemic kidney, restoration of normal blood pressure is due to a fall in peripheral resistance. This is associated with sodium retention and cannot be modified by inhibition of the renin-angiotensin system. The fall is, however, partially inhibited by chemical removal of the renal medulla by means of 2-bromo-ethylamine hydrobromide. When normal rats are chemically medullectomized, moderate hypertension is produced, which cannot be attributed to the renin-angiotensin system or sodium retention. It is concluded that a renomedullary vasodepressor system is ablated by chemical medullectomy: further, this system plays a role in the surgical correction of Goldblatt hypertension.

Failure of naloxone to influence surgical reversal of two-kidney, one-clip hypertension in the rat.

The rapid fall in blood pressure after removal of the constricting clip in two-kidney one-clip (2K-1C) hypertension in the rat is not fully explained by inhibition of the renin-angiotensin system or change in sodium balance. It has been postulated that compounds released in the renal venous effluent following unclipping of 2K-1C rats have a central opiate-like action and endogenous opioids are recognized to have profound hypotensive properties. To investigate this, we removed the clip from, or performed a sham operation in, early phase (less than 6 weeks) 2K-1C hypertensive rats during an infusion of naloxone, an opioid antagonist, or vehicle alone. The infusion of naloxone did not affect the pattern of blood pressure fall in either unclipped or sham-operated rats. Both naloxone-treated and control groups were similarly normotensive at 24 hr postoperation, the MAP being significantly lower than in the sham-operated groups, which regained previously hypertensive levels. Heart rate was unchanged 24 hr postoperatively in all groups. Morphine-induced bradycardia and hypotension were significantly reduced by naloxone infusion. Thus, naloxone infusion had no effect on blood pressure or heart rate in either the sham-operated or the unclipped groups, indicating that endogenous opioids do not have a major role in the reversal of renovascular hypertension under these circumstances.