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Residual Renal Function (residual + renal_function)
Selected AbstractsThe Effects of Angiotensin Converting Enzyme Inhibitors on Potassium Homeostasis in Dialysis Patients With and Without Residual Renal FunctionARTIFICIAL ORGANS, Issue 8 2009Elizabeth Garthwaite Abstract Hyperkalemia is exacerbated by angiotensin converting enzyme inhibitors (ACE-I). Distal potassium (K+) secretion is negligible in anuric patients. ACE-I therapy may reduce renal, peritoneal, and colonic K+ losses. We examined the effect of ACE-I therapy on serum, urinary, and dialysate K+ in a cross-section of peritoneal and hemodialysis patients. Serum, 24-h urine K+, and peritoneal dialysate excretion K+ levels were measured and the results were compared in the various dialysis and treatment groups. Eighty-one hemodialysis (HD) and 32 peritoneal dialysis (PD) patients were included. Serum K+ in HD patients with no residual renal function (RRF) was higher in those receiving ACE-I therapy (P = 0.02). Serum K+ levels in HD patients receiving ACE-I treatments with RRF was similar to that in oligoanuric HD patients not receiving an ACE-I. Urinary K+ excretion was significantly reduced in those on ACE-I therapy versus those not on an ACE-I (P < 0.05). Mean serum K+ was lower in PD versus HD patients (P < 0.05). PD patients with no RRF on ACE-I therapy had higher serum K+ concentrations (P = 0.002) and dialysate K+ excretion was lower (P = 0.05), in comparison with PD patients not on an ACE-I. PD patients with RRF on ACE-I therapy had higher serum K+ concentrations compared with those not on ACE-I therapy (P = 0.03). Both urinary and dialysate K+ excretion were reduced (P = 0.001 and P = 0.002, respectively). ACE-I therapy increases serum K+ concentration in dialysis patients. PD patients have relatively lower serum K+ levels compared with HD patients. In PD patients, ACE-I therapy reduces dialysate K+. These changes may result from reduced peritoneal movement of K+. [source] Is it time to revisit residual renal function in haemodialysis? (Review Article)NEPHROLOGY, Issue 3 2007TSUN G NG SUMMARY: Residual renal function (RRF) is not currently emphasized for patients undergoing haemodialysis (HD). The role of RRF is well recognized in the peritoneal dialysis population as studies have clearly demonstrated a survival benefit with preservation of RRF. There is however, data to suggest that RRF is important in HD patients as well. Contemporary HD therapies using high flux biocompatible synthetic dialysers, bicarbonate buffered ultrapure dialysis fluids with ultrafiltration control appear to allow better preservation of RRF. The long held belief that peritoneal dialysis is better at preserving RRF than HD may no longer be true. More robust studies are required to determine the relative importance of RRF in HD and strategies to best preserve this vital asset. [source] Association between serum bicarbonate and death in hemodialysis patients: Is it better to be acidotic or alkalotic?HEMODIALYSIS INTERNATIONAL, Issue 1 2005D.Y.J. Wu The optimal acid base status for survival in maintenance hemo-dialysis (MHD) patients (pts) remains controversial. According to some reports acidosis is associated with improved survival in MHD pts, i.e., reverse epidemiology. We examined associations between baseline (first 3-month averaged) serum bicarbonate (HCO3), divided into 12 categories, and 2-yr mortality in 56,376 MHD pts across the US after controlling for confounding effects of malnutrition-inflammation complex syndrome (MICS). Three sets of Cox regression models were evaluated to estimate hazard ratios (HR) of death and 95% confidence intervals (CI): (1) Unadjusted; (2) Multivariate adjusted for case-mix (age, gender, diabetes, race, insurance, marital status, vintage, standardized mortality ratio, residual renal function, dialysate HCO3, and Kt/V); and (3) Additional adjustments for 8 markers of MICS (body mass index, serum albumin, creatinine, ferritin, TIBC, dietary protein intake, WBC and lymphocyte counts). See Figure for HR and 95% CI: We conclude that, although high HCO3 levels appear to be associated with increased mortality in MHD pts, this paradoxical effect is almost entirely due to the overwhelming impact of MICS on survival. [source] Fallacies of High-Speed HemodialysisHEMODIALYSIS INTERNATIONAL, Issue 2 2003Zbylut J. Twardowski Chronic hemodialysis sessions, as developed in Seattle in the 1960s, were long procedures with minimal intra- and interdialytic symptoms. Financial and logistical pressures related to the overwhelming number of patients requiring hemodialysis created an incentive to shorten dialysis time to four, three, and even two hours per session in a thrice weekly schedule. This method spread rapidly, particularly in the United States, after the National Cooperative Dialysis Study suggested that time of dialysis is of minor importance as long as urea clearance multiplied by dialysis time and scaled to total body water (Kt/Vurea) equals 0.95,1.0. This number was later increased to 1.3, but the assumption remained unchanged that hemodialysis time is of minimal importance as long as it is compensated by increased urea clearance. Patients accepted short dialysis as a godsend, believing that it would not be detrimental to their well-being and longevity. However, Kt/Vurea measures only removal of low molecular weight substances and does not consider removal of larger molecules. Besides, it does not correlate with the other important function of hemodialysis, namely ultrafiltration. Whereas patients with substantial residual renal function may tolerate short dialysis sessions, the patients with little or no urine output tolerate short dialyses poorly because the ultrafiltration rate at the same interdialytic weight gain is inversely proportional to dialysis time. Rapid ultrafiltration is associated with cramps, nausea, vomiting, headache, fatigue, hypotensive episodes during dialysis, and hangover after dialysis; patients remain fluid overloaded with subsequent poor blood pressure control, left ventricular hypertrophy, diastolic dysfunction, and high cardiovascular mortality. Short, high-efficiency dialysis requires high blood flow, which increases demands on blood access. The classic wrist arteriovenous fistula, the access with the best longevity and lowest complication rates, provides "insufficient" blood flow and is replaced with an arteriovenous graft fistula or an intravenous catheter. Moreover, to achieve high blood flows, large diameter intravenous catheters are used; these fit veins "too tightly," so predispose the patient to central-vein thrombosis. Longer hemodialysis sessions (5,8 hrs, thrice weekly), as practiced in some centers, are associated with lower complication rates and better outcomes. Frequent dialyses (four or more sessions per week) provide better clinical results, but are associated with increased cost. It is my strong belief that a wide acceptance of longer, gentler dialysis sessions, even in a thrice weekly schedule, would improve overall hemodialysis results and decrease access complications, hospitalizations, and mortality, particularly in anuric patients. [source] Back to the Future: Middle Molecules, High Flux Membranes, and Optimal DialysisHEMODIALYSIS INTERNATIONAL, Issue 1 2003Raymond C. Vanholder Middle molecules can be defined as compounds with a molecular weight (MW) above 500 Da. An even broader definition includes those molecules that do not cross the membranes of standard low-flux dialyzers, not only because of molecular weight, but also because of protein binding and/or multicompartmental behavior. Recently, several of these middle molecules have been linked to the increased tendency of uremic patients to develop inflammation, malnutrition, and atheromatosis. Other toxic actions can also be attributed to the middle molecules. In the present publication we will consider whether improved removal of middle molecules by large pore membranes has an impact on clinical conditions related to the uremic syndrome. The clinical benefits of large pore membranes are reduction of uremia-related amyloidosis; maintenance of residual renal function; and reduction of inflammation, malnutrition, anemia, dyslipidemia, and mortality. It is concluded that middle molecules play a role in uremic toxicity and especially in the processes related to inflammation, atherogenesis, and malnutrition. Their removal seems to be related to a better outcome, although better biocompatibility of membranes might be a confounding factor. [source] Renal artery pseudoaneurysm after laparoscopic partial nephrectomy for renal cell carcinoma in a solitary kidneyINTERNATIONAL JOURNAL OF UROLOGY, Issue 7 2005HIROMITSU NEGORO Abstract Renal artery pseudoaneurysms are a well-documented complication following trauma or percutaneous urological procedures, but are rare after partial nephrectomy. We present the case of a 34-year-old woman who, after undergoing a left nephrectomy in childhood due to Wilms' tumor, had a pseudoaneurysm in a solitary kidney after laparoscopic right partial nephrectomy with extraperitoneal approach for a renal cell carcinoma. The segmental renal artery feeding the pseudoaneurysm was embolized with coils without significant loss of residual renal function. [source] Effect of renin,angiotensin system inhibitors on prevention of peritoneal fibrosis in peritoneal dialysis patientsNEPHROLOGY, Issue 1 2010SUN JING ABSTRACT: Aim: Long-term peritoneal dialysis (PD) may lead to peritoneal fibrosis and ultrafiltration failure. It had been demonstrated that the renin,angiotensin system (RAS) plays a key role in the regulation of peritoneal function in rats on PD. We investigated the effects of angiotensin-converting enzyme inhibitor (ACEI) or angiotensin receptor blocker (ARB) on long-term PD patients. Methods: We analyzed data from 66 patients treated with PD therapy at our centre for at least 12 months retrospectively, during which time at least two peritoneal equilibration tests (PET) were performed. Thirty-eight patients were treated with ACE/angiotensin II (AII) inhibitors (ACE/ARB group); the other 28 received none of the above drugs during the entire follow up (control group). The expression of fibronectin, transforming growth factor-,1 (TGF-,1), Aquaporin1 (AQP1) and vascular endothelial growth factor (VEGF) in the overnight effluent were examined by enzyme-linked immunosorbent assay. Results: The demographic data of the two groups showed no difference during the study. No difference between the groups was found with respect to residual renal function (RRF) at the start for both groups by the end of follow up, decreased in the vast majority of patients from both groups (P = 0.014). After 12 months, a significant difference in ultrafiltration was found between the two groups: in the control group it had decreased, while it had not changed in the ACE/ARB group (P < 0.05). In comparison with the baseline level, expression of fibronectin, TGF-,1 and VEGF in dialysate effluent were significantly increased except for AQP1 in the control group (P < 0.05), but not in the ACE/ARB group (P > 0.05). Conclusion: The findings suggest that ACE/AII inhibitors appeared to have a slower rate of decline in ultrafiltration and RRF, effectively protect against peritoneal fibrosis in long-term peritoneal dialysis. Long-term follow up seems to be required to draw more conclusions. [source] Is it time to revisit residual renal function in haemodialysis? (Review Article)NEPHROLOGY, Issue 3 2007TSUN G NG SUMMARY: Residual renal function (RRF) is not currently emphasized for patients undergoing haemodialysis (HD). The role of RRF is well recognized in the peritoneal dialysis population as studies have clearly demonstrated a survival benefit with preservation of RRF. There is however, data to suggest that RRF is important in HD patients as well. Contemporary HD therapies using high flux biocompatible synthetic dialysers, bicarbonate buffered ultrapure dialysis fluids with ultrafiltration control appear to allow better preservation of RRF. The long held belief that peritoneal dialysis is better at preserving RRF than HD may no longer be true. More robust studies are required to determine the relative importance of RRF in HD and strategies to best preserve this vital asset. [source] Maintaining clearance in peritoneal dialysisNEPHROLOGY, Issue 6 2001David W Johnson SUMMARY: Numerous studies have now established that there is a strong association between small solute clearance and improved outcomes in peritoneal dialysis (PD) patients. Preservation of both renal and peritoneal clearances is therefore of paramount importance, although very few trials have satisfactorily addressed this critical issue. Observational studies have suggested that the groups most at risk of loss of residual renal function are women, non-whites, diabetic patients, patients with congestive cardiac failure, patients who experience frequent episodes of peritonitis and, possibly, patients treated with automated PD (APD). There have been no controlled trials of renoprotective therapies in PD patients, but reasonable strategies for preventing renal functional decline include avoidance of nephrotoxins and infection, maintenance of adequate blood pressure, abstinence from smoking and possibly administration of angiotensin-converting enzyme inhibitors and/or calcium channel blockers. In contrast, peritoneal small solute removal can be maximized by augmenting fill volume, increasing exchange frequency and using either long-dwell continuous ambulatory PD (CAPD) or short-dwell (APD) therapies to suit individual patients' transport characteristics. Tidal PD may additionally increase solute clearance, although studies have reported conflicting findings. Preservation of membrane function may be achieved by minimizing episodes of peritonitis and avoiding hypertonic glucose exchanges. Newer peritoneal dialysates, such as icodextrin, amino acids, bicarbonate-buffered solutions and aldehyde-poor fluids, are more biocompatible in experimental models of PD, but their long-term clinical safety and efficacy have not yet been established by clinical trials. Moreover, no trials have demonstrated an independent effect of peritoneal clearance on patient outcomes. Further studies determining the relative value of renal and peritoneal clearances are therefore urgently required in order to optimize dialytic adequacy for PD patients. [source] Benefits and risks of furosemide in acute kidney injuryANAESTHESIA, Issue 3 2010K. M. Ho Summary Furosemide, a potent loop diuretic, is frequently used in different stages of acute kidney injury, but its clinical roles remain uncertain. This review summarises the pharmacology of furosemide, its potential uses and side effects, and the evidence of its efficacy. Furosemide is actively secreted by the proximal tubules into the urine before reaching its site of action at the ascending limb of loop of Henle. It is the urinary concentrations of furosemide that determine its diuretic effect. The severity of acute kidney injury has a significant effect on the diuretic response to furosemide; a good ,urinary response' may be considered as a ,proxy' for having some residual renal function. The current evidence does not suggest that furosemide can reduce mortality in patients with acute kidney injury. In patients with acute lung injury without haemodynamic instability, furosemide may be useful in achieving fluid balance to facilitate mechanical ventilation according to the lung-protective ventilation strategy. [source] Asymmetric Dimethylarginine in Hemodialysis, Hemodiafiltration, and Peritoneal DialysisARTIFICIAL ORGANS, Issue 5 2010Jaromír Eiselt Abstract Asymmetric dimethylarginine (ADMA) is a mediator of endothelial dysfunction. Production and elimination of ADMA may be affected by the type of renal replacement therapy used and oxidative stress. Plasma ADMA, advanced glycation end products (AGE), and homocysteine were assessed in 59 subjects: 20 hemodialysis (HD) patients, 19 patients undergoing peritoneal dialysis (PD), and 20 controls. Results were compared between the groups. The effect of 8 weeks of HD and high-volume predilution hemodiafiltration (HDF) was compared in a randomized study. HD patients showed higher ADMA (1.20 [0.90,1.39 µmol/L]) compared to controls (0.89 [0.77,0.98], P < 0.01), while ADMA in PD did not differ from controls (0.96 [0.88,1.28]). AGE and homocysteine were highest in HD, lower in PD (P < 0.01 vs. HD), and lowest in controls (P < 0.001 vs. HD and PD). PD patients had higher residual renal function than HD (P < 0.01). The decrease in ADMA at the end of HD (from 1.25 [0.97,1.33] to 0.66 [0.57,0.73], P < 0.001) was comparable to that of HDF. Switching from HD to HDF led to a decrease in predialysis homocysteine level in 8 weeks (P < 0.05), while ADMA and AGE did not change. Increased ADMA levels in patients undergoing HD, as compared to PD, may be caused by higher oxidative stress and lower residual renal function in HD. Other factors, such as diabetes and statin therapy, may also be at play. The decrease in ADMA at the end of HD and HDF is comparable. Switching from HD to HDF decreases in 8 weeks the predialysis levels of homocysteine without affecting ADMA. [source] The Effects of Angiotensin Converting Enzyme Inhibitors on Potassium Homeostasis in Dialysis Patients With and Without Residual Renal FunctionARTIFICIAL ORGANS, Issue 8 2009Elizabeth Garthwaite Abstract Hyperkalemia is exacerbated by angiotensin converting enzyme inhibitors (ACE-I). Distal potassium (K+) secretion is negligible in anuric patients. ACE-I therapy may reduce renal, peritoneal, and colonic K+ losses. We examined the effect of ACE-I therapy on serum, urinary, and dialysate K+ in a cross-section of peritoneal and hemodialysis patients. Serum, 24-h urine K+, and peritoneal dialysate excretion K+ levels were measured and the results were compared in the various dialysis and treatment groups. Eighty-one hemodialysis (HD) and 32 peritoneal dialysis (PD) patients were included. Serum K+ in HD patients with no residual renal function (RRF) was higher in those receiving ACE-I therapy (P = 0.02). Serum K+ levels in HD patients receiving ACE-I treatments with RRF was similar to that in oligoanuric HD patients not receiving an ACE-I. Urinary K+ excretion was significantly reduced in those on ACE-I therapy versus those not on an ACE-I (P < 0.05). Mean serum K+ was lower in PD versus HD patients (P < 0.05). PD patients with no RRF on ACE-I therapy had higher serum K+ concentrations (P = 0.002) and dialysate K+ excretion was lower (P = 0.05), in comparison with PD patients not on an ACE-I. PD patients with RRF on ACE-I therapy had higher serum K+ concentrations compared with those not on ACE-I therapy (P = 0.03). Both urinary and dialysate K+ excretion were reduced (P = 0.001 and P = 0.002, respectively). ACE-I therapy increases serum K+ concentration in dialysis patients. PD patients have relatively lower serum K+ levels compared with HD patients. In PD patients, ACE-I therapy reduces dialysate K+. These changes may result from reduced peritoneal movement of K+. [source] Ultrafiltration and Dry Weight,What Are the Cardiovascular Effects?ARTIFICIAL ORGANS, Issue 3 2003Article first published online: 2 APR 200, Bernd G. Stegmayr Abstract: Long-term prognosis in dialysis is poor compared to that in healthy control persons. A worsening of the prognosis is noted especially for patients who at initiation of dialysis have congestive heart failure, ischemic heart disease, or left ventricular dysfunction or hypertrophy. This is the main reason that cardiovascular causes are the most common for morbidity in these patients. The weight obtained when normal urine output is present is the dry weight. With reduced ability to excrete the volume by the kidneys in end-stage renal disease (ESRD), the body will retain water and the patient will gain weight. This extra weight is due to volume overload. While volume overload may induce a rise in blood pressure, if the heart is in acceptable condition, a fast removal of fluid by ultrafiltration (UF) during dialysis may instead cause hypotension. Ultrafiltration failure in peritoneal dialysis (PD) patients may lead to successive water retention and overhydration with subsequent cardiac failure, while volume overload may occur over a few days in hemodialysis (HD) patients. Anemia or even too-high hematocrit may impair cardiac function further and worsen conditions caused by wrong dry weight. Thus, during long-term and sustained volume overload, left ventricular (LV) hypertrophy will occur in an eccentric manner. A sustained overload then may lead to cell death and LV dilatation and, eventually, systolic dysfunction. Once a severe left ventricular dilatation has developed, the blood pressure may decrease during volume overload. A worsened prognosis is seen if malnutrition and low albumin levels are present. Volume overload necessitates ultrafiltration to achieve dry weight. Thereby, volume contraction contributes to exaggerated stimulation of or response to activation of the RAS and alpha-adrenergic sympathetic systems. If ultrafiltration goes beyond these compensatory mechanisms, hypotension will occur and increase the risk for hypoperfusion of vital organs. Such episodes may cause cardiac morbidity, aspiration pneumonia, vascular access closure, or neurological complications (seizures, cerebral infarction), besides a more rapid lowering of residual renal function. Preventive measures are, first, finding the right dry weight; second, minimizing interdialytic weight gain; third, optimizing the target for hemoglobin (110,120 g/l); fourth, lowering dialysate calcium (1.25 mmol/l); and fifth, eventually using higher dialysate potassium if long dialyses are performed. [source] Recovery of renal function after 90 d on dialysis: implications for transplantation in patients with potentially reversible causes of renal failureCLINICAL TRANSPLANTATION, Issue 2 2008Samira Siddiqui Abstract:, Background:, Late recovery of renal function in patients requiring dialysis is a well recognized but uncommon phenomenon. Moves to increase the number of live donor transplants and the recognition that early transplantation is associated with better graft survival means it is possible that patients who are going to recover renal function may be transplanted unnecessarily. Design:, Prospective survey of patients receiving dialysis for more than 90 d in south west Scotland from 1 January 1994 to 31 December 2005. Methods:, Routine measurement of residual renal function by combined urea and creatinine clearance allowed us to detect late recovery whenever this occurred. Results:, Eight of 202 (4%) patients recovered sufficient renal function to stop dialysing after 90-d treatment. The likely cause of the renal failure in five of these patients was atheroembolism. One with atherosclerotic renovascular disease had been stented and would have received a live related renal transplant had his sister not had second thoughts about the procedure. Conclusion:, It may be sensible to postpone transplantation in patients with certain types of renal failure, perhaps particularly patients with renovascular disease who have recently undergone a failed revascularization procedure. [source] | ||||||||||