Considerations in the nutritional management of patients with acute renal failure

Despite improvements in medical and dialytic therapies, mortality rates for patients with complicated acute renal failure (ARF) remains tragically high-above 50%. Mortality rates also remain persistently high in patients with ARF and preexisting or hospital-acquired malnutrition. ARF causes significant changes in substrate utilization largely because of the metabolic consequences of acute uremia compounded by underlying stress from acute illness. Alterations in protein or amino acid, carbohydrate, and lipid metabolism as well as fluid, electrolyte, and acid-base balance need to be considered when providing nutritional therapy in patients with ARF. Also, the degree of renal impairment, which influences the need for renal replacement therapy (RRT), impacts nutritional requirements. As medical management is becoming highly aggressive in treating ARF with RRT, the ability to provide adequate nutrition is enhanced; however, no consensus on optimal caloric and macro-/micronutrient requirements is available. More current research is required to clarify nutritional needs of this patient population. Nevertheless, individualizing nutrition care and integrating nutritional therapies within a team setting is essential in providing optimal patient care in the presence of ARF.     

Hemodialysis Systems for Intermittent,Semi-Continuous,and Continuous Therapies in Acute Renal Failure

As is the case in end-stage renal disease (ESRD), both intermittent and continuous renal replacement therapies (RRTs) are employed in acute renal failure (ARF). In fact, a continuum of treatment options is available in ARF. At one end of the ARF RRT spectrum is conventional intermittent hemodialysis (IHD), in which relatively high blood and dialysate flow rates are used (typically ≥250 and 500 mL/min, respectively). Continuous renal replacement therapies (CRRTs), which employ much lower flow rates, comprise the other end of the spectrum. Finally, hybrid therapies, which combine characteristics of both IHD and CRRT, have recently been described. These therapies’ removal mechanisms for solutes over a broad molecular weight range are discussed. An understanding of these mechanisms is important when determining the amount of therapy that can be provided by any RRTs. Additional studies are required to improve the understanding of solute removal by the various RRT used in ARF.     

Renal replacement therapy in the critically ill patient with acute kidney injury

The mortality of patients with acute renal failure (ARF) has remained unacceptably high for many years, with renal replacement therapy (RRT) remaining the mainstay of treatment. Clinical research has hitherto been hindered by a lack of a universal definition. However, changes are upon us in the shape of a new term, acute kidney injury (AKI), proposed to encompass the spectrum of ARF, along with a new definition and staging system. There is a renewed optimism that the establishment of clinical databases and the utilization of new clinical biomarkers will catalyze the development of new therapeutic strategies. In the interim, we must optimize the delivery of RRT to patients with AKI. It is remarkable how few studies are currently available in the literature to guide medical practitioners on the key issues of initiation, modality, type of buffer, dose of RRT, vascular access, and anticoagulation. On the horizon, the outcomes of two major clinical trials comparing doses and modalities of RRT in AKI are eagerly awaited.     

Free dialysis in Nepal: Logistical challenges explored

Nepal's Ministry of Health began offering free lifetime hemodialysis (HD) in 2016. There has been a large growth in renal replacement therapy (RRT) services offered in Nepal since 2010, when the last known data on the subject was published. In 2016, 42 HD centers existed (223% increase since 2010) serving 1975 end stage renal disease patients (303% increase since 2010); 36 nephrologists were registered (200% increase since 2010), 12 were trained in transplantation, and 790 transplants had been performed to date. We estimate the incidence of end stage renal disease to be 2900 patients (100 per million population). With an annual cost of approximately US$2300 per dialysis patient, offering free dialysis could potentially cost the government US$6.7 million per year, suggesting that 2.1% of the annual health budget would be allocated to 0.01% of the population. The geographic zone surrounding the capital city, Kathmandu, contains 50% of HD centers, but only 14.5% of Nepal's population. Forty‐eight percent of the population lives within zones without HD service, therefore infrastructure challenges exist in providing equitable access to RRT. The aim of this article is to summarize the current statistics of RRT in Nepal.     

Importance of early dialysis for acute renal failure after an open-heart surgery

Coronary artery disease is a major cause of death in patients with a renal dysfunction. Among the patients who undergo coronary artery bypass grafting, renal dysfunction is known to be a major predictor of in-hospital and out-of-hospital mortality. From 2004 to 2007, we performed elective open-heart surgeries on 2380 patients in whom there was no primary renal failure. Of those patients, only 185 in whom acute renal failure (ARF) was developed were included in the study. The patients were divided into 2 groups: a late dialysis group (n=90) and an early dialysis group (n=95). The mean age of the patients was 62.3±6.4 in the late dialysis group and 64.5±5.2 in the early dialysis group. There were 32 female and 58 male patients in the late dialysis group and 36 female and 59 male patients in the early dialysis group. Acute renal failure developed only in 185 patients out of 2380 open-heart surgery patients. The overall mortality in the 2380 open-heart surgery patients was 1.97%. Mortality among the ARF patients was 5.9%. However, there was no significant difference in hospital mortality between the 2 groups. Major complications, such as postoperative pneumonia, prolonged ventilation time, arrhythmia, the number of times postoperative hemodialysis was performed, development of chronic renal failure, time spent in the intensive care unit and the period of hospitalization, sepsis, and low cardiac output, were significantly higher in the late dialysis group. There was no difference in mortality between the 2 groups. Early dialysis for open-heart surgery patients who develop ARF postoperatively does not decrease mortality. However, it decreases morbidity, the amount of time spent in intensive care, and the period of hospitalization and thus reduces patient costs.     

Predicting Acute Renal Failure after Cardiac Surgery: Validation and Re‐definition of a Risk‐Stratification Algorithm

Background:  Acute renal failure (ARF) after cardiac surgery is associated with significant morbidity and mortality, irrespective of the need for dialysis. Previous studies have attempted to identify predictors of ARF and develop risk stratification algorithms. This study aims to validate the algorithm in an independent cohort of patients that includes a significant proportion of female and black patients and compares two different definitions of renal outcome.
Methods:  A large single center cardiac surgery database was examined (n, 24,660; 1993–2000) which included 29.9% females and 3.7% black patients. Post‐operative ARF was defined as: a) ARF requiring dialysis, b) > 50% reduction in creatinine clearance relative to baseline or requiring dialysis. Clinical variables related to baseline renal function and cardiovascular disease were used in recursive partitioning analysis for both outcome definitions. Chi‐square goodness of fit analysis was performed to validate the algorithm.
Results:  The frequency of post‐operative ARF requiring dialysis ranged between 0.5 and 15.5% based on the risk categories with the area under the receiver operating characteristic (ROC) curve of 0.78. Using the more inclusive definition of ARF, the frequency was significantly higher ranging from 2.6 to 25%(P < 0.001) with an area under ROC curve of 0.65.
Conclusions:  The renal risk stratification algorithm is valid in predicting post‐operative ARF in an independent cohort of patients, well represented by differences in gender and race. Since the need for dialysis remains subjective, a more objective and inclusive definition of ARF may help in identifying a larger number of patients 'at‐risk'.     

Case Report: Atheroembolic renal disease in a 72‐year‐old patient through coronary intervention after myocardial infarction

Cholesterol embolization or atheroembolic renal disease (AERD) is an often underdiagnosed issue in patients featuring a prevalent risk profile. It is a multisystemic disease with progressive renal insufficiency due to foreign body reaction of cholesterol crystals flushed into a small vessel system of the kidneys from the arteriosclerotic plaques. The most common setting in which it occurs is iatrogenic after vascular catheterization and less frequent spontaneously. Typical clinical symptoms are delayed impairment of renal function, cutaneous manifestations such as livedo reticularis or purple toes with persistingly palpable arterial pulse, myalgia, systemic symptoms such as weight loss and fever, and abdominal and neurological symptoms. Diagnosis is generally made by clinical appearance, risk profile, and interval of time from intervention; a definitive diagnosis can only be made by renal biopsy. Even though the exact incidence is not known because most patients do not undergo biopsy due to older age, comorbidity, and other explanations for loss of renal function, it is estimated to be 4% after vascular intervention. Patient and renal outcome is dependent on comorbidity, risk profile, and preexisting chronic kidney disease (CKD). About 30% of patients are estimated to require maintenance dialysis and these patients have a high risk of death within 24 months after the first renal replacement therapy. Prognosis is also influenced by severity. The case reported is a 72‐year‐old male patient with preexisting CKD stage 3 undergoing percutaneous coronary intervention after myocardial infarction and consecutive AERD with typical clinical appearance 6 weeks after the event.     

Effect of timing of dialysis on mortality in critically ill, septic patients with acute renal failure

Acute renal failure with concomitant sepsis in the intensive care unit is associated with significant mortality. The purpose of this study was to determine if the timing of initiation of renal replacement therapy (RRT) in septic patients had an effect on the 28-day mortality. Retrospective data on medical intensive care unit patients with sepsis and acute renal failure requiring RRT were included. Renal replacement therapy started with a blood urea nitrogen (BUN) of <100 mg/dL was defined as "early" initiation, and initiation with a BUN ≥100 mg/dL was defined as "late." Multivariate logistic regression analysis with the primary outcome of death at 14, 28, and 365 days following the initiation of RRT was performed. One hundred thirty patients were studied. The early dialysis (mean BUN 66 mg/dL) group had 85 patients; the late group (mean BUN 137 mg/dL) had 62 patients. The mean acute physiology and chronic health evaluation II score was 24.5 in both groups. The overall 14, 28, and 365-day survival rates were 58.1%, 41.9%, and 23.6%. Survival rates for the early group were 67%, 47.7%, and 30.7% at 14, 28, and 365 days. Survival rates for the late group were 46.7%, 31.7%, and 13.3% at 14, 28, and 365 days. Upon logistic regression analysis, initiating dialysis with a BUN >100 mg/dL predicted death at 14 days (odds ratio [OR] 3.6, 95% confidence interval [CI] 1.7–7.6, P=0.001), 28 days (OR 2.6, 95% CI 1.2–5.7, P=0.01), and 365 days (OR 3.5, 95% CI 1.2–10, P=0.02). Septic patients who started dialysis with a BUN <100 mg/dL had improved mortality rates up to 1 year after initiation of dialysis in this single-center, retrospective analysis.     

Clinical characteristics and outcomes of new uremic patients with extreme azotemia in southern Taiwan

Serum creatinine (SCr) had been considered to be an important predictor of mortality in end-stage renal disease (ESRD) patients at the start of renal replacement therapy (RRT). However, the data were limited about initially extreme azotemia (EA), exclusively defined as blood urea nitrogen (BUN) > or = 300 mg/dL, SCr > or = 30 mg/dL, or both. This retrospective study was conducted to clarify the characteristics and outcome in our EA patients. We had 1682 new ESRD patients from July 1988 to December 1996. With frequency match for age, gender, and starting RRT in the same period, 20 EA patients and 60 controls were included. Fifty percent of our EA patients had unknown etiology. The EA patients had significantly lower prevalence of underlying diabetic nephropathy, and comorbid hypertension. All the EA patients had late referral to nephrologists within 4 weeks before the initiation of RRT, and 90% of them had taken Chinese herbals. The EA group had significantly higher BUN, SCr, and iron storage as well as a higher prevalence of severe anemia, hyperkalemia, hypocalcemia, and acidemia. However, the similar prevalence of cardiomegaly and left ventricular hypertrophy as well as the similar early mortality rate and long-term survival were noted. Age over 40 years, comorbid diabetes mellitus, and hypoalbuminemia were independent predictors of poor survival. Our EA patients had different initial presentations from other uremic ones at the start of RRT. However, the short-term and long-term mortality rates were similar. The lower prevalence of underlying diabetic nephropathy and comorbid hypertension among the EA patients might contribute to their fair outcome.     

Percutaneous coronary intervention versus coronary artery bypass graft in chronic kidney disease: Optimal treatment options

Chronic kidney disease (CKD) is ubiquitous in the world and may eventually progress to end-stage renal disease. CKD is associated with a greater risk of coronary artery disease (CAD) which is the leading cause of mortality in this population. Current invasive treatment options include percutaneous coronary intervention or coronary artery bypass graft. We performed a PubMed search to ascertain the optimal treatment for coronary artery disease in CKD. Our review of the current literature supports the superiority of coronary artery bypass grafting which reduces repeat revascularizations, improves angina symptoms, and increases long-term survival.     

Hypoparathyroidism associated with severe mineral bone disease postrenal transplantation, treated successfully with recombinant PTH

Chronic kidney disease (CKD) is commonly, if not universally, associated with derangements in bone and mineral metabolism, characterized by hyperphosphatemia, low calcitriol levels, and secondary hyperparathyroidism. The spectrum of these disorders is termed renal osteodystrophy or chronic kidney disease-mineral bone disease complex. Aggressive phosphorus control is the cornerstone of management to prevent debilitating complications. Dietary control, phosphate binders, and administration of active vitamin D analogues is the most common initial therapy. Frequently parathyroidectomy is required to reverse or slow the pathological changes when medical management fails. The most common adverse effect of parathyroidectomy is hypocalcemia. We describe a case report of severe hypocalcemia (secondary to surgical hypoparathyroidism) and "hungry bone syndrome," treated successfully with teriparatide (Forteo^®) in a patient who underwent renal transplantation following subtotal parathyroidectomy.     

Lipoprotein (a) in Chronic Renal Failure: Effect of Maintenance Hemodialysis

Background:  Coronary artery disease accounts for significant morbidity and mortality in patients with chronic kidney disease (CKD). Besides the higher prevalence of traditional risk factors, several uremia-related factors may play a role in accelerated atherosclerosis, such as elevated levels of lipoprotein (a) (Lp(a)). The effect of maintenance hemodialysis (MHD) on Lp(a) levels is not well understood. The present work was carried out to study the Lp(a) levels in Stage 4 and Stage 5 CKD patients as well as the effect of MHD on Lp(a) levels in patients with Stage 5 CKD.
Methods:  The study subjects included 15 patients with Stage 4 CKD, 15 patients with Stage 5 CKD, and 15 age- and sex-matched healthy controls. Plasma Lp(a) was measured by ELISA in all the subjects at the time of entry into the study and after 4 weeks of MHD in patients with Stage 5 CKD. Patients on MHD were dialyzed two to three times weekly for 4 hr during each session.
Results:  Mean Lp(a) levels were significantly higher in patients with CKD than in control patients. In patients with Stage 4 CKD, the Lp(a) level was 34.0 ± 19.5 mg/dL, whereas in Stage 5 CKD the level was 49.0 ± 30.9 and in healthy controls it was 22.2 ± 16.4. In patients with Stage 5 CKD, 4 weeks of MHD led to a significant fall in Lp(a) levels by 23.6% (P < 0.001).
Conclusions:  The results of this study show that increases in Lp(a) levels start early during the course of CKD and become more pronounced with increased severity of disease. Initiation of MHD lowers Lp(a) levels and may have a long-term beneficial effect on cardiovascular morbidity and mortality.     

Survival to discharge among patients treated with continuous renal replacement therapy

Continuous renal replacement therapy (CRRT) is widely used in critically ill patients with acute renal failure (ARF). The survival of patients who require CRRT and the factors predicting their outcomes are not well defined. We sought to identify clinical features to predict survival in patients treated with CRRT. We reviewed the charts of all patients who received CRRT at the Toronto General Hospital during the year 2002. Our cohort (n=85) represented 97% of patients treated with this modality in 3 critical care units. We identified demographic variables, underlying diagnoses, transplantation status, location (medical-surgical, coronary, or cardiovascular surgery intensive care units), CRRT duration, baseline estimated glomerular filtration rate (eGFR), and presence of oliguria (<400 mL/day) on the day of CRRT initiation. The principal outcome was survival to hospital discharge. Among those alive at discharge, we assessed whether there was an ongoing need for renal replacement therapy. Greater than one-third (38%, 32/85) of patients survived to hospital discharge. Three (9%) survivors remained dialysis-dependent at the time of discharge. Survivors were younger than nonsurvivors (mean age 56 vs. 60 years), were on CRRT for a shorter duration (7 vs. 13 days), and had a higher baseline eGFR (74 vs. 62 mL/min/m(2)). Patient survival varied among different critical care units (medical surgical 33%, coronary 38%, and cardiovascular surgery 45%). Multivariable logistic regression revealed that shorter duration of CRRT, nonoliguria, and baseline eGFR >60 mL/min/m(2) were independently associated with survival to hospital discharge (p<0.05). Critically ill patients with ARF who require CRRT continue to have high in-hospital mortality. A shorter period of CRRT dependence, nonoliguria and higher baseline renal function may predict a more favorable prognosis. The majority of CRRT patients who survive their critical illness are independent of dialysis at the time of hospital discharge.     

Biomarkers upon discontinuation of renal replacement therapy predict 60‐day survival and renal recovery in critically ill patients with acute kidney injury

Introduction: There is no consensus on the specific indications for weaning critically ill patients with acute kidney injury (AKI) off renal replacement therapy (RRT). This study aimed to explore the prognostic value of several biomarkers measured upon discontinuation of RRT for their value in predicting 60‐day survival and renal recovery in an effort to add knowledge to the decision‐making process regarding RRT withdrawal. Methods: We prospectively enrolled 102 patients with AKI who required RRT from the intensive care unit. Serum osteopontin (sOPN), serum interleukin 6 (sIL‐6), serum cystatin C (sCysC), sIL‐18, serum neutrophil gelatinase‐associated lipocalin and urinary IL‐18 and urinary neutrophil gelatinase‐associated lipocalin were measured upon discontinuation of RRT. Patients were followed up at 60 days for survival and renal recovery. Findings: Patients who survived showed lower levels of all serum and urinary biomarkers. Serum OPN (OR 1.029, 95% CI 1.013–1.047, P = 0.001), diabetes (OR 23.157, 95% CI 4.507–118.981, P < 0.001) and APACHE II score (OR 1.308, 95% CI 1.121–1.527, P = 0.001) were independent predictors of 60‐day mortality. Patients whose sOPN values fell within the highest and middle tertiles showed 5.25‐ and 2.31‐fold increased risks of mortality, respectively, compared with that of patients in the lowest tertile. The addition of sOPN to the clinical model resulted in significant net reclassification improvement of 0.453 (P = 0.026) and an integrated discriminative index of 0.155 (P = 0.032). Lower levels of sOPN and sIL‐6 were associated with greater odds of 60‐day survival (AUC 0.812 and 0.741). The AUC value for predicting survival reached its highest level when all biomarkers were combined with urine output (UO) and urinary and serum creatinine upon discontinuation of RRT (0.882). Lower sCysC performed as well as higher UO in predicting 60‐day renal recovery with the greatest AUC of 0.743. Discussion: Upon discontinuation of RRT, serum and urinary biomarkers, particularly sOPN, may predict 60‐day survival and renal recovery in critically ill patients with AKI. The serum levels of OPN, IL‐6 and CysC may be useful when considering withdrawal of RRT on the basis of conventional indicators.     

Outcome among patients with acute renal failure needing continuous renal replacement therapy: A single center study

Outcome of acute renal failure (ARF) and use of continuous renal replacement therapy (CRRT) have shown a consistently high mortality. (1) Evaluate the short-term patient survival. (2) Evaluate dialysis-free survival. (3) Evaluate risk factors associated with overall survival and the continued need for intermittent dialysis. We identified adults (≥18 years) needing CRRT, treated in the critical care units of Froedtert Medical and Lutheran Hospital from January 1, 2003 till December 31, 2005. Patients were divided into two major groups needing CRRT, end stage renal disease (ESRD) (chronic dialysis) and non-ESRD with ARF. Continuous renal replacement therapy was performed with an average of 2 L replacement fluid exchanges/h. Sigma stat software was used for analysis. Comparison was done for noncontinuous variables by chi-square and t test for categorical and continuous variables, respectively. A total of 110 (ESRD 24/non-ESRD 86) patients received CRRT during study period. Over all in-hospital mortality among non-ESRD patients was 63% vs. 46% for ESRD. Among non-ESRD patients who survived, 47% needed intermittent hemodialysis on intensive care unit discharge and 28% continued to need hemodialysis at last follow-up. Among non-ESRD patients alive at discharge, those who were dialysis dependent on last follow-up were older (64.5) than those who did not require dialysis on last follow-up (58.4) P=0.347. Non-ESRD patients who died were in the hospital for an average of 17.5 days compared with 29 days for those who were discharged from the hospital. Patients with ARF needing CRRT have high in-hospital mortality. A significant percentage of patients remained dialysis dependant on last follow-up.     

End-stage renal disease patients on hemodialysis: a study from a tertiary care center in a developing country

The exact number of patients with chronic renal failure requiring renal replacement therapy in developing world is not known. Unlike the developed world, most developing countries lack renal registries. This study was initiated to know demographic and clinical data of end-stage renal disease (ESRD) patients presenting to maintenance hemodialysis (MHD) at a government funded tertiary care centre in a developing country. A prospective analysis of all new ESRD patients attending to hemodialysis at our centre from 2004 to 2007 had been done. There were 237 new hemodialysis patients during a three-year period. Males were 153 and females were 84, with the mean age 44.92 years. Diabetes mellitus (31.22%) was the most common cause of ESRD. Only 29.95% of patients had education on renal replacement therapy. 65.40% patients had emergency hemodialysis. Internal jugular catheter was the most common form of vascular access at initiation of hemodialysis. Arteriovenous fistula was secured in 29.95% of patients at presentation. Catheter-related infection appeared in 13.55% of patients on catheter. The most common infection in dialysis patients was urinary tract infection (37.14%). Renal transplantation was opted by 9.7% patients and continuous ambulatory peritoneal dialysis in 20.25% and 103 (43.45%) were lost to follow up. The rest (8.86%) continued on MHD. There were 42 (17.72%) deaths over a three-year period. The present study provided the information of the practice of hemodialysis, its population characteristics and outcomes from a developing country.     

Indoxyl sulfate,a valuable biomarker in chronic kidney disease and dialysis

Chronic kidney disease (CKD) is an increasingly recognized disease with high global incidence and mortality. Yet, the existing diagnostic tools are not sufficient enough to predict prognosis of CKD and CKD comorbidities. Indoxyl sulfate, a typical uremic toxin, is of great importance in the development of CKD with its nephrotoxicity, cardiovascular toxicity, and bone toxicity. Some reports suggest that indoxyl sulfate directly associate with renal function loss and mortality in CKD patients. This review discusses the diagnostic value of indoxyl sulfate from its biological characteristics, pathophysiological effects, related therapies, and its diagnostic value in clinical studies.     

Excellent long time survival for Swedish patients starting home‐hemodialysis with and without subsequent renal transplantations

Survival for patients on dialysis is poor. Earlier reports have indicated that home‐hemodialysis is associated with improved survival but most of the studies are old and report only short‐time survival. The characteristics of patient populations are often incompletely described. In this study, we report long‐term survival for patients starting home‐hemodialysis as first treatment and estimate the impact on survival of age, comorbidity, decade of start of home‐hemodialysis, sex, primary renal disease and subsequent renal transplantation. One hundred twenty‐eight patients starting home‐hemodialysis as first renal replacement therapy 1971–1998 in Lund were included. Data were collected from patient files, the Swedish Renal Registry and Swedish census. Survival analysis was made as intention‐to‐treat analysis (including survival after transplantation) and on‐dialysis‐treatment analysis with patients censored at the day of transplantation. Ten‐, twenty‐ and thirty‐year survival were 68%, 36% and 18%. Survival was significantly affected by comorbidity, age and what decade the patients started home‐hemodialysis. For patients younger than 60 years and with no comorbidities, the corresponding figures were 75%, 47% and 23% and a subsequent renal transplantation did not significantly influence survival. Long‐term survival for patients starting home‐hemodialysis is good, and improves decade by decade. Survival is significantly affected by patient age and comorbidity, but the contribution of subsequent renal transplantation was not significant for younger patients without comorbidities.     

Symptomatic hyperammonemia after lung transplantation: Lessons learnt

Hyperammonemia, post‐orthotopic lung transplantation, is a rare but mostly fatal complication. Various therapies, including those to decrease ammonia generation, increase nitrogen excretion, and several dialytic methods for removing ammonia have been tried. We describe three lung transplant recipients who developed acute hyperammonemia early after transplantation. Two of the three patients survived after a multidisciplinary approach including discontinuation of drugs, which impair urea cycle, aggressive ammonia reduction with prolonged daily intermittent hemodialysis (HD), and overnight slow low‐efficiency dialysis in conjunction with early weaning of steroids and other therapeutic measures. Our experience suggests that early initiation of dialysis, high dialysis dose, increased frequency, and HD preferably to less efficient modalities increases survival in these patients.