Anemia: not just an innocent bystander?
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Aged↗
Biomedical subjects
Allen R Nissenson
Publications and source records attributed to Allen R Nissenson.
Prevalence, treatment, and control of hypertension in chronic hemodialysis patients in the United States.
BACKGROUND: Hypertension is common in chronic hemodialysis patients, yet there are limited data on the epidemiology of hypertension in these patients in the United States. METHODS: We assessed the prevalence, treatment, and control of hypertension in a cohort of 2535 clinically stable, adult hemodialysis patients who participated in a multicenter study of the safety and tolerability of an intravenous iron preparation. Hypertension was defined as an average predialysis systolic blood pressure >150 mm Hg or diastolic blood pressure >85 mm Hg, or the use of antihypertensive medications. RESULTS: Hypertension was documented in 86% (n = 2173) of patients. The prevalence of hypertension, in contrast to that observed in the general population, did not increase linearly with age and was not affected by sex or ethnicity. Hypertension was controlled adequately in only 30% (n = 659) of the hypertensive patients. In the remaining patients, hypertension was either untreated (12% [252/2173]) or treated inadequately (58% [1262/2173]). CONCLUSION: Control of hypertension, particularly systolic hypertension, in chronic hemodialysis patients in the United States is inadequate, despite recognition of its prevalence and the frequent use of antihypertensive drugs. Optimizing the use of medications and closer attention to nonpharmacologic interventions, such as adjustment of dry weight, a low-sodium diet, and exercise, may improve control.
Adrenergic beta-Antagonists↗
Clinical evaluation of heme iron polypeptide: sustaining a response to rHuEPO in hemodialysis patients.
BACKGROUND: Optimizing iron and recombinant human erythropoietin (rHuEPO) therapy is necessary to achieve target hemoglobin levels and minimize costs as the end-stage renal disease (ESRD) population expands. Oral iron products in patients with ESRD have been largely abandoned, and the safety of intravenous (IV) iron preparations has improved with the introduction of new-generation compounds that have little allergenicity. Recent work suggests oral heme iron may be an effective supplement for hemodialysis (HD) patients because it is absorbed by patients with high ferritin levels, has fewer side effects, and its absorption is stimulated by erythropoietin administration. METHODS: We performed an open, 6-month, prospective evaluation of heme iron in HD patients who had been on maintenance IV iron therapy. IV iron was discontinued and replaced with oral heme iron. Serum iron level, hematocrit (Hct), and erythropoietin and IV iron dose were monitored. RESULTS: During 6 months, 4 of 37 patients (11%) dropped out because of insufficient iron supplementation or intolerance and 5 patients (14%) were dropped because of unrelated complications or protocol violation. A slight reduction in average transferrin saturation (TSAT) was seen early, but reversed, and no significant changes were seen in TSAT or Hct. A significant reduction in average serum ferritin level was seen at months 4 through 6 (P < 0.01). CONCLUSION: During the 6-month study period, heme iron polypeptide successfully replaced IV iron therapy in a majority of HD patients and maintained target Hcts with no concomitant use of IV iron. This treatment was associated with a significant increase in rHuEPO efficiency (P = 0.04).
Administration, Oral↗
Sodium ferric gluconate complex in hemodialysis patients. II. Adverse reactions in iron dextran-sensitive and dextran-tolerant patients.
BACKGROUND: Iron dextran administration is associated with a high incidence of adverse reactions including anaphylaxis and death. Although dextran, rather than iron, is believed to be the cause of these reactions, it is not known whether iron dextran-sensitive patients can be safely administered another form of parenteral iron, sodium ferric gluconate in sucrose (SFGC). METHODS: In a 69 center, prospective, double-blind, controlled trial of safety and tolerability of SFGC, the rate of reactions to SFGC and placebo in 144 iron dextran-sensitive patients was compared with 2194 patients who were previously tolerant to iron dextran preparations. Serum tryptase levels, a marker of mast cell degranulation, also were measured. RESULTS: Among 143 iron dextran-sensitive patients exposed to SFGC, three (2.1%) were intolerant. All three had suspected allergic events to SFGC, including one patient with a serious reaction (0.7%). One dextran-sensitive patient (0.7%) had a suspected allergic reaction after placebo. In contrast, among 2194 iron dextran-tolerant patients, reactions to SFGC were significantly less common, with SFGC intolerance seen in seven patients (0.3%; P = 0.020), including five (0.2%) who had suspected allergic events (P = 0.010), but none who had serious events (0.0%; P = 0.061). Two iron dextran-tolerant patients (0.09%) had allergic-like reactions following placebo injections. Two of the three suspected allergic events in the iron dextran-sensitive group were confirmed as mast cell dependent by a 100% increase in serum tryptase, while there were no confirmed allergic events in the iron dextran-tolerant group. Long-term exposure to SFGC in iron dextran-sensitive patients resulted in intolerance in only one additional patient and no serious adverse events. CONCLUSIONS: Patients with a history of iron dextran sensitivity had approximately sevenfold higher rates of reaction to both placebo and SFGC compared to iron dextran tolerant patients. However, logistic regression analysis, performed to account for the higher reaction rate to placebo, suggests that this increased reactivity was not drug-specific nor immunologically mediated, but represented host idiosyncrasy. These results support the conclusions that reactions to SFGC can be attributed to pseudoallergy, and that SFGC is not a true allergen.
Drug Hypersensitivity↗
L-carnitine use in dialysis patients: is national coverage for supplementation justified? What were CMS regulators thinking--or were they?
Careful review of all available clinical trials of L-carnitine leads to the conclusion that there is insufficient evidence to support the routine use of L-carnitine for any indication in dialysis patients. The literature suffers from a lack of adequately designed studies, and many of the studies which supposedly justify payment for L-carnitine supplementation are more than 10 years old. While some studies support a subjective improvement in symptoms after a few months of L-carnitine treatment, there is little confirming objective data. Biochemical parameters show minimal, if any, improvements. A major criticism is that many of the reported symptoms could be attributable to anemia, which at the time the L-carnitine studies were taking place, was generally being corrected with EPO. On the other hand, there is little data to support the hypothesis that L-carnitine enhances the response to EPO or overcomes EPO resistance. The decrease in the use of L-carnitine in the past several years may be related in part to difficulty with reimbursement. The decrease also suggests that practitioners have abandoned the hypothesis that L-carnitine supplementation provides substantial clinical benefits, and therefore no longer prescribe it for dialysis patients. For those physicians who plan to prescribe L-carnitine based on the recent CMS reimbursement decision, it must be remembered that the laboratory measurement of free carnitine may be difficult and inaccurate. For those patients with private insurance, payment for the lab test is out of pocket. If the free carnitine level is measured once dialysis starts, a value in the CMS "deficient" range can occur since carnitine drops early in the dialysis procedure and slowly rebounds after the treatment. Therefore, it is critical that the measurement be done pre-dialysis after a three-day interdialytic interval to obtain the most accurate value. If strict guidelines for use of L-carnitine are adhered to (i.e., the patient has true EPO-resistant anemia unexplained by any identifiable factor and true unexplained hypotension), then the use of L-carnitine in ESRD patients should be very uncommon. In conclusion, the clinical value of L-carnitine supplementation in hemodialysis patients remains to be documented by credible evidence from rigorous scientific studies. While "proof beyond a reasonable doubt" need not always be the requirement for reimbursement from payers, at a minimum "a preponderance of the evidence" should be documented in the literature. L-carnitine may prove to be a beneficial supplement. However, before justifying a national coverage policy, a new randomized, prospective controlled trial should be conducted to determine the utility of i.v. L-carnitine supplementation for anemia management and refractory dialysis-associated hypotension. Cost-benefit analysis is a critical aspect of such a study because it is important to determine the total cost (no matter who pays) of L-carnitine supplementation as compared to money saved by a reduction in EPO and iron administration. When reimbursement policies are developed, they need to be rational and based on the best evidence that is available. An NKF Carnitine Consensus Conference concluded that current literature and clinical experience leave unanswered questions regarding the use of L-carnitine in dialysis patients. Until there is scientific evidence to support use of L-carnitine supplementation, and it proves to be cost-effective, reimbursement is not justified. Therefore, the current CMS reimbursement decision for L-carnitine appears to be flawed.
Carnitine↗
Disease management improves outcomes in patients with CKD.
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Disease Management↗
Sodium ferric gluconate complex in hemodialysis patients: adverse reactions compared to placebo and iron dextran.
BACKGROUND: Parenteral iron is often required by hemodialysis patients to maintain adequate iron stores. Until recently, the only available form of intravenous iron was iron dextran, which is associated with significant adverse reactions, including anaphylaxis and death. Sodium ferric gluconate complex (SFGC) was recently approved for use in the U.S. under FDA's priority drug review. This Phase IV study was designed to evaluate the safety of a single dose of intravenous SFGC as compared to placebo and a historical iron dextran control. METHODS: This multicenter, crossover, randomized, double blind, placebo-controlled prospective comparative study was performed in hemodialysis patients requiring at least 125 mg of elemental iron. The historical control was obtained from a meta-analysis of four publications examining outcomes in patients exposed to iron dextran. SFGC naïve patients were administered SFGC without a test dose, undiluted, at a rate of 125 mg over 10 minutes, and compared to placebo comprising bacteriostatic saline. RESULTS: A total of 2534 patients were enrolled. The incidence of drug intolerance (an adverse event precluding re-exposure) was significantly less [0.44%, confidence interval (CI) 0.21 to 0.71%] after SFGC as compared to the iron dextran control (2.47%, CI 1.87 to 3.07%, P < 0.0001), but higher than after placebo (0.1%, P = 0.02). There was no difference found between SFGC and placebo in serious adverse events. A single life-threatening event occurred after SFGC (0.04%, CI 0.00 to 0.22%), which was significantly less than following iron dextran (0.61%, CI 0.36 to 0.86%), P = 0.0001. CONCLUSION: SFGC is well tolerated when given by intravenous push without a test dose. SFGC has a significantly lower incidence of drug intolerance and life-threatening events as compared to previous studies using iron dextran. The routine use of iron dextran in hemodialysis patients should be discontinued.
Adult↗
Randomized, controlled trial of darbepoetin alfa for the treatment of anemia in hemodialysis patients.
BACKGROUND: Darbepoetin alfa (Aranesp; Amgen, Thousand Oaks, CA) is a new erythropoiesis-stimulating protein with a threefold longer terminal half-life than recombinant human erythropoietin (epoetin) in patients with chronic kidney disease (CKD). The purpose of this randomized, double-blind, noninferiority study is to determine whether darbepoetin alfa is as effective as epoetin for the treatment of anemia in hemodialysis patients when administered at a reduced dosing frequency. METHODS: Patients receiving epoetin therapy were randomized to continue epoetin administered intravenously (IV) three times weekly (n = 338) or change to darbepoetin alfa administered IV once weekly (n = 169). The dose of darbepoetin alfa or epoetin was individually titrated to maintain hemoglobin concentrations within -1.0 to +1.5 g/dL (-10 to +15 g/L) of patients' baseline values and within a range of 9.0 to 13.0 g/dL (90 to 130 g/L) for up to 28 weeks (20-week dose-titration period followed by an 8-week evaluation period). The primary end point was change in hemoglobin level between baseline and the evaluation period (weeks 21 to 28). RESULTS: Mean changes in hemoglobin levels from baseline to the evaluation period were 0.24 +/- 0.10 (SE) g/dL (2.4 +/- 1.0 g/L) in the darbepoetin alfa group and 0.11 +/- 0.07 g/dL (1.1 +/- 0.7 g/L) in the epoetin group, a difference of 0.13 g/dL (95% confidence interval [CI], -0.08 +/- 0.33 [1.3 g/L; 95% CI, -0.8 to 3.3]). This difference was not statistically significant or clinically relevant despite the reduced frequency of darbepoetin alfa administration. The safety profile of darbepoetin alfa was similar to that of epoetin, and no antibody formation to either treatment was detected. CONCLUSION: These results show that darbepoetin alfa maintains hemoglobin concentrations as effectively and safely as epoetin in patients with CKD, but with a reduced dosing frequency.
Adult↗
Dosing darbepoetin alfa.
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Darbepoetin alfa↗
Opportunities for improving the care of patients with chronic renal insufficiency: current practice patterns.
There are between 2 and 13 million Americans with chronic kidney disease (CKD). Recent reports suggest that their treatment is currently suboptimal. To further investigate this issue, patterns of practice for the treatment of patients with CKD who were enrolled in a large health maintenance organization in New Mexico were analyzed. Among the >200,000 patients who were enrolled in the health maintenance organization between 1994 and 1997, a cohort of 1658 patients who exhibited at least two gender-specific, elevated creatinine concentrations (Cr), separated by at least 90 d, were identified. The proportions of patients with Cr values of <2.0, 2.0 to 2.9, 3.0 to 3.9, and > or =4.0 mg/dl were 73, 17, 3, and 7%, respectively. The majority of patients were treated by a primary care physician until Cr values reached 3.0 mg/dl, at which time a nephrologist was consulted. Care tended to be transferred to the nephrologist when the Cr reached 4.0 mg/dl. Only 7.4% of patients received erythropoietin (EPO). Use of EPO increased as Cr increased. EPO was unlikely to be prescribed unless the patient had visited a nephrologist. Fewer than one half of all patients with CKD and fewer than 20% of patients with CKD with Cr values of > or =4.0 mg/dl received an angiotensin-converting enzyme inhibitor (ACEI). Nephrologists were not more likely to prescribe ACEI than were primary care physicians. Diabetic patients were more likely to receive ACEI than were nondiabetic patients, but ACEI use was quite low even among diabetic patients with CKD. The average number of hospitalizations per patient-year increased as Cr increased and was more than twice as high for patients with Cr values of > or =4.0 mg/dl, compared with those with Cr values of <2.0 mg/dl. The reasons for hospitalization were more likely to be related to comorbidities than to CKD itself, however. There are many opportunities to improve the care of patients with CKD. Better adherence to practices known to be of clinical benefit for patients with CKD not only will improve patient outcomes but also may reduce the costs of care. Providers, policy-makers, and payers should view CKD as a major public health problem and initiate innovative programs to address this growing patient population.
Adult↗
Utilizing a disease management approach to improve ESRD patient outcomes.
In this era of processes and systems to improve quality, disease management is one methodology to improve care delivery and outcomes for patients with chronic kidney disease (CKD). In most disease management systems a senior renal nurse coordinates all aspects of the patient's care and ensures that the prescribed and necessary care is delivered for both CKD-related and comorbid conditions. The nurse also continually monitors outcomes on quality indicators and key performance measures. These outcome data are then aggregated and analyzed, are compared with local and national benchmarks, and drive the continuous quality improvement (CQI) process. Such a system attempts to centralize the currently fragmented care delivery system, continually improve patient outcomes, and conserve scarce economic resources. Early data suggest a disease management approach may improve both the morbidity and mortality of CKD patients.
Disease Management↗
Dialysis in nursing homes.
The number of geriatric end-stage renal disease (ESRD) patients in the United States is increasing disproportionately to other age groups on dialysis. Thus there will be more dialysis patients that will require the assistance of nursing homes or extended care facilities. Nursing homes may be beneficial for the geriatric patient in terms of social and physical rehabilitation. Many of these facilities, however, may not take care of or may not have the capacity to adequately care for dialysis patients. Such patients have a higher rate of peritonitis when on peritoneal dialysis (PD) and have higher mortality rates on hemodialysis (HD) or PD compared to similar dialysis patients in the community. Cooperation and communication between the dialysis center and the nursing home, given the complex management issues involved in the care of these patients, are essential. One promising approach to the care of elderly dialysis patients is an integration of nursing home and dialysis unit. Although another approach could be to more fully utilize the services of adult day care centers, this has proven logistically difficult and has not been reported to be successful since it was first suggested more than a decade ago.
Aged↗
Determinants in APD selection.
Automated peritoneal dialysis (APD) is the most prevalent form of peritoneal dialysis in the United States. Optimizing the success of this treatment requires appropriate patient selection; however, there are few data available on which patients are most likely to benefit the most from this form of therapy. The key factors to evaluate when APD is being considered include patient preferences and lifestyle, patient age, solute transport characteristics, residual renal function (RRF), cost, dialysis adequacy targets, and the potential for complications of therapy. Patients who prefer home dialysis at night, children, those with high average or high peritoneal transport characteristics, and those with significant RRF are ideal candidates for APD. Because of the flexibility that is possible in prescribing this form of dialysis, APD can be successfully performed in individuals who do not meet this ideal profile, and it can be an excellent form of dialysis, particularly as part of an integrated care program for patients with end-stage renal disease (ESRD).
Adult↗
Pure red-cell aplasia: an emerging epidemic in dialysis patients?
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Dialysis↗