Circulatory response to fluid overload removal by extracorporeal ultrafiltration in refractory congestive heart failure

Eplerenone survival benefits in heart failure patients post-myocardial infarction are independent from its diuretic and potassium-sparing effects. Insights from an EPHESUS (Eplerenone Post-Acute Myocardial Infarction Heart Failure Efficacy and Survival Study) substudy

OBJECTIVES

The purpose of this study was to determine whether a diuretic effect may be detectable in patients treated with eplerenone, a mineralocorticoid receptor antagonist, as compared with placebo during the first month of EPHESUS (Eplerenone Post-Acute Myocardial Infarction Heart Failure Efficacy and Survival study) (n = 6,080) and whether this was associated with eplerenone's beneficial effects on cardiovascular outcomes.

BACKGROUND

The mechanism of the survival benefit of eplerenone in patients with heart failure post-myocardial infarction remains uncertain.

METHODS

A diuretic effect was indirectly estimated by changes at 1 month that was superior to the median changes in the placebo group in body weight (-0.05 kg) and in the estimated plasma volume reduction (+1.4%). A potassium-sparing effect was defined as a serum potassium increase greater than the median change in the placebo group: +0.11 mmol/l.

RESULTS

In the eplerenone group, body weight (p < 0.0001) and plasma volume (p = 0.047) decreased, whereas blood protein and serum potassium increased (both, p < 0.0001), as compared with the placebo group, suggesting a diuretic effect induced by eplerenone, associated with a potassium-sparing effect. A diuretic effect, as defined by an estimated plasma volume reduction, was independently associated with 11% to 19% better outcomes (lower all-cause death, cardiovascular death or cardiovascular hospitalization, all-cause death or hospitalization, hospitalization for heart failure). Potassium sparing was also independently associated with 12% to 34% better outcomes. There was no statistically significant interaction between the observed beneficial effects of eplerenone (9% to 17%) on cardiovascular outcomes and potassium-sparing or diuretic effects.

CONCLUSIONS

Eplerenone's beneficial effects on long-term survival and cardiovascular outcomes are independent from early potassium-sparing or diuretic effects, suggesting that mineralocorticoid receptor antagonism provides cardiovascular protection beyond its diuretic and potassium-sparing properties.

Renal replacement therapy in special situations: heart failure and neurological injury

The cardiorenal syndrome is a complicated and increasingly prevalent entity requiring a multidisciplinary approach. Renal replacement therapy (RRT) in the form of slow ultrafiltration (UF) demonstrates promise for the treatment of acutely decompensated heart failure. Despite the lack of evidence for decreased mortality, there is considerable short-term benefit in decreased rehospitalizations and a restoration of diuretic responsiveness. Given the potential for improvement in quality of life and cost if hospitalizations are minimized, slow UF should be considered in patients with repeated hospitalization for decompensated heart failure. Acute neurologic injury is a highly unstable state requiring strict adherence to evidence-based guidelines to achieve the best possible functional outcomes. With improved short-term survival, a greater burden of non-neurologic injury may hinder long-term functional recovery. Acute kidney injury is among such important considerations that can lead to worsened neurological injury. Careful application of continuous modalities of therapy, probably early in the course of illness to avoid intradialytic osmolar shifts and provide hemodynamic stability, will allow for unimpeded neurologic recovery. Newer evidence on dose and RRT modality on patients with acute and chronic brain injury will certainly add important knowledge to this field.

Efficacy and cardiovascular tolerability of continuous veno-venous hemodiafiltration in acute decompensated heart failure: a randomized comparative study

BACKGROUND AND OBJECTIVES

Recently, continuous veno-venous hemodiafiltration (CVVHDF) has received increased attention in the treatment of congestive heart failure (CHF). The aim of this study is to assess the safety and efficacy of CVVHDF compared with intravenous furosemide in patients with CHF.

METHODS

Forty patients having CHF were included in this prospective, randomized, comparative trial. We randomized patients to treatment for 72 hours with CVVHDF or intravenous furosemide. Outcomes assessed were weight loss, total fluid output, length of stay (LOS) in the intensive care unit (ICU), 30-day mortality, and cardiovascular stability.

RESULTS

Demographic data were comparable in both groups. Weight loss (P ≤ .05) and total fluid output (P ≤ .01) were greater in the CVVHDF group. Length of stay in the ICU was significantly reduced in the CVVHDF group (P ≤ .05). The mortality rates were comparable in both groups. The cardiac output and the stroke volume significantly increased, whereas the pulmonary capillary wedge pressure significantly decreased (P ≤ .05) in both groups compared with the baseline. A transient attack of hypotension occurred in 1 patient in the CVVHDF group.

CONCLUSION

In CHF, the use of CVVHDF effectively and safely produced greater weight and fluid loss and decreased LOS in the ICU more than the intravenous furosemide with no hemodynamic instability.

Ultrafiltration in heart failure

Fluid overload is a key pathophysiologic mechanism underlying both the acute decompensation episodes of heart failure and the progression of the syndrome. Moreover, it represents the most important factor responsible for the high readmission rates observed in these patients and is often associated with renal function worsening, which by itself increases mortality risk. In this clinical context, ultrafiltration (UF) has been proposed as an alternative to diuretics to obtain a quicker relief of pulmonary/systemic congestion. This review illustrates technical issues, mechanisms, efficacy, safety, costs, and indications of UF in heart failure. The available evidence does not support the widespread use of UF as a substitute for diuretic therapy. Owing to its operative characteristics, UF cannot be expected to directly influence serum electrolyte levels, azotemia, and acid-base balance, or to remove high-molecular-weight substances (eg, cytokines) in clinically relevant amounts. Ultrafiltration should be used neither as a quicker way to achieve a sort of mechanical diuresis nor as a remedy for an inadequately prescribed and administered diuretic therapy. Instead, it should be reserved to selected patients with advanced heart failure and true diuretic resistance, as part of a more complex strategy aiming at an adequate control of fluid retention.

Ultrafiltration in the management of acute decompensated heart failure

PURPOSE OF REVIEW

Admissions to hospital for acute decompensated heart failure continue to increase and represent a significant burden on both patients' and healthcare resources. The majority of these admissions are for the control of volume overload; however, standard treatment with intravenous diuretics is not always effective and can lead to increased renal morbidity. One alternative to standard therapy is mechanical fluid removal with ultrafiltration, this review will highlight the current evidence and efficacy regarding ultrafiltration use in acute heart failure.

RECENT FINDINGS

Multiple recent clinical trials have demonstrated the safety and feasibility of ultrafiltration in the management of acute heart failure. Ultrafiltration may be more effective at removing fluid than standard diuretic therapy and has been associated with beneficial long-term results. However, it remains to be determined whether ultrafiltration is truly nephroprotective and when and how this therapy is best utilized.

SUMMARY

Ultrafiltration is an attractive alternative to standard diuretic therapy in the management of volume overload from acute heart failure. Further research is needed to confirm the cost-effectiveness and to determine long-term impacts on morbidity and mortality.

Effect of Subzero-Balanced Ultrafiltration on Lung Gas Exchange Capacity after Cardiopulmonary Bypass in Adult Patients with Heart Valve Disease

Objectives: This study was conducted to evaluate the effect of a new ultrafiltration techniquethe subzerobalanced ultrafiltration (SBUF)on lung gas exchange capacity after cardiopulmonary bypass (CPB) in adult patients with heart valve disease.Background: Attenuation of lung gas exchange capacity is one of the most common manifestations of an inflammatory response after CPB.Methods: Ninety-four patients who required CPB for cardiac surgery were randomized into 2 groups according to whether they received SBUF. Gas exchange capacity expressed as the oxygen index (OI), the respiratory index (RI), and the alveolar-arterial oxygen pressure difference (P(A-a)O2) were measured after intubation (T1), at the termination of CPB (T2), on admission to the intensive care unit (ICU) (T3), at postoperative hour 6 (T4), and at postoperative hour 12 (T5).Results: There were no significant differences in gas exchange capacity between the 2 groups at T1, T4, and T5. CPB produced significant changes in OI, RI, and P(A-a)O2 in the control group, whereas these changes were not significantly different in the study group. The OI in the study group was significantly higher at T2, and RI and P(A-a)O2 were significantly lower at T2 and T3. In the study group, the intubation time was shorter, and the transfusion volume within 24 hours postoperatively was less. The 2 groups were comparable with respect to the incidence of respiratory complications, length of stay in the ICU, duration of hospital stay, need for infusions of inotropic agents, and drainage volumes within 24 hours postoperatively.Conclusions: SBUF during CPB can produce an immediate improvement in lung gas exchange capacity, which may effectively minimize pulmonary dysfunction in adult patients undergoing cardiac surgery.

Urea kinetics and intermittent dialysis prescription in small animals

Hemodialysis improves survival for animals with acute kidney injury beyond what would be expected with conventional management of the same animals. Clinical evidence and experience in human patients suggest a role for earlier intervention with renal replacement to avoid the morbidity of uremia and to promote better metabolic stability and recovery. For a large population of animal patients, it is the advanced standard for the management of acute and chronic uremia, life-threatening poisoning, and fluid overload for which there is no alternative therapy.

Therapeutic options for the management of the cardiorenal syndrome

Patients with heart failure often present with impaired renal function, which is a predictor of poor outcome. The cardiorenal syndrome is the worsening of renal function, which is accelerated by worsening of heart failure or acute decompensated heart failure. Although it is a frequent clinical entity due to the improved survival of heart failure patients, still its pathophysiology is not well understood, and thus its therapeutic approach remains controversial and sometimes ineffective. Established therapeutic strategies, such as diuretics and inotropes, are often associated with resistance and limited clinical success. That leads to an increasing concern about novel options, such as the use of vasopressin antagonists, adenosine A1 receptor antagonists, and renal-protective dopamine. Initial clinical trials have shown quite encouraging results in some heart failure subpopulations but have failed to demonstrate a clear beneficial role of these agents. On the other hand, ultrafiltration appears to be a more promising therapeutic procedure that will improve volume regulation, while preserving renal and cardiac function. Further clinical studies are required in order to determine their net effect on renal function and potential cardiovascular outcomes. Until then, management of the cardiorenal syndrome remains quite empirical.

Effects of ULTRAfiltration vs. DIureticS on clinical, biohumoral and haemodynamic variables in patients with deCOmpensated heart failure: the ULTRADISCO study

AIMS

To evaluate the clinical, biohumoral, and haemodynamic effects of ultrafiltration vs. intravenous diuretics in patients with decompensated heart failure (HF). Signs and symptoms of volume overload are often present in these patients and standard therapy consists primarily of intravenous diuretics. Increasing evidence suggests that ultrafiltration can be an effective alternative treatment.

METHODS AND RESULTS

Thirty patients with decompensated HF were randomly assigned to diuretics or ultrafiltration. Haemodynamic variables, including several novel parameters indicating the overall performance of the cardiovascular system, were continuously assessed with the Pressure Recording Analytical Method before, during, at the end of treatment (EoT) and 36 h after completing treatment. Aldosterone and N-terminal pro-B-type natriuretic peptide (NT-proBNP) plasma levels were also measured. Patients treated with ultrafiltration had a more pronounced reduction in signs and symptoms of HF at EoT compared with baseline, and a significant decrease in plasma aldosterone (0.24 ± 0.25 vs. 0.86 ± 1.04 nmol/L; P < 0.001) and NT-proBNP levels (2823 ± 2474 vs. 5063 ± 3811 ng/L; P < 0.001) compared with the diuretic group. The ultrafiltration group showed a significant improvement (% of baseline) in a number of haemodynamic parameters, including stroke volume index (114.0 ± 11.7%; P < 0.001), cardiac index (123.0 ± 20.8%; P < 0.001), cardiac power output (114.0 ± 13.8%; P < 0.001), dP/dt(max) (129.5 ± 19.9%; P < 0.001), and cardiac cycle efficiency (0.24 ± 0.54 vs. -0.14 ± 0.50 units; P < 0.05), and a significant reduction in systemic vascular resistance 36 h after the treatment (88.0 ± 10.9%; P < 0.001), which was not observed in the diuretic group.

CONCLUSIONS

In patients with advanced HF, ultrafiltration facilitates a greater clinical improvement compared with diuretic infusion by ameliorating haemodynamics (assessed using a minimally invasive methodology) without a marked increase in aldosterone or NT-proBNP levels.

The role of ultrafiltration in patients with decompensated heart failure

Congestion, due in large part to hypervolemia, is the primary driver of heart failure (HF) admissions. Relief of congestion has been traditionally achieved through the use of loop diuretics, but there is increasing concern that these agents, particularly at high doses, may be deleterious in the inpatient setting. In addition, patients with HF and the cardiorenal syndrome (CRS) have diminished response to loop diuretics, making these agents less effective at relieving congestion. Ultrafiltration, a mechanical volume removal strategy, has demonstrated promise in achieving safe and effective volume removal in patients with cardiorenal syndrome and diuretic refractoriness. This paper outlines the rationale for ultrafiltration in CRS and the available evidence regarding its use in patients with HF. At present, the utility of ultrafiltration is restricted to selected populations, but a greater understanding of how this technology impacts HF and CRS may expand its use.

Effect of subzero-balanced ultrafiltration on postoperative outcome of patients after cardiopulmonary bypass

OBJECTIVE

To evaluate the effect of a new ultrafiltration technique - subzero-balanced ultrafiltration technique - on early postoperative outcomes of adult patients undergoing cardiac operations with cardiopulmonary bypass.

METHODS

A total of 120 patients who required cardiopulmonary bypass for cardiac surgery were randomized into two groups, 60 in each group. Patients in the treatment group received subzero-balanced ultrafiltration during cardiopulmonary bypass, while patients in the control group received routine cardiopulmonary bypass. Postoperative outcomes, including hospital mortality and morbidity of the two groups, were analyzed.

RESULTS

Hospital mortality was 0% (0 of 60) in the treatment group versus 1.8% (1 of 60) in the control group (P=1.000). Total hospital complications was lower in the treated patients (11 of 60 [18.3%] versus 22 of 60 [36.7%], P=0.025). Duration of intubation time was shorter and transfusion volume within 24 hours postoperatively was less in patients having received subzero-balanced ultrafiltration during cardiopulmonary bypass (14.35 + or - 1.66 versus 18.64 + or - 1.57 h, P=0.036 and 1.54 + or - 1.56 versus 3.64 + or - 2.67 U/patient, P=0.032). Length of stay on the intensive care unit, duration of hospital stay, need for infusion of inotropic agent and drainage volumes within 24 h postoperatively between the two groups were comparable.

CONCLUSIONS

Subzero-balanced ultrafiltration during cardiopulmonary bypass can effectively decrease the patients' hospital morbidity and the volume of blood transfusion: it also may promote early postoperative recovery of patients. Routine application of subzero-balanced ultrafiltration during adult cardiac operations should not be necessary, but the technique should be compared to other techniques, e.g. MUF, in further studies.

Acute kidney injury in ST-segment elevation acute myocardial infarction complicated by cardiogenic shock at admission

OBJECTIVE

To evaluate the clinical and prognostic relevance of acute kidney injury (AKI) in the setting of ST-elevation acute myocardial infarction (STEMI) complicated by cardiogenic shock (CS).

DESIGN

Prospective study.

SETTING

Single-center study, 13-bed intensive cardiac care unit at a University Cardiological Center.

PATIENTS

Ninety-seven consecutive STEMI patients with CS at admission, undergoing intra-aortic balloon pump (IABP) support and primary percutaneous coronary intervention (PCI).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We measured serum creatinine at baseline and each day for the following 3 days. Acute kidney injury was defined as a rise in creatinine >25% from baseline. Overall, AKI occurred in 52 (55%) patients, and in 12 of these patients, a renal replacement therapy was required. In multivariate analysis, age >75 yrs (p = .005), left ventricular ejection fraction < or = 40% (p = .009), and use of mechanical ventilation (p = .01) were independent predictors of AKI. Patients developing AKI had a longer hospital stay, a more complicated clinical course, and significantly higher mortality rate (50% vs. 2.2%; p <.001) than patients without AKI. In our population, AKI was the strongest independent predictor of in-hospital mortality (relative risk 12.3, 95% confidence intervals 1.78 to 84.9; p <.001).

CONCLUSIONS

In patients with STEMI complicated by CS, AKI represents a frequent clinical complication associated with a poor prognosis.

Cardiorenal syndrome: still not a defined entity

Because of the increasing incidence of cardiac failure and chronic renal failure due to the progressive aging of the population, the extensive application of cardiac interventional techniques, the rising rates of obesity and diabetes mellitus, coexistence of heart failure and renal failure in the same patient are frequent. More than half of subjects with heart failure had renal impairment, and mortality worsened incrementally across the range of renal dysfunctions. In patients with heart failure, renal dysfunction can result from intrinsic renal disease, hemodynamic abnormalities, or their combination. Severe pump failure leads to low cardiac output and hypotension, and neurohormonal activation produces both fluid retention and vasoconstriction. However, the cardiorenal connection is more elaborate than the hemodynamic model alone; effects of the renin-angiotensin system, the balance between nitric oxide and reactive oxygen species, inflammation, anemia and the sympathetic nervous system should be taken into account. The management of cardiorenal patients requires a tailored therapy that prioritizes the preservation of the equilibrium of each individual patient. Intravascular volume, blood pressure, renal hemodynamic, anemia and intrinsic renal disease management are crucial for improving patients' survival. Complications should be foreseen and prevented, looking carefully at basic physical examination, weight and blood pressure monitoring, and blood, urine urea and electrolytes measurement.

Continuous renal replacement therapy in sepsis and multisystem organ failure

This study reviews the role of continuous renal replacement therapy (CRRT) in sepsis with acute kidney injury (AKI) and septic shock with multiple organ failure. In addition to the conventional aim of replacing renal function in AKI, CRRT is often used with the concept of modulating immune response in sepsis. With the intention of influencing circulating levels of inflammatory mediators like cytokines and chemokines, the complement system, as well as factors of the coagulation system, several modifications of CRRT have been developed over the last years. These include high volume hemofiltration, high adsorption hemofiltration, use of high cut-off membranes, and hybrid systems like coupled plasma filtration absorbance. One of the most promising concepts may be the development of renal assist devices using renal tubular cells for implementing renal tubular function into CRRT.

Ultrafiltration for congestive heart failure

Relief of congestive symptoms is a primary goal in treating heart failure. Ultrafiltration is a tool that can be used to safely remove sodium and water from whole blood at a controlled rate. Ultrafiltration decreases symptoms, relieves congestion, and improves hemodynamics, neurohormonal balance, and exercise capacity. This article describes the importance of congestion as a therapeutic target in heart failure and outlines the development of ultrafiltration as a treatment to address this important physiologic state.

Ultrafiltration in the management of heart failure

PURPOSE OF REVIEW

Congestion causes the majority of hospitalizations for heart failure and contributes to heart failure progression and mortality. Intravenous loop diuretics reduce the signs and symptoms of congestion. Loop diuretics, however, may be associated with increased morbidity and mortality because of deleterious effects on neurohormonal activation, electrolyte balance, and cardiac and renal function. Ultrafiltration, an alternative method of sodium and water removal, safely improves hemodynamics in heart failure patients.

RECENT FINDINGS

The Ultrafiltration versus Intravenous Diuretics for Patients Hospitalized for Acute Decompensated Heart Failure trial has recently shown that among 200 volume overloaded heart failure patients randomized to ultrafiltration or intravenous diuretics, 48 h weight (P = 0.001) and net fluid loss (P = 0.001) were greater in the ultrafiltration group. Dyspnea scores were similar. At 90 days, the ultrafiltration group had fewer heart failure rehospitalizations/patient (P = 0.022) and patients presenting for unscheduled visits (21 vs. 44%; P = 0.009). No serum creatinine differences occurred between the groups.

SUMMARY

In decompensated heart failure, ultrafiltration safely produces greater weight and fluid loss than intravenous diuretics, reduces rehospitalization rates for heart failure and is an effective alternative therapy.

Contemporary trends in the pharmacological and extracorporeal management of heart failure: a nephrologic perspective

Heart failure and chronic kidney disease share a number of risk factors and pathophysiological pathways. These 2 pathological processes coexist in large numbers of patients. Whereas the presence of chronic kidney disease in patients with heart failure adversely influences their survival, cardiovascular disease is the major cause of mortality in individuals with chronic kidney disease. The management of heart failure by cardiologists has recently expanded from pharmacological treatment to extracorporeal strategies; the interaction between (and concurrent use of) these approaches traditionally has been part of nephrology care and training. The purpose of this review is to explore these management strategies from a nephrologic standpoint and cover the pathophysiology of diuretic resistance, new pharmaceutical strategies to induce natriuresis or aquaresis, and the physiological basis and theoretical advantages of fluid removal by nontraditional peritoneal or hemofiltration approaches. This review also focuses on the technical features, safety, and potential risks of dedicated ultrafiltration devices that do not require dialysis staff or facilities and that are now readily available to nonnephrologists.

A randomized, controlled trial of the renal effects of ultrafiltration as compared to furosemide in patients with acute decompensated heart failure

OBJECTIVES

This study was designed to evaluate the consequences of ultrafiltration (UF) and standard intravenous diuretic (furosemide) therapy on glomerular filtration rate (GFR) and renal plasma flow in patients with acute decompensated heart failure.

BACKGROUND

It has been hypothesized that treatment with diuretics may worsen renal function as the result of systemic neurohormonal activation and direct renal vascular effects. UF also removes fluid, but its actions on intrarenal hemodynamics, and therefore renal function, are unknown.

METHODS

Patients hospitalized for acute decompensated heart failure with an ejection fraction less than 40% and two or more signs of hypervolemia were randomized to receive UF or intravenous diuretics. Urine output, GFR (as measured by iothalamate), and renal plasma flow (as measured by para-aminohippurate) were assessed before fluid removal and after 48 hours.

RESULTS

Nineteen patients (59 +/- 16 years, 68% were male) were randomized to receive UF (n = 9) or intravenous diuretics (n = 10). The change in GFR (-3.4 +/- 7.7 mL/min vs. -3.6 +/- 11.5 mL/min; P = .966), renal plasma flow (26.6 +/- 62.7 mL/min vs. 16.1 +/- 42.0 mL/min; P = .669), and filtration fraction (-6.9 +/- 13.6 mL/min vs. -3.9 +/- 13.6 mL/min; P = .644) after treatment were not significantly different between the UF and furosemide treatment groups, respectively. There was no significant difference in net 48-hour fluid removal between the groups (-3211 +/- 2345 mL for UF and -2725 +/- 2330 mL for furosemide, P = .682). UF removed 3666 +/- 2402 mL. Urine output during 48 hours was significantly greater in the furosemide group (5786 +/- 2587 mL) compared with the UF group (2286 +/- 915 mL, P < .001).

CONCLUSIONS

During a 48-hour period, UF did not cause any significant differences in renal hemodynamics compared with the standard treatment of intravenous diuretics.

Peripheral ultrafiltration for patients with volume overload: a center's 4-year experience

The overall prevalence of heart failure in the United States is thought to be over 5 million people, with an additional 550 000 cases diagnosed each year. Peripheral ultrafiltration provides an additional method for relieving congestion in patients with decompensated heart failure who are resistant to diuretics. A competency-based education program for staff ensures adequate knowledge to safely care for the patient. Over a 4-year period, 120 patients have been treated for volume overload using peripheral ultrafiltration at Sharp Memorial Hospital.

Beyond pulmonary edema: diagnostic, risk stratification, and treatment challenges of acute heart failure management in the emergency department

The majority of heart failure hospitalizations in the United States originate in the emergency department (ED). Current strategies for acute heart failure syndromes have largely been tailored after chronic heart failure guidelines and care. Prospective ED-based acute heart failure syndrome trials are lacking, and current guidelines for disposition are based on either little or no evidence. As a result, the majority of ED acute heart failure syndrome patients are admitted to the hospital. Recent registry data suggest there is a significant amount of heterogeneity in acute heart failure syndrome ED presentations, and diagnostics and therapeutics may need to be individualized to the urgency of the presentation, underlying pathophysiology, and acute hemodynamic characteristics. A paradigm shift is necessary in acute heart failure syndrome guidelines and research: prospective trials need to focus on diagnostic, therapeutic, and risk-stratification algorithms that rely on readily available ED data, focusing on outcomes more proximate to the ED visit (5 days). Intermediate outcomes (30 days) are more dependent on inpatient and outpatient care and patient behavior than ED management decisions. Without these changes, the burden of acute heart failure syndrome care is unlikely to change. This article proposes such a paradigm shift in acute heart failure syndrome care and discusses areas of further research that are necessary to promote this change in approach.

Ultrafiltration in Heart Failure

Managing volume overload is essential for the treatment of symptomatic heart failure. Traditionally, it is achieved with oral and intravenous diuretics. Alternatively, the excess fluid can be removed via ultrafiltration. Modern technology has made this latter option more feasible than before for routine clinical practice. In this article we review the existing literature on the use of ultrafiltration for treating volume overload states in patients with heart failure.

Ultrafiltration versus intravenous diuretics for patients hospitalized for acute decompensated heart failure

OBJECTIVES

This study was designed to compare the safety and efficacy of veno-venous ultrafiltration and standard intravenous diuretic therapy for hypervolemic heart failure (HF) patients.

BACKGROUND

Early ultrafiltration may be an alternative to intravenous diuretics in patients with decompensated HF and volume overload.

METHODS

Patients hospitalized for HF with > or =2 signs of hypervolemia were randomized to ultrafiltration or intravenous diuretics. Primary end points were weight loss and dyspnea assessment at 48 h after randomization. Secondary end points included net fluid loss at 48 h, functional capacity, HF rehospitalizations, and unscheduled visits in 90 days. Safety end points included changes in renal function, electrolytes, and blood pressure.

RESULTS

Two hundred patients (63 +/- 15 years, 69% men, 71% ejection fraction < or =40%) were randomized to ultrafiltration or intravenous diuretics. At 48 h, weight (5.0 +/- 3.1 kg vs. 3.1 +/- 3.5 kg; p = 0.001) and net fluid loss (4.6 vs. 3.3 l; p = 0.001) were greater in the ultrafiltration group. Dyspnea scores were similar. At 90 days, the ultrafiltration group had fewer patients rehospitalized for HF (16 of 89 [18%] vs. 28 of 87 [32%]; p = 0.037), HF rehospitalizations (0.22 +/- 0.54 vs. 0.46 +/- 0.76; p = 0.022), rehospitalization days (1.4 +/- 4.2 vs. 3.8 +/- 8.5; p = 0.022) per patient, and unscheduled visits (14 of 65 [21%] vs. 29 of 66 [44%]; p = 0.009). No serum creatinine differences occurred between groups. Nine deaths occurred in the ultrafiltration group and 11 in the diuretics group.

CONCLUSIONS

In decompensated HF, ultrafiltration safely produces greater weight and fluid loss than intravenous diuretics, reduces 90-day resource utilization for HF, and is an effective alternative therapy. (The UNLOAD trial; http://clinicaltrials.gov/ct/show/NCT00124137?order=1; NCT00124137).

Practical applications of intravenous diuretic therapy in decompensated heart failure

Intravenous (IV) loop diuretics play an important role in the treatment of decompensated heart failure (DHF). They inhibit the Na(+)-K(+)-2Cl(-) reabsorptive pump in the thick ascending limb of the loop of Henle, and the resultant natriuresis and diuresis decreases volume load, improves hemodynamics, and reduces DHF symptoms. However, loop diuretics have a short half-life and their efficacy may be limited by postdiuretic sodium rebound during the period between doses in which the tubular diuretic concentration is subtherapeutic. Moreover, they can produce electrolyte abnormalities, neurohormonal activation, intravascular volume depletion, and renal dysfunction. Several studies have reported an association between diuretic therapy and increased morbidity and mortality. In addition, many patients, especially those with more advanced forms of heart failure (HF), are resistant to standard doses of loop diuretics. These high-risk, resistant patients may benefit from pharmacologic and/or nonpharmacologic interventions to improve hemodynamic performance, treatment of renovascular disease, discontinuation of aspirin and other sodium-retaining drugs, manipulation of the route of delivery or combination of diuretic classes, or hemofiltration. Despite >50 years of use, many questions regarding the use of intravenous diuretic agents in patients with DHF are still unanswered, and there remains a compelling need for well-designed randomized, controlled clinical trials to establish appropriate treatment regimens that maximize therapeutic benefit while minimizing morbidity and mortality.

The confounding issue of comorbid renal insufficiency

The United States is currently beleaguered by twin epidemics, heart failure (HF) and renal insufficiency (RI). HF and RI frequently coexist in the same patient, and this conjunction, often called the "cardiorenal syndrome," has important therapeutic and prognostic implications. Approximately 60% to 80% of patients hospitalized for HF have at least stage III renal dysfunction as defined by the National Kidney Foundation (NKF), and this comorbid RI is associated with significantly increased morbidity and mortality risk. Numerous studies have demonstrated that in patients with HF, indices of renal function are the most powerful independent mortality risk predictors. Comorbid RI can result from both intrinsic renal disease and inadequate renal perfusion. Atherosclerosis, renal vascular disease, diabetes mellitus, and hypertension are significant precursors of both HF and RI. Moreover, diminished renal perfusion is frequently a consequence of the hemodynamic changes associated with HF and its treatment. Both HF and RI stimulate neurohormonal activation, increasing both preload and afterload and reducing cardiac output. Inotropic agents augment this neurohormonal activation. In addition, diuretics can produce hypovolemia and intravenous vasodilators can cause hypotension, further diminishing renal perfusion. Management of these patients requires successfully negotiating the delicate balance between adequate volume reduction and worsening renal function. Despite this, few evidence-based data are available to guide management decisions, indicating a compelling need for additional studies in this patient population.

Beyond diuretics: management of volume overload in acute heart failure syndromes

Diuretics are an established foundation of therapy for patients with chronic heart failure (HF) as well as for those hospitalized for treatment of acute HF syndromes. Despite the accepted use of diuretics in acute HF syndromes, treatment patterns with diuretics vary widely, and there are no data from randomized studies on the benefit of diuretics on morbidity or mortality in patients hospitalized with acute HF syndromes. Additional pharmacologic therapies that complement or replace diuretics in this setting, especially in patients with diuretic resistance, include positive inotropes, nitrovasodilators, and natriuretic peptides, but data are likewise lacking on important clinical outcomes. Ultrafiltration has also been used as a nonpharmacologic strategy to treat patients with acute HF syndromes who exhibit resistance to diuretics. Effective monitoring of volume status with newer modalities may allow more selective use of diuretics and diuretic-like modalities, but additional randomized trial data are clearly needed to establish ideal strategies to promote volume removal in acute HF syndromes.

The role of peritoneal dialysis in the management of treatment-resistant congestive heart failure: A European perspective

Patients with congestive heart failure (CHF) resistant to conventional treatment have a poor prognosis. Extracorporeal ultrafiltration (UF) appears to be the therapy of choice for short-term management of such patients with severe fluid overload, whereas peritoneal dialysis (PD) may be the therapy of choice for the long-term treatment. Fluid removal results in reduction of plasma volume, improvement of hyponatremia, reduction in pulmonary capillary wedge pressure, improvement of New York Heart Association functional heart failure class, improvement of functional rehabilitation and quality of life, reduction of hospitalizations and readmissions, as well as improvement in diuretic responsiveness. Whether extracorporeal UF and/or PD modifies the survival rate of patients with refractory CHF needs to be determined in prospective randomized controlled trials.

The role of ultrafiltration in the management of heart failure

In the United States, 90% of one million annual hospitalizations for heart failure are due to symptoms of volume overload. Hypervolemia contributes to heart failure progression and mortality. Treatment guidelines recommend that therapy for patients with heart failure be aimed at achieving euvolemia. Intravenous loop diuretics induce a rapid diuresis that reduces lung congestion and dyspnea. However, loop diuretics' effectiveness declines with repeated exposure. Unresolved congestion may contribute to high re-hospitalization rates. Furthermore, loop diuretics may be associated with increased morbidity and mortality due to deleterious effects on neurohormonal activation, electrolyte balance, and cardiac and renal function. Ultrafiltration is an alternative method of sodium and water removal, which safely improves hemodynamics in patients with heart failure. Application of this technology has been limited by the need for high flow rates, large extracorporeal blood volumes, and large-bore central venous catheters. A modified ultrafiltration device has overcome these limitations. Ultrafiltration may be a safe and effective alternative to intravenous diuretics in the treatment of decompensated heart failure.

Ultrafiltration in decompensated heart failure

Fluid congestion is the hallmark of decompensated heart failure. As heart failure progresses, reduced response to diuretics is common. In these patients, ultrafiltration has been found to alleviate excess volume and improve diuretic sensitivity. Compared with diuretics, ultrafiltration provides a more predictable and safer way to achieve euvolemia with minimal electrolyte abnormalities and neurohormonal activation. The emerging familiarity and ease of use of ultrafiltration suggests that in the future this will be an important therapy for the treatment of acute and chronic volume overload associated with decompensated heart failure.

Ultrafiltration Versus Usual Care for Hospitalized Patients With Heart Failure

OBJECTIVES

The purpose of this research was to assess the safety and efficacy of ultrafiltration (UF) in patients admitted with decompensated congestive heart failure (CHF).

BACKGROUND

Ultrafiltration for CHF is usually reserved for patients with renal failure or those unresponsive to pharmacologic management. We performed a randomized trial of UF versus usual medical care using a simple UF device that does not require special monitoring or central intravenous access.

METHODS

Patients admitted for CHF with evidence of volume overload were randomized to a single, 8 h UF session in addition to usual care or usual care alone. The primary end point was weight loss 24 h after the time of enrollment.

RESULTS

Forty patients were enrolled (20 UF, 20 usual care). Ultrafiltration was successful in 18 of the 20 patients in the UF group. Fluid removal after 24 h was 4,650 ml and 2,838 ml in the UF and usual care groups, respectively (p = 0.001). Weight loss after 24 h, the primary end point, was 2.5 kg and 1.86 kg in the UF and usual care groups, respectively (p = 0.240). Patients tolerated UF well.

CONCLUSIONS

The early application of UF for patients with CHF was feasible, well-tolerated, and resulted in significant weight loss and fluid removal. A larger trial is underway to determine the relative efficacy of UF versus standard care in acute decompensated heart failure.

Reviews: The Current State of Nonuremic Applications for Extracorporeal Blood Purification

Despite the commonly accepted indications for hemodialysis and extracorporeal depuritive techniques, some clinicians have come to rely on blood purification for clinical states where the targeted substance for removal differs from uremic waste products. Over the last decade, a number of studies have emerged to help define the application of extracorporeal blood purification (ECBP) to these "nonuremic" indications. This review describes the application of extracorporeal blood purification in clinical states including sepsis, rhabdomyolysis, congestive heart failure, hepatic failure, tumor lysis syndrome, adult respiratory distress syndrome, intravenous contrast exposure, and lactic acidosis. Additional comments are provided to review existing literature on thermoregulation and osmoregulation, including acute brain injury.

Contrast-induced nephropathy

Contrast-induced nephropathy (CIN) is a leading cause of in-hospital acute renal failure in critically ill patients who undergo radiographic procedures. Critical care patients are at particular risk, often because of baseline renal dysfunction, older age, and the presence of diabetes. In addition, there are superimposed risks, including volume depletion, sepsis, and use of nephrotoxic drugs. The rates of CIN (defined as an increase in serum creatinine by >25% or 0.5 mg/dL) can be predicted by using multivariate tools. Prevention measures include adequate hydration, use of N-acetylcysteine and iso-osmolar contrast, and for patients who are at the highest risk, prophylactic hemofiltration.

Management of diuretic-refractory, volume-overloaded patients with acutely decompensated heart failure

Fluid overload is a common presentation for decompensated heart failure, yet management strategies are poorly defined because of relatively few randomized clinical trials that delineate an optimal strategy. Patients refractory to diuretic therapy may be considered for treatment with inotropes or vasodilators, and others may be considered for venovenous ultrafiltration. The rationale for use of each therapy is reviewed.

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