Mechanism of furosemide resistance in analbuminemic rats and hypoalbuminemic patients

Albumin: a comprehensive review and practical guideline for clinical use

PURPOSE

Nowadays, it is largely accepted that albumin should not be used in hypoalbuminemia or for nutritional purpose. The most discussed indication of albumin at present is the resuscitation in shock states, especially distributive shocks such as septic shock. The main evidence-based indication is also liver disease. In this review, we provided updated evidence-based instruction for definite and potential indications of albumin administration in clinical practice, with appropriate dosing and duration.

METHODS

Data collection was carried out until November 2023 by search of electronic databases including PubMed, Google Scholar, Scopus, and Web of Science. GRADE system has been used to determine the quality of evidence and strength of recommendations for each albumin indication.

RESULTS

A total of 165 relevant studies were included in this review. Fluid replacement in plasmapheresis and liver diseases, including hepatorenal syndrome, spontaneous bacterial peritonitis, and large-volume paracentesis, have a moderate to high quality of evidence and a strong recommendation for administering albumin. Moreover, albumin is used as a second-line and adjunctive to crystalloids for fluid resuscitation in hypovolemic shock, sepsis and septic shock, severe burns, toxic epidermal necrolysis, intradialytic hypotension, ovarian hyperstimulation syndrome, major surgery, non-traumatic brain injury, extracorporeal membrane oxygenation, acute respiratory distress syndrome, and severe and refractory edema with hypoalbuminemia has a low to moderate quality of evidence and weak recommendation to use. Also, in modest volume paracentesis, severe hyponatremia in cirrhosis has a low to moderate quality of evidence and a weak recommendation.

CONCLUSION

Albumin administration is most indicated in management of cirrhosis complications. Fluid resuscitation or treatment of severe and refractory edema, especially in patients with hypoalbuminemia and not responding to other treatments, is another rational use for albumin. Implementation of evidence-based guidelines in hospitals can be an effective measure to reduce inappropriate uses of albumin.

Renal function in very old critically ill patients

PURPOSE OF REVIEW

Current demographic change leads to higher number of elderly patients admitted to an ICU. Among other organs also the kidneys show age-related changes, which are associated with a decline in various aspects of renal function. The purpose of this review is to provide an overview of structural and functional changes in elderly and also to specifically address the increased risk of acute kidney injury (AKI) in this population.

RECENT FINDINGS

Ageing in the kidneys is affected by many different factors, such as low grade chronic inflammation, called inflammageing, and various comorbidities. Nevertheless, a decrease of glomerular filtration rate (GFR) occurs independent of the presence of comorbidities and a steady decline of GFR has been reported in both healthy men and women. Pharmacodynamic of many drugs is altered by these changes. Additionally the rate of diuretic resistance appears to be increased. The cause of AKI occurrence in older age is, multifactorial and includes preventable triggers (hypovolemia, hypotension, nephrotoxins) as well as changes associated with aging.

SUMMARY

Age-related alterations of the kidneys were found at microscopic and macroscopic levels of the cell. These changes lead to a reduced renal reserve and subsequently to an increased vulnerability of aged kidneys when an additional stressor is added. Age is an independent risk factor for developing AKI. Physicians should take into account the altered renal function in elderly patients and take renal protective measures at an early stage.

Etiology and Management of Edema: A Review

The development of peripheral edema can often pose a significant diagnostic and therapeutic challenge for practitioners due to its association with a wide variety of underlying disorders ranging in severity. Updates to the original Starling's principle have provided new mechanistic insights into edema formation. Additionally, contemporary data highlighting the role of hypochloremia in the development of diuretic resistance provide a possible new therapeutic target. This article reviews the pathophysiology of edema formation and discusses implications for treatment.

Co-Administration of Albumin and Furosemide in Acute Heart Failure with Diuretics Resistance

Acute heart failure is a frequent cause of hospital admission in Portugal, and has an increasing tendency given the aging population. Although most admissions for acute heart failure are caused by congestive conditions, not all patients have a congestive phenotype, reflecting the complexity of a process with multiple pathophysiological pathways. The use of diuretics, usually loop diuretics, is the mainstay of treatment for congestion. However, many patients develop resistance, thus constituting a challenge with no consensual solution to date, despite extensive debate over the years. Despite its frequent use in clinical practice, the co-administration of albumin and furosemide remains controversial in the management of patients with acute heart failure, hypoalbuminemia, and diuretic resistance. This review addresses the pathophysiological mechanisms of congestion in patients with acute heart failure and explores the theoretical basis that supports the co-administration of albumin and furosemide in this clinical context. It is intended to clarify the potential benefit of the combined approach in this specific population and identify possible gaps in the literature that could be the subject of future studies.

Impact of Albumin Binding Function on Pharmacokinetics and Pharmacodynamics of Furosemide

Background and Objectives: Albumin binding of the loop diuretic furosemide forms the basis for its transport to the kidney and subsequent tubular secretion, which is a prerequisite for its therapeutic effects. Accordingly, high albumin concentrations should result in higher efficacy of furosemide. However, study results on the combination of furosemide in conjunction with albumin, and on the efficacy of furosemide in hypoalbuminemia, did not confirm this hypothesis. The aim of this study was to determine the efficacy of furosemide not only in relation to albumin concentration, but also taking albumin function into account. Materials and Methods: In a prospective and non-interventional clinical observational trial, blood and urine samples from 50 intensive care patients receiving continuous intravenous furosemide therapy were evaluated. Albumin binding capacity (ABiC) determination allowed conclusions to be drawn about the binding site-specific loading state of albumin, by quantifying the unbound fraction of the fluorescent marker dansylsarcosine. In addition, assessment of the total concentration of furosemide in plasma and urine, as well as the concentration of free furosemide fraction in plasma, was performed by HPLC−MS. The efficacy of furosemide was evaluated by the ratio of urine excretion to fluid intake. Results: In patients with an ABiC ≥ 60% free furosemide fraction was significantly lower compared to patients with a lower ABiC (p < 0.001), urinary furosemide concentration was higher (p = 0.136), and a significantly higher proportion of infused furosemide was excreted renally (p = 0.010). ABiC was positively correlated (r = 0.908, p = 0.017) with increase in the urine excretion to fluid input ratio after initiation of furosemide therapy. Conclusions: ABiC could serve as a marker for individual response to furosemide and could be used to generate patient-specific therapeutic regimens. In view of the relatively low number of patients in this study, the relationship between furosemide efficacy and albumin function should be investigated in larger studies in the future.

Challenges in diuretic therapy: A case-based discussion

Diuretics are amongst the most prescribed medications in both the inpatient and outpatient settings. They are used extensively in diverse disease states including heart failure, acute and chronic kidney disease, cirrhosis, and diseases of excess capillary permeability such as sepsis, malignancy, and malnutrition. All are characterized by total body sodium overabundance which commonly manifests as edema. The use of diuretics is however not bereft of complications. These complications frequently limit the correction of hypervolemia, resulting in continued patient suffering and frustration for the clinician. In this review, we employ a case-based approach to discuss three common challenges encountered during diuretic therapy: diuretic resistance that characterizes the nephrotic syndrome, diuretic-induced metabolic alkalosis, and diuretic-associated hyponatremia. We empower the clinician to effectively meet these challenges by providing a mechanistic understanding of these complications and their solutions.

Efficacy of albumin with diuretics in mechanically ventilated patients with hypoalbuminemia: A systematic review and meta-analysis

BACKGROUND

Hypoalbuminemia is associated with fluid overload, the development of acute respiratory distress syndrome, and mortality. The co-administration of albumin and diuretics for the treatment of patients with hypoalbuminemia is expected to increase urine output, without hemodynamic instability, and improve pulmonary function; however, these effects have not been systematically investigated. Here, we aimed to clarify the benefits of the co-administration of albumin and diuretics in mechanically ventilated patients.

METHODS

We searched for randomized, placebo-controlled trials that investigated the effects of the co-administration of albumin and diuretics compared with placebo and diuretics, in mechanically ventilated patients with hypoalbuminemia. We searched these trials in the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE via PubMed, and EMBASE databases. Primary outcomes were hypotensive events after the intervention, all-cause mortality, and the length of mechanical ventilation. Secondary outcomes were improvement in the ratio of partial pressure arterial oxygen and fraction of inspired oxygen (P/F ratio) at 24 hours, total urine output (mL/d), and the clinical requirement of renal replacement therapy (RRT).

RESULTS

From the 1574 records identified, we selected 3 studies for quantitative analysis. The results of albumin administration were as follows: hypotensive events (risk ratio [RR] -1.05 [95% confidence interval {CI}: 0.15-0.81]), all-cause mortality (RR 1.0 [95% CI: 0.45-2.23]), the length of mechanical ventilation in days (mean difference -1.05 [95% CI: -3.35 to 1.26]), and improvement in P/F ratio (RR 2.83 [95% CI: 1.42-5.67]). None of the randomized controlled trials reported the total urine output, and one reported that no participants required RRT. Adverse events were not reported during the trials. The certainty of evidence was low (in the hypotensive events after the intervention and all-cause mortality) to moderate (in the length of mechanical ventilation in days, improvement of P/F ratio, clinical requirement of RRT, and adverse events).

CONCLUSIONS

Although this treatment combination reduced the number of days for which mechanical ventilation was required, it did not reduce the all-cause mortality at 30 days. In conclusion, the co-administration of albumin and diuretics may reduce hypotensive events and improve the P/F ratio at 24 hours.

Response Guided Slow Infusion of Albumin, Vasoconstrictors and Furosemide Improves Ascites Mobilization and Survival in Acute on Chronic Liver Failure: A Proof-of-Concept Study

Background and Aims

Acute-on-chronic liver failure (ACLF) with increasing organ failure is associated with poor outcomes. Severely deranged systemic hemodynamics and decreased effective arterial blood volume contribute to tissue damage and organ failure. Response-guided therapy with albumin, vasoconstrictors, and furosemide may help overcome effective hypovolemia, improve diuresis and impact survival.

Methods

In the observation cohort, 230 patients with ACLF (CANONIC criteria) with ascites (≥Grade II) and ACLF ≥Grade I were enrolled. A total of 136 patients (GROUP I) received response-guided (urine sodium >80mmol/day) slow albumin-furosemide infusion ± terlipressin (SAFI ± T), while 94 patients (GROUP II) received standard medical therapy. Twenty-eight-day survival, ascites mobilization (nil or grade 1), and adverse events were noted. In another mechanistic cohort (n = 40), laboratory evidences for improvement in various pathophysiological alterations; gut permeability, endotoxemia, cytokine storm, neutrophil dysfunction, and hemodynamic alterations following SAFI ± T/Noradrenaline (NAdr) were evaluated.

Results

Age, gender, CLIF-C-ACLF, SOFA and MELD scores, ACLF grades and urine sodium were not different between the two groups in the observation cohort. Ascites was mobilized in 102/136 in GROUP I (SAFI ± T) and 23/94 in GROUP II (p < 0.05). Twenty-eight-day survival was significantly higher in GROUP I = 103/136 (75.7%) vs GROUP II = 50/94 (53.2%), (P = <0.001). All those who were unable to reach urine sodium >80 mmol/day died. Four patients in GROUP I developed scrotal gangrene. In the mechanistic cohort, 72% of patients survived with significant improvement in gut permeability, endotoxemia, serum cytokines, neutrophil dysfunction, and hemodynamic alterations.

Conclusion

Ascitic fluid mobilization by response-guided SAFI ± T/NAdr therapy improves survival by improving splanchnic and systemic hemodynamics, decreasing gut congestion, gut permeability, and endotoxemia, improving neutrophil functions, and reducing pro-inflammatory cytokines in circulation.

Effect of Tolvaptan in Patients with Chronic Kidney Disease Stage G5, and Impact of Concomitant Use of Thiazide Diuretics: A Retrospective Cohort Study

BACKGROUND

The diuretic effect of tolvaptan, a vasopressin V2 receptor antagonist, in patients with severe renal dysfunction remains poorly characterized. Thiazide diuretics reduce urinary volume (UV) in patients with nephrogenic diabetes insipidus, which lacks V2 receptor function.

OBJECTIVE

This retrospective study investigated the acute urinary effects of tolvaptan in patients with stage G5 chronic kidney disease and congestive heart failure (CHF), and the impact of thiazide diuretics on the urinary effects of tolvaptan.

METHODS

UVs 24 h before and after tolvaptan administration and 30-day dialysis initiation rate were compared between patients with and without thiazide diuretic administration.

RESULTS

Thiazide diuretics were used in 26 of the 106 recruited patients (age 73.4 ± 13.0 years; estimated glomerular filtration rate 8.07 ± 3.13 mL/min/1.73 m²). The pre- and post-tolvaptan 24-h UVs were significantly higher in patients not administered thiazide diuretics (1043.4 ± 645.6 vs. 1422.2 ± 774.0 mL/day; p < 0.001) than in those administered thiazide diuretics (1177.3 ± 686.5 vs. 1173.1 ± 629.1 mL/day; p = 0.93). In a multivariate regression model, thiazide diuretic use was significantly associated with decreased 24-h UV (β coefficient - 486.7, 95% confidence interval [CI] - 674.5 to - 298.8); increased urine osmolality (β coefficient 37.7, 95% CI 17.1-58.4); increased body weight (β coefficient 0.62, 95% CI 0.31-0.92); and increased 30-day dialysis initiation rate (odds ratio 3.40, 95% CI 1.18-9.82) after tolvaptan administration.

CONCLUSIONS

Tolvaptan exhibited significant diuretic effects in patients with CHF, including those with severe renal dysfunction, which were diminished with concomitant thiazide diuretic use.

Diuretic effect of co-administration of furosemide and albumin in comparison to furosemide therapy alone: An updated systematic review and meta-analysis

BACKGROUND

It has been a matter of much debate whether the co-administration of furosemide and albumin can achieve better diuresis and natriuresis than furosemide treatment alone. There is inconsistency in published trials regarding the effect of this combination therapy. We, therefore, conducted this meta-analysis to explore the efficacy of furosemide and albumin co-administration and the factors potentially influencing the diuretic effect of such co-administration.

METHODS

In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we searched the PubMed, Embase, Medline, and Cochrane databases. Prospective studies with adult populations which comparing the effect of furosemide and albumin co-administration with furosemide alone were included. The outcomes including diuretic effect and natriuresis effect measured by hourly urine output and hourly urine sodium excretion from both groups were extracted. Random effect model was applied for conducting meta-analysis. Subgroup analysis and sensitivity analysis were performed to explore potential sources of heterogeneity of treatment effects.

RESULTS

By including 13 studies with 422 participants, the meta-analysis revealed that furosemide with albumin co-administration increased urine output by 31.45 ml/hour and increased urine excretion by 1.76 mEq/hour in comparison to furosemide treatment alone. The diuretic effect of albumin and furosemide co-administration was better in participants with low baseline serum albumin levels (< 2.5 g/dL) and high prescribed albumin infusion doses (> 30 g), and the effect was more significant within 12 hours after administration. Diuretic effect of co-administration was better in those with baseline Cr > 1.2 mg/dL and natriuresis effect of co-administration was better in those with baseline eGFR < 60 ml/min/1.73m2.

CONCLUSION

Co-administration of furosemide with albumin might enhance diuresis and natriuresis effects than furosemide treatment alone but with high heterogeneity in treatment response. According to the present meta-analysis, combination therapy might provide advantages compared to the furosemide therapy alone in patients with baseline albumin levels lower than 2.5 g/dL or in patients receiving higher albumin infusion doses or in patients with impaired renal function. Owing to high heterogeneity and limited enrolled participants, further parallel randomized controlled trials are warranted to examine our outcome.

REGISTRATION

PROSEPRO ID: CRD42020211002; https://clinicaltrials.gov/.

Pathophysiology of Diuretic Resistance and Its Implications for the Management of Chronic Heart Failure

Diuretic resistance implies a failure to increase fluid and sodium (Na+) output sufficiently to relieve volume overload, edema, or congestion, despite escalating doses of a loop diuretic to a ceiling level (80 mg of furosemide once or twice daily or greater in those with reduced glomerular filtration rate or heart failure). It is a major cause of recurrent hospitalizations in patients with chronic heart failure and predicts death but is difficult to diagnose unequivocally. Pharmacokinetic mechanisms include the low and variable bioavailability of furosemide and the short duration of all loop diuretics that provides time for the kidneys to restore diuretic-induced Na+ losses between doses. Pathophysiological mechanisms of diuretic resistance include an inappropriately high daily salt intake that exceeds the acute diuretic-induced salt loss, hyponatremia or hypokalemic, hypochloremic metabolic alkalosis, and reflex activation of the renal nerves. Nephron mechanisms include tubular tolerance that can develop even during the time that the renal tubules are exposed to a single dose of diuretic, or enhanced reabsorption in the proximal tubule that limits delivery to the loop, or an adaptive increase in reabsorption in the downstream distal tubule and collecting ducts that offsets ongoing blockade of Na+ reabsorption in the loop of Henle. These provide rationales for novel strategies including the concurrent use of diuretics that block these nephron segments and even sequential nephron blockade with multiple diuretics and aquaretics combined in severely diuretic-resistant patients with heart failure.

Furosemide stress test as a predictive marker of acute kidney injury progression or renal replacement therapy: a systemic review and meta-analysis

Background

The use of the furosemide stress test (FST) as an acute kidney injury (AKI) severity marker has been described in several trials. However, the diagnostic performance of the FST in predicting AKI progression has not yet been fully discussed.

Methods

In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we searched the PubMed, Embase, and Cochrane databases up to March 2020. The diagnostic performance of the FST (in terms of sensitivity, specificity, number of events, true positive, false positive) was extracted and evaluated.

Results

We identified eleven trials that enrolled a total of 1366 patients, including 517 patients and 1017 patients for whom the outcomes in terms of AKI stage progression and renal replacement therapy (RRT), respectively, were reported. The pooled sensitivity and specificity results of the FST for AKI progression prediction were 0.81 (95% CI 0.74–0.87) and 0.88 (95% CI 0.82–0.92), respectively. The pooled positive likelihood ratio (LR) was 5.45 (95% CI 3.96–7.50), the pooled negative LR was 0.26 (95% CI 0.19–0.36), and the pooled diagnostic odds ratio (DOR) was 29.69 (95% CI 17.00–51.85). The summary receiver operating characteristics (SROC) with pooled diagnostic accuracy was 0.88. The diagnostic performance of the FST in predicting AKI progression was not affected by different AKI criteria or underlying chronic kidney disease. The pooled sensitivity and specificity results of the FST for RRT prediction were 0.84 (95% CI 0.72–0.91) and 0.77 (95% CI 0.64–0.87), respectively. The pooled positive LR and pooled negative LR were 3.16 (95% CI 2.06–4.86) and 0.25 (95% CI 0.14–0.44), respectively. The pooled diagnostic odds ratio (DOR) was 13.59 (95% CI 5.74–32.17), and SROC with pooled diagnostic accuracy was 0.86. The diagnostic performance of FST for RRT prediction is better in stage 1–2 AKI compared to stage 3 AKI (relative DOR 5.75, 95% CI 2.51–13.33).

Conclusion

The FST is a simple tool for the identification of AKI populations at high risk of AKI progression and the need for RRT, and the diagnostic performance of FST in RRT prediction is better in early AKI population.

Efficacy of furosemide-albumin compared with furosemide in critically ill hypoalbuminemia patients admitted to intensive care unit: a prospective randomized clinical trial

BACKGROUND

Some physicians co-administer albumin with loop diuretics to overcome diuretic resistance in critically ill hypoalbuminemia patients, though previous studies have reported conflicting results on this matter.

OBJECTIVE

The effects of adding albumin to furosemide to enhance its efficacy in critically ill hypoalbuminemia patients are evaluated.

METHODS

This was a non-blinded randomized trial. 49 adult critically ill patients with hypoalbuminemia and generalized edema who received randomly furosemide and furosemide/albumin complex were enrolled. The patients' urine was collected at intervals of 2, 4, 6 and 8 h after initiation of the furosemide treatment, and the urine output and urinary excretion of furosemide and sodium were measured. The urinary excretion of furosemide was considered an indicator of drug efficacy.

RESULTS

The amount of sodium and furosemide excreted in urine showed no significant differences between the two groups; however, the mean of the urinary excretion of furosemide in the first 2 h after drug infusion was significantly higher (p = 0.03) in the furosemide/albumin group. No significant correlation between APACHE II scores and serum albumin levels and the urinary excretion of furosemide was seen.

CONCLUSION

The results indicated that there is not statistically significant differences between groups with furosemide alone and combined with albumin in urinary furosemide excretion. It seems that adding albumin for furosemide pharmacotherapy regime is not recommended as an intervention to increase furosemide efficacy in critically ill hypoalbuminemia patients.

TRIAL REGISTRATION

IRCT with the registration number IRCT201412132582N12 in 23 February 2015; https://en.irct.ir/trial/2356 Graphical abstract.

Verification of serum albumin elevating effect of cell-free and concentrated ascites reinfusion therapy for ascites patients: a retrospective controlled cohort study

Cell-free and concentrated ascites reinfusion therapy (CART) is frequently used to treat refractory ascites in Japan. However, its efficacy remains unclear. This controlled cohort study verified the serum albumin elevating effect of CART by comparisons with simple paracentesis. Ascites patients receiving CART (N = 88) or paracentesis (N = 108) at our hospital were assessed for the primary outcome of change in serum albumin level within 3 days before and after treatment. A significantly larger volume of ascites was drained in the CART group. The change in serum albumin level was +0.08 ± 0.25 g/dL in the CART group and −0.10 ± 0.30 g/dL in the paracentesis group (P < 0.001). The CART – paracentesis difference was +0.26 g/dL (95%CI +0.18 to +0.33, P < 0.001) after adjusting for potential confounders by multivariate analysis. The adjusted difference increased with drainage volume. In the CART group, serum total protein, dietary intake, and urine volume were significantly increased, while hemoglobin and body weight was significantly decreased, versus paracentesis. More frequent adverse events, particularly fever, were recorded for CART, although the period until re-drainage was significantly longer. This study is the first demonstrating that CART can significantly increase serum albumin level as compared with simple paracentesis. CART represents a useful strategy to manage patients requiring ascites drainage.

Predicting the Need for a Tier II Ototoxicity Study From Early Renal Function Data

History has established that many drugs, such as the antibiotics, chemotherapies, and loop diuretics, are capable of inducing both nephrotoxicity and ototoxicity. The exact mechanisms by which cellular damage occurs remain to be fully elucidated. Monitoring the indices of renal function conducted in the Food and Drug Administration's prescribed set of early investigational new drug (IND)-enabling studies may be the first signs of ototoxicity properties of the new drug candidate. In developing improved and efficacious new molecular entities, it is critically necessary to understand the cellular and molecular mechanisms underlying the potential ototoxic effects as early in the drug development program as possible. Elucidation of these mechanisms will facilitate the development of safe and effective clinical approaches for the prevention and amelioration of drug-induced ototoxicity prior to the first dose in man. Biomarkers for nephrotoxicity in early tier I or tier II nonclinical IND-enabling studies should raise an inquiry as to the need to conduct a full auditory function assay early in the game to clear the pipeline with a safer candidate that has a higher probability of continued therapeutic compliance once approved for distribution.

Unrecognized fluid overload during induction therapy increases morbidity in patients with acute promyelocytic leukemia

BACKGROUND

The combination of all-trans retinoic acid (ATRA) and arsenic trioxide (ATO) has proven to be the most effective therapy for patients with acute promyelocytic leukemia (APL). The majority of the morbidity and mortality from APL therapy occur during the induction phase. The objective of the current study was to identify the risk factors associated with transfer to the intensive care unit (ICU) and endotracheal intubation during induction therapy in patients with APL.

METHODS

The authors analyzed the clinical characteristics of 187 patients with newly diagnosed APL who were treated with ATRA and ATO with or without gemtuzumab ozogamicin. The authors documented the percentage change in body weight from baseline to the maximum recorded weight during induction or to the day of ICU transfer.

RESULTS

A total of 18 patients (10%) who initiated therapy with ATRA and ATO on a regular hospital floor required transfer to the ICU after a median of 12 days of induction therapy. The median volume of transfusions was 4350 mL (range, 60-30,750 mL). The volume of transfusions was the main factor associated with the risk of ICU transfer (odds ratio, 4.1; P < .001). Of the 18 patients transferred to the ICU, 10 patients (5%) required intubation. An increase in the total volume of transfusions, increase in weight ≥10% during induction therapy, and a plasma albumin level ≤3.2 g/dL at the time of diagnosis were found to be associated with an increased risk of endotracheal intubation.

CONCLUSIONS

Large volumes of blood product transfusions and unrecognized fluid overload during induction are associated with ICU transfer and endotracheal intubation in patients with APL. These can be prevented by limiting the amount of transfusions, careful monitoring for subtle signs of fluid overload, and early intervention with aggressive diuretic therapy.

Serum and Urine Albumin and Response to Loop Diuretics in Heart Failure

BACKGROUND AND OBJECTIVES

Diuretic resistance can limit successful decongestion of patients with heart failure. Because loop diuretics tightly bind albumin, low serum albumin and high urine albumin can theoretically limit diuretic delivery to the site of action. However, it is unknown if this represents a clinically relevant mechanism of diuretic resistance in human heart failure.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

In total, 208 outpatients with heart failure at the Yale Transitional Care Center undergoing diuretic treatment were studied. Blood and urine chemistries were collected at baseline and 1.5 hours postdiuretic administration. Urine diuretic levels were normalized to urine creatinine and adjusted for diuretic dose administered, and diuretic efficiency was calculated as sodium output per doubling of the loop diuretic dose. Findings were validated in an inpatient heart failure cohort (n=60).

RESULTS

Serum albumin levels in the outpatient cohort ranged from 2.4 to 4.9 g/dl, with a median of 3.7 g/dl (interquartile range, 3.5-4.1). Serum albumin had no association with urinary diuretic delivery (r=-0.05; P=0.52), but higher levels weakly correlated with better diuretic efficiency (r=0.17; P=0.02). However, serum albumin inversely correlated with systemic inflammation as assessed by plasma IL-6 (r=-0.35; P<0.001), and controlling for IL-6 eliminated the diuretic efficiency-serum albumin association (r=0.12; P=0.12). In the inpatient cohort, there was no association between serum albumin and urinary diuretic excretion (r=0.15; P=0.32) or diuretic efficiency (r=-0.16; P=0.25). In the outpatient cohort, 39% of patients had microalbuminuria, and 18% had macroalbuminuria. There was no correlation between albuminuria and diuretic efficiency after adjusting for kidney function (r=-0.02; P=0.89). Results were similar in the inpatient cohort.

CONCLUSIONS

Serum albumin levels were not associated with urinary diuretic excretion, and urinary albumin levels were not associated with diuretic efficiency.

Nephrotic Syndrome: Oedema Formation and Its Treatment With Diuretics

Oedema is a defining element of the nephrotic syndrome. Its' management varies considerably between clinicians, with no national or international clinical guidelines, and hence variable outcomes. Oedema may have serious sequelae such as immobility, skin breakdown and local or systemic infection. Treatment of nephrotic oedema is often of limited efficacy, with frequent side-effects and interactions with other pharmacotherapy. Here, we describe the current paradigms of oedema in nephrosis, including insights into emerging mechanisms such as the role of the abnormal activation of the epithelial sodium channel in the collecting duct. We then discuss the physiological basis for traditional and novel therapies for the treatment of nephrotic oedema. Despite being the cardinal symptom of nephrosis, few clinical studies guide clinicians to the rational use of therapy. This is reflected in the scarcity of publications in this field; it is time to undertake new clinical trials to direct clinical practice.

Efficacy of Long-Term Treatment With Tolvaptan to Prolong the Time Until Dialysis Initiation in Patients With Chronic Kidney Disease and Heart Failure

The short-term effectiveness of tolvaptan (TLV) against heart failure has been established. TLV is known to decrease the worsening of renal function more than loop diuretics. Long-term TLV administration decreases the rate of re-hospitalization in heart failure and prevents deterioration of kidney function. If repeated hospitalization for heart failure can be prevented in patients having concurrent chronic kidney disease (CKD), the period until dialysis initiation may be prolonged. We investigated whether long-term TLV management can extend the period until dialysis initiation in patients with CKD and heart failure. A retrospective, observational study was conducted among patients with CKD stage G4 and G5 admitted because of heart failure between April 2013 and July 2018. They were divided into those with TLV and those without TLV. They were followed up until August 2018 and relevant data was collected. Data from 115 patients (68 men and 47 women), with a mean age of 73.4 ± 11.9 (median 76.0 and IQR 66.5-82.0) years and a mean eGFR of 11.8 ± 5.7 (median 9.9 and IQR 7.5-14.8) mL/min/1.73m² were included in the analysis. Twenty-five patients had received long-term TLV treatment, and 90 had not. Multivariate analysis after adjustment showed that long-term use of TLV significantly lowered the hazard ratio (HR) for time taken to reach dialysis initiation (HR: 0.3286, 95%CI: 0.1282-0.8423, P = 0.0205). Propensity score-matched analysis showed similar results (HR: 0.3220, 95%CI: 0.1107-0.9369, P = 0.0376). In patients with CKD G4 and G5 and heart failure, long-term treatment with TLV can prolong the time until dialysis initiation.

Effects of tolvaptan on urine output in hospitalized heart failure patients with hypoalbuminemia or proteinuria

Hypoalbuminemia is an independent prognostic factor in hospitalization for heart failure (HHF). Hypoalbuminemia or proteinuria is related to resistance to loop diuretics. Tolvaptan is an oral non-peptide, competitive antagonist of vasopressin receptor-2. It has been used for the treatment of volume overload in HHF patients in several Asian countries. Several studies have demonstrated marked improvement in congestion in HHF patients. However, whether tolvaptan is useful for HHF patients with hypoalbuminemia or proteinuria (both of which are related to resistance to loop diuretics) has not been clarified. We examined the diuretic response to tolvaptan in HHF patients with hypoalbuminemia or proteinuria. We defined hypoalbuminemia as a serum level of albumin < 2.6 g/dl. Fifty-one HHF patients who received additional tolvaptan upon therapies with loop diuretics were divided into the hypoalbuminemia group (n = 24) or control group (n = 27). The changes in urine output per day were not different between the two groups [610 (range 100–1032); 742 (505–1247) ml, P = 0.313]. There was no difference in diuretic responses between patients with and without proteinuria. The serum level of albumin did not correlate with changes in urine output per day after tolvaptan treatment (P = 0.276, r = 0.156). Thus, additional administration of tolvaptan elicited a good diuretic response in HHF patients with hypoalbuminemia or proteinuria. These data suggest that tolvaptan might be beneficial for such HHF patients.

Treatment of Disorders of Sodium Balance in Chronic Kidney Disease

Extracellular fluid volume expansion is nearly universal in patients with CKD. Such volume expansion has features similar to the syndrome of heart failure with preserved ejection fraction, which not only leads to symptoms but can also lead to further organ damage. Unique treatment challenges are present in this patient population, including low glomerular filtration, which limits sodium chloride filtration, intrinsic tubule predisposition to sodium chloride retention, and proteinuria. In addition, pharmacokinetic considerations alter the disposition of diuretics in patients with CKD and nephrotic syndrome. Maintaining extracellular fluid volume near to normal is often necessary for hypertension treatment in this population, but it may also help prevent progressive cardiovascular and kidney damage. Although powerful diuretics can often accomplish this goal, this often comes at a cost of competing adverse effects. An approach to reduce extracellular fluid volume while avoiding adverse effects, therefore, requires a nuanced yet aggressive therapeutic approach.

Prevention of acute kidney injury and protection of renal function in the intensive care unit: update 2017 : Expert opinion of the Working Group on Prevention, AKI section, European Society of Intensive Care Medicine

BACKGROUND

Acute kidney injury (AKI) in the intensive care unit is associated with significant mortality and morbidity.

OBJECTIVES

To determine and update previous recommendations for the prevention of AKI, specifically the role of fluids, diuretics, inotropes, vasopressors/vasodilators, hormonal and nutritional interventions, sedatives, statins, remote ischaemic preconditioning and care bundles.

METHOD

A systematic search of the literature was performed for studies published between 1966 and March 2017 using these potential protective strategies in adult patients at risk of AKI. The following clinical conditions were considered: major surgery, critical illness, sepsis, shock, exposure to potentially nephrotoxic drugs and radiocontrast. Clinical endpoints included incidence or grade of AKI, the need for renal replacement therapy and mortality. Studies were graded according to the international GRADE system.

RESULTS

We formulated 12 recommendations, 13 suggestions and seven best practice statements. The few strong recommendations with high-level evidence are mostly against the intervention in question (starches, low-dose dopamine, statins in cardiac surgery). Strong recommendations with lower-level evidence include controlled fluid resuscitation with crystalloids, avoiding fluid overload, titration of norepinephrine to a target MAP of 65-70 mmHg (unless chronic hypertension) and not using diuretics or levosimendan for kidney protection solely.

CONCLUSION

The results of recent randomised controlled trials have allowed the formulation of new recommendations and/or increase the strength of previous recommendations. On the other hand, in many domains the available evidence remains insufficient, resulting from the limited quality of the clinical trials and the poor reporting of kidney outcomes.

Effects of tolvaptan in patients with chronic kidney disease and chronic heart failure

BACKGROUND

Tolvaptan, a vasopressin V₂ receptor blocker, has a diuretic effect for patients with heart failure. However, there were a few data concerning the effects of tolvaptan in patients with chronic kidney disease (CKD).

METHODS

We retrospectively analyzed 21 patients with chronic heart failure and CKD. Tolvaptan was co-administered with other diuretics in-use, every day. We compared clinical parameters before and after the treatments with tolvaptan. Furthermore, we examined the correlations between baseline data and the change of body weight.

RESULTS

Tolvaptan decreased the body weight and increased the urine volume (p = 0.001). The urine osmolality significantly decreased throughout the study period. Urinary Na/Cr ratio and FENa changed significantly after 4 h, and more remarkable after 8 h (p = 0.003, both). Serum creatinine increased slightly after 1 week of treatment (p = 0.012). The alteration of body weight within the study period correlated negatively with the baseline urine osmolality (r = -0.479, p = 0.038), the baseline urine volume (r = -0.48, p = 0.028), and the baseline inferior vena cava diameter (IVCD) (r = -0.622, p = 0.017). Hyponatremia was improved to the normal value, and the augmentations of the sodium concentration were negatively associated with the basal sodium levels (p = 0.01, r = -0.546).

CONCLUSIONS

Tolvaptan is effective in increasing diuresis and improved hyponatremia, even in patients with CKD. The baseline urine osmolality, urine volume, and IVCD may be useful predictors for diuretic effects of tolvaptan.

A Practical Comprehensive Approach to Management of Acute Decompensated Heart Failure

Heart failure (HF) has a high incidence and prevalence in the USA and worldwide. It is a very common cause of significant morbidity and mortality with serious cost implications on the US health sector. The primary focus of this review is to synthesize an effective comprehensive care plan for patients in acute decompensated heart failure (ADHF) based on the most current evidence available. It begins with a brief overview of the pathophysiology, clinical presentation and evaluation of patients in ADHF. It then reviews management goals and treatment guidelines, with emphasis on challenges presented by diuretic resistance and worsening renal function (WRF). It provides information on recognition of advanced HF even during acute presentation, estimation of prognosis and proactive identification of patients that will benefit from mechanical cardiac devices, transplantation and palliative care/hospice. In addition, it presents strategies to address the problem of readmissions, which is an ominous prognostic factor with enormous economic burden.

Albuminuria confers renal resistance to loop diuretics via the stimulation of NLRP3 inflammasome/prostaglandin signaling in thick ascending limb

Renal resistance to loop diuretics is a frequent complication in a number of kidney disease patients with elusive mechanism. Employing human renal biopsy specimens, albumin overload mouse model, and primary cultures of mouse renal tubular cells, albuminuria effect on NKCC2 expression and function and the underlying mechanisms were investigated. In the renal biopsy specimens of albuminuric patients, we found that NKCC2 was significantly downregulated with a negative correlation with albuminuria severity as examined by immunohistochemistry. Meanwhile, NLRP3 and mPGES-1 were stimulated in NKCC2 positive tubules (thick ascending limb, TAL) paralleled with increased urinary PGE2 excretion. To examine the role of albuminuria in the downregulation of NKCC2 and the potential role of NLRP3/prostaglandin signaling in NKCC2 downregulation, an albumin overload mouse model was employed. Interestingly, we discovered that albuminuria downregulated NKCC2 protein expression in murine kidney and impaired the renal response to loop diuretic furosemide. Specifically, albuminuria suppressed NKCC2 expression and function through NLRP3/prostaglandin dependent signaling in TAL. In primary cultures of renal tubular cells, albumin directly reduced NKCC2 but enhanced NLRP3, COX-2, and mPGES-1 expression. These novel findings demonstrated that albuminuria is of importance in mediating the renal resistance to loop diuretics via NLRP3/prostaglandin signaling-dependent NKCC2 downregulation in TAL. This may also offer novel, effective targets for dealing with the resistance of loop diuretics in proteinuric renal diseases.

Clinical Implications of Serum Albumin Levels in Acute Heart Failure: Insights From DOSE-AHF and ROSE-AHF

BACKGROUND

Hypoalbuminemia is common in patients with chronic heart failure and, as a marker of disease severity, is associated with an adverse prognosis. Whether hypoalbuminemia contributes to (or is associated with) worse outcomes in acute heart failure (AHF) is unclear. We sought to determine the implications of low serum albumin in patients receiving decongestive therapies for AHF.

METHODS AND RESULTS

Baseline serum albumin levels were measured in 456 AHF subjects randomized in the DOSE-AHF and ROSE-AHF trials. We assessed the relationship between admission albumin levels (both as a continuous variable and stratified by median albumin [≥3.5 g/dL]) and worsening renal function (WRF), worsening heart failure (WHF), and clinical decongestion by 72 hours; 7-day cardiorenal biomarkers; and post-discharge outcomes. The mean baseline albumin level was 3.5 ± 0.5 g/dL. Albumin was not associated with WRF, WHF, or clinical decongestion by 72 hours. Furthermore, there was no association between continuous albumin levels and symptom change according to visual analog scale or weight change by 72 hours. Albumin was not associated with 60-day mortality, rehospitalization, or unscheduled emergency room visits.

CONCLUSIONS

Baseline serum albumin levels were not associated with short-term clinical outcomes for AHF patients undergoing decongestive therapies. These data suggest that serum albumin may not be a helpful tool to guide decongestion strategies.

Furosemide Pharmacokinetics in Adult Rats become Abnormal with an Adverse Intrauterine Environment and Modulated by a Post-Weaning High-Fat Diet

Adult individuals born with intrauterine growth restriction (IUGR) have physiological maladaptations that significantly increase risk of chronic disease. We suggested that such abnormalities in organ function would alter pharmacokinetics throughout life, exacerbated by environmental mismatch. Pregnant and lactating rats were fed either a purified control diet (18% protein) or low-protein diet (9% protein) to produce IUGR offspring. Offspring were weaned onto either laboratory chow (11% fat) or high-fat diet (45% fat). Adult offspring (5 months old) were dosed with furosemide (10 mg/kg i.p.) and serum and urine collected. The overall exposure profile in IUGR males was significantly reduced due to a ~35% increase in both clearance and volume of distribution. Females appeared resistant to the IUGR phenotype. The effects of the high-fat diet trended in the opposite direction to that of IUGR, with increased drug exposure due to decreases in both clearance (31% males, 46% females) and volume of distribution (24% males, 44% females), with a 10% longer half-life in both genders. The alterations in furosemide pharmacokinetics and pharmacodynamics were explained by changes in the expression of renal organic anion transporters 1 and 3, and sodium-potassium-chloride cotransporter-2. In summary, this study suggests that IUGR and diet interact to produce subpopulations with similar body-weights but dissimilar pharmacokinetic profiles; this underlines the limitation of one-size-fits-all dosing which does not account for physiological differences in body composition resulting from IUGR and diet.

Albumin and Furosemide Combination for Management of Edema in Nephrotic Syndrome: A Review of Clinical Studies

The treatment of edema in patients with nephrotic syndrome is generally managed by dietary sodium restriction and loop diuretics. However, edema does not improve in some patients despite adequate sodium restriction and maximal dose of diuretics. In such patients, combination of albumin and a loop diuretic may improve edema by diuresis and natriuresis. The response to this combination of albumin and a diuretic has not been observed in all studies. The purpose of this review is to discuss the physiology of diuresis and natriuresis of this combination therapy, and provide a brief summary of various studies that have used albumin and a loop diuretic to improve diuretic-resistant edema. Also, the review suggests various reasons for not observing similar results by various investigators.

Clinical Use of Diuretics in Heart Failure, Cirrhosis, and Nephrotic Syndrome

Diuretics play significant role in pharmacology and treatment options in medicine. This paper aims to review and evaluate the clinical use of diuretics in conditions that lead to fluid overload in the body such as cardiac failure, cirrhosis, and nephrotic syndrome. To know the principles of treatment it is essential to understand the underlying pathophysiological mechanisms that cause the need of diuresis in the human body. Various classes of diuretics exist, each having a unique mode of action. A systemic approach for management is recommended based on the current guidelines, starting from thiazides and proceeding to loop diuretics. The first condition for discussion in the paper is cardiac failure. Treatment of ascites in liver cirrhosis with spironolactone as the primary agent is highlighted with further therapeutic options. Lastly, management choices for nephrotic syndrome are discussed and recommended beginning from basic sodium restriction to combined diuretic therapies. Major side effects are discussed.

Can serum albumin level affect the pharmacological action of tolvaptan in patients with liver cirrhosis? A post hoc analysis of previous clinical trials in Japan

BACKGROUND

Patients with hypoalbuminemia often fail to respond to increased doses of loop diuretics. We therefore performed a post hoc analysis to investigate the pharmacological action of tolvaptan and whether it is dependent on the serum albumin level.

METHODS

This analysis was based on four previous clinical trials of tolvaptan in patients with liver cirrhosis who exhibited insufficient response to conventional diuretics. We analyzed the correlation between the change in the initial 24-h cumulative urine volume from baseline and the serum albumin level at baseline, and assessed potential predictive factors of response to tolvaptan.

RESULTS

The correlation coefficient was 0.029 in the placebo group and -0.112 in the 7.5 mg tolvaptan group of patients with liver cirrhosis. Administration of tolvaptan provoked a stable response regardless of the serum albumin level. Tolvaptan use was identified as a significant predictor of pharmacological action, and was shown to change the initial urine volume by 885 mL (P < 0.0001) in liver cirrhosis patients.

CONCLUSIONS

In this post hoc analysis, tolvaptan increased the initial urine volume from baseline regardless of serum albumin levels. Use of tolvaptan as an add-on therapy to loop diuretics can be considered an optimal therapeutic option in patients with insufficient response to loop diuretics.

Sclederma of Poria cocos exerts its diuretic effect via suppression of renal aquaporin-2 expression in rats with chronic heart failure

ETHNOPHARMACOLOGICAL RELEVANCE

Sclederma of Poria cocos (Hoelen) has been used as a diuretic in traditional Asian medicine. However, the underlying mechanism by which Sclederma of Poria cocos (hoelen) exerts its diuretic effect has not been well identified. The aim of the present study was to evaluate the effects of Sclederma of Poria cocos (hoelen) in rats with chronic heart failure (CHF) induced by acute myocardial infarction and to investigate the underlying mechanisms.

MATERIALS AND METHODS

An aqueous extract of Sclederma of Poria cocos (hoelen) (2.4 g/kg/d, 1.2 g/kg/d or 0.6 g/kg/d) or furosemide (20 mg/kg/d) was administered orally to male Sprague-Dawley rats starting on the day of coronary ligation. The urine output of all rats was quantified and collected every day for 1 or 4 weeks. The expression of aquaporin-2 (AQP2) was examined after treatment for 1 or 4 weeks.

RESULTS

Urinary output increased significantly and urinary osmolality decreased after oral administration of Sclederma of Poria cocos (hoelen) for both 1 and 4 weeks. Sclederma of Poria cocos (hoelen) caused less electrolyte disorder than furosemide. Furthermore, Sclederma of Poria cocos (hoelen) reduced the levels of plasma BNP in CHF rats, whereas furosemide had no effect. Importantly, both mRNA and protein expression of AQP2 were down-regulated and urinary excretion of AQP2 was decreased after administration of Sclederma of Poria cocos (hoelen) to CHF rats. Similarly, Sclederma of Poria cocos (hoelen) reduced plasma arginine vasopressin (AVP) level and down-regulated vasopressin type 2 receptor (V2R) mRNA expression.

CONCLUSIONS

Sclederma of Poria cocos (hoelen) exerts its diuretic effect and improves cardiac function in CHF rats via the AVP-V2R-AQP2 axis.

Tolvaptan for the treatment of liver cirrhosis oedema

No alternative therapeutic option exists if liver cirrhosis patients have insufficient response to conventional diuretics and/or experience conventional diuretic-related adverse events. In 2013, tolvaptan (7.5 mg/day), an arginine vasopressin V2 receptor antagonist, was approved in Japan for the treatment of liver cirrhosis with oedema. Short-term use of tolvaptan produced decreases in body weight, reduction in ascites volume and increases in urine volume when compared to placebo, despite the use of conventional diuretics. Additionally, approximately 60% of patients with oedema-related symptoms improved. Low-dose tolvaptan, 3.75 mg, was also efficacious. Even in patients with low serum albumin (<2.5 g/dL), decrease in body weight was greater with tolvaptan than with placebo. For future research, the efficacy and safety of lower tolvaptan doses for the treatment of liver cirrhosis patients with oedema should be confirmed in Japan. The results of this research could be used as an indicator or a guideline for physicians around the world.

The Refit model for end-stage liver disease-Na is not a better predictor of mortality than the Refit model for end-stage liver disease in patients with cirrhosis and ascites

Background/Aims

The modification of the Model for End-Stage Liver Disease (MELD) scoring system (Refit MELD) and the modification of MELD-Na (Refit MELDNa), which optimized the MELD coefficients, were published in 2011. We aimed to validate the superiority of the Refit MELDNa over the Refit MELD for the prediction of 3-month mortality in Korean patients with cirrhosis and ascites.

Methods

We reviewed the medical records of patients admitted with hepatic cirrhosis and ascites to the Konkuk University Hospital between January 2006 and December 2011. The Refit MELD and Refit MELDNa were compared using the predictive value of the 3-month mortality, as assessed by the Child-Pugh score.

Results

In total, 530 patients were enrolled, 87 of whom died within 3 months. Alcohol was the most common etiology of their cirrhosis (n=271, 51.1%), and the most common cause of death was variceal bleeding (n=20, 23%). The areas under the receiver operating curve (AUROCs) for the Child-Pugh, Refit MELD, and Refit MELDNa scores were 0.754, 0.791, and 0.764 respectively; the corresponding values when the analysis was performed only in patients with persistent ascites (n=115) were 0.725, 0.804, and 0.796, respectively. The significant difference found among the Child-Pugh, Refit MELD, and Refit MELDNa scores was between the Child-Pugh score and Refit MELD in patients with persistent ascites (P=0.039).

Conclusions

Refit MELD and Refit MELDNa exhibited good predictability for 3-month mortality in patients with cirrhosis and ascites. However, Refit MELDNa was not found to be a better predictor than Refit MELD, despite the known relationship between hyponatremia and mortality in cirrhotic patients with ascites.

Pharmacokinetics of drugs in mutant Nagase analbuminemic rats and responses to select diuretics

OBJECTIVES

To report (1) the pharmacokinetics of drugs that are mainly metabolized via hepatic cytochrome P450s (CYPs) or mainly excreted via the urine and bile, (2) the mechanism for the urinary excretion of drugs (such as glomerular filtration or renal active secretion or re-absorption), and (3) the diuretic effect of some loop diuretics in mutant Nagase analbuminaemic rats (NARs), an animal model for human familial analbuminaemia based on the pharmacokinetics of drugs reported in the literatures.

KEY FINDINGS

In NARs, the changes in the time-averaged non-renal clearances (CL(NR)s) of drugs that are mainly metabolized via CYPs were explained in terms of changes in the hepatic intrinsic clearance (mainly because of changes in CYPs), free (unbound) fractions of drugs in the plasma (fp) and hepatic blood-flow rate (QH) depending on the hepatic excretion ratios of drugs.

SUMMARY

The CL(NR) changes of drugs mainly metabolized via hepatic CYPs can be sufficiently explained by the three earlier mentioned factors. The plasma albumin (furosemide) or globulin (azosemide, bumetanide and torasemide) binding affects their diuretic effects.

Co-administration of furosemide with albumin for overcoming diuretic resistance in patients with hypoalbuminemia: a meta-analysis

PURPOSE

To systematically review clinical studies of co-administration of albumin and loop diuretics in hypoalbuminemic patients as a strategy to overcome diuretic resistance.

MATERIALS AND METHODS

Systematic search of electronic databases up to October 2012. We included randomized clinical trials of adults with hypoalbuminemia, comparing co-administration of loop diuretics and albumin versus loop diuretics alone. Quantitative data were synthesized with meta-analytic techniques for clinical, surrogate (urinary volume and urinary sodium excretion) and intermediate (pharmacokinetic and hemodynamic parameters) outcomes.

RESULTS

Ten studies were included, of which 8 trials with crossover design were synthesized with meta-analysis. A statistically significant increase in the amount of urine volume (increment of 231 mL [95% confidence interval 135.5-326.5]) and sodium excreted (15.9 mEq [4.9-26.8]) at 8 hours were found in favor of co-administration of albumin and furosemide. These differences were no longer statistically significant at 24 hours. Meta-analyses for intermediate outcomes (ie, furosemide excretion, distribution volume etc.) did not reveal statistically significant differences.

CONCLUSIONS

Synthesis of a heterogeneous body of evidence shows transient effects of modest clinical significance for co-administration of albumin with furosemide in hypoalbuminemic patients. Pragmatic, large-scale randomized studies are needed to delineate the role of this strategy.

The Effect of Continuous Infusion Loop Diuretics in Patients With Acute Decompensated Heart Failure With Hypoalbuminemia

Purpose:

Hypoalbuminemia is believed to decrease diuretic effectiveness and contribute to diuretic resistance that is observed in patients with nephrotic syndrome. Hypoalbuminemia is also seen in patients with acute decompensated heart failure (ADHF). However, the role of hypoalbuminemia on the effectiveness of continuous infusion diuretics in patients with ADHF is not known.

Methods:

To evaluate hypoalbuminemia (albumin ≤3 g/dL) and diuretic effectiveness, we performed a retrospective study in 162 patients admitted to a tertiary care center for treatment of ADHF over a 3-year period. All patients received continuous infusion diuretic for at least a 2-day time period.

Results:

A total of 33 patients were determined to have hypoalbuminemia. Average net urine output over a 2-day study period was similar between patients with and without hypoalbuminemia (−1462 ± 1734 vs −1233 ± 1560 mL, P = .46, respectively). In addition, diuretic doses (furosemide equivalent/24 hours) were similar between the 2 groups (788 ± 671 vs 778 ± 713 mg, P = .91, respectively) as was baseline serum creatinine (1.6 ± 0.6 vs 1.6 ± 0.6 mg/dL, P = .5, respectively).

Conclusion:

Overall, hypoalbuminemia did not decrease the diuretic effectiveness when measured by the net urine output in patients receiving continuous infusion diuretics for the treatment of ADHF.

The added-up albumin enhances the diuretic effect of furosemide in patients with hypoalbuminemic chronic kidney disease: a randomized controlled study

Background

Chronic kidney disease (CKD) with edema is a common clinical problem resulting from defects in water and solute excretion. Furosemide is the drug of choice for treatment. In theory, good perfusion and albumin are required for the furosemide to be secreted at the tubular lumen. Thus, in the situation of low glomerular filtration rate (GFR) and hypoalbuminemia, the efficacy of furosemide alone might be limited. There has been no study to validate the effectiveness of the combination of furosemide and albumin in this condition.

Methods

We conducted a randomized controlled crossover study to compare the efficacy of diuretics between furosemide alone and the combination of furosemide plus albumin in stable hypoalbuminemic CKD patients by measuring urine output and sodium. The baseline urine output/sodium at 6 and 24 hours were recorded. The increment of urine output/sodium after treatment at 6 and 24 hours were calculated by using post-treatment minus baseline urine output/sodium at the corresponding period.

Results

Twenty-four CKD patients (GFR = 31.0 ± 13.8 mL/min) with hypoalbuminemia (2.98 ± 0.30 g/dL) were enrolled. At 6 hours, there were significant differences in the increment of urine volume (0.47 ± 0.40 vs 0.67 ± 0.31 L, P < 0.02) and urine sodium (37.5 ± 29.3 vs 55.0 ± 26.7 mEq, P < 0.01) between treatment with furosemide alone and with furosemide plus albumin. However, at 24 hours, there were no significant differences in the increment of urine volume (0.49 ± 0.47 vs 0.59 ± 0.50 L, P = 0.46) and urine sodium (65.3 ± 47.5 vs 76.1 ± 50.1 mEq, P = 0.32) between the two groups.

Conclusion

The combination of furosemide and albumin has a superior short-term efficacy over furosemide alone in enhancing water and sodium diuresis in hypoalbuminemic CKD patients.

Trial registration

The Australian New Zealand Clinical Trials Registration (ANZCTR12611000480987)

Effect of albumin on diuretic response to furosemide in patients with hypoalbuminemia

BACKGROUND

Albumin is broadly prescribed for critically ill patients although it does not have a mortality benefit over crystalloids. One common use of albumin is to promote diuresis. Objectives To compare urine output in patients treated with furosemide with and without albumin and to assess other variables possibly associated with enhanced diuresis.

METHODS

A retrospective study was conducted on patients in a medical intensive care unit who received furosemide therapy as a continuous infusion with and without 25% albumin for more than 6 hours. Primary end points were urine output and net fluid loss.

RESULTS

A total of 31 patients were included in the final analysis. Mean urine output in patients treated with furosemide alone did not differ significantly from output in patients treated with furo-semide plus albumin at 6, 24, and 48 hours: mean output, 1119 (SD, 597) mL vs 1201 (SD, 612) mL, P = .56; 4323 (SD, 1717) mL vs 4615 (SD, 1741) mL, P = .42; and 7563 mL (SD, 2766) vs 7432 (SD, 2324) mL, P = .94, respectively. Additionally, net fluid loss did not differ significantly between the 2 groups at 6, 24, and 48 hours. Higher concentrations of serum albumin did not improve urine output. The only independent variable significantly associated with enhanced urine output at 24 and 48 hours was increased fluid intake.

CONCLUSION

Addition of albumin to a furosemide infusion did not enhance diuresis obtained with furosemide alone in critically ill patients.

Update in diuretic therapy: clinical pharmacology

All diuretics except spironolactone exert their effects from the lumen of the nephron. Thus, to exert an effect, they must reach the urine. Pharmacokinetics (PK) describes this access. Different edematous disorders can affect access to this site of action and therein affect response to a diuretic. In addition, once a diuretic reaches the site of action, a response ensues. The characteristics of this response that can be affected by a patient's clinical condition are described by the pharmacodynamics (PD) of a diuretic. To understand the mechanisms of abnormal response to a diuretic one must dissect its PK and PD in different edematous disorders. For example, in patients with renal insufficiency, the mechanism of poor diuretic response is PK. In contrast, in patients with cirrhosis or in those with congestive heart failure, it is PD. In patients with nephrotic syndrome, both PK and PD are operative. These different mechanisms mandate differences in therapeutic strategy, as explained in this article.

[Serum albumin and heart failure: recent advances on a new paradigm]

Hypoalbuminemia is a common condition in patients with heart failure and is mainly related to the malnutrition-inflammation complex syndrome. Other causal factors can be involved, which include hemodilution, liver dysfunction, increased transcapillary escape rate, renal and enteral loss. Evidence is growing that hypoalbuminemia independently predicts incident heart failure in patients with end-stage renal disease and elderly patients, as well as mortality in patients with heart failure regardless of left ventricular ejection fraction and clinical presentation. Hypoalbuminemia induces a low plasma oncotic pressure, which facilitates pulmonary edema in patients without critical increase in pulmonary capillary hydrostatic pressures. Hypoalbuminemia may also contribute to the progression of heart failure by favoring myocardial edema, volume overload, diuretic resistance and exacerbation of oxidative stress and inflammation. If relevant, removal of subclinical excess of fluid and renutrition may be indicated in patients with heart failure and hypoalbuminemia. Additional research is warranted to determine the specific role of serum albumin in the pathophysiologic process of heart failure and the potential benefits of targeted therapeutic interventions.

The cardiorenal syndrome: a review

Cardiorenal syndrome (CRS) is the umbrella term used to describe clinical conditions in which cardiac and renal dysfunctions coexist. Much has been written on this subject, but underlying pathophysiological mechanisms continue to be unravelled and implications for management continue to be debated. A classification system—incorporating five subtypes—has recently been proposed though it has yet to permeate into day-to-day clinical practice. CRS has garnered much attention from both the cardiological and nephrological communities since the condition is associated with significant morbidity and mortality. Renal dysfunction is highly prevalent amongst patients with heart failure and has been shown to be as powerful and independent a marker of adverse prognosis as ejection fraction. Similarly, patients with renal failure are considerably more likely to suffer cardiovascular disease than matched subjects from the general population. This paper begins by reviewing the epidemiology and classification of CRS before going on to consider the different pathological mechanisms underlying cardiorenal dysfunction. We then focus on management strategies and conclude by discussing future directions in the diagnosis and management of patients suffering with CRS.