Metabolic and toxicological considerations for diuretic therapy in patients with acute heart failure

Tidal peritoneal dialysis versus ultrafiltration in type 1 cardiorenal syndrome: A prospective randomized study

Background:

Ultrafiltration is an alternative strategy to diuretic therapy for the treatment of patients with acute decompensated heart failure. Little is known about the efficacy and safety of peritoneal dialysis in patients with acute decompensated heart failure complicated by acute cardiorenal syndrome.

Methods:

We randomly assigned a total of 88 patients with type 1 acute cardiorenal syndrome to a strategy of ultrafiltration therapy (44 patients) or tidal peritoneal dialysis (44 patients). The primary endpoint was the change from baseline in the serum creatinine level and left ventricular function represented as ejection fraction, as assessed 72 and 120 h after random assignment. Patients were followed for 90 days after discharge from the hospital.

Results:

Ultrafiltration therapy was inferior to tidal peritoneal dialysis therapy with respect to the primary endpoint of the change in the serum creatinine levels at 72 and 120 h ( p = 0.041) and ejection fraction at 72 and 120 h after enrollment ( p = 0.044 and p = 0.032), owing to both an increase in the creatinine level in the ultrafiltration therapy group and a decrease in its level in the tidal peritoneal dialysis group. At 120 h, the mean change in the creatinine level was 1.4 ± 0.5 mg/dL in the ultrafiltration therapy group, as compared with 2.4 ± 1.3 mg/dL in the tidal peritoneal dialysis group ( p = 0.023). At 72 and 120 h, there was a significant difference in weight loss between patients in the ultrafiltration therapy group and those in the tidal peritoneal dialysis group ( p = 0.025). Net fluid loss was also greater in tidal peritoneal dialysis patients ( p = 0.018). Adverse events were more observed in the ultrafiltration therapy group ( p = 0.007). At 90 days post-discharge, tidal peritoneal dialysis patients had fewer rehospitalization for heart failure (14.3% vs 32.5%, p = 0.022).

Conclusion:

Tidal peritoneal dialysis is a safe and effective means for removing toxins and large quantities of excess fluid from patients with intractable heart failure. In patients with cardiorenal syndrome type 1, the use of tidal peritoneal dialysis was superior to ultrafiltration therapy for the preservation of renal function, improvement of cardiac function, and net fluid loss. Ultrafiltration therapy was associated with a higher rate of adverse events.

Continuous infusion of furosemide versus intermittent boluses in acute decompensated heart failure: Effect on thoracic fluid content

INTRODUCTION

The administration of loop diuretics in the management of acute decompensated heart failure (ADHF) whether IV boluses or continuous infusion is still controversial. We intended to evaluate differences between the two administration routes on the thoracic fluid content (TFC) and the renal functions.

METHODS

Sixty patients with ADHF admitted to the critical care medicine department (Cairo University, Egypt) were initially enrolled in the study. Twenty patients were excluded due to EF > 40%, myocardial infarction within 30 days, and baseline serum creatinine level > 4.0 mg/dL. Furosemide (120 mg/day) was given to the remaining 40 pts who continued the study after 1:1 randomization to either continuous infusion (group-I, 20 pts) or three equal intermittent daily doses (group-II, 20 pts). Subsequent dose titration was allowed after 24 h, but not earlier, according to patient's response. No other diuretic medications were allowed. All patients were daily evaluated for NYHA class, urine output, TFC, body weight, serum K+, and renal chemistry.

RESULTS

The median age (Q1-Q3) was 54.5 (43.8-63.8) years old with 24 (60%) males. Apart from TFC which was significantly higher in group-I, the admission demographic, clinical, laboratory and co-morbid conditions were similar in both groups. There was statistically insignificant tendency for increased urine output during the 1st and 2nd days in group-I compared to group-II (p = .08). The body weight was decreased during the 1st day by 2 (1.5-2.5) kg in group-I compared to 1.5 (1-2) kg in group-II, (p = .03). These changes became insignificant during the 2nd day (p = .4). The decrease of TFC was significantly higher in group-I than in group-II [10 (6.3-14.5) vs 7 (3.3-9.8) kΩ-1 during the first day and 8 (6-11) vs 6 (3.3-8.5) kΩ-1 during the second day in groups-I&II respectively, P = .02 for both]. There was similar NYHA class improvement in both groups (p = .7). The serum creatinine was increased by 0.2 (0.1-0.5) vs 0 (-0.1 to 0.2) mg% and the CrCl was decreased by 7.4 (4.5-12.3) vs 3.1 (0.2-8.8) ml/min in groups-I&II respectively (p = .009 and .02 respectively).

CONCLUSIONS

We concluded that continuous furosemide infusion in ADHF might cause greater weight loss and more decrease in TFC with no symptomatic improvement and possibly with more nephrotoxic effect.

Imaging Congestion With a Pocket Ultrasound Device: Prognostic Implications in Patients With Chronic Heart Failure

BACKGROUND

Venous congestion is common in patients with chronic heart failure (HF). We used a pocket-sized ultrasound imaging device (PID) to assess the patients' congestive status and related our findings to prognosis.

METHODS AND RESULTS

One hundred four consecutive outpatients from an HF outpatient clinic were studied. Interstitial lung water (ILW), pleural effusion (PE), and the diameter of the inferior vena cava (VCI) were assessed with the use of a PID. ILW was assessed by demonstration of B-lines (comet tail artifact (CTA). Out of the 104 patients, 28 had CTA and 8 had PE. Median VCI diameter was 18 mm (interquartile range 14-22 mm). Each of these parameters correlated weakly (r = 0.26-0.37; P < .05) with the HF biomarker N-terminal pro-B-type natriuretic peptide (NT-proBNP). During the median follow-up time of 530 days, 18 hospitalizations and 14 deaths were registered. Findings of CTA, PE, or both increased the risk of death or hospitalization (hazard ratio 3-4; P < .05). After adjustment for age, cardiac systolic function, and NT-proBNP, this difference remained significant for CTA alone and CTA + PE combined, but not for PE alone.

CONCLUSIONS

With the use of a handheld ultrasound device, signs of pulmonary congestion could be demonstrated. When found, these had a significant prognostic impact in clinically stable HF.

Indications and management of mechanical fluid removal in critical illness

BACKGROUND

The Acute Dialysis Quality Initiative (ADQI) dedicated its Twelfth Consensus Conference (2013) to all aspects of fluid therapy, including the management of fluid overload (FO). The aim of the working subgroup 'Mechanical fluid removal' was to review the indications, prescription, and management of mechanical fluid removal within the broad context of fluid management of critically ill patients.

METHODS

The working group developed a list of preliminary questions and objectives and performed a modified Delphi analysis of the existing literature. Relevant studies were identified through a literature search using the MEDLINE database and bibliographies of relevant research and review articles.

RESULTS

After review of the existing literature, the group agreed the following consensus statements: (i) in critically ill patients with FO and with failure of or inadequate response to pharmacological therapy, mechanical fluid removal should be considered as a therapy to optimize fluid balance. (ii) When using mechanical fluid removal or management, targets for rate of fluid removal and net fluid removal should be based upon the overall fluid balance of the patient and also physiological variables, individualized, and reassessed frequently. (iii) More research on the role and practice of mechanical fluid removal in critically ill patients not meeting fluid balance goals (including in children) is necessary.

CONCLUSION

Mechanical fluid removal should be considered as a therapy for FO, but more research is necessary to determine its exact role and clinical application.

Continuous versus bolus intermittent loop diuretic infusion in acutely decompensated heart failure: a prospective randomized trial

Introduction

Intravenous loop diuretics are a cornerstone of therapy in acutely decompensated heart failure (ADHF). We sought to determine if there are any differences in clinical outcomes between intravenous bolus and continuous infusion of loop diuretics.

Methods

Subjects with ADHF within 12 hours of hospital admission were randomly assigned to continuous infusion or twice daily bolus therapy with furosemide. There were three co-primary endpoints assessed from admission to discharge: the mean paired changes in serum creatinine, estimated glomerular filtration rate (eGFR), and reduction in B-type natriuretic peptide (BNP). Secondary endpoints included the rate of acute kidney injury (AKI), change in body weight and six months follow-up evaluation after discharge.

Results

A total of 43 received a continuous infusion and 39 were assigned to bolus treatment. At discharge, the mean change in serum creatinine was higher (+0.8 ± 0.4 versus -0.8 ± 0.3 mg/dl P <0.01), and eGFR was lower (-9 ± 7 versus +5 ± 6 ml/min/1.73 m²P <0.05) in the continuous arm. There was no significant difference in the degree of weight loss (-4.1 ± 1.9 versus -3.5 ± 2.4 kg P = 0.23). The continuous infusion arm had a greater reduction in BNP over the hospital course, (-576 ± 655 versus -181 ± 527 pg/ml P = 0.02). The rates of AKI were comparable (22% and 15% P = 0.3) between the two groups. There was more frequent use of hypertonic saline solutions for hyponatremia (33% versus 18% P <0.01), intravenous dopamine infusions (35% versus 23% P = 0.02), and the hospital length of stay was longer in the continuous infusion group (14. 3 ± 5 versus 11.5 ± 4 days, P <0.03). At 6 months there were higher rates of re-admission or death in the continuous infusion group, 58% versus 23%, (P = 0.001) and this mode of treatment independently associated with this outcome after adjusting for baseline and intermediate variables (adjusted hazard ratio = 2.57, 95% confidence interval, 1.01 to 6.58 P = 0.04).

Conclusions

In the setting of ADHF, continuous infusion of loop diuretics resulted in greater reductions in BNP from admission to discharge. However, this appeared to occur at the consequence of worsened renal filtration function, use of additional treatment, and higher rates of rehospitalization or death at six months.

Trial registration

ClinicalTrials.gov NCT01441245. Registered 23 September 2011.

The hemodynamic and nonhemodynamic crosstalk in cardiorenal syndrome type 1

The organ crosstalk can be defined as the complex biological communication and feedback between distant organs mediated via cellular, molecular, neural, endocrine and paracrine factors. In the normal state, this crosstalk helps to maintain homeostasis and optimal functioning of the human body. However, during disease states this very crosstalk can carry over the influence of the diseased organ to initiate and perpetuate structural and functional dysfunction in the other organs. Heart performance and kidney function are intimately interconnected, and the communication between these organs occurs through a variety of bidirectional pathways. The cardiorenal syndrome (CRS) is defined as a complex pathophysiological disorder of the heart and the kidneys whereby acute or chronic dysfunction in one organ may induce acute or chronic dysfunction in the other organ. In particular, CRS type 1 is characterized by a rapid worsening of the cardiac function leading to acute kidney injury. This clinical condition requires a more complex management given its more complicated hospital course and higher mortality. A lot of research has emerged in the last years trying to explain the pathophysiology of CRS type 1 which remains in part poorly understood. This review primarily focuses on the hemodynamic and nonhemodynamic mechanisms involved in this syndrome.

Loop diuretic strategies in patients with acute decompensated heart failure: a meta-analysis of randomized controlled trials

PURPOSE

The safety and efficacy of continuous infusion vs bolus injection of intravenous loop diuretics to treat acute decompensated heart failure were debated. Our aim is to compare the administration routes of diuretics in hospitalized patients with acute decompensated heart failure.

METHODS

A systematic review and meta-analysis of randomized controlled trials was performed to evaluate the effects of continuous infusion vs bolus administration of loop diuretics in patients with acute decompensated heart failure. The primary end points were urine outputs, body weight loss, all causes of mortality, and death from cardiovascular causes. Secondary end points were electrolyte imbalance, change in creatinine levels, tinnitus or hearing loss, and days of hospitalization.

RESULTS

Ten randomized controlled trials with 518 patients were identified. Continuous infusion of diuretics was associated with a significantly greater weight loss (weighted mean difference, 0.78; 95% confidence interval, 0.03-1.54) compared with bolus injection. Urine output, the incidence of electrolyte imbalance, change in creatinine level, length of hospitalization, the incidence of ototoxicity, cardiac mortality, and all-cause mortality showed no significant differences between the 2 groups.

CONCLUSION

Meta-analysis of the existing limited studies did not confirm any significant differences in the safety and efficacy with continuous administration of loop diuretic, compared with bolus injection in patients with acute decompensated heart failure.

Cardiorenal syndrome in critical care: the acute cardiorenal and renocardiac syndromes

Heart and kidney disease often coexist in the same patient, and observational studies have shown that cardiac disease can directly contribute to worsening kidney function and vice versa. Cardiorenal syndrome (CRS) is defined as a complex pathophysiological disorder of the heart and the kidneys in which acute or chronic dysfunction in one organ may induce acute or chronic dysfunction in the other organ. This has been recently classified into five subtypes on the basis of the primary organ dysfunction (heart or kidney) and on whether the organ dysfunction is acute or chronic. Of particular interest to the critical care specialist are CRS type 1 (acute cardiorenal syndrome) and type 3 (acute renocardiac syndrome). CRS type 1 is characterized by an acute deterioration in cardiac function that leads to acute kidney injury (AKI); in CRS type 3, AKI leads to acute cardiac injury and/or dysfunction, such as cardiac ischemic syndromes, congestive heart failure, or arrhythmia. Both subtypes are encountered in high-acuity medical units; in particular, CRS type 1 is commonly seen in the coronary care unit and cardiothoracic intensive care unit. This paper will provide a concise review of the epidemiology, pathophysiology, prevention strategies, and selected kidney management aspects for these two acute CRS subtypes.