Showing papers by "Amir Kazory published in 2019"

Hepatorenal Syndrome or Hepatocardiorenal Syndrome: Revisiting Basic Concepts in View of Emerging Data.

Abstract: Background Accumulating evidence on the pathophysiology of hepatorenal syndrome has challenged the conventional model of liver-kidney connection. While liver cirrhosis is traditionally considered the origin of a cascade of pathophysiologic mechanisms directly affecting other organs such as the kidney, emerging data point to the heart as the potential mediator of the untoward renal effects. Summary Herein, we briefly review the often-overlooked contribution of the heart to circulatory dysfunction in hepatorenal syndrome and put forward evidence arguing for the involvement of systemic inflammation and endothelial dysfunction in this setting. The temporality of cardiorenal interactions in hepatorenal syndrome and the observed beneficial effects of portosystemic shunting on these pathways lend further support to the notion that cardiac involvement plays a key role in the development of renal dysfunction in severe cirrhosis. Key Messages: The disturbances traditionally bundled within hepatorenal syndrome could represent a hepatic form of cardiorenal syndrome whereby the liver affects the kidney in part through cardiorenal pathways. This new model has practical implications and calls for a shift in the focus of diagnostic and therapeutic approaches to renal dysfunction in advanced cirrhosis.

Point of care renal ultrasonography for the busy nephrologist: A pictorial review.

Abstract: The application of bedside ultrasonography in routine clinical practice has dramatically evolved over the last few decades and will likely continue to grow as technological advances lead to enhanced portability and affordability of the equipment. Despite mounting interest, most nephrology fellowship training programs do not offer formal training in renal ultrasonography and there is inertia among practicing nephrologists to adopt this skill as a practice-changing advancement. Lack of familiarity with the topic is considered a key reason for this inertia. Understanding of basic ultrasound physics, instrumentation, principles of optimal image acquisition and interpretation is critical for enhanced efficiency and patient safety while using this tool. Herein, we provide a brief overview of the basic principles of diagnostic renal ultrasonography as well as introduction to common sonographic pathologies encountered in day-to-day nephrology practice with illustrative images.

Customization of Peritoneal Dialysis in Cardiorenal Syndrome by Optimization of Sodium Extraction.

Abstract: Background Peritoneal dialysis (PD) has emerged as a mechanistically relevant therapeutic option for patients with heart failure (HF), volume overload, and varying degrees of renal dysfunction (i.e., chronic cardiorenal syndrome). Congestion has been identified as a potent ominous prognostic factor in this patient population, outperforming a number of established risk factors. As such, excess fluid removal is recognized as a relevant therapeutic target in this setting. Methods Accumulating evidence points to the importance of sodium removal as part of any decongestive strategy because extraction of sodium-free water has little or no impact on the outcomes of these patients. Hence, optimization of sodium removal by PD should be the primary focus in the setting of HF and cardiorenal syndrome, especially if PD is started when the patient still has adequate residual renal function for clearance of waste products. Results Herein, we provide an overview of approaches that can tailor PD treatment to the patients' characteristics and clinical needs (e.g., choice of PD modality) to fully exploit its decongestive properties. Other methods that could prove helpful in the future will also be briefly discussed. Conclusion While these strategies could help with efficient sodium extraction and volume optimization, future studies are needed to evaluate their impact on the outcomes of this specific patient population.

Are We Barking Up the Wrong Tree? Rise in Serum Creatinine and Heart Failure.

Abstract: A significant subset of patients with heart failure (HF) experience small to moderate rise in serum creatinine (RSC) in the setting of otherwise beneficial therapies such as aggressive diuresis or renin-angiotensin-aldosterone system (RAAS) inhibition. Accumulating data suggest that RSC in this setting is dissimilar from conventional causes of renal insult in that it has a negligible impact on the outcomes. There is also emerging evidence on the lack of association between biomarkers of renal injury and RSC in the setting of aggressive diuresis. A similar pattern has been observed in recent hypertension trials where the RSC in patients with intensive blood pressure control has not been associated with biomarker evidence of renal injury or adverse outcomes. Based on these findings, RSC, rather than acute kidney injury, appears to be the preferred terminology in HF (and possibly in hypertension) because of its purely descriptive nature that lacks any potentially inaccurate implication of mechanistic or prognostic reference. From a pragmatic viewpoint, we believe that small to moderate RSC is to be anticipated and tolerated with RAAS inhibition and/or aggressive diuresis in acute or chronic HF and should not prompt discontinuation of the therapy unless complications such as hypotension and severe hyperkalemia develop.

Defining the role of peritoneal dialysis in management of congestive heart failure.

Abstract: Introduction: Congestion is an integral component of heart failure (HF) pathophysiology and portends an adverse impact on outcome. Peritoneal dialysis (PD) is a home-based therapeutic modality that has been used in the setting of refractory congestive HF to help optimize volume status. Not only does PD allow for customized sodium and water removal, but it also provides the opportunity for the patients to fully benefit from guideline-directed medical therapy for HF that could have otherwise been challenging to use. Areas covered: Authors provide an overview of the pathophysiologic basis for the use of PD in HF, followed by a review of the findings of the main clinical trials such as the salutary impact on HF re-admissions and quality of life. Since the goals of therapy in this setting differ from those for patients with end-stage renal disease, pertinent practical considerations in the use of this modality are then discussed as well as potential barriers. Expert opinion: For patients with chronic refractory HF, PD represents an alternative to medical therapy alone. Identification of patients that would benefit most from this modality and detection of major enablers and obstacles for the implementation of this therapy should be the focus of future studies.

Left Ventricular Assist Device and the Kidney: Getting to the Heart of the Matter

Abstract: Left ventricular assist devices (LVADs) are increasingly used for the management of patients with advanced heart failure (AHF) due to their established salutary impact on hemodynamic status and survival benefit. Impairment in kidney function is common in the setting of AHF and is associated with adverse impact on the outcomes. Cardiorenal interactions represent a complex pattern in these patients rendering their care a challenge that needs to be addressed by multidisciplinary approaches. Following LVAD implantation, AHF patients have the potential to achieve marked improvement in kidney function due to increased cardiac output and kidney perfusion as well as reduction in renal venous congestion. However, a subset of these patients is also at risk for acute kidney injury and resurgence of kidney dysfunction on continued mechanical circulatory support. Herein, we provide an overview of various aspects of changes in kidney function pre- and post-LVAD implantation, review potential underlying pathophysiologic mechanisms, and the impact on the outcomes. Moreover, the currently available data on renal replacement therapy of LVAD-treated patients, whether in the acute setting or as a maintenance therapy, are discussed in detail along with areas of high clinical relevance where a clear gap in knowledge exists.

Acute kidney injury in non-critical care setting: elaboration and validation of an in-hospital death prognosis score

Abstract: Acute kidney injury (AKI) is still characterized by a high mortality rate. While most patients with AKI are admitted in conventional medical units, current available data are still obtained from studies designed for patients admitted in intensive care units (ICU). Our study aimed to elaborate and validate an in-hospital death prognosis score for AKI admitted in conventional medical care units. We included two prospective cohorts of consecutive patients with AKI admitted between 2001 and 2004 (elaboration cohort (EC)) and between 2010 and 2014 (validation cohort (VC)). We developed a scoring system from clinical and biological parameters recorded at admission from the EC to predict in-hospital mortality. This score was then tested for validation in the VC. Three-hundred and twenty-three and 534 patients were included in the EC and VC cohorts, respectively. The proportion of in-hospital death were 15.5% (EC) and 8.9% (VC), mainly due to sepsis. The parameters independently associated with the in-hospital death in the EC were Glasgow score, oxygen requirement, fluid overload, blood diastolic pressure, multiple myeloma and prothrombin time. The in-hospital death prognosis score AUC was 0.845 +/− 0.297 (p < 0.001) after validation in the VC. Our in-hospital death prognosis score is the first to be prospectively developed and validated for AKI admitted in a conventional medical care unit. Based on current parameters, easily collected at time of admission, this score could be a useful tool for physicians and nephrologists to determine the in-hospital death prognosis of this AKI population.

Expanding the Boundaries of Combined Renal Replacement Therapy for Non-Renal Indications.

Abstract: Over the last decades, there have been major advancements in the field of renal replacement therapy (RRT) with utilization of newer technologies and advent of various modalities Once exclusively used for treatment of renal failure and its metabolic consequences, the science of RRT has expanded to include non-renal indications such as treatment of fluid overload in patients with refractory heart failure Hepatic encephalopathy due to sudden rise in serum ammonia level in the setting of acute liver failure represents an underexplored area in which RRT can potentially be helpful While the key role of hyperammonemia in the pathogenesis of hepatic encephalopathy in patients with liver failure is well established, emerging data points to distinct pathophysiologic mechanisms underlying chronic alterations in neural metabolic functions and acute changes in cerebral perfusion In the acute setting, ammonia can cross the blood-brain barrier at high levels leading to sudden formation of strong osmolytes, significant transcellular shift of water, and cerebral edema Herein, we provide a brief overview of the role of RRT in management of acute hyperammonemia in the setting of acute liver failure and discuss the practical aspects of the available therapeutic modalities Larger studies are needed to shed light on a number of clinical aspects such as the impact on the outcomes, criteria for selection of the patients that would benefit most from this therapeutic approach, optimal timing of initiation of RRT, and the most appropriate modality

The never-ending quest for the appropriate role of ultrafiltration.

Abstract: We read with great interest the article by Dr Mullens and colleagues, recently published in this Journal.1 In this interesting position paper, the authors provide an overview of certain decongestive strategies for patients with heart failure (HF). In the ultrafiltration section, they state ‘renal replacement therapy allows for management of metabolic complications of anuria/oliguria such as hyperkalaemia, acidosis and uraemia’.1 While this statement is certainly true regarding renal replacement therapy in general (for example intermittent haemodialysis or continuous haemofiltration), it does not apply to ultrafiltration. The concept of isolated ultrafiltration therapy is limited to mechanical fluid extraction across a haemofilter. As no dialysate or replacement fluid is involved, it does not possess any clearance property and is not meant to address complications of renal dysfunction (for example acidosis and hyperkalaemia). If the authors are referring to poor outcomes associated with ‘post-ultrafiltration’ need for renal replacement therapy, as it happened to a significant number of patients in the reference of that sentence, then it would apply to any therapeutic modality and is not unique to ultrafiltration. The great majority of ultrafiltration trials has indeed excluded patients with advanced kidney disease. On a separate but related note, while we do concur with the authors that no compelling evidence necessarily supports the use of ultrafiltration as a first-line therapy for acute HF, it remains a matter of debate whether it should be delayed and, if so, for how long. No study has, so far, focused on comparison of early vs. late initiation of ultrafiltration in this setting, but available data seem to favour an early initiation strategy (for example before any rise in serum creatinine ensues). Those studies that were designed to randomize patients within 24 h of admission, hence avoiding exposure to significant doses of diuretics prior to ultrafiltration (for example UNLOAD and AVOID-HF), led to favourable outcomes while CARRESS-HF, where the patients had to experience a rise in serum creatinine to be eligible for inclusion, could not reproduce similar results.2–4 In our opinion, the lack of clearance property should be taken into account when ultrafiltration is within the therapeutic plan laid down for a patient with HF and lingering congestion. Moreover, some studies have reported a salutary effect for ultrafiltration therapy in the reduction of HF-related hospital admissions.5 As such, in the subset of HF patients with a history of frequent hospitalizations, it might conceivably be advantageous to consider prioritizing ultrafiltration over diuretic-based medical therapy.

Radiographic manifestations of abnormal bone and mineral metabolism in end‐stage renal disease

Abstract: Chronic kidney disease-mineral and bone disorder (CKD-MBD) refers to a broader clinical syndrome that develops as a systemic disorder due to CKD, manifested by abnormalities in bone and mineral metabolism and/or extraskeletal calcification. In addition to serum biomarkers, imaging is a main tool in assessing extraskeletal calcification in CKD patients.