Point-of-Care Echocardiography Improves Assessment of Volume Status in Cirrhosis and Hepatorenal Syndrome

Pathophysiology of Hepatorenal Syndrome

Hepatorenal syndrome type 1 (HRS-1) is a unique form of acute kidney injury that affects individuals with decompensated cirrhosis with ascites. The primary mechanism leading to reduction of kidney function in HRS-1 is hemodynamic in nature. Cumulative evidence points to a cascade of events that led to a profound reduction in kidney perfusion. A state of increased intrahepatic vascular resistance characteristic of advanced cirrhosis and portal hypertension is accompanied by maladaptive peripheral arterial vasodilation and reduction in systemic vascular resistance and mean arterial pressure. As a result of a fall in effective arterial blood volume, there is a compensatory activation of the sympathetic nervous system and the renin-angiotensin system, local renal vasoconstriction, loss of renal autoregulation, decrease in renal blood flow, and ultimately a fall in glomerular filtration rate. Systemic release of nitric oxide stimulated by the fibrotic liver, bacterial translocation, and inflammation constitute key components of the pathogenesis. While angiotensin II and noradrenaline remain the critical mediators of renal arterial and arteriolar vasoconstriction, other novel molecules have been recently implicated. Although the above-described mechanistic pathway remains the backbone of the pathogenesis of HRS-1, other noxious elements may be present in advanced cirrhosis and likely contribute to the renal impairment. Direct liver-kidney crosstalk via the hepatorenal sympathetic reflex can further reduce renal blood flow independently of the systemic derangements. Tense ascites may lead to intraabdominal hypertension and abdominal compartment syndrome. Cardio-hemodynamic processes have also been increasingly recognized. Porto-pulmonary hypertension, cirrhotic cardiomyopathy, and abdominal compartment syndrome may lead to renal congestion and complicate the course of HRS-1. In addition, a degree of ischemic or toxic (cholemic) tubular injury may overlap with the underlying circulatory dysfunction and further exacerbate the course of acute kidney injury. Improving our understanding of the pathogenesis of HRS-1 may lead to improvements in therapeutic options for this seriously ill population.

Echocardiographic hemodynamic assessment in decompensated cirrhosis: comparison between Intensivists and Gastroenterologists

BACKGROUND & AIMS

Ascites is a frequent complication of cirrhosis. In intensive care units, initial hemodynamic assessment is frequently performed by echocardiography. This study evaluated the feasibility and usefulness of early hemodynamic assessment in the gastroenterology ward.

METHODS

This observational cohort study prospectively included all patients admitted to a teaching hospital's gastroenterology unit for decompensated cirrhosis. A gastroenterologist with minimal training and an intensivist both performed an echocardiography exam. The primary outcome was inter-rater agreement and reliability for three echocardiography parameters: visual LVEF (Left Ventricular Ejection Fraction), subaortic VTI (velocity time integral) and E wave velocity. Secondary outcomes were agreement for presence of pleural effusion, description of 3 hemodynamics profiles (hypovolemic, hyperkinetic and intermediate), and 28-day mortality.

RESULTS

From March 2018 to March 2020, 53 patients were included. The median age was 62 years and 81% were men. Patients presented mostly advanced liver disease, with 43% Child-Pugh C and median MELD score of 15.2. The limits of agreement between intensivists and gastroenterologists for subaortic VTI were - 6.6 to 7.2 cm, and ranged from - 0.6 to 0.37 m.s-1 for E wave velocity. Clinically significant differences between intensivists and gastroenterologists were found in 22% for subaortic VTI and 24.5% for E wave velocity. Reliability was good for subaortic VTI (ICC: 0.79, 95% CI [0.58; 0.9;]) and moderate for E wave velocity (0.53, 95% CI [0.19; 0.74]). The three hemodynamics profiles had different prognosis, with a 28-day mortality for Hypovolemic, Intermediate and Hyperkinetic group of 31, 18, and 4%, respectively.

CONCLUSION

Reliability of hemodynamic assessment by gastroenterologists was good, while agreement was unsatisfactory, advocating for further training. Transthoracic echocardiography can differentiate hypovolemia from hyperkinetic states. The role of transthoracic echocardiography in managing decompensated cirrhosis requires further study.

CLINICAL TRIAL NUMBER

NCT03650660.

The Diagnosis and Non-pharmacological Management of Acute Kidney Injury in Patients with Cirrhosis

Acute kidney injury in patients with cirrhosis is quite common, and is seen in up to 50% of patients hospitalized for decompensated cirrhosis. Causes of acute kidney injury include prerenal, renal, or postrenal etiologies. The diagnosis and early institution of nonpharmacologic and pharmacologic management are key to the recovery of renal function. The objective of this review is to provide a practical approach to the use of diagnostic biomarkers and highlight the nonpharmacologic management and prevention of acute kidney injury.

Mastering Core Recommendations during HEPAtology ROUNDS in Patients with Advanced Chronic Liver Disease

Efficient and thorough care of hospitalized patients with advanced chronic liver disease is of utter importance to improve outcomes and optimize quality of life. This requires understanding current evidence and best practices. To facilitate focus on up-to-date knowledge and a practical approach, we have created the HEPA-ROUNDS mnemonic while outlining a practical review of the literature with critical appraisal for the busy clinician. The HEPA-ROUNDS mnemonic provides a structured approach that incorporates critical concepts in terms of prevention, management, and prognostication of the most common complications frequently encountered in patients with advanced chronic liver disease. In addition, implementing the HEPA-ROUNDS mnemonic can facilitate education for trainees and staff caring for patients with advanced chronic liver disease.

The Conundrum of Volume Status Assessment: Revisiting Current and Future Tools Available for Physicians at the Bedside

Assessment of patients’ volume status at the bedside is a very important clinical skill that physicians need in many clinical scenarios. Hypovolemia with hypotension and tissue under-perfusion are usually more alarming to physicians, but hypervolemia is also associated with poor outcomes, making euvolemia a crucial goal in clinical practice. Nevertheless, the assessment of volume status can be challenging, especially in the absence of a gold standard test that is reliable and easily accessible to assist with clinical decision-making. Physicians need to have a broad knowledge of the individual non-invasive clinical tools available for them at the bedside to evaluate volume status. In this review, we will discuss the strengths and limitations of the traditional tools, which include careful history taking, physical examination, and basic laboratory tests, and also include the relatively new tool of point-of-care ultrasound.

Point-of-Care Echocardiography and Hemodynamic Monitoring in Cirrhosis and Acute-on-Chronic Liver Failure in the COVID-19 Era

Point-of-Care (POC) transthoracic echocardiography (TTE) is transforming the management of patients with cirrhosis presenting with septic shock, acute kidney injury, hepatorenal syndrome and acute-on-chronic liver failure (ACLF) by correctly assessing the hemodynamic and volume status at the bedside using combined echocardiography and POC ultrasound (POCUS). When POC TTE is performed by the hepatologist or intensivist in the intensive care unit (ICU), and interpreted remotely by a cardiologist, it can rule out cardiovascular conditions that may be contributing to undifferentiated shock, such as diastolic dysfunction, myocardial infarction, myocarditis, regional wall motion abnormalities and pulmonary embolism. The COVID-19 pandemic has led to a delay in seeking medical treatment, reduced invasive interventions and deferment in referrals leading to "collateral damage" in critically ill patients with liver disease. Thus, the use of telemedicine in the ICU (Tele-ICU) has integrated cardiology, intensive care, and hepatology practices across the spectrum of ICU, operating room, and transplant healthcare. Telecardiology tools have improved bedside diagnosis when introduced as part of COVID-19 care by remote supervision and interpretation of POCUS and echocardiographic data. In this review, we present the contemporary approach of using POC echocardiography and offer a practical guide for primary care hepatologists and gastroenterologists for cardiac assessment in critically ill patients with cirrhosis and ACLF. Evidenced based use of Tele-ICU can prevent delay in cardiac diagnosis, optimize safe use of expert resources and ensure timely care in the setting of critically ill cirrhosis, ACLF and liver transplantation in the COVID-19 era.

The Effects of Positional Change on Hemodynamic Parameters in Spinal Immobilization

INTRODUCTION

The use of a long backboard and cervical collar are commonly recommended by international guidelines for spinal immobilization, but both devices may cause several side effects. In a recent study, it was reported that spinal immobilization at 20° eliminated the decrease in pulmonary function secondary to spinal immobilization performed at 0°. Spinal immobilization at 20° is a new recommendation, but other potential effects need to be explored before it can be implemented in clinical use.

STUDY OBJECTIVE

Hemodynamic observation is important in the management of trauma patients. The aim of this study was to investigate the effect of spinal immobilization at a 20° position instead of 0° on hemodynamic parameters.

METHODS

This study included 53 healthy volunteers who underwent spinal immobilization in the supine position (00) and in an elevated position (200). Systolic arterial pressure (SAP), diastolic arterial pressure (DAP), mean arterial pressure (MAP), heart rate (HR), left ventricular outflow tract velocity time integral (LVOT-VTI), left ventricular stroke volume (LVSV), cardiac output (CO), inferior vena cava diameter inspiration (IVC diameter insp), IVC diameter expiration (IVC diameter exp), and inferior vena cava collapsibility index (IVC-CI) were measured at the 0th and 30th minutes of spinal immobilization in both positions. The data were compared for demonstrating the efficiency of both positions in spinal immobilization.

RESULTS

A statistically significant difference was found in the parameters of the IVC diameter (exp), IVC diameter (insp), LVOT-VTI, LVSV, and CO through the measurements starting in the 0th minute of the transition from 0° to 20° (P <.001). Delta values (∆) of hemodynamic parameters (∆IVC diameter [exp], ∆IVC diameter [insp], ∆LVOT-VTI, ∆SV, ∆CO, ∆IVC-CI, ∆MAP, ∆SAP, ∆DAP, and ∆HR) were similar in spinal immobilization at 0° and 20°.

CONCLUSION

The findings obtained from this study illustrate that spinal immobilization at 20° does not cause clinically significant hemodynamic changes in healthy subjects compared to spinal immobilization at 0°.

Reappraising the spectrum of AKI and hepatorenal syndrome in patients with cirrhosis

The occurrence of acute kidney injury (AKI) in patients with end-stage liver disease constitutes one of the most challenging clinical scenarios in in-hospital and critical care medicine. Hepatorenal syndrome type 1 (HRS-1), which is a specific type of AKI that occurs in the context of advanced cirrhosis and portal hypertension, is associated with particularly high mortality. The pathogenesis of HRS-1 is largely viewed as a functional derangement that ultimately affects renal vasculature tone. However, new insights suggest that non-haemodynamic tubulo-toxic factors, such as endotoxins and bile acids, might mediate parenchymal renal injury in patients with cirrhosis, suggesting that concurrent mechanisms, including those traditionally associated with HRS-1 and non-traditional factors, might contribute to the development of AKI in patients with cirrhosis. Moreover, histological evidence of morphological abnormalities in the kidneys of patients with cirrhosis and renal dysfunction has prompted the functional nature of HRS-1 to be re-examined. From a clinical perspective, a diagnosis of HRS-1 guides utilization of vasoconstrictive therapy and decisions regarding renal replacement therapy. Patients with cirrhosis are at risk of AKI owing to a wide range of factors. However, the tools currently available to ascertain the diagnosis of HRS-1 and guide therapy are suboptimal. Short of liver transplantation, goal-directed haemodynamically targeted pharmacotherapy remains the cornerstone of treatment for this condition; improved understanding of the underlying pathogenic mechanisms might lead to better clinical outcomes. Here, we examine our current understanding of the pathophysiology of HRS-1 and existing challenges in its diagnosis and treatment.

Acute kidney injury spectrum in patients with chronic liver disease: Where do we stand?

Acute kidney injury (AKI) is a common complication of liver cirrhosis and is of the utmost clinical and prognostic relevance. Patients with cirrhosis, especially decompensated cirrhosis, are more prone to develop AKI than those without cirrhosis. The hepatorenal syndrome type of AKI (HRS–AKI), a spectrum of disorders in prerenal chronic liver disease, and acute tubular necrosis (ATN) are the two most common causes of AKI in patients with chronic liver disease and cirrhosis. Differentiating these conditions is essential due to the differences in treatment. Prerenal AKI, a more benign disorder, responds well to plasma volume expansion, while ATN requires more specific renal support and is associated with substantial mortality. HRS–AKI is a facet of these two conditions, which are characterized by a dysregulation of the immune response. Recently, there has been progress in better defining this clinical entity, and studies have begun to address optimal care. The present review synopsizes the current diagnostic criteria, pathophysiology, and treatment modalities of HRS–AKI and as well as AKI in other chronic liver diseases (non-HRS–AKI) so that early recognition of HRS–AKI and the appropriate management can be established.

The utility of point-of-care ultrasound in the assessment of volume status in acute and critically ill patients

BACKGROUND

Volume resuscitation has only been demonstrated to be effective in approximately fifty percent of patients. The remaining patients do not respond to volume resuscitation and may even develop adverse outcomes (such as acute pulmonary edema necessitating endotracheal intubation). We believe that point-of-care ultrasound is an excellent modality by which to adequately predict which patients may benefit from volume resuscitation.

DATA RESOURCES

We performed a search using PubMed, Scopus, and MEDLINE. The following search terms were used: fluid responsiveness, ultrasound, non-invasive, hemodynamic, fluid challenge, and passive leg raise. Preference was given to clinical trials and review articles that were most relevant to the topic of assessing a patient's cardiovascular ability to respond to intravenous fluid administration using ultrasound.

RESULTS

Point-of-care ultrasound can be easily employed to measure the diameter and collapsibility of various large vessels including the inferior vena cava, common carotid artery, subclavian vein, internal jugular vein, and femoral vein. Such parameters are closely related to dynamic measures of fluid responsiveness and can be used by providers to help guide fluid resuscitation in critically ill patients.

CONCLUSION

Ultrasound in combination with passive leg raise is a non-invasive, cost- and time-effective modality that can be employed to assess volume status and response to fluid resuscitation. Traditionally sonographic studies have focused on the evaluation of large veins such as the inferior vena cava, and internal jugular vein. A number of recently published studies also demonstrate the usefulness of evaluating large arteries to predict volume status.