Need for Objective Assessment of Volume Status in Critically Ill Patients with COVID-19: The Tri-POCUS Approach

Use of POCUS for the assessment of dehydration in pediatric patients-a narrative review

In pediatric practice, POCUS (point-of-care ultrasound) has been mostly implemented to recognize lung conditions and pleural and pericardial effusions, but less to evaluate fluid depletion. The main aim of this review is to analyze the current literature on the assessment of dehydration in pediatric patients by using POCUS. The size of the inferior vena cava (IVC) and its change in diameter in response to respiration have been investigated as a tool to screen for hypovolemia. A dilated IVC with decreased collapsibility (< 50%) is a sign of increased right atrial pressure. On the contrary, a collapsed IVC may be indicative of hypovolemia. The IVC collapsibility index (cIVC) reflects the decrease in the diameter upon inspiration. Altogether the IVC diameter and collapsibility index can be easily determined, but their role in children has not been fully demonstrated, and an estimation of volume status solely by assessing the IVC should thus be interpreted with caution. The inferior vena cava/abdominal aorta (IVC/AO) ratio may be a suitable parameter to assess the volume status in pediatric patients even though there is a need to define age-based thresholds. A combination of vascular, lung, and cardiac POCUS could be a valuable supplementary tool in the assessment of dehydration in several clinical scenarios, enabling rapid identification of life-threatening primary etiologies and helping physicians avoid inappropriate therapeutic interventions.   Conclusion: POCUS can provide important information in the assessment of intravascular fluid status in emergency scenarios, but measurements may be confounded by a number of other clinical variables. The inclusion of lung and cardiac views may assist in better understanding the patient's physiology and etiology regarding volume status. What is Known: • In pediatric practice, POCUS (point-of-care ultrasound) has been mostly implemented to recognize lung conditions (like pneumonia and bronchiolitis) and pleural and pericardial effusions, but less to evaluate fluid depletion. • The size of the IVC (inferior vena cava) and its change in diameter in response to respiration have been studied as a possible screening tool to assess the volume status, predict fluid responsiveness, and assess potential intolerance to fluid loading. What is New: • The IVC diameter and collapsibility index can be easily assessed, but their role in predicting dehydration in pediatric age has not been fully demonstrated, and an estimation of volume status only by assessing the IVC should be interpreted carefully. • The IVC /AO(inferior vena cava/abdominal aorta) ratio may be a suitable parameter to assess the volume status in pediatric patients even though there is a need to define age-based thresholds. A combination of vascular, lung, and cardiac POCUS can be a valuable supplementary tool in the assessment of intravascular volume in several clinical scenarios.

Inferior vena cava ultrasound and other techniques for assessment of intravascular and extravascular volume: an update

Goals of volume management are to accurately assess intravascular and extravascular volume and predict response to volume administration, vasopressor support or volume removal. Data are reviewed that support the following: (i) Dynamic parameters reliably guide volume administration and may improve clinical outcomes compared with static parameters, but some are invasive or only validated with mechanical ventilation without spontaneous breathing. (ii) Ultrasound visualization of inferior vena cava (IVC) diameter variations with respiration reliably assesses intravascular volume and predicts volume responsiveness. (iii) Although physiology of IVC respiratory variations differs with mechanical ventilation and spontaneous breathing, the IVC collapsibility index (CI) and distensibility index are interconvertible. (iv) Prediction of volume responsiveness by IVC CI is comparable for mechanical ventilation and spontaneous breathing patients. (v) Respiratory variations of subclavian/proximal axillary and internal jugular veins by ultrasound are alternative sites, with comparable reliability. (vi) Data support clinical applicability of IVC CI to predict hypotension with anesthesia, guide ultrafiltration goals, predict dry weight, predict intra-dialytic hypotension and assess acute decompensated heart failure. (vii) IVC ultrasound may complement ultrasound of heart and lungs, and abdominal organs for venous congestion, for assessing and managing volume overload and deresuscitation, renal failure and shock. (viii) IVC ultrasound has limitations including inadequate visualization. Ultrasound data should always be interpreted in clinical context. Additional studies are required to further assess and validate the role of bedside ultrasonography in clinical care.

Intensive care nurse-led point of care ultrasound in the assessment and management of the critically ill COVID-19 patient: A single centre case series

Focused ultrasound can be used to rapidly diagnose COVID-19 disease, assess disease severity, and inform management of COVID-19 and associated pathologies, reducing radiation exposure from other imaging modalities and minimizing spread of infection. Ultrasound examinations performed by trained nurses in the intensive care unit (ICU) enable more patients to receive these assessments. This case series evaluates the use of nurse-led focused cardiac and lung ultrasound for clinical management of ICU patients with COVID-19. We describe common pathophysiological findings and how findings were used to inform clinical decision-making. An ultrasound trained ICU nurse performed Focused Ultrasound in Intensive Care (FUSIC) cardiac and lung scans enabling calculation of a lung severity score on adult ICU patients with a confirmed COVID-19 diagnosis in a single-centre setting. Fifteen scans were performed on 15 patients. Thirteen (87%) patients had normal left ventricular function; 12 (80%) normal right ventricular function. All 15 (100%) scans identified abnormal lung findings including irregular thickened pleura, B-lines, sub-pleural consolidation and hepatization. Worse lung severity scores were correlated with higher Acute Physiology and Chronic Health Evaluation (APACHE II) scores (r = 0.70; p = .003). Of the 15 scans, 10 (67%) identified abnormal pathology contributing to a change in clinical management. This included targeted fluid removal (4, 27%), change in respiratory management (3, 20%) and need for formal echocardiographic assessment (3, 20%). Findings from five (33%) scans required no intervention. This case series demonstrates nurse-led ultrasound could be a useful adjunct in the management of the COVID-19 patient.

Ultrasound during the COVID-19 Pandemic: A Global Approach

SARS-CoV-2 (severe acute respiratory syndrome Coronavirus-2) rapidly spread worldwide as COVID-19 (Coronavirus disease 2019), causing a costly and deadly pandemic. Different pulmonary manifestations represent this syndrome's most common clinical manifestations, together with the cardiovascular complications frequently observed in these patients. Ultrasound (US) evaluations of the lungs, heart, and lower limbs may be helpful in the diagnosis, follow-up, and prognosis of patients with COVID-19. Moreover, POCUS (point-of-care ultrasound) protocols are particularly useful for patients admitted to intensive care units. The present review aimed to highlight the clinical conditions during the SARS-CoV-2 pandemic in which the US represents a crucial diagnostic tool.

Supportive Care in Patients with Critical Coronavirus Disease 2019

Specific therapies for the treatment of coronavirus disease 2019 (COVID-19) have limited efficacy in the event a patient worsens clinically and requires admission to the intensive care unit (ICU). Thus, providing quality supportive care is essential to the overall management of patients with critical COVID-19. Patients with respiratory failure not requiring intubation should be supported with noninvasive positive pressure ventilation, continuous positive airway pressure, or high flow oxygenation. Use of these respiratory modalities may prevent patients from subsequently requiring intubation. Basic components of supportive care for the critically ill should be applied equally to patients with COVID-19 in the ICU.

Phase angle and standardized phase angle from bioelectrical impedance measurements as a prognostic factor for mortality at 90 days in patients with COVID-19: A longitudinal cohort study

BACKGROUND & AIMS

Severe acute COVID-19 has taken on pandemic proportions with growing interest in identification of prognostic factors for mortality. Standardized bioelectrical impedance (BI) phase angle (SPhA), which is PhA adjusted by age and sex, has been related to mortality in patients with several diseases but never investigated in COVID-19. Inflammation, a consequence of COVID-19 infection, affects fluid status (hydration) and can be identified with PhA. The aim of this study was to determine the predictive role of PhA on 90 days survival of adults with COVID-19.

METHODS

We studied 127 consecutive patients diagnosed with COVID-19. BI measurements determined with a 50 kHz phase-sensitive BI device, body composition parameters and laboratory markers were evaluated as predictors of mortality.

RESULTS

Non-surviving COVID-19 patients had significantly lower PhA and SPhA values (p < 0.001) and increased hydration (p < 0.001) compared to surviving patients. Patients in the lowest SPhA quartile had increased (p < 0.001) mortality and hospital stay, hyperhydration (p < 0.001), increased inflammation biomarkers [CRP (p < 0.001)], decreased nutritional parameters: body mass cell index [BCMI (p < 0.001) albumin (p < 0.001)], and reduced other biomarkers [D-dimer (p = 0.002)]. Multivariate analysis (Cox regression) revealed that PhA and hydration status, adjusted for age, sex, BMI, diabetes, hypertension, dyslipidaemia or heart disease, were associated (p < 0.001) with increased mortality. The hazard ratio was 2.48 (95% CI, 1.60-3.84, p < 0.001) for PhA and 1.12 (95% CI, 1.04-1.20, p = 0.003) for hydration percentage. PhA <3.95° was the cut-off for predicting mortality in acute COVID-19 with 93.8% sensitivity and 66.7% specificity. PhA offers greater sensitivity as a predictive prognostic test at admission, compared to the established analytical parameters of poor prognosis (CRP, lymphocytes, prealbumin).

CONCLUSIONS

Low PhA (<3.95°), independent of age, sex, BMI, and comorbidities, is a significant predictor of mortality risk in COVID-19. These findings suggest that the evaluation of body composition with single-frequency phase-sensitive BI measurements should be included in the routine clinical assessment of COVID-19 patients at hospital admission to identify patients at increased mortality risk.

Classification of clinically relevant intravascular volume status using point of care ultrasound and machine learning

Purpose

This is a foundational study in which multiorgan system point of care ultrasound (POCUS) and machine learning (ML) are used to mimic physician management decisions regarding the functional intravascular volume status (IVS) and need for diuretic therapy. We present this as an impactful use case of an application of ML in aided decision making for clinical practice. IVS represents complex physiologic interactions of the cardiac, renal, pulmonary, and other organ systems. In particular, we focus on vascular congestion and overload as an evolving concept in POCUS diagnosis and clinical relevance. It is critical for physicians to be able to evaluate IVS without disrupting workflow or exposing patients to unnecessary testing, radiation, or cost. This work utilized a small retrospective dataset as a feasibility test for ML binary classification of diuretic administration validated with clinical decision data. Future work will be directed toward artificial intelligence (AI) delivery at the bedside and assessment of the impact on patient-centered outcomes and physician workflow improvement.

Approach

We retrospectively reviewed and processed 1039 POCUS video clips, including cardiac, thoracic, and inferior vena cava (IVC) views. Multiorgan POCUS clips were correlated with clinical data extracted from the electronic health record and deidentified for algorithm training and validation. We implemented a two-stream three-dimensional (3D) deep learning approach that fuses heart and IVC data to perform binary classification of the need for diuretic use.

Results

Our proposed approach achieves high classification accuracy (84%) for the determination of diuretic use with 0.84 area under the receiver operating characteristic curve.

Conclusions

Our two-stream 3D deep neural network is able to classify POCUS video clips that match physicians' classification for or against diuretic use with high accuracy. This serves as a foundational step in the progress toward AI-aided diagnosis and AI implementation in the field of IVS evaluation by POCUS.

Integrative Volume Status Assessment

Volume status assessment is a critical but challenging clinical skill and is especially important for the management of patients in the emergency department, intensive care unit, and dialysis unit where accurate intravascular assessment is necessary to guide appropriate fluid management. Assessment of volume status is subjective and can vary from provider to provider, posing clinical dilemmas. Traditional non-invasive methods of volume assessment include assessment of skin turgor, axillary sweat, peripheral edema, pulmonary crackles, orthostatic vital signs, and jugular venous distension. Invasive assessments of volume status include direct measurement of central venous pressure and pulmonary artery pressures. Each of these has their own limitations, challenges, and pitfalls and were often validated based on small cohorts with questionable comparators. In the past 30 years, the increased availability, progressive miniaturization, and falling price of ultrasound devices has made point of care ultrasound (POCUS) widely available. Emerging evidence base and increased uptake across multiple subspecialities has facilitated the adoption of this technology. POCUS is now widely available, relatively inexpensive, free of ionizing radiation, and can help providers make medical decisions with more precision. POCUS is not intended to replace the physical exam, but rather to complement clinical assessment, guiding providers to give thorough and accurate clinical care to their patients. We should be mindful of the nascent literature supporting the use of POCUS and other limitations as uptake increases among providers and be wary not to use POCUS to substitute clinical judgement, but integrate ultrasonographic findings carefully with history and clinical examination.

Utility of Nephrologist-Performed Point of Care Ultrasonography in the Evaluation of Hyponatremia

Point of care ultrasonography can be a valuable adjunct to conventional physical examination in patients with hyponatremia that aids in clinical decision making. It can address the shortcomings of traditional volume status assessment such as the inherent low sensitivity of 'classic' signs such as lower extremity edema. Herein, we present a case of a 35-year-old woman where discrepant clinical findings led to confusion in the accurate assessment of volume status but addition of point of care ultrasonography helped to guide the therapy.

Building and Maintaining an Ultrasound Program: It Takes a Village

Building and maintaining a successful point-of-care ultrasound program is a complex process that involves establishing an ecosystem between three unique but overlapping domains: ultrasound equipment, ultrasound users, and the health care system. By highlighting the different areas of focus and each of the key stakeholders and components, a group can ensure adequate attention is paid to all aspects of point-of-care ultrasound program development in nephrology.

The role of PoCUS in the assessment of COVID-19 patients

The Coronavirus disease 19 (COVID-19) pandemic has increased the burden of stress on the global healthcare system in 2020. Point of care ultrasound (PoCUS) is used effectively in the management of pulmonary, cardiac and vascular pathologies. POCUS is the use of traditional ultrasound imaging techniques in a focused binary manner to answer a specific set of clinical questions. This is an imaging technique that delivers no radiation, is inexpensive, ultraportable and provides results instantaneously to the physician operator at the bedside. In regard to the pandemic, PoCUS has played a significant adjunctive role in the diagnosis and management of co-morbidities associated with COVID-19. PoCUS also offers an alternative method to image obstetric patients and the pediatric population safely in accordance with the ALARA principle. Finally, there have been numerous PoCUS protocols describing the effective use of this technology during the COVID-19 pandemic.

SARS-CoV-2-related ARDS in a maintenance hemodialysis patient: case report on tailored approach by daily hemodialysis, noninvasive ventilation, tocilizumab, anxiolytics, and point-of-care ultrasound

Without rescue drugs approved, holistic approach by daily hemodialysis, noninvasive ventilation, anti-inflammatory medications, fluid assessment by bedside ultrasound, and anxiolytics improved outcomes of a maintenance hemodialysis patient affected by severe COVID-19.

Dynamic Changes in Portal Vein Flow during Decongestion in Patients with Heart Failure and Cardio-Renal Syndrome: A POCUS Case Series

INTRODUCTION

Optimal method for noninvasive assessment of venous congestion remains an unresolved issue. Portal vein (PV) and intrarenal venous flow alterations are markers of abdominal venous congestion and have been associated with acute kidney injury (AKI) in cardiac surgery patients. It is currently unknown if portal vein flow (PVF) alterations in heart failure can be reversed with diuretic treatment and track decongestion.

OBJECTIVE

The aim of this study is to evaluate PVF alterations in patients with ADHF at arrival and after decongestive treatment.

METHODS

Assessment of venous congestion using point-of-care ultrasound was performed in 12 patients with ADHF (6 patients with left-sided heart failure and 6 patients with right-sided heart failure). Evaluation included inferior vena cava (IVC) size and collapsibility in addition to PV Doppler to determine pulsatility fraction (PF).

RESULTS

Increased PV PF (81.75 ± 13%) was found on admission. After effective decongestive treatment, it improved to (17.43 ± 2.2%). Improvement in IVC size and collapsibility was seen in most patients with left-sided heart failure and none of the patients with right-sided heart failure. Improvement in PV PF coincided with return to baseline of Serum Cr in patients that presented with AKI.

CONCLUSIONS

Evaluation of abdominal venous congestion by point-of-care ultrasound could aid in diagnosis and follow-up of patients with congestive kidney injury.

Point-of-care ultrasound in the COVID-19 era: A scoping review

In the midst of the COVID-19 pandemic, unprecedented pressure has been added to healthcare systems around the globe. Imaging is a crucial component in the management of COVID-19 patients. Point-of-care ultrasound (POCUS) such as hand-carried ultrasound emerges in the COVID-19 era as a tool that can simplify the imaging process of COVID-19 patients, and potentially reduce the strain on healthcare providers and healthcare resources. The preliminary evidence available suggests an increasing role of POCUS in diagnosing, monitoring, and risk-stratifying COVID-19 patients. This scoping review aims to delineate the challenges in imaging COVID-19 patients, discuss the cardiopulmonary complications of COVID-19 and their respective sonographic findings, and summarize the current data and recommendations available. There is currently a critical gap in knowledge in the role of POCUS in the COVID-19 era. Nonetheless, it is crucial to summarize the current preliminary data available in order to help fill this gap in knowledge for future studies.

Emergency Tracheal Intubation in Patients with COVID-19: Experience from a UK Centre

This retrospective observational case series describes a single centre's preparations and experience of 53 emergency tracheal intubations in patients with COVID-19 respiratory failure. The findings of a contemporaneous online survey exploring technical and nontechnical aspects of airway management, completed by intubation team members, are also presented. Preparations included developing a COVID-19 intubation standard operating procedure and checklist, dedicated airway trolleys, a consultant-led mobile intubation team, and an airway education programme. Tracheal intubation was successful in all patients. Intubation first-pass success rate was 85%, first-line videolaryngoscopy use 79%, oxygen desaturation 49%, and hypotension 21%. Performance was consistent across all clinical areas. The main factor impeding first-pass success was larger diameter tracheal tubes. The majority of intubations was performed by consultant anaesthetists. Nonconsultant intubations demonstrated higher oxygen desaturation rates (75% vs. 45%, p=0.610) and lower first-pass success (0% vs. 92%, p < 0.001). Survey respondents (n = 29) reported increased anxiety at the start of the pandemic, with statistically significant reduction as the pandemic progressed (median: 4/5 very high vs. 2/5 low anxiety, p < 0.001). Reported procedural/environmental challenges included performing tasks in personal protective equipment (62%), remote-site working (48%), and modification of normal practices (41%)-specifically, the use of larger diameter tracheal tubes (21%). Hypoxaemia was identified by 90% of respondents as the most challenging patient-related factor during intubations. Our findings demonstrate that a consultant-led mobile intubation team can safely perform tracheal intubation in critically ill COVID-19 patients across all clinical areas, aided by thorough preparation and training, despite heightened anxiety levels.

Combatting COVID-19: is ultrasound an important piece in the diagnostic puzzle?

The current COVID-19 pandemic is causing diagnostic and risk stratification difficulties in Emergency Departments (ED) worldwide. Molecular tests are not sufficiently sensitive, and results are usually not available in time for decision making in the ED. Chest x-ray (CXR) is a poor diagnostic test for COVID-19, and computed tomography (CT), while sensitive, is impractical as a diagnostic test for all patients. Lung ultrasound (LUS) has an established role in the evaluation of acute respiratory failure and has been used during the COVID-19 outbreak as a decision support tool. LUS shows characteristic changes in viral pneumonitis, and while these changes are not specific for COVID-19, it may be a useful adjunct during the diagnostic process. It is quick to perform and repeat and may be done at the bedside. The authors believe that LUS can help to mitigate uncertainty in undifferentiated patients with respiratory symptoms. This review aims to provide guidance regarding indications for LUS, describe the typical sonographic abnormalities seen in patients with COVID-19 and provide recommendations around the logistics of performing LUS on patients with COVID-19 and managing the infection control risk of the procedure. The risk of anchoring bias during a pandemic and the need to consider alternative pathologies are emphasised throughout this review. LUS may be a useful point-of-care test for emergency care providers during the current COVID-19 pandemic if used within a strict framework that governs education, quality assurance and proctored scanning protocols.

Cohort Study of Outpatient Hemodialysis Management Strategies for COVID-19 in North-West London

Background

Dialysis patients are at risk of severe coronavirus disease 2019 (COVID-19). We managed COVID-19 hemodialysis outpatients in dedicated satellite dialysis units. This provided rare opportunity to study early disease progress in community-based patients. We aimed to (i) understand COVID-19 progression, (ii) identify markers of future clinical severity, and (iii) assess associations between dialysis management strategies and COVID-19 clinical outcomes.

Methods

We conducted a cohort study of all outpatients managed at a COVID-19 hemodialysis unit. We analyzed data recorded as part of providing COVID-19 clinical care. We analyzed associations between features at diagnosis and the first 3 consecutive hemodialysis sessions in patients who required future hospital admission, and those who had died at 28 days.

Results

Isolated outpatient hemodialysis was provided to 106 patients over 8 weeks. No patients received antiviral medication or hydroxychloroquine. Twenty-one patients (20%) were admitted at COVID-19 diagnosis; 29 of 85 patients (34%) were admitted after initial outpatient management; 16 patients (15%) died. By multivariate analysis, nonactive transplant list status, use of institutional transport, and increased white cell count associated with future hospitalization and increased age associated with death. Oxygen saturations progressively decreased over the first 3 dialysis sessions in the cohorts that progressed to future hospital admission or death. Mean ultrafiltration volume of the first 3 hemodialysis sessions was reduced in the same cohorts.

Conclusions

Outpatient hemodialysis in patients with COVID-19 is safe for patients and staff. Features at the first 3 dialysis sessions can identify individuals at risk of future hospitalization and death from COVID-19.