S o u n d   S a v e s   L i v e s ASE Statement on Point-of-Care Ultrasound (POCUS) During the 2019 Novel Coronavirus Pandemic © 2020 American Society of Echocardiography Amer M. Johri, MD, MSc, FRCPC, FASE (Chair), Benjamin Galen, MD, FACP, James N. Kirkpatrick, MD, FASE, Michael Lanspa, MD, FASE, FCCM, Sharon Mulvagh, MD, FASE, FRCPC, Ritu Thamman, MD, FASE, Kingston, Ontario, Canada; Bronx, New York; Seattle, Washington; Salt Lake City, Utah; Halifax, Nova Scotia, Canada; Pittsburgh, Pennsylvania From Queen’s University, Kingston, Ontario, Canada (A.M.J.); Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, New York (B.G.); University of Washington Medical Center, Seattle, Washington (J.N.K.); Intermountain Medical Center and the University of Utah, Salt Lake City, Utah (M.L.); Dalhousie University, Halifax, Nova Scotia, Canada (S.M.); University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania (R.T.). The following authors reported no actual or potential conflicts of interest in relation to this document: Amer M. Johri, MD, MSc, FRCPC, FASE, Benjamin Galen, MD, FACP, James N. Kirkpatrick, MD, FASE, Michael Lanspa, MD, FASE, FCCM, Ritu Thamman, MD, FASE. The following authors reported relationships with one or more commercial interests: Sharon Mulvagh, MD, FASE, FRCPC, is a consultant for Lantheus Medical Imaging and serves on the steering committee/SOUL trial for NovoNordisk. Notice and Disclaimer: This statement reflects recommendations based on expert opinion, national guidelines, and available evidence. Our knowledge with regard to coronavirus disease (COVID-19) continues to evolve, as do our institutional protocols for dealing with invasive and non-invasive procedures and practice of personal protective equipment (PPE). Readers are urged to follow national guidelines and their institutional recommendations regarding best practices to protect their patients and themselves. These reports are made available by the American Society of Echocardiography (ASE) as a courtesy reference source for its members. The reports contain recommendations only and should not be used as the sole basis to make medical practice decisions or for disciplinary action against any employee. The statements and recommendations contained in these reports are primarily based on the opinions of experts, rather than on scientifically-verified data. ASE makes no express or implied warranties regarding the completeness or accuracy of the information in these reports, including the warranty of merchantability or fitness for a particular purpose. In no event shall ASE be liable to you, your patients, or any other third parties for any decision made or action taken by you or such other parties in reliance on this information. Nor does your use of this information constitute the offering of medical advice by ASE or create any physician-patient relationship between ASE and your patients or anyone else.
Why Conduct POCUS in COVID-19 Infection?
Although lung injury is common in COVID-19 infection, myocardial injury may be present in more than a quarter of patients with critical disease. 1 Thus the rapid, bedside assessment of the heart, chest, and vessels by point-of-care ultrasound (POCUS) has propelled this tool to the frontlines of the fight against the COVID-19 pandemic. POCUS is usually conducted by the treating provider to obtain real-time information for management decisions. Cardiac views are frequently obtained along with non-cardiac views such as the chest (lung, pleura) and vessels (neck and leg veins, aorta). In infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in particular, POCUS may help triage the dyspneic patient and determine need for subsequent imaging (echocardiogram, echo; computerized tomography, CT; etc). A modified version of the ASE POCUS protocol may be of value in suspected or confirmed COVID-19 infection (Figure 1). The base ASE POCUS protocol can be accessed free online at: https://aseuniversity.org/ase/lessons/47.² POCUS protocol includes, basic cardiac views, subcostal views for IVC and pericardial fluid, and chest views. This protocol may assist in the initial cardiopulmonary assessment of patients with COVID-19 infection if POCUS is deemed indicated. IVC, inferior vena cava. Cardiac POCUS: A well-illustrated case series of the application of focused ultrasound in patients with severe COVID-19 infection and associated cardiovascular (CV) disease from Wuhan was recently presented.³ Table 1 lists cardiac POCUS findings and indications. Early reports suggest that cardiac POCUS indications in COVID-19 include: 1. Detection or characterization of pre-existing CV disease. 2. Early identification of worsening cardiac function, either due to known pre-existing disease or associated with the infection. 3. Monitoring and examination: POCUS may be able to assess changes in cardiac function over time through quick routine examinations, perhaps in lieu of heart and lung auscultation, which can be challenging in critical care settings due to pronation, ambient noise, and PPE. 4. Elucidation of CV abnormalities potentially associated with COVID-19: Early reports suggest that some patients develop pericardial effusion and/or a. myocarditis that can progress to shock. 4 b. A hypercoagulable state may be associated, leading to deep venous thrombosis (DVT) and pulmonary embolism with associated right ventricular findings and acute pulmonary hypertension c.   LV systolic dysfunction, either global or regional, may be associated with myocarditis, stress-induced cardiomyopathy pattern, or epicardial or microvascular coronary thrombosis.
Lung Pocus: When
radiographic studies such as CT scan might be limited, lung POCUS can be used to trend severity of COVID-19 pneumonia as an adjunct to oximetry and physical examination. Lung and vascular POCUS applications in COVID-19 are listed in Table 1. Characteristic lung findings in preliminary publications are consistent with a viral pneumonia: a thickened and irregular pleural line, and scattered B-lines (mild disease). In severe disease, this can progress to confluent B-lines with pulmonary consolidation, including air bronchograms. POCUS is useful to exclude other chest pathologies in critically ill patients, such as pneumothorax (particularly in patients on positive pressure ventilation) and symptomatic large pleural effusion. Table 1.  ASE POCUS Protocol in Suspected or Confirmed COVID-19 Infection.  A
Vascular POCUS for procedural guidance and access is well Vascular JVP or Subcostal CHF, established in acute settings. Fluid Status hypovolemia IVC Assessment of the inferior vena cava (IVC) and/or jugular venous +/- Ley Veins* 2 point compression* DVT pulsation (JVP) plays an important role in hemodynamic assessment of *Leg veins may be assessed if the operator has training in this technique, clinical suspicion exists, and the critically ill patients to enhance the sonographer is not available. ACS, acute coronary syndrome; TR, tricuspid regurgitation; PASP, pulmonary artery systolic pressure; PE, physical exam and in the pulmonary embolism; CV, cardiovascular; ARDS, acute respiratory distress syndrome; JVP, jugular venous pulsation; IVC, inferior vena cava. CHF, congestive heart failure; DVT, deep vein thrombosis. assessment of fluid status. Deep vein thrombosis risk increases with any critically ill bed-bound patient; moreover, early reports indicate an association between COVID-19 and a prothrombotic state. A unilateral DVT study performed by a sonographer is relatively quick and focused. However in the case that a sonographer is not available, and in context of the pandemic, the 2-point compression POCUS technique may be considered by practitioners trained in the technique. 5
When to Perform POCUS in COVID-19?
COVID-19 Suspected/ Not all patients with COVID-19 infection confirmed. Initial Evaluation: History require a POCUS examination. However, if Physical Exam cardiac and chest ultrasound is indicated, Laboratory some institutions may choose POCUS as the first-line application of ultrasound. Deterioration in clinical status may then trigger a more extensive exam such as a Cardiopulmonary Disease Suspected requiring limited transthoracic echocardiography evaluation (TTE) guided by the POCUS images. The primary advantage of using POCUS first in COVID-19 is reduction of exposure to other personnel and locations, permitting POCUS conservation of PPE. Disadvantages include potentially poorer imaging resolution compared with systems used for comprehensive TTE, missed findings, operator inexperience, archiving issues, and POCUS insufficient and POCUS Sufficient to Exclude inability to immediately convert the POCUS or Define Cardiopulmonary Echo Indicated to a comprehensive examination if needed. Abnormality A workflow algorithm for patients with COVID-19 infection in whom further cardiopulmonary ultrasound is indicated is No Further TTE Indicated TTE if Appropriate provided in Figure 2. If POCUS examination – guided by POCUS Revaluate If Clinical Change is available, and the scan sufficiently answers the clinical question, then the need for subsequent TTE may be obviated. If the POCUS scan is insufficient, or reveals Figure 2.  POCUS Workflow in Suspected or Confirmed COVID- findings requiring comprehensive evaluation, 19 Infection. Potential workflow for POCUS during the COVID-19 then TTE may be considered as appropriate. pandemic, in the instance that cardiopulmonary ultrasound is Limited TTE can be planned and guided by indicated . If available, and there is suspicion of cardiopulmonary the POCUS findings to minimize sonographer abnormality requiring further evaluation, POCUS can be the first- line ultrasound performed. If the POCUS performed by a trained exposure. In some instances, POCUS may be operator is sufficient to either exclude or define the insufficient to exclude a suspected cardiac cardiopulmonary abnormality, then further TTE may not be abnormality, for example in the case of difficult required. If the POCUS was insufficient then limited or image acquisition, and it may be more efficient comprehensive TTE may be considered as appropriate. PPE, personal protective equipment; TTE transthoracic for a skilled sonographer to rapidly scan the echocardiography. patient, rather than have a POCUS operator struggle with prolonged attempts. Judicious use of ultrasound must be considered to avoid unnecessary exposure of personnel to contagion and conserve the use of limited resources such as PPE. Caution must be exercised to ensure that the suggested POCUS workflow algorithm is not increasing utilization of unnecessary or inappropriate TTE.
How to Perform POCUS in COVID-19 infection
Safety and cleaning: PPE implementation for sonographers, and machine cleaning principles are described in the parent document to this supplement and apply to POCUS. Because of the size and flexibility of POCUS devices, institutions may decide to dedicate these devices to a fixed location, such as an isolated COVID-19 unit, with meticulous cleaning between patient exams and at the end of each day in a dedicated cleaning storage facility within the unit. The suggestions for scanning and cleaning are summarized in Table 2 (modified from the American College of Emergency Physicians (ACEP)) 6 . This is a suggested checklist; however specific steps, procedures, and their order may vary depending upon institutional guidance, the care environment, and management pathway. It is important to recognize that institutions may develop their own protocols for decontamination; and that these should be posted clearly. Additional information on transducer cleaning can be found on the American Institute of Ultrasound in Medicine (AIUM) website. 8
Archiving and storage: Given the potential for deterioration in patients with COVID-19 infection, every attempt should be made to store, archive and document POCUS results to allow for image comparison. This helps to reduce the need for repeat scans that would impinge upon scarce PPE resources, and the risk of exposure. At the very least, results should be documented in the physical exam or investigations section of the patient's chart.
Who Should Perform POCUS?
All POCUS practitioners should operate within their skillset as described by the ASE Recommendations for Echo Labs Participating in POCUS and Critical Care Echocardiography Training. 9 Some users may have POCUS credentials from societies such as the American College of Chest Physicians and/or the Society for Hospital Medicine. Many institutions have planned for the possibility of a tiered response to the crisis, as proposed by the Society of Critical Care Medicine. 10 In such a response, non-intensivist physicians might be directly managing patients with COVID-19. Novice practitioners may be recruited to use POCUS in the midst of a surge of patients. These individuals should receive proper training, but the usual modes of teaching by practicing on patients are currently inadvisable. Simulators are an approach to introduce POCUS image acquisition and interpretation. Several on-line modules are available that offer an ability to learn background knowledge, such as the ASE modules² and introductory lung modules available at PocusJournal.com. 11 To enhance training and enable access to experts, commercially available platforms now exist that utilize interactive teleconsultative tools for remote guidance and supervision.
Summary
In the case that cardiopulmonary ultrasound is indicated in a patient with COVID-19 infection, POCUS may be considered the first-line ultrasound examination performed, which then guides the need for further imaging. This approach may help to conserve personnel and PPE, as well as limit exposure to other personnel and locations. Given the potential for rapid clinical deterioration in patients with COVID-19 infection, every attempt should be made to store and document POCUS results to reduce the need for repeat examination. Meticulous cleaning of any POCUS device is critical to reduce the risk of SARS-CoV-2. POCUS must be performed by individuals with the correct skill set, an understanding of the limitations of this technology, and meticulous attention to PPE and machine cleaning.