Echocardiographic Findings in Critically Ill COVID-19 Patients Treated With and Without Extracorporeal Membrane Oxygenation.

OBJECTIVES: To describe echocardiographic findings among mechanically ventilated patients with COVID-19 acute respiratory distress syndrome, comparing those with and without venovenous extracorporeal membrane oxygenation (VV ECMO) support. DESIGN: Single-center, retrospective cohort study. SETTING: Intensive care unit (ICU) of a quaternary academic center. PARTICIPANTS: Patients with COVID-19 admitted between March 2020 and June 2021 receiving mechanical ventilation, with an echocardiogram within 72 hours of admission. INTERVENTIONS: Admission and follow-up echocardiograms during ICU stay. MEASUREMENTS: Patient characteristics and echocardiographic findings were analyzed. Mortality odds ratio (OR) for right ventricular (RV) systolic dysfunction and acute cor pulmonale (ACP) was calculated. MAIN RESULTS: Among 242 patients, 145 (60%) received VV ECMO. Median (IQR) PaO2/FiO2 was 76 (65-95) and 98 (85-140) in ECMO and non-ECMO patients, respectively (p ≤ 0.001). Initial echocardiograms showed no significant differences in left ventricular systolic dysfunction (10% v 15 %, p = 0.31) and RV systolic dysfunction (38% v. 27%, p = 0.27) between ECMO and non-ECMO patients. ACP was more frequent in the ECMO group at baseline (41% v. 26 %, p = 0.02). During the ICU stay, patients on ECMO exhibited a higher prevalence of RV systolic dysfunction (55% v 34%, p = 0.001) and ACP (51% v 26%, p = 0.002). RV systolic dysfunction (OR 1.99; 95% CI 1.09-3.63) and ACP (OR 2.95; 95% CI 1.55-5.62) on the follow-up echocardiograms were associated with higher odds of ICU mortality. CONCLUSIONS: The prevalence of echocardiographic abnormalities, in particular RV dysfunction, was frequent among patients with COVID-19 receiving VV ECMO support and was associated with worse clinical outcomes.

Head-to-toe bedside ultrasound for adult patients on extracorporeal membrane oxygenation.

Bedside ultrasound represents a well-suited diagnostic and monitoring tool for patients on extracorporeal membrane oxygenation (ECMO) who may be too unstable for transport to other hospital areas for diagnostic tests. The role of ultrasound, however, starts even before ECMO initiation. Every patient considered for ECMO should have a thorough ultrasonographic assessment of cardiac and valvular function, as well as vascular anatomy without delaying ECMO cannulation. The role of pre-ECMO ultrasound is to confirm the indication for ECMO, identify clinical situations for which ECMO is not indicated, rule out contraindications, and inform the choice of ECMO configuration. During ECMO cannulation, the use of vascular and cardiac ultrasound reduces the risk of complications and ensures adequate cannula positioning. Ultrasound remains key for monitoring during ECMO support and troubleshooting ECMO complications. For instance, ultrasound is helpful in the assessment of drainage insufficiency, hemodynamic instability, biventricular function, persistent hypoxemia, and recirculation on venovenous (VV) ECMO. Lung ultrasound can be used to monitor signs of recovery on VV ECMO. Brain ultrasound provides valuable diagnostic and prognostic information on ECMO. Echocardiography is essential in the assessment of readiness for liberation from venoarterial (VA) ECMO. Lastly, post decannulation ultrasound mainly aims at identifying post decannulation thrombosis and vascular complications. This review will cover the role of head-to-toe ultrasound for the management of adult ECMO patients from decision to initiate ECMO to the post decannulation phase.

High and intermediate risk pulmonary embolism in the ICU.

Pulmonary embolism (PE) is a common and important medical emergency, encountered by clinicians across all acute care specialties. PE is a relatively uncommon cause of direct admission to the intensive care unit (ICU), but these patients are at high risk of death. More commonly, patients admitted to ICU develop PE as a complication of an unrelated acute illness. This paper reviews the epidemiology, diagnosis, risk stratification, and particularly the management of PE from a critical care perspective. Issues around prevention, anticoagulation, fibrinolysis, catheter-based techniques, surgical embolectomy, and extracorporeal support are discussed.

Outcomes of patients with respiratory failure declined for extracorporeal membrane oxygenation: a prospective observational study.

PURPOSE: Descriptive information on referral patterns and short-term outcomes of patients with respiratory failure declined for extracorporeal membrane oxygenation (ECMO) is lacking. METHODS: We conducted a prospective single-centre observational cohort study of ECMO referrals to Toronto General Hospital (receiving hospital) for severe respiratory failure (COVID-19 and non-COVID-19), between 1 December 2019 and 30 November 2020. Data related to the referral, the referral decision, and reasons for refusal were collected. Reasons for refusal were grouped into three mutually exclusive categories selected a priori: "too sick now," "too sick before," and "not sick enough." In declined referrals, referring physicians were surveyed to collect patient outcome on day 7 after the referral. The primary study endpoints were referral outcome (accepted/declined) and patient outcome (alive/deceased). RESULTS: A total of 193 referrals were included; 73% were declined for transfer. Referral outcome was influenced by age (odds ratio [OR], 0.97; 95% confidence interval [CI], 0.95 to 0.96; P < 0.01) and involvement of other members of the ECMO team in the discussion (OR, 4.42; 95% CI, 1.28 to 15.2; P < 0.01). Patient outcomes were missing in 46 (24%) referrals (inability to locate the referring physician or the referring physician being unable to recall the outcome). Using available data (95 declined and 52 accepted referrals; n = 147), survival to day 7 was 49% for declined referrals (35% for patients deemed "too sick now," 53% for "too sick before," 100% for "not sick enough," and 50% for reason for refusal not reported) and 98% for transferred patients. Sensitivity analysis setting missing outcomes to directional extreme values retained robustness of survival probabilities. CONCLUSION: Nearly half of the patients declined for ECMO consideration were alive on day 7. More information on patient trajectory and long-term outcomes in declined referrals is needed to refine selection criteria.

RéSUMé: OBJECTIF: On manque d'informations descriptives sur les schémas de références et les devenirs à court terme des patient·es atteint·es d'insuffisance respiratoire n'ayant pas pu recevoir une oxygénation par membrane extracorporelle (ECMO). MéTHODE: Nous avons réalisé une étude de cohorte observationnelle prospective monocentrique sur les références vers l'ECMO à l'Hôpital général de Toronto (hôpital d'accueil) pour insuffisance respiratoire grave (COVID-19 et non-COVID-19), entre le 1er décembre 2019 et le 30 novembre 2020. Les données relatives à la référence, à la décision de référence et aux motifs du refus ont été recueillies. Les motifs de refus ont été regroupés en trois catégories mutuellement exclusives sélectionnées a priori : « Trop malade maintenant ¼, « Trop malade avant ¼ et « Pas assez malade ¼. En ce qui concerne les références refusées, un sondage envoyé aux médecins traitant·es avait pour objectif de recueillir les devenirs des patient·es le jour 7 suivant la référence. Les critères d'évaluation principaux de l'étude étaient le résultat de la référence (accepté/refusé) et le devenir des patient·es (vivant·e/décédé·e). RéSULTATS: Au total, 193 références ont été incluses; le transfert a été refusé dans 73 % des cas. L'acceptation ou le refus de la référence était influencé par l'âge (rapport de cotes [RC], 0,97; intervalle de confiance [IC] à 95 %, 0,95 à 0,96; P < 0,01) et la participation d'autres membres de l'équipe ECMO à la discussion (RC, 4,42; IC 95 %, 1,28 à 15,2; P < 0,01). Les devenirs des patient·es étaient manquants pour 46 (24 %) des personnes référées (incapacité de localiser les médecins traitant·es ou incapacité des médecins de se souvenir du devenir). À l'aide des données disponibles (95 références refusées et 52 références acceptées; n = 147), la survie jusqu'au jour 7 était de 49 % pour les références refusées (35 % pour la patientèle jugée « trop malade maintenant ¼, 53 % pour celle « trop malade avant ¼, 100 % pour celle « pas assez malade ¼ et 50 % pour les cas où la raison du refus n'était pas déclarée) et 98 % pour les patient·es transféré·es. L'analyse de sensibilité établissant les résultats manquants à des valeurs extrêmes directionnelles a conservé la robustesse des probabilités de survie. CONCLUSION: Près de la moitié des patient·es pour lesquel·les un traitement sous ECMO a été refusé étaient en vie au jour 7. Davantage d'informations concernant la trajectoire et les devenirs à long terme des patient·es refusé·es sont nécessaires pour parfaire les critères de sélection.

Prognostic echocardiographic findings in patients supported with venoarterial extracorporeal membrane oxygenation for cardiogenic shock.

AIMS: Echocardiography is critical in the management of patients supported with veno-arterial extracorporeal membrane oxygenation (V-A ECMO). This study aimed to identify the incidence of critical echocardiographic findings and determine their prognostic significance. METHODS AND RESULTS: All available echocardiograms, hemodynamic variables and outcomes of patients with CS supported with V-A in the period of 2011-2018 at the Toronto General Hospital were retrospectively reviewed. Critical echocardiographic findings were defined as minimal to no left ventricular (LV) ejection, the presence of intra-cardiac clot, significant pericardial effusion and malpositioning of ECMO cannulae. 130 patients were included in this study with in-hospital mortality of 58.5%. Critical findings were most often seen in the first echocardiogram (42/121; 35%). The incidence of critical findings in the first echocardiogram was minimal to no LV ejection in 28 patients (23%), intracardiac thromboses in 8 patients (6.6%), tamponade in 5 patients (4%) and malpositioned cannulae in 1 patient (0.8%). Presence of a critical finding in the first study was associated with an odds ratio for in-hospital mortality of 2.32 (95% CI 1.01-5.06, P = 0.011). CONCLUSION: The initial echocardiogram was most likely to demonstrate a critical finding of which the most common was minimal to no LV ejection. Critical echocardiographic findings carried prognostic significance for in-hospital mortality.

The "Lightbulb" Sign: A Novel Echocardiographic Finding Using Ultrasound Enhancing Agent in Fulminant COVID-19-Related Myocarditis.

We report a case of fulminant COVID-19-related myocarditis requiring venoarterial extracorporeal membrane oxygenation where the use of an ultrasound-enhancing agent demonstrated a previously undescribed echocardiographic finding, the "lightbulb" sign. This sign potentially represents a new area for the use of an ultrasound enhancing agent in the echocardiographic diagnosis of myocarditis.

Transesophageal Echocardiography-Guided Extracorporeal Membrane Oxygenation Cannulation in COVID-19 Patients.

OBJECTIVES: A paucity of data supports the use of transesophageal echocardiography (TEE) for bedside extracorporeal membrane oxygenation (ECMO) cannulation. Concerns have been raised about performing TEEs in patients with COVID-19. The authors describe the use and safety of TEE guidance for ECMO cannulation for COVID-19. DESIGN: Single-center retrospective cohort study. SETTING: The study took place in the intensive care unit of an academic tertiary center. PARTICIPANTS: The authors included 107 patients with confirmed SARS-CoV-2 infection who underwent bedside venovenous ECMO (VV ECMO) cannulation under TEE guidance between May 2020 and June 2021. INTERVENTIONS: TEE-guided bedside VV ECMO cannulation. MEASUREMENTS: Patient characteristics, physiologic and ventilatory parameters, and echocardiographic findings were analyzed. The primary outcome was the number of successful TEE-guided bedside cannulations without complications. The secondary outcomes were cannulation complications, frequency of cannula repositioning, and TEE-related complications. MAIN RESULTS: TEE-guided cannulation was successful in 99% of the patients. Initial cannula position was adequate in all but 1 patient. Fourteen patients (13%) required cannula repositioning during ECMO support. Forty-five patients (42%) had right ventricular systolic dysfunction, and 9 (8%) had left ventricular systolic dysfunction. Twelve patients (11%) had intracardiac thrombi. One superficial arterial injury and 1 pneumothorax occurred. No pericardial tamponade, hemothorax or intraabdominal bleeding occurred in the authors' cohort. No TEE-related complications or COVID-19 infection of healthcare providers were reported during this study. CONCLUSIONS: Bedside TEE guidance for VV ECMO cannulation is safe in patients with severe respiratory failure due to COVID-19. No tamponade or hemothorax, nor TEE-related complications were observed in the authors' cohort.

Machines that save lives in the intensive care unit: the ultrasonography machine.

This article highlights the ultrasonography machine as a machine that saves lives in the intensive care unit. We review its utility in the limited resource intensive care unit and some elements of machine design that are relevant to both the constrained operating environment and the well-resourced intensive care unit. As the ultrasonography machine can only save lives, if is operated by a competent intensivist; we discuss the challenges of training the frontline clinician to become competent in critical care ultrasonography followed by a review of research that supports its use.

Evaluation of an advanced critical care echocardiography program: a mixed methods study.

PURPOSE: Limited data exist on advanced critical care echocardiography (CCE) training programs for intensivists. We sought to describe a longitudinal echocardiography program and investigate the effect of distributed conditional supervision vs predefined en-bloc supervision, as well as the effect of an optional echocardiography laboratory rotation, on learners' engagement. METHODS: In this mixed methods study, we enrolled critical care fellows and faculty from five University of Toronto-affiliated intensive care units (ICU) between July 2015 and July 2018 in an advanced training program, comprising theoretical lectures and practical sessions. After the first year, the program was modified with changes to supervision model and inclusion of a rotation in the echo laboratory. We conducted semistructured interviews and investigated the effects of curricular changes on progress toward portfolio completion (150 transthoracic echocardiograms) using a Bayesian framework. RESULTS: Sixty-five learners were enrolled and 18 were interviewed. Four (9%) learners completed the portfolio. Learners reported lack of time and supervision, and skill complexity as the main barriers to practicing independently. Conditional supervision was associated with a higher rate of submitting unsupervised echocardiograms than unconditional supervision (rate ratio, 1.11, 95% credible interval, 1.08 to 1.14). After rotation in the echocardiography laboratory, submission of unsupervised echocardiograms decreased. CONCLUSION: Trainees perceived lack of time and limited access to supervision as major barriers to course completion. Nevertheless, successful portfolio completion was related to factors other than protected time in the echocardiography laboratory or unconditional direct supervision in ICU. Further research is needed to better understand the factors promoting success of CCE training programs.

RéSUMé: OBJECTIF: Il n'existe que peu de données sur les programmes de formation avancés en échocardiographie pour les soins intensifs (écho-USI) destinés aux intensivistes. Nous avons cherché à décrire un programme longitudinal d'échocardiographie et à étudier l'effet d'une supervision conditionnelle distribuée vs une supervision prédéfinie en bloc, ainsi que l'effet d'une rotation facultative en laboratoire d'échocardiographie, sur le niveau d'implication des apprenants. MéTHODE: Dans cette étude à méthodes mixtes, nous avons recruté des fellows en soins intensifs et des professeurs de cinq unités de soins intensifs (USI) affiliées à l'Université de Toronto entre juillet 2015 et juillet 2018 pour participer à un programme de formation avancée comprenant des conférences théoriques et des séances pratiques. Après la première année, le programme a été modifié en apportant des changements au modèle de supervision et en incluant une rotation dans le laboratoire d'écho. Nous avons mené des entretiens semi-structurés et étudié les effets des changements du programme d'études sur les progrès vers la réussite de la formation (150 échocardiogrammes transthoraciques) en utilisant un cadre bayésien. RéSULTATS: Soixante-cinq apprenants étaient inscrits et 18 ont été interviewés. Quatre (9 %) apprenants ont complété la formation. Les apprenants ont signalé que le manque de temps et de supervision ainsi que la complexité des compétences constituaient les principaux obstacles à une pratique autonome. La supervision conditionnelle était associée à un taux plus élevé de soumission d'échocardiogrammes non supervisés que la supervision inconditionnelle (ratio de taux, 1,11, intervalle crédible à 95 %, 1,08 à 1,14). Après la rotation dans le laboratoire d'échocardiographie, la soumission d'échocardiogrammes non supervisés a diminué. CONCLUSION: Les stagiaires ont perçu le manque de temps et l'accès limité à la supervision comme des obstacles majeurs à la réussite de la formation. Néanmoins, l'achèvement du cours était lié à des facteurs autres que le temps protégé au laboratoire d'échocardiographie ou la supervision directe inconditionnelle aux soins intensifs. D'autres recherches sont nécessaires pour mieux comprendre les facteurs favorisant le succès des programmes de formation en écho-USI.

When is tamponade not an echocardiographic diagnosis Or is it ever?

Although cardiac tamponade remains a clinical diagnosis, echocardiography is an essential tool to detect fluid in the pericardial space. Interpretation of echocardiographic findings and assessment of physiologic and hemodynamic consequences of a pericardial effusion require a thorough understanding of pathophysiologic processes. Certain echocardiographic signs point toward the presence of cardiac tamponade: a dilated inferior vena cava (IVC), collapse of the cardiac chambers, an inspiratory bulge of the interventricular septum into the left ventricle (LV) (the "septal bounce"), and characteristic respiratory variations of Doppler flow velocity recordings. However, in certain circumstances (e.g., mechanical ventilation, post-surgical patients, and pulmonary hypertension), these echocardiographic signs can be missing, despite the presence of clinical tamponade. Failure to recognize a potentially life-threatening clinical condition due to the absence of corresponding echocardiographic findings can delay both diagnosis and life-saving treatment. Thus, in the context of critical care, echocardiography should only be used to confirm the presence of pericardial fluid or localized hematoma, and the diagnosis of tamponade should rely on clinical criteria.

Basic ultrasound head-to-toe skills for intensivists in the general and neuro intensive care unit population: consensus and expert recommendations of the European Society of Intensive Care Medicine.

PURPOSE: To provide consensus, and a list of experts' recommendations regarding the basic skills for head-to-toe ultrasonography in the intensive care setting. METHODS: The Executive Committee of the European Society of Intensive Care (ESICM) commissioned the project and supervised the methodology and structure of the consensus. We selected an international panel of 19 expert clinicians-researchers in intensive care unit (ICU) with expertise in critical care ultrasonography (US), plus a non-voting methodologist. The panel was divided into five subgroups (brain, lung, heart, abdomen and vascular ultrasound) which identified the domains and generated a list of questions to be addressed by the panel. A Delphi process based on an iterative approach was used to obtain the final consensus statements. Statements were classified as a strong recommendation (84% of agreement), weak recommendation (74% of agreement), and no recommendation (less than 74%), in favor or against. RESULTS: This consensus produced a total of 74 statements (7 for brain, 20 for lung, 20 for heart, 20 for abdomen, 7 for vascular Ultrasound). We obtained strong agreement in favor for 49 statements (66.2%), 8 weak in favor (10.8%), 3 weak against (4.1%), and no consensus in 14 cases (19.9%). In most cases when consensus was not obtained, it was felt that the skills were considered as too advanced. A research agenda and discussion on training programs were implemented from the results of the consensus. CONCLUSIONS: This consensus provides guidance for the basic use of critical care US and paves the way for the development of training and research projects.

Teaching Ultrasound at the Point of Care in Times of Social Distancing.

Point-of-care ultrasound has become an integral aspect of critical care training. The Bedside Assessment by Sonography In Critical Care Medicine Curriculum was established at the University of Toronto to train critical care trainees in basic echocardiography and general critical care ultrasound. During the coronavirus disease (COVID-19) pandemic, our program needed to adapt quickly to ensure staff safety and adherence to infection-control protocols. In this article, we share our experience and reflect on the challenges and benefits of shifting from a primarily in-person teaching model to a hybrid model of remote and in-person teaching. Curricular changes were threefold: the transition to entirely web-based interactive didactic teaching and online imaging interpretation modules, the recruitment of sonographers at multiple academic sites as instructors to facilitate in-person practices with lower instructor to trainee ratio, and the use of a mobile application for informal group case-based discussions. Challenges included lost opportunities for scanning healthy volunteers, variability in attendance at online lectures, and a lower number of study submissions for review. However, curricular changes enabled maintenance of directly observed practice, high levels of engagement with recorded content, and an expansion of our reach to a global audience. We believe that future curricula should combine high-quality online curriculum and resources with the ongoing in-person delivery of key elements of curriculum to allow for direct observation and feedback as well as the maintenance of self-directed point-of-care ultrasound portfolios.