Ten reasons for performing hemodynamic monitoring using transesophageal echocardiography

Role of cardiac and lung ultrasound in the COVID-19 era

INTRODUCTION

The primary diagnostic method of Coronavirus disease 2019 is reverse transcription polymerase chain reaction of the nucleic acid of severe acute respiratory syndrome coronavirus 2 in nasopharyngeal swabs. There is growing evidence regarding the 2019 coronavirus disease imaging results on chest X-rays and computed tomography but the accessibility to standard diagnostic methods may be limited during the pandemic.

EVIDENCE ACQUISITION

Databases used for the search were MEDLINE (PubMed), Scopus Search, and Cochrane Library. The research took into consideration studies published in English until March 2022 and was conducted using the following research query: ((((sars cov [MeSH Terms])) OR (COVID-19)) OR (Sars-Cov2)) OR (Coronavirus)) AND (((((2d echocardiography [MeSH Terms]) OR (doppler ultrasound imaging [MeSH Terms]))) OR (echography [MeSH Terms])) OR (LUS)) OR ("LUNG ULTRASOUND")).

EVIDENCE SYNTHESIS

Pulmonary and cardiac ultrasound are cost-effective, widely available, and provide information that can influence management.

CONCLUSIONS

Point-of-care ultrasonography is a method that can provide relevant clinical and therapeutic information in patients with COVID-19 where other diagnostic methods may not be easily accessible.

An Intensivist-Led Extracorporeal Membrane Oxygenation Program: Design, Implementation, and Outcomes of the First Five Years

We describe the development, implementation, and outcomes of an intensivist-led adult extracorporeal life support (ECLS) program using intensivists both to perform venovenous (V-V), venoarterial (V-A), and extracorporeal cardiopulmonary resuscitation (ECPR) cannulations, and to manage patients on ECLS throughout their ICU course. All adults supported with ECLS at the University of New Mexico Hospital (UNMH) from February 1, 2017 to December 31, 2021 were retrospectively analyzed. A total of 203 ECLS cannulations were performed in 198 patients, including 116 V-A cannulations (including 65 during ECPR) and 87 V-V cannulations (including 38 in patients with COVID-19). UNMH intensivists performed 195 cannulations, with 9 cannulation complications. Cardiothoracic surgeons performed 8 cannulations. Overall survival to hospital discharge or transfer was 46.5%. Survival was 32.3% in the ECPR group and 56% in the non-ECPR V-A group. In the V-V cohort, survival was 66.7% in the COVID-19-negative patients and 34.2% in the COVID-19-positive patients. This large series of intensivist-performed ECLS cannulations-including V-A, V-V, and ECPR modalities-demonstrates the successful implementation of a comprehensive intensivist-led ECLS program. With outcomes comparable to those in the literature, our program serves as a model for the initiation and development of ECLS programs in settings with limited access to local subspecialty cardiothoracic surgical services.

Fully automatic estimation of global left ventricular systolic function using deep learning in transoesophageal echocardiography

Aims

To improve monitoring of cardiac function during major surgery and intensive care, we have developed a method for fully automatic estimation of mitral annular plane systolic excursion (auto-MAPSE) using deep learning in transoesophageal echocardiography (TOE). The aim of this study was a clinical validation of auto-MAPSE in patients with heart disease.

Methods and results

TOE recordings were collected from 185 consecutive patients without selection on image quality. Deep-learning-based auto-MAPSE was trained and optimized from 105 patient recordings. We assessed auto-MAPSE feasibility, and agreement and inter-rater reliability with manual reference in 80 patients with and without electrocardiogram (ECG) tracings. Mean processing time for auto-MAPSE was 0.3 s per cardiac cycle/view. Overall feasibility was >90% for manual MAPSE and ECG-enabled auto-MAPSE and 82% for ECG-disabled auto-MAPSE. Feasibility in at least two walls was ≥95% for all methods. Compared with manual reference, bias [95% limits of agreement (LoA)] was -0.5 [-4.0, 3.1] mm for ECG-enabled auto-MAPSE and -0.2 [-4.2, 3.6] mm for ECG-disabled auto-MAPSE. Intra-class correlation coefficient (ICC) for consistency was 0.90 and 0.88, respectively. Manual inter-observer bias [95% LoA] was -0.9 [-4.7, 3.0] mm, and ICC was 0.86.

Conclusion

Auto-MAPSE was fast and highly feasible. Inter-rater reliability between auto-MAPSE and manual reference was good. Agreement between auto-MAPSE and manual reference did not differ from manual inter-observer agreement. As the principal advantages of deep-learning-based assessment are speed and reproducibility, auto-MAPSE has the potential to improve real-time monitoring of left ventricular function. This should be investigated in relevant clinical settings.

Is There a Role for Transesophageal Echocardiography in the Perioperative Trauma Patient?

Purpose of Review

This review article summarizes the advantages and potential uses of focused transesophageal echocardiography (TEE) in the perioperative period for trauma patients. We suggest a locally developed TEE protocol for trauma and provide strategies to achieve widespread use of TEE in the anesthesia care of trauma patients.

Recent Findings

In recent years, TEE has gained interest as an additional modality as point-of-care ultrasound (POCUS) for the resuscitation of acutely ill patients in whom transthoracic echocardiography is not feasible or non-diagnostic. Nevertheless, its use among non-cardiac anesthesiologists is still limited compared to the more traditional POCUS applications.

Summary

A goal-directed, focused TEE can be performed at the bedside in different locations and mechanically ventilated patients. TEE provides relevant diagnostic information to guide the resuscitation of acutely injured patients, particularly to identify life-threatening hidden thoracic injuries in the scenario of patients with multi-system trauma.

Feasibility, utility, and safety of fully incorporating transesophageal echocardiography into emergency medicine practice

Introduction

Transthoracic echocardiography (TTE) is a standard procedure for emergency physicians (EPs). Transesophageal echocardiography (TEE) is known to have great utility in patients who are critically ill or in cardiac arrest and has been used by some EPs with specialized ultrasound (US) training, but it is generally considered outside the reach of the majority of EPs. We surmised that all of our EPs could learn to perform focused TEE (F‐TEE), so we trained and credentialed all of the physicians in our group.

Methods

We trained 52 EPs to perform and interpret F‐TEEs using a 4‐h simulator‐based course. We kept a database of all F‐TEE examinations for quality assurance and continuous quality feedback. Data are reported using descriptive statistics.

Results

Emergency physicians attempted 557 total F‐TEE examinations (median = 10, interquartile range = 5–15) during the 42‐month period following training. Clinically relevant images were obtained in 99% of patients. EPs without fellowship or other advanced US training performed the majority of F‐TEEs (417, 74.9%) and 94.3% (95% confidence interval [CI] = 91.4%–96.3%) had interpretable images recorded. When TTE and TEE were both performed (n = 410), image quality of TEE was superior in 378 (93.3%, 95% CI = 89.7%–95%). Indications for F‐TEE included periarrest states (55.7%), cardiac arrest (32.1%), and shock (12.2%). There was one case of endotracheal tube dislodgement during TEE placement, but this was immediately identified and replaced without complication.

Conclusion

After initiating a mandatory group F‐TEE training and credentialing program, we report the largest series to date of EP‐performed resuscitative F‐TEE. The majority of F‐TEE examinations (75%) were performed by EPs without advanced US training beyond residency.

Application of POCUS in patients with COVID-19 for acute respiratory distress syndrome management: a narrative review

COVID-19 has inflicted the world for over two years. The recent mutant virus strains pose greater challenges to disease prevention and treatment. COVID-19 can cause acute respiratory distress syndrome (ARDS) and extrapulmonary injury. Dynamic monitoring of each patient's condition is necessary to timely tailor treatments, improve prognosis and reduce mortality. Point-of-care ultrasound (POCUS) is broadly used in patients with ARDS. POCUS is recommended to be performed regularly in COVID-19 patients for respiratory failure management. In this review, we summarized the ultrasound characteristics of COVID-19 patients, mainly focusing on lung ultrasound and echocardiography. Furthermore, we also provided the experience of using POCUS to manage COVID-19-related ARDS.

Echocardiography, lung ultrasound, and cardiac magnetic resonance findings in COVID-19: A systematic review

BACKGROUND

The manifestations of COVID-19 as outlined by imaging modalities such as echocardiography, lung ultrasound (LUS), and cardiac magnetic resonance (CMR) imaging are not fully described.

METHODS

We conducted a systematic review of the current literature and included studies that described cardiovascular manifestations of COVID-19 using echocardiography, CMR, and pulmonary manifestations using LUS. We queried PubMed, EMBASE, and Web of Science for relevant articles. Original studies and case series were included.

RESULTS

This review describes the most common abnormalities encountered on echocardiography, LUS, and CMR in patients infected with COVID-19.

Critical Care Transesophageal Echocardiography in Patients during the COVID-19 Pandemic

BACKGROUND

The COVID-19 pandemic has placed an extraordinary strain on healthcare systems across North America. Defining the optimal approach for managing a critically ill COVID-19 patient is rapidly changing. Goal-directed transesophageal echocardiography (TEE) is frequently used by physicians caring for intubated critically ill patients as a reliable imaging modality that is well suited to answer questions at bedside.

METHODS

A multidisciplinary (intensive care, critical care cardiology, and emergency medicine) group of experts in point-of-care echocardiography and TEE from the United States and Canada convened to review the available evidence, share experiences, and produce a consensus statement aiming to provide clinicians with a framework to maximize the safety of patients and healthcare providers when considering focused point-of-care TEE in critically ill patients during the COVID-19 pandemic.

RESULTS

Although transthoracic echocardiography can provide the information needed in most patients, there are specific scenarios in which TEE represents the modality of choice. TEE provides acute care clinicians with a goal-directed framework to guide clinical care and represents an ideal modality to evaluate hemodynamic instability during prone ventilation, perform serial evaluations of the lungs, support cardiac arrest resuscitation, and guide veno-venous ECMO cannulation. To aid other clinicians in performing TEE during the COVID-19 pandemic, we describe a set of principles and practical aspects for performing examinations with a focus on the logistics, personnel, and equipment required before, during, and after an examination.

CONCLUSIONS

In the right clinical scenario, TEE is a tool that can provide the information needed to deliver the best and safest possible care for the critically ill patients.

Hemodynamic monitoring using trans esophageal echocardiography in patients with shock

Circulatory shock is a life-threatening condition responsible for inadequate tissue perfusion. The objectives of hemodynamic monitoring in this setting are multiple: identifying the mechanisms of shock (hypovolemic, distributive, cardiogenic, obstructive); choosing the adequate therapeutic intervention, and evaluating the patient's response. Echocardiography is proposed as a first line tool for this assessment in the intensive care unit. As compared to trans-thoracic echocardiography (TTE), trans-esophageal echocardiography (TEE) offers a better echogenicity and is the best way to evaluate deep anatomic structures. The therapeutic implication of TEE leads to frequent changes in clinical management. It also allows depicting sources of inaccuracy of thermodilution-based hemodynamic monitoring. It is a semi invasive tool with a low rate of complications. The first step in the hemodynamic evaluation of shock is to characterize the mechanisms of circulatory failure among hypovolemia, vasoplegia, cardiac dysfunction, and obstruction. Echocardiographic evaluation includes evaluation of LV systolic and diastolic function, as well as RV function, pericardium, measure of stroke volume and cardiac output, and evaluation of hypovolemia and fluid responsiveness. TEE can be used as a semi-continuous monitoring tool and can be repeated before and after therapeutic interventions (vasopressors, inotropes, fluid therapy, specific treatment such as pericardial effusion evacuation) to evaluate efficacy and tolerance of therapeutic interventions. In conclusion, TEE plays an important role in the management of circulatory failure when TTE is not enough to answer to the questions, although it is not a continuous tool of monitoring. TEE results must be integrated in a global evaluation, the first step being clinical examination. Whether TEE-directed therapy and close hemodynamic monitoring of shock has an impact on outcome remains debated.

Continuous cardiac output assessment or serial echocardiography during septic shock resuscitation?

Septic shock is the leading cause of cardiovascular failure in the intensive care unit (ICU). Cardiac output is a primary component of global oxygen delivery to organs and a sensitive parameter of cardiovascular failure. Any mismatch between oxygen delivery and rapidly varying metabolic demand may result in tissue dysoxia, hence organ dysfunction. Since the intricate alterations of both vascular and cardiac function may rapidly and widely change over time, cardiac output should be measured repeatedly to characterize the type of shock, select the appropriate therapeutic intervention, and evaluate patient's response to therapy. Among the numerous techniques commercially available for measuring cardiac output, transpulmonary thermodilution (TPT) provides a continuous monitoring with external calibration capability, whereas critical care echocardiography (CCE) offers serial hemodynamic assessments. CCE allows early identification of potential sources of inaccuracy of TPT, including right ventricular failure, severe tricuspid or left-sided regurgitations, intracardiac shunt, very low flow states, or dynamic left ventricular outflow tract obstruction. In addition, CCE has the unique advantage of depicting the distinct components generating left ventricular stroke volume (large cavity size vs. preserved contractility), providing information on left ventricular diastolic properties and filling pressures, and assessing pulmonary artery pressure. Since inotropes may have deleterious effects if misused, their initiation should be based on the documentation of a cardiac dysfunction at the origin of the low flow state by CCE. Experts widely advocate using CCE as a first-line modality to initially evaluate the hemodynamic profile associated with shock, as opposed to more invasive techniques. Repeated assessments of both the efficacy (amplitude of the positive response) and tolerance (absence of side-effect) of therapeutic interventions are required to best guide patient management. Overall, TPT allowing continuous tracking of cardiac output variations and CCE appear complementary rather than mutually exclusive in patients with septic shock who require advanced hemodynamic monitoring.

Less or more hemodynamic monitoring in critically ill patients

PURPOSE OF REVIEW

Hemodynamic investigations are required in patients with shock to identify the type of shock, to select the most appropriate treatments and to assess the patient's response to the selected therapy. We discuss how to select the most appropriate hemodynamic monitoring techniques in patients with shock as well as the future of hemodynamic monitoring.

RECENT FINDINGS

Over the last decades, the hemodynamic monitoring techniques have evolved from intermittent toward continuous and real-time measurements and from invasive toward less-invasive approaches. In patients with shock, current guidelines recommend the echocardiography as the preferred modality for the initial hemodynamic evaluation. In patients with shock nonresponsive to initial therapy and/or in the most complex patients, it is recommended to monitor the cardiac output and to use advanced hemodynamic monitoring techniques. They also provide other useful variables that are useful for managing the most complex cases. Uncalibrated and noninvasive cardiac output monitors are not reliable enough in the intensive care setting.

SUMMARY

The use of echocardiography should be initially encouraged in patients with shock to identify the type of shock and to select the most appropriate therapy. The use of more invasive hemodynamic monitoring techniques should be discussed on an individualized basis.

Critical care echocardiography and outcomes in the critically ill

PURPOSE OF REVIEW

Critical care echocardiography offers a comprehensive assessment of cardiac anatomy and function performed by the intensivist at point of care. This has resulted in widespread use of critical care echocardiography in ICUs leading to the question if this increased usage has resulted in improved patient outcomes.

RECENT FINDINGS

Recent studies have evaluated the role of critical care echocardiography in the ICU with an emphasis on establishing accurate diagnosis and measurement of haemodynamic variables. There are no prospective randomized controlled trials that have examined the effect of critical care echocardiography on patient outcomes SUMMARY: Although the effect of critical care echocardiography on patient outcomes has not yet been established, its value as a diagnostic tool has been well demonstrated. We can only assume that its diagnostic capability leads to an improvement in patient outcomes.

Transient systolic anterior motion with junctional rhythm after mitral valve repair in the intensive care unit

Systolic anterior motion (SAM) after mitral valve repair (MVR) can adversely affect hemodynamics due to exacerbation of left ventricular outflow tract obstruction and mitral regurgitation. Intraoperative transient SAM after MVR can usually be managed with hemodynamic maneuvers under continuous monitoring by transesophageal echocardiography (TEE). However, during postoperative intensive care management, transient SAM is seldom diagnosed and the start of treatment may be delayed. We present a case of transient SAM after MVR with abrupt deterioration due to junctional rhythm in the intensive care unit (ICU). TEE revealed that conversion from normal sinus rhythm into junctional rhythm induced the exacerbation of SAM. TEE was useful for identifying the etiology of unstable hemodynamics after cardiac surgery in the ICU, similar to its use in the operating room.

Cardiovascular failure and weaning

Cardiac patients are at high risk of weaning failure due to the abrupt burden to the cardiovascular system resulting from the transition from positive-pressure ventilation to spontaneous breathing. Similarly, numerous patients with borderline cardiac function, left ventricular diastolic dysfunction, chronic obstructive pulmonary disease, especially with associated fluid overload or cumulative positive fluid balance, are at high risk of weaning failure of cardiac origin. The diagnosis of weaning-induced pulmonary oedema (WiPO) relies on the measurement of elevated left ventricular filling pressure, or on the presence of a surrogate reflecting pulmonary or cardiac congestion. Plasma concentration of B-type natriuretic peptide and N-terminal proBNP, biological signs of hemoconcentration (increased circulating protein or hemoglobin levels), or measurement of extravascular pulmonary lung water using transpulmonary thermodilution have been proved valuable surrogates for the identification of weaning failure. Nevertheless, studies have not yet compared these indirect methods to precisely determine their respective diagnostic values for the identification of WiPO, especially in heart failure patients. In addition, none of these approaches directly assess left ventricular filling pressure and the mechanism of WiPO. In contrast, critical care echocardiography is ideally suited to establish the diagnosis of weaning failure of cardiac origin. It allows identifying the high-risk population, monitoring hemodynamically the patient at risk, depicting an abrupt increase of left ventricular filling pressure consistent with WiPO when the patient fails weaning, identifying the underlying mechanism of WiPO, and finally it allows tailoring the therapeutic management of the patient who failed weaning. The impact on patient-centered outcomes of such integrated management strategy based on critical care echocardiography deserves to be prospectively tested in a large population of patients at high risk of weaning failure of cardiac origin.

Effects of hemodynamic monitoring using a single-use transesophageal echocardiography probe in critically ill patients - study protocol for a randomized controlled trial

BACKGROUND

Hemodynamic instability is one of the leading causes of intensive care unit (ICU) admission. Early stabilization of hemodynamics is associated with improved outcome. The monitoring used to guide hemodynamic support may influence the time needed to achieve stable hemodynamics. Visualization of the heart using echocardiography offers the advantage of direct measurement of cardiac volumes and ventricular function. A miniaturized monoplane transesophageal echocardiography (TEE) probe was developed, allowing for almost continuous qualitative hemodynamic TEE assessment (hTEE) after brief bedside training. The primary objective of the study is to assess whether hemodynamic monitoring using the hTEE technology shortens time to resolution of shock in ICU patients in comparison to standard monitoring using a central venous catheter, pulmonary artery catheter, or conventional echocardiography.

METHODS

Five hundred consecutive subjects with circulatory shock (low mean arterial blood pressure (MAP) and signs of organ hypoperfusion) at the time of ICU admission are included in the study. The subjects are randomly assigned to one of four groups using a 2 × 2 factorial design stratified by method of hemodynamic monitoring (hTEE vs standard hemodynamic monitoring) and frequency of hemodynamic assessments (minimum every 4 h vs standard of care). The primary study outcome is the time from study inclusion to resolution of circulatory shock, defined as MAP >  60 mmHg for ≥ 4 h after discontinuation of vasopressors and inotropes. The hTEE monitoring consists of the acquisition of three defined echocardiography views: Transgastric mid-esophageal short axis with measurement of fractional area change of left ventricle, mid-esophageal four-chamber view with measurement of the ratio of right to left ventricular area, and mid-esophageal ascending aortic short-axis view with measurement of the superior vena cava collapsibility index. In the control groups, monitoring modalities, including conventional TTE and TEE but not hTEE, are at the discretion of the treating physician. The interpretation of hemodynamic monitoring and the subsequent changes in patient management are recorded after each hemodynamic assessment. Differences in the primary and further secondary time-to-event outcomes will be assessed using a competing risk model accounting for the competing risk of death.

DISCUSSION

The effect of using echocardiography as a monitoring modality on relevant patient outcomes has not been established so far. The study at hand may be one of the first trials to provide detailed data on effectiveness and safety of echocardiography to guide treatment in patients with circulatory shock.

TRIAL REGISTRATION

ClinicalTrials.gov, ID: NCT02048566. Registered on January 29, 2014.

Impact of Simulator-Based Training in Focused Transesophageal Echocardiography: A Randomized Controlled Trial

BACKGROUND

The aim of the study was to determine if training in transesophageal echocardiography (TEE) using a TEE simulator improves the ability of novice operators to perform and interpret a focused critical care TEE.

METHODS

In this prospective, randomized, controlled study with blinded outcome assessment, 44 intensive care unit trainees were randomly assigned to a control group receiving 4 hours of lecture-based training only, or an intervention group which was additionally trained for 4 hours using a TEE simulator. After the training intervention, each participant performed 2 TEEs in intensive care unit patients which were evaluated by blinded assessors. The imaging quality of TEEs was measured using a predefined examination quality score ranging from 0 to 100 points. The correct quantification of pathologies and the interpretation of the TEEs were evaluated by blinded assessors using focused and comprehensive expert TEEs as comparators.

RESULTS

A total of 114 TEEs were assessed. The mean examination quality score was 55.9 (95% confidence interval [CI], 50.3-61.5) for TEEs of the control group, 75.6 (95% CI, 70.1-81.0) for TEEs of the intervention group, and 88.5 (95% CI, 79.3-97.7) for TEEs in the expert group. The multiple comparisons revealed significant differences between all groups (19.7 [95% CI, 12.8-26.6], P < .001 for intervention versus control; 32.6 [95% CI, 23.0-42.3], P < .001 for expert versus control; 12.9 [95% CI, 3.4-22.5], P = .008 for expert versus intervention). Substantial agreement of the quantification and interpretation ratings of basic TEEs by the intervention (86.7% for quantification and 97.1% for interpretation) or expert group (93.2% for quantification and 98.4% for interpretation) with blinded assessors was detected. The control groups TEEs agreed less (75.6% for quantification and 91.8% for interpretation).

CONCLUSIONS

Simulation-based TEE training improves the ability of novice operators to perform a focused critical care TEE in comparison to lecture-based education only. After 8 hours of simulator and lecture-based training, the majority of TEEs of novices are of sufficient quality for clinical use. Furthermore, a substantial skill level in correct quantification and interpretation of imaging is achieved.