A decade of progress in critical care echocardiography: a narrative review

Transesophageal echocardiography-associated tracheal microaspiration and ventilator-associated pneumonia in intubated critically ill patients: a multicenter prospective observational study

BACKGROUND

Microaspiration of gastric and oropharyngeal secretions is the main causative mechanism of ventilator-associated pneumonia (VAP). Transesophageal echocardiography (TEE) is a routine investigation tool in intensive care unit and could enhance microaspiration. This study aimed at evaluating the impact of TEE on microaspiration and VAP in intubated critically ill adult patients.

METHODS

It is a four-center prospective observational study. Microaspiration biomarkers (pepsin and salivary amylase) concentrations were quantitatively measured on tracheal aspirates drawn before and after TEE. The primary endpoint was the percentage of patients with TEE-associated microaspiration, defined as: (1) ≥ 50% increase in biomarker concentration between pre-TEE and post-TEE samples, and (2) a significant post-TEE biomarker concentration (> 200 μg/L for pepsin and/or > 1685 IU/L for salivary amylase). Secondary endpoints included the development of VAP within three days after TEE and the evolution of tracheal cuff pressure throughout TEE.

RESULTS

We enrolled 100 patients (35 females), with a median age of 64 (53-72) years. Of the 74 patients analyzed for biomarkers, 17 (23%) got TEE-associated microaspiration. However, overall, pepsin and salivary amylase levels were not significantly different between before and after TEE, with wide interindividual variability. VAP occurred in 19 patients (19%) within 3 days following TEE. VAP patients had a larger tracheal tube size and endured more attempts of TEE probe introduction than their counterparts but showed similar aspiration biomarker concentrations. TEE induced an increase in tracheal cuff pressure, especially during insertion and removal of the probe.

CONCLUSIONS

We could not find any association between TEE-associated microaspiration and the development of VAP during the three days following TEE in intubated critically ill patients. However, our study cannot formally rule out a role for TEE because of the high rate of VAP observed after TEE and the limitations of our methods.

The PRICES statement: an ESICM expert consensus on methodology for conducting and reporting critical care echocardiography research studies

PURPOSE

Echocardiography is a common tool for cardiac and hemodynamic assessments in critical care research. However, interpretation (and applications) of results and between-study comparisons are often difficult due to the lack of certain important details in the studies. PRICES (Preferred Reporting Items for Critical care Echocardiography Studies) is a project endorsed by the European Society of Intensive Care Medicine and conducted by the Echocardiography Working Group, aiming at producing recommendations for standardized reporting of critical care echocardiography (CCE) research studies.

METHODS

The PRICE panel identified lists of clinical and echocardiographic parameters (the "items") deemed important in four main areas of CCE research: left ventricular systolic and diastolic functions, right ventricular function and fluid management. Each item was graded using a critical index (CI) that combined the relative importance of each item and the fraction of studies that did not report it, also taking experts' opinion into account.

RESULTS

A list of items in each area that deemed essential for the proper interpretation and application of research results is recommended. Additional items which aid interpretation were also proposed.

CONCLUSION

The PRICES recommendations reported in this document, as a checklist, represent an international consensus of experts as to which parameters and information should be included in the design of echocardiography research studies. PRICES recommendations provide guidance to scientists in the field of CCE with the objective of providing a recommended framework for reporting of CCE methodology and results.

[Ultrasound in the management of the critically ill patient with SARS-CoV-2 infection (COVID-19): narrative review]

The clinical picture of SARS-CoV-2 infection (COVID-19) is characterized in its more severe form, by an acute respiratory failure which can worsen to pneumonia and acute respiratory distress syndrome (ARDS) and get complicated with thrombotic events and heart dysfunction. Therefore, admission to the Intensive Care Unit (ICU) is common. Ultrasound, which has become an everyday tool in the ICU, can be very useful during COVID-19 pandemic, since it provides the clinician with information which can be interpreted and integrated within a global assessment during the physical examination. A description of some of the potential applications of ultrasound is depicted in this document, in order to supply the physicians taking care of these patients with an adapted guide to the intensive care setting. Some of its applications since ICU admission include verification of the correct position of the endotracheal tube, contribution to safe cannulation of lines, and identification of complications and thrombotic events. Furthermore, pleural and lung ultrasound can be an alternative diagnostic test to assess the degree of involvement of the lung parenchyma by means of the evaluation of specific ultrasound patterns, identification of pleural effusions and barotrauma. Echocardiography provides information of heart involvement, detects cor pulmonale and shock states.

Narrative review of ultrasound in the management of the critically ill patient with SARS-CoV-2 infection (COVID-19): clinical applications in intensive care medicine

The clinical picture of SARS-CoV-2 infection (COVID-19) is characterized in its more severe form, by an acute respiratory failure which can worsen to pneumonia and acute respiratory distress syndrome (ARDS), and get complicated with thrombotic events and heart dysfunction. Therefore, admission to the Intensive Care Unit (ICU) is common.

Ultrasound, which has become an everyday tool in the ICU, can be very useful during COVID-19 pandemic, since it provides the clinician with information which can be interpreted and integrated within a global assessment during the physical examination. A description of some of the potential applications of ultrasound is depicted in this document, in order to supply the physicians taking care of these patients with a adapted guide to the intensive care setting.

Some of its applications since ICU admission include verification of the correct position of the endotracheal tube, contribution to safe cannulation of lines, and identification of complications and thrombotic events. Furthermore, pleural and lung ultrasound can be an alternative diagnostic test to assess the degree of involvement of the lung parenchyma by means of the evaluation of specific ultrasound patterns, identification of pleural effusions and barotrauma. Echocardiography provides information of heart involvement, detects cor pulmonale and shock states.

This is your toolkit in hemodynamic monitoring

PURPOSE OF REVIEW

To appraise the basic and more advanced methods available for hemodynamic monitoring, and describe the definitions and criteria for the use of hemodynamic variables.

RECENT FINDINGS

The hemodynamic assessment in critically ill patients suspected of circulatory shock follows a step-by-step algorithm to help determine diagnosis and prognosis. Determination of accurate diagnosis and prognosis in turn is crucial for clinical decision-making. Basic monitoring involving clinical examination in combination with hemodynamic variables obtained with an arterial catheter and a central venous catheter may be sufficient for the majority of patients with circulatory shock. In case of uncertainty of the underlying cause or to guide treatment in severe shock may require additional advanced hemodynamic technologies, and each is utilized for different indications and has specific limitations. Future developments include refining the clinical examination and performing studies that demonstrate better patient outcomes by targeting hemodynamic variables using advanced hemodynamic monitoring.

SUMMARY

Determination of accurate diagnosis and prognosis for patients suspected of circulatory shock is essential for optimal decision-making. Numerous techniques are available, and each has its specific indications and value.

Implementation and Calibration of a Deep Neural Network to Predict Parameters of Left Ventricular Systolic Function Based on Pulmonary and Systemic Arterial Pressure Signals

The evaluation of cardiac contractility by the assessment of the ventricular systolic elastance function is clinically challenging and cannot be easily obtained at the bedside. In this work, we present a framework characterizing left ventricular systolic function from clinically readily available data, including systemic and pulmonary arterial pressure signals. We implemented and calibrated a deep neural network (DNN) consisting of a multi-layer perceptron with 4 fully connected hidden layers and with 16 neurons per layer, which was trained with data obtained from a lumped model of the cardiovascular system modeling different levels of cardiac function. The lumped model included a function of circulatory autoregulation from carotid baroreceptors in pulsatile conditions. Inputs for the DNN were systemic and pulmonary arterial pressure curves. Outputs from the DNN were parameters of the lumped model characterizing left ventricular systolic function, especially end-systolic elastance. The DNN adequately performed and accurately recovered the relevant hemodynamic parameters with a mean relative error of less than 2%. Therefore, our framework can easily provide complex physiological parameters of cardiac contractility, which could lead to the development of invaluable tools for the clinical evaluation of patients with severe cardiac dysfunction.

Teaching vs learning: Impact of deliberate practice and formative feedback on developing point of care ultrasound skills

PURPOSE

The study investigators hypothesized that Point of Care Ultrasound (POCUS) training through bolus didactic and workshop experiences may be sufficient for trainees to learn the cognitive aspects, while an extended period of exposure with formative feedback is responsible for developing the psychomotor skills critical for POCUS.

METHODS

The investigators studied trainees over the course of an academic year. They compared trainees' performance on written (cognitive) and observed image acquisition (psychomotor) exams at baseline and at each subsequent quarter, using a stepped-wedge design. They performed linear regression analysis to determine which variables contributed to knowledge and psychomotor skill development.

RESULTS

Twenty-six trainees met the study requirements and participated in the POCUS curriculum. Participating in a POCUS rotation was consistently associated with an increase in psychomotor scores. There was no consistent variable to predict an increase in trainee's score on written knowledge assessments.

CONCLUSIONS

Extended exposure to POCUS over a 4-week rotation with direct and indirect formative feedback can explain difference in scores on psychomotor skills assessments. Trainees scored similarly on the written assessment with or without a POCUS rotation. Training through didactic and workshop experiences may be sufficient to learn the cognitive aspects, but not psychomotor skills required for POCUS.

Association of weaning failure from mechanical ventilation with transthoracic echocardiography parameters: a systematic review and meta-analysis

BACKGROUND

Weaning from mechanical ventilation is a challenging step during recovery from critical illness. Weaning failure or early reintubation are associated with increased morbidity and mortality, exposing patients to life-threatening complications. Cardiac dysfunction represents the most common cause of weaning failure. We conducted a systematic review and meta-analysis to evaluate the association between transthoracic echocardiographic parameters and weaning failure.

METHODS

We performed a systematic search of MEDLINE and EMBASE screening for prospective studies providing echocardiographic data collected just before the beginning of spontaneous breathing trial and outcome of the weaning attempt. We primarily focused on parameters currently recommended for evaluation of left ventricular (LV) systolic or diastolic dysfunction.

RESULTS

We included 11 studies in our primary analysis, which included data on LV ejection fraction (LVEF, n=10 studies) and parameters recommended for the assessment of LV diastolic function (E/e' ratio n=10; E/A ratio n=9; E wave n=8; and e' wave n=7). Weaning failure was significantly associated to a higher E/e' ratio (standardised mean difference [SMD]=1.70, 95% confidence interval [CI; 0.78-2.62]; P<0.001), lower e' wave (SMD=-1.22, 95% CI [-2.33 to -0.11]; P=0.03), and higher E wave (SMD=0.97, 95% CI [0.29-1.65]; P=0.005). We found no association between weaning failure and LVEF (SMD=-0.86, 95% CI [-1.92-0.20]; P=0.11) and E/A ratio (SMD=0.00, 95% CI [-0.30-0.31]; P=0.98).

CONCLUSIONS

Weaning failure is associated with parameters indicating worse LV diastolic function (E/e', e' wave, E wave) and increased LV filling pressure (E/e' ratio). The association between weaning failure and LV systolic dysfunction as evaluated by LVEF is more unclear. More studies are needed to clarify this aspect and regarding the role of right ventricular function.

Can Left ventricular outflow tract aortic velocity time integral guide fluid resuscitation in septic patients? - A case report

Hemodynamic monitoring of unstable patients is an everyday issue for Emergency Physicians (EP). Considering the difficulty, in Emergency Department (ED) settings, to assess invasively Stroke Volume (SV), Cardiac Output (CO) and Peripheral Vascular Resistance (PVR), EP should be familiar with non-invasive, easy and reproducible methods that can estimate these parameters. The use of Left Ventricular Outflow Tract aortic Velocity Time Integral (LVOT-VTI) with echocardiography, as estimate of SV, integrated with inferior vena cava collapse index and clinical examination could give the opportunity to non-invasively understand at which point of an ideal cardiac output/central venous pressure relation (according to the Frank Starling law) the patient is situated. In this case report we describe a septic patient accessing the ED with both respiratory and cardiac failure, and we show that the use of aortic LVOT-VTI is an easy and reproducible approach to understand cardiac hemodynamic in scenarios involving multiple pathologic mechanisms.

Subcostal versus transhepatic view to assess the inferior vena cava in critically ill patients

BACKGROUND

Evaluation of the inferior vena cava (IVC) is not always possible through the subcostal (SC) window.

METHODS

Inferior vena cava diameters measured by transhepatic (TH) and SC views were compared by Bland and Altman analysis.

RESULTS

131 patients were enrolled, including 88 (67%) under mechanical ventilation. The echogenicity was statistically poorer through the TH view in comparison with the SC view (P = .002). The correlation between the SC and TH views was good and better for respiratory variation than for end-expiratory or end-inspiratory diameter measurements (r = 0.86). Despite low bias, the limits of agreement were wide (-7.5 and 7.7 mm for end-expiratory diameter, -8.7 and 8.5 mm for end-inspiratory diameter, and -5.3 and 5.8 mm for respiratory variation). Complementary analysis showed that the concordance between the SC and the TH views was better when the IVC was distended. However, the limits of agreement remained broad.

CONCLUSIONS

Although feasible in almost all patients, the TH view does not provide better echogenicity in comparison with the SC view. Despite a good correlation with the SC view and a low bias, the limits of agreement were wide, especially when the IVC has an ellipsoidal shape, suggesting caution in the interpretation of data obtained by the TH view.

Training and Accreditation Pathways in Critical Care and Perioperative Echocardiography

In recent years, there has been a dramatic rise in the use of echocardiography in perioperative and critical care medicine. It is now recommended widely as a first-line diagnostic tool when approaching patients in shock, due to its ability to identify shock etiology and response to treatment noninvasively. To match the increasing training demand, and to ensure maintenance of high-quality and reproducible scanning, several accreditation pathways have been developed worldwide. Critical care echocardiography training pathways can include both transthoracic and transesophageal scanning and range from basic focused protocols to advanced comprehensive scans. The complexity of each individual training program is reflected in its accreditation process. While basic accreditations may require only course attendance and a relatively brief logbook, comprehensive accreditations often require extensive logbooks and written and practical examinations. Currently, the use of transoesophageal echocardiography remains restricted largely to cardiothoracic anesthesia and critical care; however, its use in the general intensive care setting is growing. This narrative review summarizes the most common training pathways, their curricula, and accreditation requirements. The authors initially focus on echocardiography training in the United Kingdom, and then go on to describe similar international accreditations available in Europe, North America, and Australasia.

Indications for and Findings on Transthoracic Echocardiography in COVID-19

Background

Despite growing evidence of cardiovascular complications associated with coronavirus disease 2019 (COVID-19), there are few data regarding the performance of transthoracic echocardiography (TTE) and the spectrum of echocardiographic findings in this disease.

Methods

A retrospective analysis was performed among adult patients admitted to a quaternary care center in New York City between March 1 and April 3, 2020. Patients were included if they underwent TTE during the hospitalization after a known positive diagnosis for COVID-19. Demographic and clinical data were obtained using chart abstraction from the electronic medical record.

Results

Of 749 patients, 72 (9.6%) underwent TTE following positive results on severe acute respiratory syndrome coronavirus-2 polymerase chain reaction testing. The most common clinical indications for TTE were concern for a major acute cardiovascular event (45.8%) and hemodynamic instability (29.2%). Although most patients had preserved biventricular function, 34.7% were found to have left ventricular ejection fractions ≤ 50%, and 13.9% had at least moderately reduced right ventricular function. Four patients had wall motion abnormalities suggestive of stress-induced cardiomyopathy. Using Spearman rank correlation, there was an inverse relationship between high-sensitivity troponin T and left ventricular ejection fraction (ρ = −0.34, P = .006). Among 20 patients with prior echocardiograms, only two (10%) had new reductions in LVEF of >10%. Clinical management was changed in eight individuals (24.2%) in whom TTE was ordered for concern for acute major cardiovascular events and three (14.3%) in whom TTE was ordered for hemodynamic evaluation.

Conclusions

This study describes the clinical indications for use and diagnostic performance of TTE, as well as findings seen on TTE, in hospitalized patients with COVID-19. In appropriately selected patients, TTE can be an invaluable tool for guiding COVID-19 clinical management.

Evolving Role of Anesthesiology Intensivists in Cardiothoracic Critical Care

The role of cardiothoracic anesthesiology intensivists has expanded over the past few decades. Cardiothoracic anesthesiology intensivists are taking on larger roles in cardiac critical care specializing in cardiogenic shock and extracorporeal membrane oxygenation.

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.

Sepsis-Induced Cardiomyopathy: a Comprehensive Review

Purpose of Review

To briefly review epidemiology and pathophysiology of SICM and provide a more extensive review of the data on diagnostic and management strategies.

Recent Findings

SICM is likely underdiagnosed and that has mortality implications. Current evidence supports speckle tracking echocardiography to identify decreased contractility irrespective of left ventricular ejection fraction for the diagnosis of SICM. There continues to be a dearth of large clinical trials evaluating the treatment of SICM and current consensus focuses on supportive measures such as vasopressors and inotropes.

Summary

Sepsis is a significant cause of mortality, and sepsis-induced cardiomyopathy has both prognostic and management implications for these patients. Individualized work-up and management of these patients is crucial to improving outcomes.

Systematic review and literature appraisal on methodology of conducting and reporting critical-care echocardiography studies: a report from the European Society of Intensive Care Medicine PRICES expert panel

Background

The echocardiography working group of the European Society of Intensive Care Medicine recognized the need to provide structured guidance for future CCE research methodology and reporting based on a systematic appraisal of the current literature. Here is reported this systematic appraisal.

Methods

We conducted a systematic review, registered on the Prospero database. A total of 43 items of common interest to all echocardiography studies were initially listed by the experts, and other “topic-specific” items were separated into five main categories of interest (left ventricular systolic function, LVSF n = 15, right ventricular function, RVF n = 18, left ventricular diastolic function, LVDF n = 15, fluid management, FM n = 7, and advanced echocardiography techniques, AET n = 17). We evaluated the percentage of items reported per study and the fraction of studies reporting a single item.

Results

From January 2000 till December 2017 a total of 209 articles were included after systematic search and screening, 97 for LVSF, 48 for RVF, 51 for LVDF, 36 for FM and 24 for AET. Shock and ARDS were relatively common among LVSF articles (both around 15%) while ARDS comprised 25% of RVF articles. Transthoracic echocardiography was the main echocardiography mode, in 87% of the articles for AET topic, followed by 81% for FM, 78% for LVDF, 70% for LVSF and 63% for RVF. The percentage of items per study as well as the fraction of study reporting an item was low or very low, except for FM. As an illustration, the left ventricular size was only reported by 56% of studies in the LVSF topic, and half studies assessing RVF reported data on pulmonary artery systolic pressure.

Conclusion

This analysis confirmed sub-optimal reporting of several items listed by an expert panel. The analysis will help the experts in the development of guidelines for CCE study design and reporting.

Respiratory muscle ultrasonography: methodology, basic and advanced principles and clinical applications in ICU and ED patients-a narrative review

Respiratory muscle ultrasound is used to evaluate the anatomy and function of the respiratory muscle pump. It is a safe, repeatable, accurate, and non-invasive bedside technique that can be successfully applied in different settings, including general intensive care and the emergency department. Mastery of this technique allows the intensivist to rapidly diagnose and assess respiratory muscle dysfunction in critically ill patients and in patients with unexplained dyspnea. Furthermore, it can be used to assess patient-ventilator interaction and weaning failure in critically ill patients. This paper provides an overview of the basic and advanced principles underlying respiratory muscle ultrasound with an emphasis on the diaphragm. We review different ultrasound techniques useful for monitoring of the respiratory muscle pump and possible therapeutic consequences. Ideally, respiratory muscle ultrasound is used in conjunction with other components of critical care ultrasound to obtain a comprehensive evaluation of the critically ill patient. We propose the ABCDE-ultrasound approach, a systematic ultrasound evaluation of the heart, lungs and respiratory muscle pump, in patients with weaning failure.

Cardiopulmonary resuscitation in newborn infants with ultrasound in the delivery room

Point of care ultrasound has emerged as useful tool in cardiac arrest situations in adult population. Despite of these, there is not a protocol for cardiopulmonary resuscitation in the delivery room for newborns. We describe two case were ultrasound helped to rule out the cardiopulmonary arrest case and we propose and algorithm were ultrasound is integrated in the newborn resuscitation and may help to diagnose the cardiac arrest cause.