Focused critical care echocardiography

Hemodynamic Support in Sepsis

This review discusses recent evidence in managing sepsis-induced hemodynamic alterations and how it can be integrated with previous knowledge for actionable interventions in adult patients.

Is 1 Day of Focused Training in Echocardiographic Assessment Using Subxiphoid-Only (EASy) Examination Enough? A Tertiary Hospital Response to the COVID-19 Crisis and the Use of the EASy Examination to Support Unit-Wide Image Acquisition

OBJECTIVES

We assessed the efficacy of 1-day training in echocardiography assessment using subxiphoid-only (EASy) followed by supervised image interpretation and decision-making during patient rounds as a novel approach to scaling up the use of point-of-care ultrasound (POCUS) in critically ill patients.

DESIGN

Retrospective analysis of medical records and EASy examination images.

SETTING

Tertiary care academic hospital.

PATIENTS

A total of 14 adults (> 18 yr old) with COVID-19-associated respiratory failure under the care of Albany Medical Center's surge response team from April 6-17, 2020 who received at least one EASy examination.

INTERVENTIONS

Residents (previously novice sonographers) were trained in EASy examination using 1 day of didactic and hands-on training, followed by independent image acquisition and supervised image interpretation, identification of hemodynamic patterns, and clinical decision-making facilitated by an echocardiography-certified physician during daily rounds.

MEASUREMENTS AND MAIN RESULTS

We recorded the quality of resident-obtained EASy images, scanning time, and frequency with which the supervising physician had to repeat the examination or obtain additional images. A total of 63 EASy examinations were performed; average scanning time was 4.3 minutes. Resident-obtained images were sufficient for clinical decision-making on 55 occasions (87%), in the remaining 8 (13%) the supervising physician obtained further images.

CONCLUSIONS

EASy examination is an efficient, valuable tool under conditions of scarce resources. The educational model of 1-day training followed by supervised image interpretation and decision-making allows rapid expansion of the pool of sonographers and implementation of bedside echocardiography into routine ICU patient management.

Quantification of left ventricular ejection fraction and cardiac output using a novel semi-automated echocardiographic method: a prospective observational study in coronary artery bypass patients

BACKGROUND

Echocardiographic quantification of ejection fraction (EF) by manual endocardial tracing requires training, is time-consuming and potentially user-dependent, whereas determination of cardiac output by pulmonary artery catheterization (PAC) is invasive and carries a risk of complications. Recently, a novel software for semi-automated EF and CO assessment (AutoEF) using transthoracic echocardiography (TTE) has been introduced. We hypothesized that AutoEF would provide EF values different from those obtained by the modified Simpson's method in transoesophageal echocardiography (TOE) and that AutoEF CO measurements would not agree with those obtained via VTI_LVOT in TOE and by thermodilution using PAC.

METHODS

In 167 patients undergoing coronary artery bypass graft surgery (CABG), TTE cine loops of apical 4- and 2-chamber views were recorded after anaesthesia induction under steady-state conditions. Subsequently, TOE was performed following a standardized protocol, and CO was determined by thermodilution. EF and CO were assessed by TTE AutoEF as well as TOE, using the modified Simpson's method, and Doppler measurements via velocity time integral in the LV outflow tract (VTI_LVOT). We determined Pearson's correlation coefficients r and carried out Bland-Altman analyses. The primary endpoints were differences in EF and CO. The secondary endpoints were differences in left ventricular volumes at end diastole (LVEDV) and end systole (LVESV).

RESULTS

AutoEF and the modified Simpson's method in TOE showed moderate EF correlation (r = 0.38, p < 0.01) with a bias of -12.6% (95% limits of agreement (95%LOA): -36.6 - 11.3%). AutoEF CO correlated poorly both with VTI_LVOT in TOE (r = 0.19, p < 0.01) and thermodilution (r = 0.28, p < 0.01). The CO bias between AutoEF and VTI_LVOT was 1.33 l min^-1 (95%LOA: -1.72 - 4.38 l min^-1) and 1.39 l min^-1 (95%LOA -1.34 - 4.12 l min^-1) between AutoEF and thermodilution, respectively. AutoEF yielded both significantly lower EF (EF_AutoEF: 42.0% (IQR 29.0 - 55.0%) vs. EF_{TOE Simpson}: 55.2% (IQR 40.1 - 70.3%), p < 0.01) and CO values than the reference methods (CO_{AutoEF biplane}: 2.30 l min^-1 (IQR 1.30 - 3.30 l min^-1) vs. CO_{VTI LVOT}: 3.64 l min^-1 (IQR 2.05 - 5.23 l min^-1) and CO_PAC: 3.90 l min^-1 (IQR 2.30 - 5.50 l min^-1), p < 0.01)).

CONCLUSIONS

AutoEF correlated moderately with TOE EF determined by the modified Simpson's method but poorly both with VTI_LVOT and thermodilution CO. A systematic bias was detected overestimating LV volumes and underestimating both EF and CO compared to the reference methods.

TRIAL REGISTRATION

German Register for Clinical Trials (DRKS-ID DRKS00010666, date of registration: 08/07/2016).

Anesthetic management of patients undergoing cardiac myxoma resection: a single-center retrospective analysis

Background

Myxomas are the most common primary cardiac tumors. Intracardiac myxomas, although benign, could cause serious consequences such as tricuspid or mitral valve obstruction, hemodynamic collapse, and acute heart failure, which pose challenges during anesthetic management. The current study was designed to summarize the anesthetic management of patients undergoing cardiac myxoma resection.

Methods

This study was performed retrospectively from the perioperative period of patients who underwent myxoma resection. Patients were divided into two groups according to whether the myxoma prolapsed into the ventricle (group O) or not (group N) to evaluate the impact of tricuspid or mitral valve with obstruction.

Results

110 patients, aged 17-78 years, undergoing cardiac myxoma resection between January 2019 and December 2021 were collected, and their perioperative characteristics were recorded. In the preoperative evaluation, common clinical symptoms included dyspnea and palpitation, whereas embolic events occurred in 8 patients, including 5 (4.5%) cerebral thromboembolic events, 2 (1.8%) femoral artery, and 1 (0.9%) obstructive coronary artery. According to the echocardiography, left atrial myxoma was detected in 104 (94.5%) patients, the average dimension of myxoma was 4.03 cm ± 1.52 cm in the largest diameter, and 48 patients were divided into group O. During intraoperative anesthetic management, hemodynamic instability occurred in 38 (34.5%) patients after anesthesia induction. More patients in group O had hemodynamic instability (47.9% vs. 24.2%, p = 0.009) than in group N. The mean postoperative length of stay in the hospital was 10.64 ± 3.01 days, and most of the patients made an uneventful postoperative recovery.

Conclusions

Anesthetic management for myxoma resection can be composed by assessing the myxoma, particularly the echocardiography evaluation and preventing cardiovascular instability. Typically, tricuspid or mitral valve with obstruction is a premier ingredient in anesthetic management.

Focused cardiac ultrasound examination in the emergency and critical care equine patient: Training for non-specialist veterinarians and evaluation of proficiency

Background

Focused cardiac ultrasound examination (FoCUS) is rapidly emerging for point‐of‐care cardiac assessment using hand‐carried ultrasound (HCU) devices. A specific FoCUS protocol for horses and adequate training guidelines currently are not available.

Hypothesis

To gain knowledge about the training necessary to become proficient in performing FoCUS using a HCU device.

Animals

Three healthy Warmblood horses were used for practical training of veterinarians and veterinary students in equine focused cardiac ultrasound (eFoCUS).

Methods

Prospective educational study. An eFoCUS protocol and 1‐day training course were developed. Pre‐ and post‐course written tests were administered to participants to evaluate proficiency in knowledge of echocardiography and echocardiographic pathology. A post‐course practical examination involved performing eFoCUS and storage of representative images. Images were evaluated using an image quality score and compared between participants with some practical experience and participants with no practical experience.

Results

Participants' knowledge of echocardiography increased significantly. Recognition of echocardiographic pathology pre‐course ranged from 40% to 90% (mean score, 65.7%) and post‐course from 85% to 100% (mean score, 92%). Eighteen of 21 participants were proficient in performing eFoCUS with a median image quality score of 79% (range, 42%‐95%). Image quality did not differ between participants with some practical experience compared to participants with no experience.

Conclusions and Clinical Importance

Veterinarians and veterinary students independent of previous experience can become proficient in performing eFoCUS after completion of a 1‐day training course.

Point-of-care ultrasound in cardiorespiratory arrest (POCUS-CA): narrative review article

The POCUS-CA (Point-of-care ultrasound in cardiac arrest) is a diagnostic tool in the Intensive Care Unit and Emergency Department setting. The literature indicates that in the patient in a cardiorespiratory arrest it can provide information of the etiology of the arrest in patients with non-defibrillable rhythms, assess the quality of compressions during cardiopulmonary resuscitation (CPR), and define prognosis of survival according to specific findings and, thus, assist the clinician in decision-making during resuscitation. This narrative review of the literature aims to expose the usefulness of ultrasound in the setting of cardiorespiratory arrest as a tool that allows making a rapid diagnosis and making decisions about reversible causes of this entity. More studies are needed to support the evidence to make ultrasound part of the resuscitation algorithms. Teamwork during cardiopulmonary resuscitation and the inclusion of ultrasound in a multidisciplinary approach is important to achieve a favorable clinical outcome.

Comparison of qualitative information obtained with the echocardiographic assessment using subcostal-only view and focused transthoracic echocardiography examinations: a prospective observational study

Purpose

To evaluate whether echocardiographic assessment using the subcostal-only window (EASy) compared with focused transthoracic echocardiography (FTTE) using three windows (parasternal, apical, and subcostal) can provide critical information to serve as an entry-point technique for novice sonographers.

Methods

We conducted a retrospective study to compare diagnostic information acquired during EASy and FTTE examinations on qualitative left ventricular (LV) size, LV contractility, right ventricular (RV) size, RV contractility, interventricular septal position, and the presence of a significant pericardial effusion. Anesthesiology residents (novice users) performed FTTE for hemodynamic instability and/or respiratory distress or to define volume status in the perioperative setting, and later collected images were grouped into EASy and FTTE examinations. Both examinations were reviewed independently by a board-certified cardiologist and an anesthesiologist proficient in critical care echocardiography. FTTE and EASy findings were compared utilizing Gwet’s AC1 coefficient to consider disagreement due to chance.

Results

We reviewed 102 patients who received FTTE over a period of 14 months. Of those, 82 had usable subcostal views and were included in the analysis. There was substantial agreement for qualitatively evaluating RV size (Gwet’s AC1, 0.70; 95% confidence interval [CI], 0.54 to 0.85), LV size (Gwet’s AC1, 0.73; 95% CI, 0.58 to 0.88), and LV contractility (Gwet’s AC1, 0.73; 95% CI, 0.58 to 0.88) utilizing EASy and FTTE. Additionally, there was an almost perfect agreement when assessing the presence of pericardial effusion (Gwet’s AC1, 0.98; 95% CI, 0.95 to 1.0) and RV contractility (Gwet’s AC1, 0.84; 95% CI, 0.74 to 0.95) and evaluating the motion of the interventricular septum (Gwet’s AC1, 0.92; 95% CI, 0.85 to 0.99).

Conclusions

When images could be obtained from the subcostal window (the EASy examination), qualitative diagnostic information was sufficiently accurate compared with information obtained during FTTE examination. Our findings suggest that the EASy examination can serve as the entry point technique to FTTE for novice clinicians.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12630-021-02152-6.

The Impact of Focused Cardiac Ultrasound Performed by Pediatric Intensivists: A Prospective Study

OBJECTIVES

Focused cardiac ultrasound is an echocardiographic method used by medical intensivists for fast and reliable hemodynamic assessment. Prospective studies and guidelines have defined its role in adult critical care. Data regarding its use in pediatric critical care are scarce. This is the first prospective study that aims to evaluate its impact in this setting.

METHODS

This is a single-center prospective study performed in a tertiary referral hospital pediatric intensive care unit (PICU). For a period of 6 months, when performing an echocardiogram, pediatric intensivists filled out a questionnaire that included the patient's clinical data and indication for the examination. The intensivists had to record both the clinical impression regarding that indication and therapeutic plan before and after the echocardiogram. All the patients with an echocardiogram performed by the pediatric intensive care unit medical staff were included.

RESULTS

There were 80 echocardiograms performed on 35 patients during the study period. The most common patient diagnostic groups were respiratory infections (38%, n = 30) and septic shock (21%, n = 17). The main indication for the examination was assessment of intravascular volume status and left ventricular systolic function. After the echocardiogram, the clinical impression was maintained in 49% (n = 39) and changed in 44% (n = 35). There were new findings unrelated to the initial evaluation in 7% (n = 6). The planned treatment was maintained in 55% (n = 44) and changed in 45% (n = 36).

CONCLUSIONS

The echocardiogram changed the clinical impression and therapeutic plan in almost half of the patients. These data show the value of focused cardiac ultrasound as a diagnostic and hemodynamic monitoring tool in pediatric intensive care and emphasize the importance of a rigorous training program.

Vasopressors in Trauma: A Never Event?

Vasopressor use in severely injured trauma patients is discouraged due to concerns that vasoconstriction will worsen organ perfusion and result in increased mortality and organ failure in hypotensive trauma patients. Hypotensive resuscitation is advocated based on limited data that lower systolic blood pressure and mean arterial pressure will result in improved mortality. It is classically taught that hypotension and hypovolemia in trauma are associated with peripheral vasoconstriction. However, the pathophysiology of traumatic shock is complex and involves multiple neurohormonal interactions that are ultimately manifested by an initial sympathoexcitatory phase that attempts to compensate for acute blood loss and is characterized by vasoconstriction, tachycardia, and preserved mean arterial blood pressure. The subsequent hypotension observed in hemorrhagic shock reflects a sympathoinhibitory vasodilation phase. The objectives of hemodynamic resuscitation in hypotensive trauma patients are restoring adequate intravascular volume with a balanced ratio of blood products, correcting pathologic coagulopathy, and maintaining organ perfusion. Persistent hypotension and hypoperfusion are associated with worse coagulopathy and organ function. The practice of hypotensive resuscitation would appear counterintuitive to the goals of traumatic shock resuscitation and is not supported by consistent clinical data. In addition, excessive volume resuscitation is associated with adverse clinical outcomes. Therefore, in the resuscitation of traumatic shock, it is necessary to target an appropriate balance with intravascular volume and vascular tone. It would appear logical that vasopressors may be useful in traumatic shock resuscitation to counteract vasodilation in hemorrhage as well as other clinical conditions such as traumatic brain injury, spinal cord injury, multiple organ dysfunction syndrome, and vasodilation of general anesthetics. The purpose of this article is to discuss the controversy of vasopressors in hypotensive trauma patients and advocate for a nuanced approach to vasopressor administration in the resuscitation of traumatic shock.

Quality Assurance and Improvement Project in Echocardiography Laboratory: The Pivotal Importance of Organizational and Managerial Processes

Echocardiography plays a vital role in the diagnosis and management of cardiovascular conditions. Echocardiography use is progressively increasing nowadays, and this is correlated to the evolving echo indications, to the relatively new available echocardiography modes (tissue Doppler imaging, speckle tracking imaging, three-dimensional mode, etc.) and modalities (transthoracic, transesophageal, and intracardiac) along with the various available clinical approaches (point of care echo, portable echo, etc.). Quality assurance in echocardiography is correlated to appropriate use criteria, adequate equipment, standardization of performance and reporting, along with timely storage and archiving. Quality improvement plan must target strategic planning, with metrics and timeline for assessment and re-assessment of results. Improvement project aims to ensure and enhance conformity with appropriate use criteria and standardization, timely completion of exams and reports, detection of discrepancies, and continuous improvement of knowledge and skills. Strategic planning is essential in this context in order to develop organizational and managerial processes, with regular auditing for a highly professional and advanced level of echocardiography, while ensuring teamwork and standards of ethical values.

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.

Transesophageal echocardiography instead or in addition to transthoracic echocardiography in evaluating haemodynamic problems in intubated critically ill patients

Background

Transesophageal echocardiography (TEE) performed by intensivists is increasingly used in critically ill patients. However, TEE is usually not the preferred monitoring tool, especially when transthoracic echocardiography (TTE) appears to have addressed the clinical problems. As a result, it remains largely unknown whether TEE is a clinically valuable replacement or supplement for TTE as a primary tool in evaluating haemodynamic problems in critically ill surgical patients. The purpose of this study was to assess the diagnostic and therapeutic value of TEE instead or in addition to TTE in critically ill surgical patients with hemodynamic instability.

Methods

A prospective observational study was conducted. A total of 68 consecutive patients were enrolled from December 2016 to February 2018. TEE was routinely performed in addition to TTE, and the imaging data from TTE and TEE were successively disclosed to two different primary physicians, who reported any resulting changes in management. The two physicians were required to reach a consensus if there was any disagreement. The results of the additional TEE examination were compared with the clinical findings and TTE information. The image quality of TTE views was classified as a good (score 2), suboptimal (score 1) or poor view (score 0). According to the scores of TTE images, the patients were divided into two groups: patients with adequate TTE views (score ≥6) and inadequate TTE views (score <6).

Results

The results of additional TEE examination were classified into four categories. TEE failed to provide additional information about the initial diagnosis and therapy (class 1) in 26 patients (38.2%). Of the remaining 42 patients (61.8%), TEE instead or in addition to TTE revealed new findings or led to significant changes in therapy, as TTE supplied inadequate information. TEE used in addition to TTE led to a new diagnosis without therapeutic implications (class 2) in 11 patients (16.2%) and made a major clinical contribution leading to a therapeutic change (class 3) in 23 patients (33.8%). TEE used instead of TTE determined the diagnosis and therapy in 8 patients (11.8%) whose haemodynamic problems could not be addressed by TTE (class 4). In total, TEE had critical therapeutic benefits (class 3 and 4) that was not provided by TTE in 31 patients (45.6%). Of particular concern was that TEE had a higher proportion of therapeutic benefits to patients with inadequate TTE views than those with adequate TTE views (54.3% vs. 27.3%, P=0.036).

Conclusions

TEE as a feasible clinical tool is useful for critically ill surgical patients with hemodynamic instability, especially for the patients with inadequate TTE views. TEE instead or in addition to TTE could provide valuable information for diagnosis, which may bring significant therapeutic benefits.

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.

Physicians' abilities to obtain and interpret focused cardiac ultrasound images from critically ill patients after a 2-day training course

Background

This study aimed to determine whether a focused 2-day cardiac ultrasound training course could enable physicians to obtain and interpret focused cardiac ultrasound (FCU) images from critically ill patients.

Methods

We retrospectively reviewed the FCU images submitted by the physicians who attended a 2-day FCU training courses. Three experienced trainers reviewed the images separately. They determined whether the images were assessable and scored the images on an 8-point scale. They also decided whether the physicians provided correct responses for visual estimations of the left ventricular ejection fraction (LVEF) and right ventricle (RV) dilatation and septal motion.

Results

Among the 327 physicians, 291 obtained images that were considered assessable (89%). The scores for parasternal short-axis view were lower than those obtained for other transthoracic echocardiographic views, p < 0.001. More physicians provided incorrect appraisals of LVEF than of RV dilatation and septal motion (19.9% vs. 3.1%, p < 0.001). The percentages of incorrect answers by LVEF category were as follows: 34.8% on images of LVEF < 30, 24.7% on images of LVEF 30–54, and 16.4% on images of LVEF ≥55%, p < 0.001. A logistic regression analysis showed that patients with abnormal LVEF were associated with physicians’ incorrect assessment of LVEF, with an odds ratio of 1.923 (95% confidence interval (CI):1.071–3.456, p = 0.029).

Conclusions

A large proportion of physicians could obtain and interpret FCU images from critically ill patients after a 2-day training course. However, they still scored low on the parasternal short-axis view and were more likely to make an incorrect assessment of LVEF in patients with abnormal left ventricular systolic function.

Association of ultrasound-related interruption during cardiopulmonary resuscitation with adult cardiac arrest outcomes: A video-reviewed retrospective study

OBJECTIVES

To determine the association of focused transthoracic echocardiography (ECHO) related interruption during cardiopulmonary resuscitation (CPR) with patient outcomes in the Emergency Department (ED).

METHODS

This was a retrospective, single center, cohort study, conducted in an urban community teaching ED. Eligible study subjects were adult patients in the ED with sustained cardiac arrest. Exclusion criteria include traumatic cardiac arrest and age less than 18. All resuscitations were video recorded and were subsequently reviewed by 2 study investigators. The no-flow time from chest compression interruption was analyzed using video review and separated into ECHO-related and non-ECHO related. Our primary outcome was patient survival to hospital discharge and the secondary outcome was the rate of return of spontaneous circulation (ROSC). Multivariate logistic regression analyses were performed to examine the associations between independent variables and outcomes.

RESULTS

From January 2016 to May 2017, a total of 210 patients were included for final analysis. The median total no-flow time observed on video was 99.5 s (IQR: 54.0-160.0 s). Among these, a median of 26.5 s (IQR: 0.0-59.0 s) was ECHO-related and a median of 60.5 s (IQR: 34.0-101.9) was non-ECHO-related. The ECHO-related no-flow time between 77 and 122 s (OR: 7.31, 95 % confidence interval [CI]: 1.59-33.59; p-value = 0.01) and ECHO-related interruption ≦ 2 times (OR: 8.22, 95% CI: 1.51-44.64; p-value = 0.01) were positively associated with survival to hospital discharge. ECHO-related interruption ≦ 2 times (OR: 5.55, 95% CI: 2.44-12.61; p-value < 0.001) was also positively associated with ROSC.

CONCLUSION

Short ECHO-related interruption during CPR was positively associated with ROSC and survival to hospital discharge. While ECHO can be a valuable diagnostic tool during CPR, the no-flow time associated with ECHO should be minimized.

Cardiac output measured by transthoracic echocardiography and Swan-Ganz catheter. A comparative study in mechanically ventilated patients with high positive end-expiratory pressure

Objective

To compare cardiac output measurements by transthoracic echocardiography and a pulmonary artery catheter in mechanically ventilated patients with high positive end-expiratory pressure. To evaluate the effect of tricuspid regurgitation.

Methods

Sixteen mechanically ventilated patients were studied. Cardiac output was measured by pulmonary artery catheterization and transthoracic echocardiography. Measurements were performed at different levels of positive end-expiratory pressure (10cmH₂O, 15cmH₂O, and 20cmH₂O). The effect of tricuspid regurgitation on cardiac output measurement was evaluated. The intraclass correlation coefficient was studied; the mean error and limits of agreement were studied with the Bland-Altman plot. The error rate was calculated.

Results

Forty-four pairs of cardiac output measurements were obtained. An intraclass correlation coefficient of 0.908 was found (p < 0.001). The mean error was 0.44L/min for cardiac output values between 5 and 13L/min. The limits of agreement were 3.25L/min and -2.37L/min. With tricuspid insufficiency, the intraclass correlation coefficient was 0.791, and without tricuspid insufficiency, 0.935. Tricuspid insufficiency increased the error rate from 32% to 52%.

Conclusions

In patients with high positive end-expiratory pressure, cardiac output measurement by transthoracic echocardiography is comparable to that with a pulmonary artery catheter. Tricuspid regurgitation influences the intraclass correlation coefficient. In patients with high positive end-expiratory pressure, the use of transthoracic echocardiography to measure cardiac output is comparable to invasive measures.

Two-dimensional echocardiography after return of spontaneous circulation and its association with in-hospital survival after in-hospital cardiopulmonary resuscitation

This retrospective cohort study investigated the association between in-hospital survival and two-dimensional (2D) echocardiography within 24 hours after the return of spontaneous circulation (ROSC) in patients who underwent in-hospital cardiopulmonary resuscitation (ICPR) after in-hospital cardiopulmonary arrest (IHCA). The 2D-echo and non-2D-echo groups comprised eligible patients who underwent transthoracic 2D echocardiography performed by the cardiology team within 24 hours after ROSC and those who did not, respectively. After propensity score (PS) matching, 142 and 284 patients in the 2D-echo and non-2D-echo groups, respectively, were included. A logistic regression analysis showed that the likelihood of in-hospital survival was 2.35-fold higher in the 2D-echo group than in the non-2D-echo group (P < 0.001). Regarding IHCA aetiology, in-hospital survival after cardiac arrest of a cardiac cause was 2.51-fold more likely in the 2D-echo group than in the non-2D-echo group (P < 0.001), with no significant inter-group difference in survival after cardiac arrest of a non-cardiac cause (P = 0.120). In this study, 2D echocardiography performed within 24 hours after ROSC was associated with better in-hospital survival outcomes for patients who underwent ICPR for IHCA with a cardiac aetiology. Thus, 2D echocardiography may be performed within 24 hours after ROSC in patients experiencing IHCA to enable better treatment.

Cardiac Ultrasound in the Intensive Care Unit: A Review

Transthoracic echocardiography (TTE) is an incredibly valuable tool in today’s emergency rooms and intensive care units (ICUs). It has the ability to provide a complete evaluation of the structure and function of the heart, the valves, stroke volume, ejection fraction, and much more. Previous academic studies have also determined that point-of-care TTE done by non-cardiologist physicians can also provide higher accuracy in patient assessment and management, with potential prognostic impact by assessing the severity of cardiac dysfunction and response to treatment. The aim of this review article is to examine further these point-of-care evaluations, what they entail, their benefits, and where further research would better our own understanding.

Assessing how emergency and trauma ultrasonography is taught to medical students

Objective

To evaluate a method aimed at teaching ultrasound techniques to medical students in emergency settings.

Methods

A prospective study conducted with 66 sixth-year undergraduate medical students. Students participated in theory and practicing sessions with a 5-hour load; knowledge acquisition was assessed through pre- and post-course and 90-day tests. A questionnaire were distributed to the students after course completion for theoretical and practical knowledge assessment.

Results

Average pre-test grade in theoretical content evaluation was 4.9, compared to 7.6 right after course completion, and 5.9 within 90 days (p<0.001). Questions addressing technical aspects and image acquisition were mostly answered correctly; in contrast, questions related to clinical management of patients tended to be answered incorrectly. In practical evaluation, 54 students (81.8%) were able to correctly interpret images.

Conclusion

Ultrasound applicability and image acquisition techniques can be taught to medical students in emergency settings. However, teaching should be focused on technical aspects rather than clinical management of patients.

Levels of training in critical care echocardiography in adults. Recommendations from the College of Intensive Care Medicine Ultrasound Special Interest Group

Critical care echocardiography (CCE) is commonly performed in many intensive care units across Australia and New Zealand (ANZ). The scope of practice ranges from Basic CCE through to Advanced CCE and includes the use of transthoracic echocardiography and transoesophageal echocardiography. Many training and qualification pathways exist with no standardisation of education goals. This document defines different levels of CCE expertise and recommends minimum training standards for each level of adult CCE in ANZ. Guidelines committee of College of Intensive Care Medicine's Ultrasound Special Interest Group held multiple face to face meetings, organised teleconferences, conducted a survey of the Fellows of the college and reviewed the international CCE training pathways prior to writing these guidelines.

Self-learning of point-of-care cardiac ultrasound - Can medical students teach themselves?

Background

Point-of-care ultrasonography (PoCUS) is a rapidly evolving discipline that aims to train non-cardiologists, non-radiologists clinicians in performing bedside ultrasound to guide clinical decision. Training of PoCUS is challenging, time-consuming and requires large amount of resources. The objective of our study was to evaluate if this training process can be simplified by allowing medical students self-train themselves with a web-based cardiac ultrasound software.

Methods

A prospective, single blinded, cohort study, comparing performance of 29 medical students in performing a six-minutes cardiac ultrasound exam. Students were divided into two groups: self-learning group, using a combination of E-learning software and self-practice using pocket ultrasound device compared to formal, frontal cardiac ultrasound course.

Results

All 29 students completed their designated courses and performed the six-minutes exam: 20 students participated in the frontal cardiac ultrasound course and 9 completed the self-learning course. The median (Q1,Q3) test score for the self-learning group was higher than the frontal course group score, 18 (15,19) versus 15 (12,19.5), respectively. Nevertheless, no statistically significant difference was found between the two study groups (p = 0.478). All students in the self-learning course group (9/9, 100%) and 16 (16/20, 80%) of students in the frontal ultrasound course group obtained correct alignment of the parasternal long axis view (p = 0.280).

Conclusions

Self-learning students combining E-learning software with self-practice cardiac ultrasound were as good as students who received a validated, bedside, frontal cardiac ultrasound course. Our findings suggest that independent cardiac ultrasound learning, combining utilization of E–learning software and self-practice, is feasible. Self-E- learning of cardiac ultrasound may serve as an important, cost-effective adjunct to heavily resource consuming traditional teaching.

Critical care ultrasonography in circulatory shock

PURPOSE OF REVIEW

The objective was to define the role of ultrasound in the diagnosis and the management of circulatory shock by critical appraisal of the literature.

RECENT FINDINGS

Assessment of any patient's hemodynamic profile based on clinical examination can be sufficient in several cases, but many times unclarities remain. Arterial catheters and central venous lines are commonly used in critically ill patients for practical reasons, and offer an opportunity for advanced hemodynamic monitoring. Critical care ultrasonography may add to the understanding of the hemodynamic profile at hand. Improvements in ultrasound techniques, for example, smaller devices and improved image quality, may reduce limitations and increase its value as a complementary tool. Critical care ultrasonography has great potential to guide decisions in the management of shock, but operators should be aware of limitations and pitfalls as well. Current evidence comes from cohort studies with heterogeneous design and outcomes.

SUMMARY

Use of ultrasonography for hemodynamic monitoring in critical care expands, probably because of absence of procedure-related adverse events. Easy applicability and the capacity of distinguishing different types of shock add to its increasing role, further supported by consensus statements promoting ultrasound as the preferred tool for diagnostics in circulatory shock.

Rapid decay of transthoracic echocardiography skills at 1 month: A prospective observational study

OBJECTIVE

Focused transthoracic echocardiography (FTTE) is an emerging tool in the management of critically ill patients, but the lack of adequate training models has limited the expansion of this technology. Although basic FTTE training courses have been shown to be sufficient in developing echocardiography skills, limited data exist regarding skill retention. In an effort to develop an adequate FTTE training model, we sought to determine the degree of skill retention after FTTE training.

DESIGN

A prospective, observational study.

SETTING

An academic center.

PARTICIPANTS

Surgical residents and medical students: 31 subjects were enrolled from February to June 2016.

RESULTS

Participants underwent a 2-hour FTTE course including didactics and a hands-on session measuring ejection fraction of left ventricle (LV) and inferior vena cava (IVC) diameter. Written knowledge and performance examinations applying FTTE were conducted before the course, immediately after, and at 1- and 3-month intervals, which were evaluated on a 0 to 9 scale and analyzed with paired t-tests. Performance examination scores obtaining the LV and IVC views preinitial and postinitial training increased from 1.7 to 6.5 (LV) and from 2.0 to 6.8 (IVC) (p < 0.01), decreased to 5.0 and 4.8, respectively, at 1 month (posttraining vs 1 month, p < 0.01), and did not significantly change at 3 months (5.4 and 5.0, respectively). Written examination scores increased from 42% to 62% (pretraining vs posttraining, p < 0.01), decreased to 48% in 1 month (posttraining vs 1 month, p < 0.01), and further decreased to 34% at 3 months (1 month vs 3 month, p < 0.01).

CONCLUSIONS

Although a short training course appears sufficient to impart basic FTTE skills and knowledge, skills are significantly decayed at 1 month and knowledge continually decreases at 1 and 3 months. Future FTTE training models should consider the rapid degradation of knowledge and skills in determining frequency of refresher training and ongoing evaluation.

Respiratory changes in subclavian vein diameters predicts fluid responsiveness in intensive care patients: a pilot study

The present pilot study investigated whether respiratory variation in subclavian vein (SCV) diameters correlates with fluid responsiveness in mechanically ventilated patients. Monocentric, prospective clinical study on fluid responsiveness in adult sedated, mechanically ventilated ICU patient, monitored with the PiCCO™ system (Pulsion Medical System, Germany), and requiring a fluid challenge (FC). A 10-min fluid bolus of 500 mL of 0.9% saline was administered. Cardiac output (CO) and dynamic parameters [stroke volume variation (SVV) and pulse pressure variation (PPV)] measured by transpulmonary thermodilution and pulse contour analysis (PiCCO™) as well as classical hemodynamic parameters were recorded at baseline and after FC. Fluid responsiveness was described as an increase in CO of ≥ 15%. Ultrasound measurements obtained in the subclavian long-axis view were used to calculate the SCV_variability index. A cut-off value for SCV variation for the prediction of fluid responsiveness was determined using receiver operating curve (ROC) analysis. Nine of 20 FCs (45%) induced an increase in CO of ≥ 15%. At baseline, the SCV_variability index was greater in responders than in non-responders (34.0 ± 21.4 vs. 9.0 ± 5.5; p = 0.0005). Diagnostic performance for the SCV_variability index revealed a cut-off value of 14 with a sensitivity of 100% [Confidence interval (CI) 95% (90; 100)] and a specificity of 82% [CI 95% (48; 98)] for the prediction of fluid responsiveness. Other parameters, such as SVV and PPV, could not predict fluid responsiveness. The correlation coefficient between CO variation and the SCV_variability index was 0.73 (p < 0.001). The SCV_variability index was a reliable, non-invasive parameter for the prediction of fluid responsiveness at the bedside of mechanically ventilated, critically ill patients in this pilot study.

Management of the Critically Ill Adult With Congenital Heart Disease

Survival of adults with congenital heart disease (CHD) has improved significantly over the last 2 decades, leading to an increase in hospital and intensive care unit (ICU) admissions of these patients. Whereas most of the ICU admissions in the past were related to perioperative management, the incidence of medical emergencies from long-term sequelae of palliative or corrective surgical treatment of these patients is rising. Intensivists now are confronted with patients who not only have complex anatomy after congenital cardiac surgery, but also complex pathophysiology due to decades of living with abnormal cardiac anatomy and diseases of advanced age. Comorbidities affect all organ systems, including cognitive function, pulmonary and cardiovascular systems, liver, and kidneys. Critical care management requires an in-depth understanding of underlying anatomy and pathophysiology in order to apply contemporary concepts of adult ICU care to this population and optimize patient outcomes. In this review, the main CHD lesions and their common surgical management approaches are described, and the sequelae of CHD physiology are discussed. In addition, the effects of chronic comorbidities on the management of critically ill adults are explored, and the adjustments of current ICU management modalities and pharmacology to optimize care are discussed.

Focused Critical Care Echocardiography: Development and Evaluation of an Image Acquisition Assessment Tool

OBJECTIVES

Little attention has been placed on assessment tools to evaluate image acquisition quality for focused critical care echocardiography. We designed a novel assessment tool to objectively evaluate the image acquisition skills of critical care trainees learning focused critical care echocardiography and examined the tool for evidence of validity.

DESIGN

Prospective observational study.

SETTING

Medical-surgical ICUs at a tertiary care teaching hospital.

SUBJECTS

Trainees in our critical care medicine fellowship program.

INTERVENTIONS

Six trainees completed a focused critical care echocardiography training curriculum followed by performing 20 transthoracic echocardiograms on patients receiving invasive mechanical ventilation. At three assessment intervals (the 1st and 2nd examinations, 10th and 11th examinations, and 19th and 20th examinations), echocardiograms performed by trainees were compared with those of critical care physicians certified in echocardiography and scored according to the focused critical care echocardiography assessment tool. The primary outcome was an efficiency score (overall assessment tool score divided by examination time). Differences in mean efficiency scores between echocardiographers of differing skill levels and changes in trainees' mean efficiency scores with increasing focused critical care echocardiography experience were compared by using t tests.

MEASUREMENTS AND MAIN RESULTS

On the initial assessment, mean efficiency scores (SD) for trainees and experienced physicians were 1.55 (0.95) versus 2.78 (1.38), respectively (p = 0.02), and for the second and third assessments, the corresponding efficiency ratings for trainees and experienced physicians were 2.48 (0.97) versus 4.55 (1.32) (p < 0.01) and 2.61 (1.37) versus 4.17 (2.12) (p = 0.04), respectively.

CONCLUSIONS

Trainees' efficiency in focused critical care echocardiography image acquisition improved quickly in the first 10 studies, yet, it could not match with the performance of experienced physicians after 20 focused critical care echocardiography studies. The focused critical care echocardiography assessment tool demonstrated evidence of validity and could discern changes in trainees' image acquisition performance with increasing experience.

Bedside echocardiography in critically ill patients

The echocardiography has become a vital tool in the diagnosis of critically ill patients. The use of echocardiography by intensivists has been increasing since the 1990’s. This tool has become a common procedure for the cardiovascular assessment of critically ill patients, especially because it is non-invasive and can be applied in fast and guided manner at the bedside. Physicians with basic training in echocardiography, both from intensive care unit or emergency department, can assess the left ventricle function properly with good accuracy compared with assessment made by cardiologists. The change of treatment approach based on echocardiographic findings is commonly seen after examination of unstable patient. This brief review focuses on growing importance of echocardiography as an useful tool for management of critically ill patients in the intensive care setting along with the cardiac output assessment using this resource.

Hemodynamic Bedside Ultrasound Image Quality and Interpretation After Implementation of a Training Curriculum for Pediatric Critical Care Medicine Providers

OBJECTIVE

Bedside ultrasound for hemodynamic evaluation in critically ill children is increasingly recognized as an important skill for pediatric critical care medicine providers. Our institution implemented a training curriculum leading to institutional credentialing for pediatric critical care providers in nonprocedural bedside ultrasound core applications. We hypothesized that hemodynamic studies performed or supervised by credentialed providers (credentialed providers group) have better image quality and greater accuracy in interpretation than studies performed by non-credentialed providers without supervision (non-credentialed providers group).

DESIGN

Retrospective descriptive study.

SETTING

Single-center tertiary non-cardiac 55-bed PICU in a children's hospital.

PATIENTS

Patients from October 2013 to January 2015, with hemodynamic bedside ultrasound performed and interpreted by pediatric critical care providers exposed to bedside ultrasound training.

INTERVENTIONS

A cardiologist blinded to performer scored hemodynamic bedside ultrasound image quality for five core cardiac views (excellent = 3, good = 2, fair = 1, unacceptable = 0; median = quality score) and interpretation within 5 hemodynamic domains (agreement = 3, minor disagreement = 2, major disagreement = 1; median = interpretation score), as well as a global assessment of interpretation.

MEASUREMENTS AND MAIN RESULTS

Eighty-one studies (45 in the credentialed providers group and 36 in the non-credentialed providers group) were evaluated. There was no statistically significant difference in quality score between groups (median: 1.4 [interquartile range: 0.8-1.8] vs median: 1.2 [interquartile range: 0.75-1.6]; p = 0.14]. Studies in the credentialed providers group had higher interpretation score than those in the non-credentialed providers group (median: 3 [interquartile range: 2.5-3) vs median: 2.67 [interquartile range: 2.25-3]; p = 0.04). Major disagreement between critical care provider and cardiology review occurred in 25 of 283 hemodynamic domains assessed (8.8%), with no statistically significant difference between credentialed providers and non-credentialed providers groups (6.1% vs 11.9%; p = 0.12).

CONCLUSION

Hemodynamic bedside ultrasound performed or supervised by credentialed pediatric critical care providers had more accurate interpretation than studies performed by unsupervised non-credentialed providers. A rigorous pediatric critical care medicine bedside ultrasound credentialing program can train intensivists to attain adequate images and interpret those images appropriately.

Using ultrasound to teach medical students cardiac physiology

Ultrasound is being incorporated more into undergraduate medical education. Studies have shown that medical students have positive perceptions about the value of ultrasound in teaching courses like anatomy and physiology. The purpose of the present study was to provide objective evidence of whether ultrasound helps students learn cardiac physiology. In this study, 20 medical students took a pretest to assess their background knowledge of cardiac physiology. Next, they acquired ultrasound video loops of the heart. Faculty members taught them nonelectrical aspects of cardiac physiology using those loops. Finally, students took a posttest to evaluate for improvements in their knowledge. Students also completed an anonymous questionnaire about their experience. The mean pretest score was 4.8 of 9 (53.3%). The mean posttest score was 7.35 of 9 (81.7%). The mean difference was significant at P < 0.0001. Student feedback was very positive about the ultrasound laboratory. Ninety-five percent of the students agreed or strongly agreed that the ultrasound laboratory was a valuable teaching tool and that it improved their understanding of cardiac physiology. All students agreed or strongly agreed the laboratory was helpful from a visual learning standpoint. A hands-on ultrasound laboratory can indeed help medical students learn the nonelectrical components of cardiac physiology.

A rare cause of postoperative hypotension

A 62-year-old woman presented with a 3-month history of abdominal distension and decreased exercise tolerance. A chest radiograph showed a probable left pleural effusion (Fig 1). A CT scan of the abdomen revealed a solid ovarian mass with omental caking and a large volume of ascites; there was also confirmation of a left pleural effusion. Three days before surgery a CT pulmonary angiogram (CTPA) showed no evidence of pulmonary thromboembolism (PTE). The patient had some improvement in her symptoms after paracentesis and thoracentesis with drainage of 2,000 mL and 250 mL of fluid, respectively. She underwent total abdominal hysterectomy, bilateral oophorectomy, and partial sigmoid resection with an estimated blood loss of 850 mL. During the operation, she received 5 L of crystalloid and required phenylephrine at 40 to 80 μg/min to maintain a mean arterial pressure &gt; 65 mm Hg. She was extubated after surgery, but immediately after extubation, she became markedly hypotensive and hypoxemic with a BP of 50/20 mm Hg and an oxygen saturation of 70%. An ECG showed T-wave inversions from V1 to V5 and an S1Q3T3 pattern (Fig 2). A bedside echocardiogram showed an enlarged right ventricle (RV), septal dyskinesia, and obliteration of the left ventricle, all consistent with systolic and diastolic RV overload (Fig 3).

Implementation and assessment of a curriculum for bedside ultrasound training

OBJECTIVES

This study assessed a curriculum for bedside ultrasound (US) and compared outcomes from 2 common training pathways.

METHODS

The program consisted of e-learning paired with expert-led hands-on training administered to pulmonary/critical care and cardiology fellows with no prior formal training in bedside US. This "simulation-based learner" group completed a survey of attitudes and confidence before and after training, and knowledge and skills were assessed after training. The surveys and scores of the simulation-based learners were compared to the scores of "experts," who were US-trained emergency physicians, and "apprentice learners," who were intensivist physicians informally trained in bedside US on the job during fellowships.

RESULTS

There was a significant difference in the self-reported level of prior training between the groups (simulation-based learners, 2.8; apprentice learners, 3.7; experts, 4.1, on a scale of 1-5 [P= .02]) but no difference in the interest level or perceived importance of bedside US. The study curriculum was successful, as shown by scores that exceeded the comparison groups in the cardiac and pulmonary courses (cardiac: simulation-based learners, 80%; apprentice learners, 73%; experts, 62% [P= .001]; pulmonary: 84%, 75%, and 72%, respectively [P =.02]). The simulation-based learners gained confidence in skills, whereas the comparison groups lost confidence after testing (P < .005); however, the simulation-based learners gained confidence in US subject areas that were not taught (abdomen [P <.002] and miscellaneous [P =.005]).

CONCLUSIONS

The simulation-based learner curriculum resulted in comparable or greater knowledge and confidence in each area of US versus the comparison groups. Findings of overgeneralization of confidence highlight the importance of quality assurance and supervision in bedside US training programs.

Clinical utility of semi-automated estimation of ejection fraction at the point-of-care

INTRODUCTION

To compare estimation of ejection fraction at the bedside by AutoEF compared with conventional methods and to assess feasibility and time consumption.

METHODS

A total of 102 relatively hemodynanically stable mixed medical and surgical patients were included. All patients underwent ultrasonography of the heart at the bedside performed by a novice examiner. Three assessments of ejection fraction were made: 1) Expert eyeballing by a single specialist in cardiology and expert in echocardiography; 2) Manual planimetry by an experienced examiner; 3) AutoEF by a novice examiner with limited experience in echocardiography.

RESULTS

Expert eyeballing of ejection fraction was performed in 100% of cases. Manual planimetry was possible in 89% of cases and AutoEF was possible in 83% of cases. The correlation between expert eyeballing and AutoEF was r=0.82, p < 0.001, for manual planimetry and for AutoEF it was r=0.82, p < 0.001; for expert eyeballing and manual planimetry it was r=0.80, p < 0.001. The mean time consumption for manual planimetry was 98 ( 90-106 ) seconds; correspondingly the mean time spent for AutoEF was 41 ( 36-46 ) seconds, which was significantly less (p < 0.001).

CONCLUSIONS

AutoEF seems to be a valid supplement to the clinical assessment of ejection fraction in the hands of less experienced examiners, yielding result similar to manual planimetry with less time consumption and less intra-observer variability. However, manual editing may be required and training is thus recommended before AutoEF is applicable for use by novices.

Basic critical care echocardiography by pulmonary fellows: learning trajectory and prognostic impact using a minimally resourced training model*

OBJECTIVES

The spread of basic critical care echocardiography may be limited by training resources. Another barrier is the lack of information about the learning trajectory and prognostic impact of individual basic critical care echocardiography domains like acute cor pulmonale determination and left ventricular function estimation. We thus developed a minimally resourced training model and studied the latter outcomes.

DESIGN

Prospective observational study.

SETTING

Twenty-bed medical ICU.

SUBJECTS

Echocardiography-naive trainees enrolled in the first year of our Pulmonary Medicine Fellowship Program from September 2012 to September 2013.

INTERVENTIONS

We described the learning trajectory in six basic critical care echocardiography domains (adequate views, pericardial effusion, acute cor pulmonale, left ventricular ejection fraction, mitral regurgitation, and inferior vena cava variability) and correlated abnormalities in selected basic critical care echocardiography domains with clinical outcomes (mortality and length of stay).

MEASUREMENTS AND MAIN RESULTS

Three-hundred forty-three basic critical care echocardiography scans were done for 318 patients by seven fellows (median of 40 scans per fellow; range, 34-105). Only one-third patients had normal basic critical care echocardiography studies. Accuracy in various basic critical care echocardiography domains was high (> 90%), especially beyond the first 30 examinations. Acute cor pulmonale was associated with ICU mortality when adjusted for Acute Physiology and Chronic Health Evaluation II score and presence of sepsis, whereas mitral regurgitation was associated with longer hospitalization only on univariate analysis.

CONCLUSIONS

Basic critical care echocardiography training using minimal resources is feasible. New trainees can achieve reasonable competency in most basic critical care echocardiography domains after performing about 30 examinations within the first year. The relatively high prevalence of abnormalities and the significant association of acute cor pulmonale with ICU mortality support the need for basic critical care echocardiography training.