Echocardiography in cardiac arrest:

The Role of Echocardiography in Extracorporeal Membrane Oxygenation

PURPOSE OF REVIEW

Extracorporeal membrane oxygenation (ECMO) is increasingly used to temporarily support patients in severe circulatory and/or respiratory failure. Echocardiography is a core component of successful ECMO deployment. Herein, we review the role of echocardiography at different phases on extracorporeal support including candidate identification, cannulation, maintenance, complication vigilance, and decannulation.

RECENT FINDINGS

During cannulation, ultrasound is used to confirm intended vascular access and appropriate inflow cannula positioning. While on ECMO, echocardiographic evaluation of ventricular loading conditions and hemodynamics, cannula positioning, and surveillance for intracardiac or aortic thrombi is needed for complication mitigation. Echocardiography is crucial during all phases of ECMO use. Specific echocardiographic queries depend on the ECMO type, V-V, or V-A, and the specific cannula configuration strategy employed.

State-of-the-Art Multimodality Imaging in Sudden Cardiac Arrest with Focus on Idiopathic Ventricular Fibrillation: A Review

Idiopathic ventricular fibrillation is a rare cause of sudden cardiac arrest and a diagnosis by exclusion. Unraveling the mechanism of ventricular fibrillation is important for targeted management, and potentially for initiating family screening. Sudden cardiac arrest survivors undergo extensive clinical testing, with a growing role for multimodality imaging, before diagnosing "idiopathic" ventricular fibrillation. Multimodality imaging, considered as using multiple imaging modalities as diagnostics, is important for revealing structural myocardial abnormalities in patients with cardiac arrest. This review focuses on combining imaging modalities (echocardiography, cardiac magnetic resonance and computed tomography) and the electrocardiographic characterization of sudden cardiac arrest survivors and discusses the surplus value of multimodality imaging in the diagnostic routing of these patients. We focus on novel insights obtained through electrostructural and/or electromechanical imaging in apparently idiopathic ventricular fibrillation patients, with special attention to non-invasive electrocardiographic imaging.

Point-of-Care Resuscitative Echocardiography Diagnosis of Intracardiac Thrombus during cardiac arrest (PREDICT Study): A retrospective, observational cohort study

Background

Point-of-care ultrasound (POCUS) has been previously studied in cardiac arrest, without definitive markers for futile resuscitation efforts identified. Intracardiac thrombus during cardiac arrest has not been systematically studied. Our objective was to describe the incidence of intracardiac thrombus and spontaneous echo contrast found during cardiac arrest.

Methods

A two hospital, retrospective, observational cohort study of 56 cardiac arrest patients who were assessed with POCUS (between January 1st, 2017 to April 30th, 2020). Eligible studies were reviewed for echocardiographic findings (e.g. presence of intracardiac thrombus or spontaneous echo contrast), baseline patient demographics, cardiac arrest-related data, and clinical outcomes. Primary outcome was in-hospital mortality.

Results

Fifty-six intra-arrest POCUS echocardiograms were identified (out of 738 out-of-hospital cardiac arrests). The median patient age was 63 years (interquartile range [IQR]: 51–72), with 25% female patients, and median Charlson Comorbidity Index score of 4 (IQR: 2–6). The incidence of intracardiac thrombus was 21 out of 56 patients (38%). Time-to-new thrombus formation during cardiac arrest was approximately 6 minutes (IQR: 2-–8). All patients with intracardiac thrombus during cardiac arrest had termination of resuscitation.

Conclusions

Intracardiac thrombus is potentially common during out-of-hospital cardiac arrests and was observed more frequently in those in whom termination of resuscitation was recommended. However, this is only hypothesis-generating at this time, and further study is required to determine if the presence of intracardiac thrombus may be used as a potential marker of resuscitation futility.

Prognostic Role of Myocardial Edema as Evidenced by Early Cardiac Magnetic Resonance in Survivors of Out-of-Hospital Cardiac Arrest: A Multicenter Study

Background Sudden cardiac arrest (SCA) may be caused by an acute and reversible myocardial injury, a chronic and irreversible myocardial damage, or a primary ventricular arrhythmia. Cardiac magnetic resonance imaging may identify myocardial edema (ME), which denotes acute and reversible myocardial damage. We evaluated the arrhythmic outcome of SCA survivors during follow-up and tested the prognostic role of ME. Methods and Results We included a consecutive series of 101 (71% men, median age 47 years) SCA survivors from 9 collaborative centers who underwent early (<1 month) cardiac magnetic resonance imaging and received an implantable cardioverter-defibrillator (ICD). On T2-weighted sequences, ME was found in 18 of 101 (18%) patients. According to cardiac magnetic resonance imaging findings, the arrhythmic SCA was ascribed to acute myocardial injury (either ischemic [n=10] or inflammatory [n=8]), to chronic structural heart diseases (ischemic heart disease [n=11], cardiomyopathy [n=20], or other [n=23]), or to primarily arrhythmic syndrome (n=29). During a follow-up of 47 months (28 to 67 months), 24 of 101 (24%) patients received an appropriate ICD intervention. ME was associated with a significantly higher survival free from both any ICD interventions (log-rank=0.04) and ICD shocks (log-rank=0.03) and remained an independent predictor of better arrhythmic outcome after adjustment for left ventricular ejection fraction and late gadolinium enhancement. The risk of appropriate ICD intervention was unrelated to the type of underlying heart disease. Conclusions ME on early cardiac magnetic resonance imaging, which denotes an acute and transient arrhythmogenic substrate, predicted a favorable long-term arrhythmic outcome of SCA survivors. These findings may have a substantial impact on future guidelines on the management of SCA survivors.

Point-of-Care Ultrasound (POCUS) for the Cardiothoracic Anesthesiologist

Point-of-Care Ultrasound (POCUS) is a valuable bedside diagnostic tool for a variety of expeditious clinical assessments or as guidance for a multitude of acute care procedures. Varying aspects of nearly all organ systems can be evaluated using POCUS and, with the increasing availability of affordable ultrasound systems over the past decade, many now refer to POCUS as the 21^st-century stethoscope. With the current available and growing evidence for the clinical value of POCUS, its utility across the perioperative arena adds enormous benefit to clinical decision-making. Cardiothoracic anesthesiologists routinely have used portable ultrasound systems for nearly as long as the technology has been available, making POCUS applications a natural extension of existing cardiothoracic anesthesia practice. This narrative review presents a broad discussion of the utility of POCUS for the cardiothoracic anesthesiologist in varying perioperative contexts, including the preoperative clinic, the operating room (OR), intensive care unit (ICU), and others. Furthermore, POCUS-related education, competence, and certification are addressed.

Barriers to point-of-care ultrasound utilization during cardiac arrest in the emergency department: a regional survey of emergency physicians

INTRODUCTION

Though point-of-care ultrasound (POCUS) is recognized as a useful diagnostic and prognostic intervention during cardiac arrest (CA), critics advise caution. The purpose of this survey study was to determine the barriers to POCUS during CA in the Emergency Department (ED).

METHODS

Two survey instruments were distributed to emergency medicine (EM) attending and resident physicians at three academic centers in the South Florida. The surveys assessed demographics, experience, proficiency, attitudes and barriers. Descriptive and inferential statistics along with Item Response Theory Logistic Model and the Friedman Test with Wilcoxon Signed Rank tests were used to profile responses and rank barriers.

RESULTS

206 EM physicians were invited to participate in the survey, and 187 (91%) responded. 59% of attending physicians and 47% of resident physicians reported that POCUS is performed in all their cases of CA. 5% of attending physicians and 0% of resident physicians reported never performing POCUS during CA. The top-ranked departmental barrier for attending physicians was "No structured curriculum to educate physicians on POCUS." The top-ranked personal barriers were "I do not feel comfortable with my POCUS skills" and "I do not have sufficient time to dedicate to learning POCUS." The top-ranked barriers for resident physicians were "Time to retrieve and operate the machine" and "Chaotic milieu."

CONCLUSIONS

While our study demonstrates that most attending and resident physicians utilize POCUS in CA, barriers to high-quality implementation exist. Top attending physician barriers relate to POCUS education, while the top resident physician barriers relate to logistics and the machines. Interventions to overcome these barriers might lead to optimization of POCUS performance during CA in the ED.

A practical guideline for performing a comprehensive transthoracic echocardiogram in adults: the British Society of Echocardiography minimum dataset

Since cardiac ultrasound was introduced into medical practice around the middle twentieth century, transthoracic echocardiography has developed to become a highly sophisticated and widely performed cardiac imaging modality in the diagnosis of heart disease. This evolution from an emerging technique with limited application, into a complex modality capable of detailed cardiac assessment has been driven by technological innovations that have both refined 'standard' 2D and Doppler imaging and led to the development of new diagnostic techniques. Accordingly, the adult transthoracic echocardiogram has evolved to become a comprehensive assessment of complex cardiac anatomy, function and haemodynamics. This guideline protocol from the British Society of Echocardiography aims to outline the minimum dataset required to confirm normal cardiac structure and function when performing a comprehensive standard adult echocardiogram and is structured according to the recommended sequence of acquisition. It is recommended that this structured approach to image acquisition and measurement protocol forms the basis of every standard adult transthoracic echocardiogram. However, when pathology is detected and further analysis becomes necessary, views and measurements in addition to the minimum dataset are required and should be taken with reference to the appropriate British Society of Echocardiography imaging protocol. It is anticipated that the recommendations made within this guideline will help standardise the local, regional and national practice of echocardiography, in addition to minimising the inter and intra-observer variation associated with echocardiographic measurement and interpretation.

Intraoperative Cardiac Arrest

Cardiac arrest in the operating room and in the immediate postoperative period is a potentially catastrophic event that is almost always witnessed and is frequently anticipated. Perioperative crises and perioperative cardiac arrest, although often catastrophic, are frequently managed in a timely and directed manner because practitioners have a deep knowledge of the patient's medical condition and details of recent procedures. It is hoped that the approaches described here, along with approaches for the rapid identification and management of specific high-stakes clinical scenarios, will help anesthesiologists continue to improve patient outcomes.

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.

The Value of Focused Echocardiography During Cardiac Arrest

Cardiac arrest is the absence of a centrally palpable pulse and no respiratory effort in an unresponsive patient. This often-lethal medical condition affects hundreds of thousands of people in the United States alone every year. Immediate intervention is crucial to provide the patient with any chance of survival. Advanced cardiac life support (ACLS) is the cornerstone therapy for cardiac arrest. Increased awareness and proper identification of life-threatening arrhythmias is critical, as it may lead to prompt medical treatment and improved mortality. The use of focused echocardiography, during a cardiac arrest, has been a developing area of interest over the past several years. The specific aim of this literature review was to emphasize the role of a focused echocardiogram and the valuable information that can be provided during a cardiac arrest.

Point of care ultrasound for the clinical anesthesiologist

Diagnostic ultrasonography was first utilized in the 1940s. The past 70+ years have seen an explosion in both ultrasound technology and availability of ultrasound technology to more and more clinicians. As ultrasound technology and availability have grown, the utility of ultrasound technology in the clinical setting as only been limited by clinicians' imagination. Due to its lack of radiation, non-invasive nature, and gentle learning curve, medical ultrasonography is now a tremendously useful Point of Care technology in the clinical arena. What follows is a discussion of Point of Care Ultrasound (PoCUS) and how it can be incorporated in the daily practice of any regional anesthesiology. While most regional anesthesiologists usually focus on the interventional aspects of ultrasonography (i.e. nerve blocks), our discussion will center on the diagnostic value of ultrasonography-especially concerning assessment of cardiac physiology and pathophysiology, gastric anatomy, airway anatomy, and intracranial pathophysiology. After reading and reviewing this chapter, the learner will have the knowledge to start training themselves in a variety of PoCUS exams that will allow rapid diagnosis of normal and abnormal patient conditions. Once an accurate diagnosis is established, the anesthesiologist and his/her team can then confidently optimize an anesthetic pain, prevent harm, and/or treat a patient condition. In this day and age, the ability to rapidly establish an accurate diagnosis cannot be overstated-especially in a critical situation. It is the authors' sincerest hope that the following discussion will help regional anesthesiologist to become even better and well-rounded clinical leaders.

Impact of right ventricular dysfunction on mortality in adults with cardiac arrest undergoing coronary angiogram

OBJECTIVE

We sought to identify the impact of echocardiographic right ventricular (RV) systolic dysfunction on mortality in adults with cardiac arrest (CA).

METHODS

The study population included 147 adults hospitalized with CA who underwent both echocardiogram and coronary angiogram at an academic tertiary medical center. The primary outcome of interest was all-cause in-hospital mortality.

RESULTS

Of the 147 patients studied, 20 (13.6%) had evidence of RV systolic dysfunction while 127 (86.4%) did not. Patients with RV dysfunction had higher rates of prior surgical and percutaneous coronary revascularization. They also had higher rates of mechanical ventilation, therapeutic hypothermia, vasopressor and inotrope use, and a trend towards higher rates of mechanical support. Coronary angiogram revealed higher rates of multivessel disease, right coronary artery intervention, and glycoprotein IIb-IIIa inhibitor use in those with RV dysfunction, alongside with lower echocardiographic left ventricular ejection fraction. In-hospital mortality rates were higher in adults with RV dysfunction compared to those without (55% vs 11%, p < 0.001). In multivariate analysis, RV dysfunction was the strongest independent predictor of higher mortality [odds ratio 4.71, 95% confidence interval 1.27-17.50].

CONCLUSIONS

In this observational contemporary study, RV dysfunction was independently associated with higher mortality in adults with CA undergoing coronary angiogram. RV dysfunction may be useful for risk stratification and management in this high-mortality population.

Échographie et prise en charge de l’arrêt cardiaque

L’arrêt cardiorespiratoire (ACR) est une situation fréquente pour les structures d’urgences et de réanimation, et l’utilisation de l’échographie y est recommandée par les sociétés savantes. Elle doit impérativement se faire sans augmentation des temps d’interruption du massage cardiaque externe. Après formation, elle permet de détecter rapidement et facilement la présence d’une contractilité myocardique qui est un élément pronostique important pouvant aider dans la décision d’arrêter la RCP. Le recours à des protocoles bien établis avec des équipes entraînées permet d’éviter une interruption prolongée de la RCP. Cependant, aucune étude humaine de grande ampleur n’a permis de décrire de manière fiable pendant l’ACR la sémiologie échographique des causes curables que constituent l’hypovolémie, l’embolie pulmonaire, la tamponnade et le pneumothorax compressif.

Diagnostic value and prognostic implications of early cardiac magnetic resonance in survivors of out-of-hospital cardiac arrest

BACKGROUND

In patients who survived out-of-hospital cardiac arrest (OHCA), it is crucial to establish the underlying cause and its potential reversibility.

OBJECTIVE

The purpose of this study was to assess the incremental diagnostic and prognostic role of early cardiac magnetic resonance (CMR) in survivors of OHCA.

METHODS

Among 139 consecutive OHCA patients, the study enrolled 44 patients (median age 43 years; 84% male) who underwent coronary angiography and CMR ≤7 days after admission. The CMR protocol included T2-weighted sequences for myocardial edema and late gadolinium enhancement (LGE) sequences for myocardial fibrosis.

RESULTS

Coronary angiography identified obstructive coronary artery disease in 18 of 44 patients in whom CMR confirmed the diagnosis of ischemic heart disease by demonstrating subendocardial or transmural LGE. The presence of myocardial edema allowed differentiation between acute myocardial ischemia (n = 12) and postinfarction myocardial scar (n = 6). Among the remaining 26 patients without obstructive coronary artery disease, CMR in 19 (73%) showed dilated cardiomyopathy in 5, myocarditis in 4, mitral valve prolapse associated with LGE in 3, ischemic scar in 2, idiopathic nonischemic scar in 2, arrhythmogenic cardiomyopathy in 1, hypertrophic cardiomyopathy in 1, and takotsubo cardiomyopathy in 1. In this subgroup of 26 patients, 6 (23%) had myocardial edema. During mean follow-up of 36 ± 17 months, all 18 patients with myocardial edema had an uneventful outcome, whereas 9 of 26 (35%) without myocardial edema experienced sudden arrhythmic death (n = 1), appropriate defibrillator interventions (n = 5), and nonarrhythmic death (n = 3; P = .006).

CONCLUSION

In survivors of OHCA, early CMR with a comprehensive tissue characterization protocol provided additional diagnostic and prognostic value. The identification of myocardial edema was associated with a favorable long-term outcome.

Prehospital Echocardiography During Resuscitation Impacts Treatment in a Physician-Staffed Helicopter Emergency Medical Service: an Observational Study

BACKGROUND

Patients in cardiac arrest must receive algorithm-based management such as basic life support and advanced (cardiac) life support. International guidelines dictate diagnosing and treating any factor that may have caused the arrest or may be complicating the resuscitation. Ultrasound may be of potential value in this process and can be used in a prehospital setting. The objective is to evaluate the use of prehospital ultrasound during traumatic and non-traumatic CPR and determine its impact on prehospital treatment decisions in a Dutch helicopter emergency medical service (HEMS).

METHODS

We conducted an observational study in cardiac arrest patients, of any cause, in whom the Nijmegen HEMS performed CPR with concurrent echocardiography. The participating physicians had to adhere to Advanced Life Support protocols as per standard operating procedure. Simultaneous with the interruptions of chest compressions to allow for heart rhythm analysis, ultrasound-trained HEMS physicians performed echocardiography according to study protocol. The HEMS nurse and physician recorded patient data and data on impacted (supported or altered) patient treatment decisions.

RESULTS

From February 2014 through November 2016, we included 56 patients who underwent 102 ultrasound examinations. Sixty-two (61%) ultrasound examinations impacted 78 treatment decisions in 49 patients (88%). The impacted treatment was related to termination of CPR in 32 (57%), fluid management (14%), drugs selection and doses (14%), and choice of destination hospital (5%). Causes of cardiac arrest included trauma (48%), cardiac (21%), medical (14%), asphyxia (9%), and other (7%).

CONCLUSION

Prehospital echocardiography has an impact on patient treatment and may be a useful tool to support decision-making during CPR in a Dutch HEMS.

Echocardiography in cardiac arrest: An emergency medicine review

INTRODUCTION

Cardiac arrest management primarily focuses on optimal chest compressions and early defibrillation for shockable cardiac rhythms. Non-shockable rhythms such as pulseless electrical activity (PEA) and asystole present challenges in management. Point-of-care ultrasound (POCUS) in cardiac arrest is promising.

OBJECTIVES

This review provides a focused assessment of POCUS in cardiac arrest, with an overview of transthoracic (TTE) and transesophageal echocardiogram (TEE), uses in arrest, and literature support.

DISCUSSION

Cardiac arrest can be distinguished between shockable and non-shockable rhythms, with management varying based on the rhythm. POCUS provides a diagnostic and prognostic tool in the emergency department (ED), which may improve accuracy in clinical decision-making. Several protocols incorporate POCUS based on different cardiac views. TTE includes parasternal long axis, parasternal short axis, apical 4-chamber, and subxiphoid views, which may be used in cardiac arrest for diagnosis of underlying cause and potential prognostication. TEE is conducted by inserting the probe into the esophagus of intubated patients, with several studies evaluating its use in cardiac arrest. It is associated with few adverse effects, while allowing continued compressions (and evaluation of those compressions) and not interrupting resuscitation efforts.

CONCLUSIONS

POCUS is a valuable diagnostic and prognostic tool in cardiac arrest, with recent literature supporting its diagnostic ability. TTE can guide resuscitation efforts dependent on the rhythm, though TTE should not interrupt other resuscitation measures. TEE can be useful during arrest, but further studies based in the ED are needed.

Sudden cardiac arrest in hypertrophic cardiomyopathy with dynamic cavity obstruction: The case for a decatecholaminisation strategy

Catecholamines are entrenched in the management of shock states. A paradigm shift has pervaded the critical care arena in recent years acknowledging their propensity to cause harm and fuel a 'death-spiral'. We present the case of a 21-year-old male following a witnessed out-of-hospital cardiac arrest who received high-quality cardiopulmonary resuscitation and standard advanced life support for refractory ventricular fibrillation until return of spontaneous circulation after 70 min. Early post-admission echocardiography revealed severe diffuse sub-basal left ventricular hypertrophy with dynamic mid-cavity obstruction and akinetic apical pouching. Within this context, a decatecholaminised strategy comprising a beta-blocker was used to augment the left ventricular end-diastolic volume and attain cardiovascular stability.

The Right Ventricle Is Dilated During Resuscitation From Cardiac Arrest Caused by Hypovolemia: A Porcine Ultrasound Study

OBJECTIVES

Dilation of the right ventricle during cardiac arrest and resuscitation may be inherent to cardiac arrest rather than being associated with certain causes of arrest such as pulmonary embolism. This study aimed to compare right ventricle diameter during resuscitation from cardiac arrest caused by hypovolemia, hyperkalemia, or primary arrhythmia (i.e., ventricular fibrillation).

DESIGN

Thirty pigs were anesthetized and then randomized to cardiac arrest induced by three diffrent methods. Seven minutes of untreated arrest was followed by resuscitation. Cardiac ultrasonographic images were obtained during induction of cardiac arrest, untreated cardiac arrest, and resuscitation. The right ventricle diameter was measured. Primary endpoint was the right ventricular diameter at the third rhythm analysis.

SETTING

University hospital animal laboratory.

SUBJECTS

Female crossbred Landrace/Yorkshire/Duroc pigs (27-32 kg).

INTERVENTIONS

Pigs were randomly assigned to cardiac arrest caused by either hypovolemia, hyperkalemia, or primary arrhythmia.

MEASUREMENTS AND MAIN RESULTS

At the third rhythm analysis during resuscitation, the right ventricle diameter was 32 mm (95% CI, 29-35) in the hypovolemia group, 29 mm (95% CI, 26-32) in the hyperkalemia group, and 25 mm (95% CI, 22-28) in the primary arrhythmia group. This was larger than baseline for all groups (p = 0.03). When comparing groups at the third rhythm analysis, the right ventricle was larger for hypovolemia than for primary arrhythmia (p < 0.001).

CONCLUSIONS

The right ventricle was dilated during resuscitation from cardiac arrest caused by hypovolemia, hyperkalemia, and primary arrhythmia. These findings indicate that right ventricle dilation may be inherent to cardiac arrest, rather than being associated with certain causes of arrest. This contradicts a widespread clinical assumption that in hypovolemic cardiac arrest, the ventricles are collapsed rather than dilated.

Reduced right ventricular diameter during cardiac arrest caused by tension pneumothorax - a porcine ultrasound study

INTRODUCTION

Advanced life support (ALS) guidelines recommend ultrasound to identify reversible causes of cardiac arrest. Right ventricular (RV) dilatation during cardiac arrest is commonly interpreted as a sign of pulmonary embolism. The RV is thus a focus of clinical ultrasound examination. Importantly, in animal studies ventricular fibrillation and hypoxia results in RV dilatation. Tension pneumothorax (tPTX) is another reversible cause of cardiac arrest, however, the impact on RV diameter remains unknown.

AIM

To investigate RV diameter evaluated by ultrasound in cardiac arrest caused by tPTX or hypoxia.

METHODS

Pigs were randomized to cardiac arrest by either tPTX (n = 9) or hypoxia (n = 9) and subsequently resuscitated. Tension pneumothorax was induced by injection of air into the pleural cavity. Hypoxia was induced by reducing tidal volume. Ultrasound images of the RV were obtained throughout the study. Tension pneumothorax was decompressed after the seventh rhythm analysis. The primary endpoint was RV diameter after the third rhythm analysis.

RESULTS

At cardiac arrest the RV diameter was 17 mm (95% CI: 13; 21) in the tPTX group and 36 mm (95% CI: 33; 40) in the hypoxia group (P < 0.01, n = 9 for both). At third rhythm analysis RV diameter was smaller in the tPTX group: 12 mm (95% CI: 7; 16) vs. hypoxia group: 28 mm (25; 32) (P < 0.01). After decompression no difference existed between groups: tPTX 29 mm (95% CI: 23; 34) vs. hypoxia 29 mm (95% CI: 20; 38).

CONCLUSION

The RV diameter is smaller during cardiopulmonary resuscitation in cardiac arrest caused by tPTX when compared with hypoxia. The difference disappears after tPTX decompression.

Predictors of death among cardiac arrest patients after therapeutic hypothermia: A non-tertiary care center's initial experience

INTRODUCTION AND OBJECTIVES

Therapeutic hypothermia (TH) is recommended for patients with return of spontaneous circulation (ROSC) after cardiac arrest (CA). There is still uncertainty about management, target temperature and duration of TH. In the present study we aim to describe the initial experience of a non-tertiary care center with TH after CA and to determine predictors of mortality.

METHODS

During the period 2011-2014, out of 2279 patients hospitalized in the intensive care unit, 82 had a diagnosis of CA with ROSC. We determined predictors of mortality and neurological outcome in comatose patients with ROSC after CA treated by TH.

RESULTS

A total of 15 patients were included, mean age 47.3±14 years, 10 (67.0%) male. CA occurred out-of-hospital (n=11; 73.3%) or in-hospital (n=4; 26.7%), in initial shockable (n=10; 66.7%) or non-shockable (n=5, 33.3%) rhythm. The mean time from CA to ROSC (CA-ROSC) was 44.7±36.5 min. All patients met the 24-hour TH target temperature of 33°C. The mean neuron-specific enolase (NSE) level was 93.7±109.0 μg/l. Seven patients (46.7%) were discharged with good cerebral performance and eight (53.3%) died. Patients who survived had lower median age (p=0.032), shorter CA-ROSC (p=0.048), lower NSE levels (p=0.020) and initial ventricular fibrillation rhythm (p=NS).

CONCLUSIONS

The effectiveness of TH appears to be related to younger age, shockable initial rhythm and shorter CA-ROSC time. This results indicates some lines of inquiry that should be developed in appropriate prospective studies. The role of biomarkers as predictors of prognosis is an open question, with NSE potentially playing an important role.

Echocardiography for adult patients supported with extracorporeal membrane oxygenation

Venoarterial (VA) and venovenous (VV) extracorporeal membrane oxygenation (ECMO) support is increasingly being used in recent years in the adult population. Owing to the underlying disease precipitating severe respiratory or cardiac failure, echocardiography plays an important role in the management of these patients. Nevertheless, there are currently no guidelines on the use of echocardiography in the setting of ECMO support. This review describes the current state of application of echocardiography for patients supported with both VA and VV ECMO.

International evidence-based recommendations for focused cardiac ultrasound

BACKGROUND

Focused cardiac ultrasound (FoCUS) is a simplified, clinician-performed application of echocardiography that is rapidly expanding in use, especially in emergency and critical care medicine. Performed by appropriately trained clinicians, typically not cardiologists, FoCUS ascertains the essential information needed in critical scenarios for time-sensitive clinical decision making. A need exists for quality evidence-based review and clinical recommendations on its use.

METHODS

The World Interactive Network Focused on Critical UltraSound conducted an international, multispecialty, evidence-based, methodologically rigorous consensus process on FoCUS. Thirty-three experts from 16 countries were involved. A systematic multiple-database, double-track literature search (January 1980 to September 2013) was performed. The Grading of Recommendation, Assessment, Development and Evaluation method was used to determine the quality of available evidence and subsequent development of the recommendations. Evidence-based panel judgment and consensus was collected and analyzed by means of the RAND appropriateness method.

RESULTS

During four conferences (in New Delhi, Milan, Boston, and Barcelona), 108 statements were elaborated and discussed. Face-to-face debates were held in two rounds using the modified Delphi technique. Disagreement occurred for 10 statements. Weak or conditional recommendations were made for two statements and strong or very strong recommendations for 96. These recommendations delineate the nature, applications, technique, potential benefits, clinical integration, education, and certification principles for FoCUS, both for adults and pediatric patients.

CONCLUSIONS

This document presents the results of the first International Conference on FoCUS. For the first time, evidence-based clinical recommendations comprehensively address this branch of point-of-care ultrasound, providing a framework for FoCUS to standardize its application in different clinical settings around the world.

[Clinical practice of systemic lysis in prehospital resuscitation. Success and complication rates]

BACKGROUND

Systemic thrombolysis was introduced as the sole prehospital treatment option in patients with cardiac arrest in the setting of acute myocardial ischemia or pulmonary embolism; however, it remains the subject of discussion.

PATIENTS AND METHODS

A total of 194 patients with sudden prehospital cardiac arrest were included in this retrospective case control study. Of these patients, 96 in whom circulatory arrest due to cardiac disease (pulmonary artery embolism or myocardial ischemia) was suspected underwent thrombolytic treatment and were compared to the remaining 98 patients that did not undergo thrombolytic therapy. In addition to the circumstances of circulatory arrest, the course and success of resuscitation, as well as in-hospital course (including bleeding complications), overall survival and neurological outcomes were compared.

RESULTS

There were no significant differences between patients with or without thrombolysis in terms of the circumstances of cardiac arrest. Patients that received thrombolytic treatment were significantly younger and were more frequently treated with anticoagulants, platelet aggregation inhibitors and amiodarone. They also received higher doses of epinephrine and arrived at hospital under ongoing resuscitation significantly more frequently. A trend toward more prehospital return of spontaneous circulation (ROSC) following thrombolytic treatment was seen in the entire cohort. However, patients pre-treated with acetylsalicylic acid and heparin did not show better prehospital ROSC rates as a result of additional thrombolytic therapy. Significant differences in terms of bleeding complications or the need for blood transfusion could not be seen due to the small number of patients.

DISCUSSION

The indication for systemic thrombolysis in the context of prehospital resuscitation should remain restricted to patients with clear symptoms of acute pulmonary embolism or recurrent episodes of ventricular fibrillation in the setting of acute myocardial infarction. Due to a lack of evidence, systemic thrombolysis should not be used as a treatment of last resort in younger patients with persistent ventricular fibrillation.

CRITICAL CARE ECHO ROUNDS: Echo in cardiac arrest

Management of medical cardiac arrest is challenging. The internationally agreed approach is highly protocolised with therapy and diagnosis occurring in parallel. Early identification of the precipitating cause increases the likelihood of favourable outcome. Echocardiography provides an invaluable diagnostic tool in this context. Acquisition of echo images can be challenging in cardiac arrest and should occur in a way that minimises disruption to cardiopulmonary resuscitation (CPR). In this article, the reversible causes of cardiac arrest are reviewed with associated echocardiography findings.

CASE

A 71-year-old patient underwent right upper lobectomy for lung adenocarcinoma. On the 2nd post-operative day, he developed respiratory failure with rising oxygen requirement and right middle and lower lobe collapse and consolidation on chest X-ray. He was commenced on high-flow oxygen therapy and antibiotics. His condition continued to deteriorate and on the 3rd post-operative day he was intubated and mechanically ventilated. Six hours after intubation, he became suddenly hypotensive with a blood pressure of 50 systolic and then lost cardiac output. ECG monitoring showed pulseless electrical activity. CPR was commenced and return of circulation occurred after injection of 1 mg of adrenaline. Focused echocardiography was performed, which demonstrated signs of massive pulmonary embolism. Thrombolytic therapy with tissue plasminogen activator was given and his condition stabilised.

A framework for implementation, education, research and clinical use of ultrasound in emergency departments by the Danish Society for Emergency Medicine

The first Danish Society for Emergency Medicine (DASEM) recommendations for the use of clinical ultrasound in emergency departments has been made. The recommendations describes what DASEM believes as being current best practice for training, certification, maintenance of acquired competencies, quality assurance, collaboration and research in the field of clinical US used in an ED.

Effect of prehospital ultrasound on clinical outcomes of non-trauma patients--a systematic review

BACKGROUND

Advances in technology have made prehospital ultrasound (US) examination available. Whether US in the prehospital setting can lead to improvement in clinical outcomes is yet unclear.

OBJECTIVE

The aim of this systematic review was to assess whether prehospital US improves clinical outcomes for non-trauma patients.

METHOD

We conducted a systematic review on non-trauma patients who had an US examination performed in the prehospital setting. We searched MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials and the ISI Web of Science and the references of the included studies for additional relevant studies. We then performed a risk of bias analysis and descriptive data analysis.

RESULTS

We identified 1707 unique citations and included ten studies with a total of 1068 patients undergoing prehospital US examination. Included publications ranged from case series to non-randomized, descriptive studies, and all showed a high risk of bias. The large heterogeneity between the different studies made further statistical analysis impossible.

CONCLUSION

There are currently no randomized, controlled studies on the use of US for non-trauma patients in the prehospital setting. The included studies were of large heterogeneity and all showed a high risk of bias. We were thus unable to assess the effect of prehospital US on clinical outcomes. However, consistent reports suggested that US may improve patient management with respect to diagnosis, treatment, and hospital referral.