Outcome in cardiac arrest patients found to have cardiac standstill on the bedside emergency department echocardiogram

Impact of Modified Treatment in Echocardiographically Confirmed Pseudo-Pulseless Electrical Activity in Out-of-Hospital Cardiac Arrest Patients with Constant End-Tidal Carbon Dioxide Pressure during Compression Pauses

This study evaluated the ability of focused echocardiography (FE) and capnography to differentiate between pulseless electrical activity (PEA) and pseudo-PEA in out-of-hospital cardiac arrest, and the potential survival benefits with modified treatment. In PEA patients with stable end-tidal carbon dioxide pressure ( PetCO2) during the compression pause and concomitant FE showing cardiac kinetic activity, the compression pause was prolonged for 15 s and an additional 20 IU vasopressin was administered. If pulselessness persisted, compressions were continued. Fifteen of the 16 patients studied (94%) achieved restoration of spontaneous circulation (ROSC); eight patients (50%) attained a good neurological outcome (Cerebral Performance Category 1–2). In an historical PEA group with stable PetCO2 values ( n = 48), ROSC was achieved in 26 patients (54%); four patients (8%) attained Cerebral Performance Category 1–2. Echocardiographical verification of the pseudo-PEA state enabled additional vasopressor treatment and cessation of chest compressions, and was associated with significantly higher rates of ROSC, survival to discharge and good neurological outcome.

Bedside emergency cardiac ultrasound in children

Bedside emergency ultrasound has rapidly developed over the past several years and has now become part of the standard of care for several applications. While it has only recently been applied to critically ill pediatric patients, several of the well-established adult indications may be applied to pediatric patients. One of the most important and life-saving applications is bedside echocardiography. While bedside emergency ultrasonography does not serve to replace formal comprehensive studies, it serves as an extension of the physical examination. It is especially useful as a rapid and effective tool in the diagnosis of pericardial effusions, tamponade and in distinguishing potentially reversible causes of pulseless electrical activity from asystole. Most recently, left ventricular function and inferior vena cava measurements have proven helpful in the assessment of undifferentiated hypotension and shock in adults and children. Future research remains to be carried out in determining the efficacy of bedside ultrasonography in pediatric-specific pathology such as congenital heart disease. This article serves as a comprehensive review of the adult literature and a review of the recent applications in the pediatric emergency department. It also highlights the techniques of bedside ultrasonography with examples of normal and pathologic images.

Focused examination of cerebral blood flow in peri-resuscitation: a new advanced life support compliant concept—an extension of the focused echocardiography evaluation in life support examination

Aim

To introduce a new concept of the extension of focused echocardiography evaluation in life support (FEEL) with advanced life support (ALS)-compliant duplex sonography of the extracranial internal carotid artery (ICA) blood flow velocity for monitoring of cerebral blood circulation during peri-resuscitation.

Concept and results

With respect to pulseless electrical activity states, the question of adequate cerebral blood flow (CBF) cannot be answered by echocardiography alone. Pulse checks are unreliable. To build up a concept for assessing CBF, we analyzed duplex sonography workflow in three adults on the intensive care unit (postoperative, cardiogenic shock, cardiac standstill), and in simulated procedures. We decided to use duplex flow velocity of the ICA, for it is an accepted measurement for estimating CBF and it seems to be easy to obtain a window and interpretation during peri-resuscitation. The presence of an arterial blood flow pattern and an end-diastolic flow velocity of more than 20 cm/s, arbitrarily set, is considered to indicate sufficient CBF. The method of ICA flow velocity analysis during peri-resuscitation was tentatively added to the FEEL concept and is described with algorithm, workflow and three cases. This method may give an assist to answer the question, if CBF is sufficient, when myocardial wall motion is detectable in peri-resuscitation care.

Conclusion

This new concept of an ALS-conformed analysis of ICA blood flow velocity by duplex sonography may provide a simple, fast applicable and inexpensive method to qualitatively assess CBF in the peri-resuscitation setting.

Pilot study to determine the feasibility of training Army National Guard medics to perform focused cardiac ultrasonography

OBJECTIVE

To assess the ability of Army National Guard combat medics to perform a limited bedside echocardiography (BE) to determine cardiac activity after a brief training module.

METHODS

Twelve Army National Guard health care specialists trained to the level of emergency medical technician-basic (EMT-B) underwent an educational session consisting of a 5-minute lecture on BE followed by hands-on practical training. After the training session, each medic performed BEs, in either the subxiphoid (SX) or parasternal (PS) location at his or her discretion, on four healthy volunteers. The time required to complete the BE and the anatomic location of the examination (SX vs. PS) was documented. A 3-second video clip representing the best image was recorded for each BE. These clips were subsequently reviewed independently by two of the investigators with experience performing and interpreting BE; each BE was graded on a six-point scale designed for the study, the Cardiac Ultrasound Structural Assessment Scale (CUSAS). A score of 3 or greater was considered to be adequate to assess for the presence of cardiac activity. Where there was disagreement on the CUSAS score, the reviewers viewed the clip together and agreed on a consensus CUSAS score. We calculated the median time to completion and interquartile range (IQR) for each BE, the median CUSAS scores and IQR for examinations performed in the SX and PS locations, and kappa for agreement between the two reviewers on the CUSAS.

RESULTS

A total of 48 BEs were recorded and reviewed. Thirty-seven of 48 (77%) were obtained in the SX location, and 11 of 48 (23%) were obtained in the PS location. Forty-four of 48 (92%) were scored as a 3 or higher on the CUSAS. Median time to completion of a BE was 5.5 seconds (IQR: 3.7-10.9 seconds). The median CUSAS score in the SX location was 4 (IQR: 4-5), and the median CUSAS score in the PS location was 4 (IQR: 4-4). Weighted kappa for the CUSAS was 0.6.

CONCLUSION

With minimal training, the vast majority of the medics in our study were able to rapidly perform a focused BE on live models that was adequate to assess for the presence of cardiac activity.

Pulseless electrical activity, focused abdominal sonography for trauma, and cardiac contractile activity as predictors of survival after trauma

BACKGROUND

Pulseless electrical activity (PEA) secondary to both blunt and penetrating trauma is associated with minimal survival. The pericardial view of the focused abdominal sonography for trauma (p-FAST) can differentiate between patients with and without organized cardiac activity and may assist in the decision to terminate ongoing resuscitation.

METHODS

A retrospective review was performed for all patients presenting to a level I trauma center from January 2006 through January/2009 who had PEA on arrival or developed PEA in the emergency department. Additional data abstracted included outcome, the p-FAST findings, and mechanism of injury. Recorded FAST examinations were reviewed by a blinded ultrasound trained physician.

RESULTS

During the study period 25 patients presented with PEA and three developed PEA during initial resuscitation. Contractile cardiac activity was present in nine patients with PEA on presentation and immediately after deterioration to PEA in the three patients developing PEA. Four patients had a penetrating mechanism and 24 were blunt. Two pericardial effusions were present on examination, both after blunt trauma. Three patients survived beyond the emergency department (89% early mortality). The survivors had presented in PEA with organized cardiac contractile activity on ultrasound and had tension pneumothorax, tension hemothorax, and hypovolemia treated. Two patients died in the operating room of uncontrolled hemorrhage and one patient died 6 days after admission because of closed head injury.

CONCLUSIONS

The presence of PEA at any time during initial resuscitation is a grave prognostic indicator. p-FAST is a useful test to identify contractile cardiac activity. p-FAST may identify those patients with potential for survival.

Portable ultrasound for remote environments, part II: current indications

BACKGROUND

With recent advances in ultrasound technology, it is now possible to deploy lightweight portable imaging devices in the field. Techniques and studies initially developed for hospital use have been extrapolated out of the hospital setting in a wide variety of environments in an effort to increase diagnostic accuracy in austere or prehospital environments.

OBJECTIVES

This review summarizes current ultrasound applications used in out-of-hospital arenas and highlights existing evidence for such use. The diversity of applications and environments is organized by indication to better inform equipment selection as well as future directions for research and development.

DISCUSSION

Trauma evaluation, casualty triage, and assessment for pneumothorax, acute mountain sickness, and other applications have been studied by field medical teams. A wide range of outcomes have been reported, from alterations in patient care to determinations of accuracy compared to clinical judgment or other diagnostic modalities.

CONCLUSIONS

The use of lightweight portable ultrasound shows great promise in augmenting clinical assessment for field medical operations. Although some studies of diagnostic accuracy exist in this setting, further research focused on clinically relevant outcomes data is needed.

The RUSH exam: Rapid Ultrasound in SHock in the evaluation of the critically lll

The RUSH exam (Rapid Ultrasound in SHock examination), presented in this article, represents a comprehensive algorithm for the integration of bedside ultrasound into the care of the patient in shock. By focusing on a stepwise evaluation of the shock patient defined here as "Pump, Tank, and Pipes," clinicians will gain crucial anatomic and physiologic data to better care for these patients.

Resident training in emergency ultrasound: consensus recommendations from the 2008 Council of Emergency Medicine Residency Directors Conference

Over the past 25 years, research performed by emergency physicians (EPs) demonstrates that bedside ultrasound (US) can improve the care of emergency department (ED) patients. At the request of the Council of Emergency Medicine Residency Directors (CORD), leaders in the field of emergency medicine (EM) US met to delineate in consensus fashion the model "US curriculum" for EM residency training programs. The goal of this article is to provide a framework for providing US education to EM residents. These guidelines should serve as a foundation for the growth of resident education in EM US. The intent of these guidelines is to provide minimum education standards for all EM residency programs to refer to when establishing an EUS training program. The document focuses on US curriculum, US education, and competency assessment. The use of US in the management of critically ill patients will improve patient care and thus should be viewed as a required skill set for all future graduating EM residents. The authors consider EUS skills critical to the development of an emergency physician, and a minimum skill set should be mandatory for all graduating EM residents. The US education provided to EM residents should be structured to allow residents to incorporate US into daily clinical practice. Image acquisition and interpretation alone are insufficient. The ability to integrate findings with patient care and apply them in a busy clinical environment should be stressed.

Ventricular fibrillation diagnosed with trans-thoracic echocardiography

Electrocardiographic artifacts on scope are frequently observed in pre-hospital settings. They can lead to misdiagnosis or inappropriate resuscitation treatments. Here we report a case of ventricular fibrillation by electrical injury masked by ECG artifacts, after the savage of a victim, due to persistent 50Hz domestic current and identified by trans-thoracic ultrasonography. No clinical randomized studies define precisely the benefit of such an examination. In cases where ECG analysis is impossible due to artifacts, ultrasonographic exam could be useful to identify ventricular fibrillation. This case underlines also the need for a correct device ECG analysis in any circumstances.

Use of ultrasound by emergency medical services: a review

Prehospital ultrasound has been deployed in certain areas of the USA and Europe. Physicians, emergency medical technicians, and flight nurses have utilized a variety of medical and trauma ultrasound assessments to impact patient care in the field. The goal of this review is to summarize the literature on emergency medical services (EMS) use of ultrasound to more clearly define the potential utility of this technology for prehospital providers.

The utility of cardiac sonography and capnography in predicting outcome in cardiac arrest

Emergency physicians and intensivists are increasingly utilizing capnography and bedside echocardiography during medical resuscitations. These techniques have shown promise in predicting outcomes in cardiac arrest, and no cases of return of spontaneous circulation in the setting of sonographic cardiac standstill and low end-tidal carbon dioxide have been reported. This case report illustrates an example of such an occurrence. Our aims are to report a case of return of spontaneous circulation in a patient with sonographic cardiac standstill, electrocardiographic pulseless electrical activity, and low end-tidal carbon dioxide tensions and to place the case in the context of previous literature on this topic. Case report and brief review of the literature. In 254 cases reported, no patient has survived in the setting of sonographic cardiac standstill and low end-tidal carbon dioxide tension, making the reported case unique. This case should serve to illustrate the utility and limitations of combined cardiac sonography and end-tidal carbon dioxide measurement in determining prognosis during cardiac arrest.

Monitoring the quality of cardiopulmonary resuscitation

PURPOSE OF REVIEW

Numerous recent reports have described limitations in the quality of cardiopulmonary resuscitation. Thus, there has been increasing interest in the techniques available to monitor quality. This review focuses on the major publications since the review published by the International Liaison Committee on Resuscitation in 2005. Some key articles published prior to this time period have also been included.

RECENT FINDINGS

A number of devices can monitor various components of the quality of cardiopulmonary resuscitation. End-tidal CO2 measurement assists in confirming placement of endotracheal tubes, correlates with cardiac output and detects the return of spontaneous circulation. Turbine flow-meters monitor respiratory rate and tidal volume. Transthoracic impedance monitoring measures respiratory rate, and may assist in confirmation of endotracheal tube placement. A new mechanical device (CPREzy) and a new defibrillator/monitor allow estimation of depth (and rate) of compressions. Ventricular-fibrillation waveform analysis may facilitate better timing of defibrillation. Echocardiography detects conditions that may impair the quality of cardiopulmonary resuscitation.

SUMMARY

Many options are available to monitor the quality of cardiopulmonary resuscitation. Some have significant limitations, and others are only readily available in hospital. The use of the information from this more intensive monitoring promises to improve outcomes of cardiopulmonary resuscitation.

Bedside ultrasound in the pediatric emergency department

PURPOSE OF REVIEW

Emergency bedside ultrasound has been used by emergency and critical care physicians for over two decades. Its use has grown rapidly in emergency medicine and the range of diagnostic and procedural applications has continued to expand; only recently, however, has this tool been embraced by pediatric emergency and critical care physicians. As this technology develops and becomes more available pediatricians should understand its uses and limitations.

RECENT FINDINGS

Use of emergency bedside ultrasound for victims of trauma and for procedural applications such as central venous access are well established in adults. Recent published studies suggest that utilizing bedside ultrasound for these purposes may be beneficial in pediatric emergency medicine. Other reports portend future pediatric applications such as assessment of volume status and dehydration, fracture identification and reduction, and aiding in the performance of lumbar punctures.

SUMMARY

In a review of the literature, it is clear that emergency bedside ultrasound has a role in pediatric emergency and critical care medicine. Much more research is needed, however, to determine which sonographic assessments are of the greatest value. Collaborative efforts will likely be needed to establish definitive applications.

Transesophageal echocardiography during cardiopulmonary arrest in the emergency department

Management of patients in cardiopulmonary arrest is challenging and can be resource consuming. Outcomes continue to be poor and physicians may feel a sense of futility when running a resuscitation. Bedside ultrasound has been utilized to guide resuscitations, diagnose correctable cardiac pathology leading to an arrest and has proved to have a prognostic value when utilized in the initial stages of resuscitation. Bedside emergency ultrasound is limited by inability to scan during chest compression and poor image quality in obese patients and those with emphysema. During cardiopulmonary resuscitation pulse checks need to be rapid and leave little time for transducer manipulation during image acquisition. Recent American Heart Association guidelines further stress the need for quality chest compressions and minimizing intervals with no compressions. Transesophageal echocardiography offers high resolution and clarity of images in the vast majority of patients. It allows for constant visualization of the heart, even during chest compressions, cardioversion and other procedures. This case series describes the use of transesophageal echocardiography (TEE) during cardiac arrest by emergency physicians. The cases illustrate some of the potential benefits of TEE during cardiopulmonary arrest.

Bedside ultrasound in pediatric emergency medicine

Bedside emergency ultrasound has been used by emergency physicians for >20 years for a variety of conditions. In adult centers, emergency ultrasound is routinely used in the management of victims of blunt abdominal trauma, in patients with abdominal aortic aneurysm and biliary disease, and in women with first-trimester pregnancy complications. Although its use has grown dramatically in the last decade in adult emergency departments, only recently has this tool been embraced by pediatric emergency physicians. As the modality advances and becomes more available, it will be important for primary care pediatricians to understand its uses and limitations and to ensure that pediatric emergency physicians have access to the proper training, equipment, and experience. This article is meant to review the current literature relating to emergency ultrasound in pediatric emergency medicine, as well as to describe potential pediatric applications.

The dead continue to teach the living: examining the role of computed tomography and magnetic resonance imaging in the setting of postmortem examinations

High-resolution imaging methods are used more frequently in the setting of postmortem investigation. Used for some time in forensics, computed tomography (CT) and magnetic resonance imaging (MRI) are now being evaluated as complementary or even as alternative means of postmortem examination. We review briefly the history of autopsy and the reasons for the gradual decrease in autopsy rates. An overview of advantages and limitations of modern imaging autopsy techniques is then presented, which includes a discussion of the potential role of imaging autopsy in medical and surgical education. Potential future applications of this technology in postmortem analysis, which includes the incorporation of ultrasound technology, are then discussed.

C.A.U.S.E.: Cardiac arrest ultra-sound exam—A better approach to managing patients in primary non-arrhythmogenic cardiac arrest

Cardiac arrest is a condition frequently encountered by physicians in the hospital setting including the Emergency Department, Intensive Care Unit and medical/surgical wards. This paper reviews the current literature involving the use of ultrasound in resuscitation and proposes an algorithmic approach for the use of ultrasound during cardiac arrest. At present there is the need for a means of differentiating between various causes of cardiac arrest, which are not a direct result of a primary ventricular arrhythmia. Identifying the cause of pulseless electrical activity or asystole is important as the underlying cause is what guides management in such cases. This approach, incorporating ultrasound to manage cardiac arrest aids in the diagnosis of the most common and easily reversible causes of cardiac arrest not caused by primary ventricular arrhythmia, namely; severe hypovolemia, tension pneumothorax, cardiac tamponade, and massive pulmonary embolus. These four conditions are addressed in this paper using four accepted emergency ultrasound applications to be performed during resuscitation of a cardiac arrest patient with the aim of determining the underlying cause of a cardiac arrest. Identifying the underlying cause of cardiac arrest represents the one of the greatest challenges of managing patients with asystole or PEA and accurate determination has the potential to improve management by guiding therapeutic decisions. We include several clinical images demonstrating examples of cardiac tamponade, massive pulmonary embolus, and severe hypovolemia secondary to abdominal aortic aneurysm. In conclusion, this protocol has the potential to reduce the time required to determine the etiology of a cardiac arrest and thus decrease the time between arrest and appropriate therapy.

Medical futility in asystolic out-of-hospital cardiac arrest

OBJECTIVES

To study the factors associated with short- and long-term survival after asystolic out-of-hospital cardiac arrest, with a reference to medical futility.

METHODS

This is a retrospective observational study conducted in Helsinki, Finland during 1 January 1997 to 31 December 2005. All out-of-hospital cardiac arrests were prospectively registered in the cardiac arrest database. Of 3291 arrests, 1455 had asystole as the first registered rhythm. These patients represent the study population.

RESULTS

A short time interval to the initiation of advanced life support (ALS) was associated with a long-term benefit, but a short first responding unit (FRU) response time had only a short-term benefit. Conversion of asystole into a shockable rhythm provided only a short-term benefit. The prognosis was poor if the FRU response time was over 10 min or the ALS response time was over 11 min in bystander-witnessed arrests, and if the duration of resuscitation was over 8 min in emergency medical services (EMS)-witnessed arrests. Bystander-CPR was associated with increased 30-day mortality. The 30-day survival rate after an unwitnessed arrest (n=548) was 0.5%. All survivors in this group were either hypothermic or were victims of near-drowning.

CONCLUSIONS

Resuscitation should be withheld in cases of unwitnessed asystole, excluding cases of hypothermia and near-drowning. The prognosis is poor if the FRU response time is over 10 min or the ALS response time is over 10-15 min in bystander-witnessed arrests. The decision of whether or not to attempt resuscitation should not be influenced by the presence of bystander-CPR. Early initiation of ALS should be prioritised in the treatment of out-of-hospital asystole.

Who survives from out-of-hospital pulseless electrical activity?

AIM OF THE STUDY

To study factors associated with short-term and long-term survival after out-of-hospital cardiac arrest presenting with pulseless electrical activity (PEA).

MATERIALS AND METHODS

This was a retrospective observational study. All out-of-hospital cardiac arrests in Helsinki, Finland during 1 January 1997-31 December 2005 were prospectively registered in the cardiac arrest database. Of 3291 arrests 984 had PEA as the first registered rhythm.

RESULTS

The use of adrenaline was the only factor associated with long-term survival, by increasing mortality. Increasing delay to the return of spontaneous circulation (ROSC) was the only factor associated with survival among patients that survived to admission, also by increasing mortality. There were no survivors that were discharged in overall performance category (OPC) 1-2 after a bystander-witnessed arrest (excluding cases of hypothermia and/or near-drowning) with first responding unit (FRU)-delay over 14 min, or that were resuscitated for more than 20 min. There were no survivors who were discharged in OPC 1-2 after an unwitnessed arrest with the duration of advanced life support (ALS) exceeding 5.5 min.

CONCLUSIONS

The use of adrenaline during resuscitation was the only significant factor which was found to decrease the long-term survival. Among admitted patients, short delay to ROSC was the only factor associated with increased survival. Bystander-CPR and delays to the arrival of the FRU or to the initiation of ALS were not associated with survival. Therefore, it seems difficult to increase survival rates of PEA by improving the chain of survival. More effort should be put to education of the public to call for an ambulance before the cardiac arrest occurs.

History of emergency and critical care ultrasound: The evolution of a new imaging paradigm

The tradition of clinical ultrasound in the hands of physicians who provide critical care to the most acutely ill patients stretches back into the 1980s and is rich with experiences from surgical, emergency medicine, and other practices. Now, as critical care ultrasound explodes around the world, it is important to realize the path its development has taken and learn from trials and tribulations of early practitioners in the field. The development and battles for the right to use ultrasound at the patient's bedside for >20 yrs is described in relation to its emergency medicine and surgical origins. Approaches to education, scanning, documentation, and organization at the national and regional levels are described.

Focused echocardiographic evaluation in resuscitation management: Concept of an advanced life support–conformed algorithm

Emergency ultrasound is suggested to be an important tool in critical care medicine. Time-dependent scenarios occur during preresuscitation care, during cardiopulmonary resuscitation, and in postresuscitation care. Suspected myocardial insufficiency due to acute global, left, or right heart failure, pericardial tamponade, and hypovolemia should be identified. These diagnoses cannot be made with standard physical examination or the electrocardiogram. Furthermore, the differential diagnosis of pulseless electrical activity is best elucidated with echocardiography. Therefore, we developed an algorithm of focused echocardiographic evaluation in resuscitation management, a structured process of an advanced life support-conformed transthoracic echocardiography protocol to be applied to point-of-care diagnosis. The new 2005 American Heart Association/European Resuscitation Council/International Liaison Committee on Resuscitation guidelines recommended high-quality cardiopulmonary resuscitation with minimal interruptions to reduce the no-flow intervals. However, they also recommended identification and treatment of reversible causes or complicating factors. Therefore, clinicians must be trained to use echocardiography within the brief interruptions of advanced life support, taking into account practical and theoretical considerations. Focused echocardiographic evaluation in resuscitation management was evaluated by emergency physicians with respect to incorporation into the cardiopulmonary resuscitation process, performance, and physicians' ability to recognize characteristic pathology. The aim of the focused echocardiographic evaluation in resuscitation management examination is to improve the outcomes of cardiopulmonary resuscitation.

Death, dying, and last wishes

Issues regarding patient care near the end of life can be challenging and rewarding for emergency physicians. Knowledge of the patient's wishes is essential, and may be accomplished by advance directives or communication with patients and surrogates. Resuscitative efforts are appropriate for many patients, but inappropriate for others. The goals of medicine remain the following: providing optimal health care, provision of the best possible symptom control, communication, empathy, and caring. As death approaches, provision of the best possible medical care, in accordance with the patient's wishes, can be rewarding for patients, families, and health care providers.

Emergency department ultrasound and echocardiography

Bedside sonography has become an important tool in the emergency physician's diagnostic armamentarium. Sonography is useful in the evaluation of a number of conditions, including cholecystitis, abdominal aortic aneurysm, and ectopic pregnancy. Applied to the heart, sonography aids in the assessment of pericardial tamponade, electromechanical dissection, pulmonary embolus, and other cardiorespiratory emergencies. Echocardiography also has a role in differentiating patients with cardiac activity from those in ventricular standstill and in estimating central venous pressure. This article reviews these and other clinical applications and the physics of ultrasound, techniques for sonographic evaluation, and the practical aspects of emergency department use, such as strategic placement of the equipment for quick activation and storage of collected data.

Does the presence or absence of sonographically identified cardiac activity predict resuscitation outcomes of cardiac arrest patients?

This study evaluated the ability of cardiac sonography performed by emergency physicians to predict resuscitation outcomes of cardiac arrest patients. A convenience sample of cardiac arrest patients prospectively underwent bedside cardiac sonography at 4 emergency medicine residency-affiliated EDs as part of the Sonography Outcomes Assessment Program. Cardiac arrest patients in pulseless electrical activity (PEA) and asystole underwent transthoracic cardiac ultrasound B-mode examinations during their resuscitations to assess for the presence or absence of cardiac kinetic activity. Several end points were analyzed as potential predictors of resuscitations: presenting cardiac rhythms, the presence of sonographically detected cardiac activity, prehospital resuscitation time intervals, and ED resuscitation time intervals. Of 70 enrolled subjects, 36 were in asystole and 34 in PEA. Patients presenting without evidence of cardiac kinetic activity did not have return of spontaneous circulation (ROSC) regardless of their cardiac rhythm, asystole, or PEA. Of the 34 subjects presenting with PEA, 11 had sonographic evidence of cardiac kinetic activity, 8 had ROSC with subsequent admission to the hospital, and 1 had survived to hospital discharge with scores of 1 on the Glasgow-Pittsburgh Cerebral Performance scale and 1 in the Overall Performance category. The presence of sonographically identified cardiac kinetic motion was associated with ROSC. Time interval durations of cardiac resuscitative efforts in the prehospital environment and in the ED were not accurate predictors of ROSC for this cohort. Cardiac kinetic activity, or lack thereof, identified by transthoracic B-mode ultrasound may aid physicians' decision making regarding the care of cardiac arrest patients with PEA or asystole.

Rapid cardiac ultrasound of inpatients suffering PEA arrest performed by nonexpert sonographers

Cardiac arrest presenting as pulseless electrical activity (PEA) currently has a very low survival rate. Many of the conditions underlying PEA (cardiac tamponade, hypovolemia, and pulmonary embolus) are associated with specific cardiac ultrasound findings. The aim of this study was to evaluate a rapid cardiac ultrasound assessment performed by trained nonexpert sonographers integrated into the ACLS response system at a major medical center.

METHODS

An emergency sonography system was created and deployed to each inpatient cardiac arrest occurring at Dartmouth Hitchcock Medical Center between November 1, 2003 and April 30, 2004. Thirteen internal medicine house officers received training to perform a limited subcostal cardiac ultrasound examination designed to diagnose cardiac tamponade, pulmonary embolus, severe hypovolemia, and lack of cardiac motion. Time from arrest alert to sonographic result, and correlation with over-reading by blinded echocardiography physicians were assessed.

RESULTS

A complete emergency ultrasound examination was performed in five PEA arrests. The average time from arrest alert to interpretation was 7.75 min. (95% CI 2.8-18.3 min). Three of these examinations (60%, 95% CI 14.7-94.7%) were adequate for interpretation. Agreement between the nonexpert sonographer and echocardiography physician occurred in four of five (kappa=0.706) cases.

CONCLUSION

Rapid cardiac sonography can be successfully integrated in the ACLS response. Nonexpert sonographers may be able to provide useful interpretive information when sufficiently trained.

Red flag in the Emergency Department: Fracture and primary failure of a prosthetic valve

This case report concerns a patient with fracture and primary dysfunction of a prosthetic valve. A 40-year-old man presented to the Emergency Department with a chief complaint of breakthrough pleuritic back pain and shortness of breath. Past surgical history was significant only for an aortic valve replacement and mitral valve replacement performed 16 years prior. The transthoracic echocardiography raised suspicion of prosthesis malposition. The patient was taken to the operating room by cardiothoracic surgeons for valve replacement. Operative findings revealed that a prosthetic valve leaflet in the mitral position had broken off. Primary prosthetic valve failure should not be overlooked in the differential diagnosis of patients with valve replacement and a rapidly deteriorating clinical course. Emergency echocardiography is a guide to convenient diagnosis and management. Early surgical consultation and early reparative surgery might prevent unnecessary morbidity and mortality.

Electrical therapy for post defibrillatory pulseless electrical activity

BACKGROUND

Defibrillation may convert ventricular fibrillation (VF) only to reveal profound mechanical dysfunction. Survival following this dysfunction, known as pulseless electrical activity (PEA) and electromechanical dissociation (EMD), is uncommon. We sought to evaluate an electrical therapy for primary post shock PEA following short duration VF.

METHODS AND RESULTS

Forty-eight episodes of VF, lasting 110 +/- 25 s, were induced in 16 anesthetized dogs. Following defibrillation, 35 episodes met PEA criteria (ABP < or = 36 mmHg diastolic and pulse pressure < or = 14 mmHg in the first 20 s post shock). These post defibrillation PEA episodes were either Not Treated (NT) or Treated (T) with packets of 4-20 monophasic 0.2 ms 50-100 Hz pulses of 20-60 V applied across the tip and coil of an integrated bipolar transvenous defibrillation lead positioned in the right ventricle. The therapeutic endpoint was return of spontaneous circulation (ROSC; self-sustained ABP > or = 60 mmHg diastolic and/or > or = 100 mmHg systolic) for over 2 min. In the Not Treated group, only 4 of 19 (21%) episodes spontaneously recovered to ROSC in 123 +/- 49 s while in the Treated group, 11 of 16 (69%) of the PEA episodes achieved ROSC in 102 +/- 92 s.

CONCLUSIONS

Electrical therapy increased the likelihood of ROSC in primary post defibrillation PEA three-fold (P < 0.01). Recovery occurred in the absence of thoracic compression, mechanical ventilation, or adjunctive drug therapy.

Cardiac ultrasound

The use of echocardiography in the ED is well established and continues to gain widespread use in the evaluation of critically ill patients. In certain circumstances such as chest trauma, pericardial effusion, and cardiac arrest,EPs can perform and interpret echocardiographic examinations reliably. In other circumstances such as the diagnosis of acute coronary syndromes, PE,and endocarditis, the EP should be aware of the uses and limitations of echocardiography and obtain appropriate consultation when necessary.Academic- and community-based EPs should seek to incorporate further the use of echocardiography in their respective clinical practices, with special attention given to training and quality assurance. As EPs continue to improve their skills in cardiac ultrasound, their ability to diagnose a wider spectrum of cardiac diseases undoubtedly will grow proportionally.

Emergency echocardiography to detect pericardial effusion in patients in PEA and near-PEA states

OBJECTIVES

Emergency echocardiography (EM echo) has been proposed to assist in decision-making in patients with pulseless electric activity (PEA) or PEA-like states. We observed the value of EM echo by emergency physicians in detecting pericardial effusion in patients in PEA and near PEA states.

MATERIALS AND METHODS

Observational, prospective series at a Level 1 urban ED of patients with non-traumatic PEA or near PEA states who had EM echoes performed by emergency physicians during an 18-month period. Outcomes of patients with EM echoes were established by review of clinical course, formal echocardiography, radiography, operation or autopsy.

RESULTS

Twenty patients had EM echo for non-traumatic hemodynamic collapse. Eight of 20 patients (40%) were without cardiac ventricular motion and were refractory to ACLS measures. Twelve of 20 (60%) patients had cardiac kinetic motion observed on echo. Eight of the 12 (67%) patients with cardiac motion had a pericardial effusion observed on EM echo. Formal echocardiography or other imaging studies confirmed all pericardial effusion cases. The following diagnoses were subsequently confirmed in patients with pericardial effusion: one aortic aneurysm, two aortic dissections, two metastatic cancers, one post-dialysis effusion, two minimal effusions. Three patients had tamponade with emergency pericardial drainage or surgery. In two of four patients with cardiac activity without pericardial effusion, EM echo was useful by detecting pacer capture and ROSC, respectively.

CONCLUSIONS

Emergency echocardiography performed by emergency physicians in patients in PEA or near PEA states can detect pericardial effusions with correctable etiologies versus true PEA with ventricular standstill.

Stroke volumes and end-tidal carbon dioxide generated by precordial compression during ventricular fibrillation

OBJECTIVE

The objective of this study was to measure stroke volumes produced by precordial compression during cardiopulmonary resuscitation and to quantitate relationships of stroke volume to measurements of end-tidal carbon dioxide.

DESIGN

A prospective, observational animal study.

SETTING

Medical research laboratory in a university-affiliated research and educational foundation.

SUBJECTS

Domestic pigs.

INTERVENTIONS

Eighteen anesthetized male, domestic pigs weighing between 40 and 45 kg were investigated. Ventricular fibrillation was electrically induced and continued for intervals ranging from 4 to 10 mins. Precordial compression was maintained at 80 per minute together with mechanical ventilation after endotracheal intubation.

MEASUREMENTS AND MAIN RESULTS

Stroke volumes were measured with the aid of transesophageal echocardiographic imaging. End-tidal carbon dioxide was quantitated with conventional capnography. Baseline values of thermodilution cardiac output were highly correlated with echocardiographic measurements (r =.92). The stroke volume index produced by precordial compression averaged 0.45 mL/kg or approximately 37% of the average prearrest value of 1.22 mL/kg. The end-tidal carbon dioxide was highly predictive of stroke volume index (r =.88, p <.001) with a mean bias of 0.003 mL/kg.

CONCLUSIONS

We confirmed that precordial compression produces approximately one third of prearrest stroke volumes during cardiopulmonary resuscitation and demonstrated that end-tidal carbon dioxide was quantitatively predictive of stroke volume index estimated by transesophageal echocardiographic imaging.

A novel use of ultrasound in pulseless electrical activity: the diagnosis of an acute abdominal aortic aneurysm rupture

We report a case of a patient who presented to the Emergency Department with pulseless electrical activity. A rapid diagnosis of ruptured abdominal aortic aneurysm was made by Emergency Medicine bedside ultrasonography. On arrival, the patient was without palpable pulses and bradycardic. Therapy with epinephrine, fluids, and atropine was initiated. A bedside ultrasound was immediately performed and revealed coordinated cardiac motion with empty ventricles. A rapid search for signs of blood loss in the abdomen revealed a large abdominal aortic aneurysm. Pulses were restored with fluid, blood, and epinephrine and surgical intervention was begun within 30 min of patient arrival.