Echocardiography in cardiac arrest:

Intra-arrest formation of right-heart thrombi -- a case illustrated by real-time ultrasonography

The presence of free-floating right-heart thrombus has been reported in a cardiac arrest patient in the periarrest period. Free-floating right atrial thrombus is a rare phenomenon seen in patients developing severe pulmonary embolism, and is associated with increased mortality. However, there have been no previously reported cases of right-heart thrombus formation during a resuscitated cardiac arrest. We present the pre-hospital case of a woman in the clinical setting of cardiogenic shock due to acute myocardial infarction who developed asystolic cardiac arrest on the scene. Recent implementation of ultrasonography into the regional pre-hospital care protocol enabled sonographic investigation before and during cardiac arrest. This allowed detection of right atrial septal thrombus formation in the course of advanced life support and its migration through the tricuspid valve. The pathophysiological consequences, clinical significance and potential therapeutic options are discussed.

Use of ultrasound for non-trauma patients in the emergency department

OBJECTIVE

In the past decade, there has been substantial knowledge translation in the use of ultrasound (US) by critical care physicians to aid diagnosis of the non-trauma patient. This study aimed to determine emergency doctors' level of training in ultrasonography, pattern of US use in regular practice and barriers to US use for the non-trauma patient presenting to an emergency department.

METHOD

A survey on the use of US in non-trauma patients was conducted, targeting all emergency physicians and emergency medicine trainees in a single adult tertiary referral centre.

RESULTS

The response rate was 92.7% with 38 completed surveys analysed. A course in non-trauma US had been completed by 58% of respondents. The most common non-trauma formal US training was in vascular access (82%, 95% confidence interval [CI] 66.8-90.6), detection of abdominal aortic aneurysm (79%, 95% CI 63.7-88.9) and pericardial fluid (84%, 95% CI 69.6-92.6). Upon completion of formal training, US was used significantly more frequently for obtaining vascular access (odds ratio [OR] 12.0), detection of abdominal aortic aneurysms (OR 4.3) and detection of pericardial fluid (OR 15.5). Most doctors felt the greatest barriers to the use of US in the non-trauma patient were the lack of teaching, confidence in findings, experienced supervisors and time.

CONCLUSIONS

Among ED personnel, use of US to diagnose several non-traumatic conditions was low, but specific training was associated with significantly more US use. Increased training and availability of US-experienced supervisors might further improve utility of this important adjunct to the practice of emergency medicine.

Algorithm for the resuscitation of traumatic cardiac arrest patients in a physician-staffed helicopter emergency medical service

Survival rates following traumatic cardiac arrest (TCA) are known to be poor but resuscitation is not universally futile. There are a number of potentially reversible causes to TCA and a well-defined group of survivors. There are distinct differences in the pathophysiology between medical cardiac arrests and TCA. The authors present some of the key differences and evidence related to resuscitation in TCA, and suggest a separate algorithm for the management of out-of-hospital TCA attended by a highly trained physician and paramedic team.

Prehospital stroke diagnosis and treatment in ambulances and helicopters-a concept paper

Stroke is the second common cause of death and the primary cause of early invalidity worldwide. Different from other diseases is the time sensitivity related to stroke. In case of an ischemic event occluding a brain artery, 2000000 neurons die every minute. Stroke diagnosis and treatment should be initiated at the earliest time point possible, preferably at the site or during patient transport. Portable ultrasound has been used for prehospital diagnosis for applications other than stroke, and its acceptance as a valuable diagnostic tool "in the field" is growing. The intrahospital use of transcranial ultrasound for stroke diagnosis has been described extensively in the literature. Beyond its diagnostic use, first clinical trials as well as numerous preclinical work demonstrate that ultrasound can be used to accelerate clot lysis (sonothrombolysis) in presence as well as in absence of tissue plasminogen activator. Hence, the use of transcranial ultrasound for diagnosis and possibly treatment of stroke bares the potential to add to current stroke care paradigms significantly. The purpose of this concept article is to describe the opportunities presented by recent advances in transcranial ultrasound to diagnose and potentially treat large vessel embolic stroke in the prehospital environment.

Acute Myocardial Infarction and Massive Pulmonary Embolus Presenting as Cardiac Arrest: Initial Rhythm as a Diagnostic Clue

Myocardial infarction (MI) and massive pulmonary embolism (MPE) are common causes of cardiac arrest. We present two cases with similar clinical presentation and EKG findings but different initial rhythms. Case  1. A 55-year-old African American male (AAM) was brought to the emergency room (ER) with cardiac arrest and pulseless electrical activity (PEA). Twelve-lead electrocardiogram (EKG) was suggestive of ST segment elevations (STEs) in anterolateral leads. Coronary angiogram did not reveal any significant obstruction. An echocardiogram was suggestive of a pulmonary embolus (PE). Autopsy revealed a saddle PE. Case  2. A 45-year-old AAM with a history of coronary artery disease was brought to the ER after ventricular fibrillation (VF) arrest. Twelve-lead EKG was suggestive of STE in anterior leads. Coronary angiogram revealed in-stent thrombosis. In cardiac arrests, distinguishing the two major etiologies (MI and MPE) can be challenging. PEA is more commonly associated with MPE versus MI due to near complete obstruction of pulmonary blood flow with an intact electrical conduction system. MI is more commonly associated with VF as the electrical conduction system is affected more often by ischemia. In conclusion, the previous cases illustrate that initial rhythm may be a vital diagnostic clue.

Student tutors for hands-on training in focused emergency echocardiography--a randomized controlled trial

BACKGROUND

Focused emergency echocardiography performed by non-cardiologists has been shown to be feasible and effective in emergency situations. During resuscitation a short focused emergency echocardiography has been shown to narrow down potential differential diagnoses and to improve patient survival. Quite a large proportion of physicians are eligible to learn focused emergency echocardiography. Training in focused emergency echocardiography usually comprises a lecture, hands-on trainings in very small groups, and a practice phase. There is a shortage of experienced echocardiographers who can supervise the second step, the hands-on training. We thus investigated whether student tutors can perform the hands-on training for focused emergency echocardiography.

METHODS

A total of 30 volunteer 4th and 5th year students were randomly assigned to a twelve-hour basic echocardiography course comprising a lecture followed by a hands-on training in small groups taught either by an expert cardiographer (EC) or by a student tutor (ST). Using a pre-post-design, the students were evaluated by an OSCE. The students had to generate two still frames with the apical five-chamber view and the parasternal long axis in five minutes and to correctly mark twelve anatomical cardiac structures. Two blinded expert cardiographers rated the students' performance using a standardized checklist. Students could achieve a maximum of 25 points.

RESULTS

Both groups showed significant improvement after the training (p < .0001). In the group taught by EC the average increased from 2.3±3.4 to 17.1±3.0 points, and in the group taught by ST from 2.7±3.0 to 13.9±2.7 points. The difference in improvement between the groups was also significant (p = .03).

CONCLUSIONS

Hands-on training by student tutors led to a significant gain in echocardiography skills, although inferior to teaching by an expert cardiographer.

Applications of minimally invasive cardiac output monitors

Because of the increasing age of the population, critical care and emergency medicine physicians have seen an increased number of critically ill patients over the last decade. Moreover, the trend of hospital closures in the United States t imposes a burden of increased efficiency. Hence, the identification of devices that facilitate accurate but rapid assessments of hemodynamic parameters without the added burden of invasiveness becomes tantamount. The purpose of this review is to understand the applications and limitations of these new technologies.

[Coronary revascularization during cardiopulmonary resuscitation. The bridge code]

Cardiac arrest is one of the major current challenges, due to both its high incidence and mortality and the fact that it leads to severe brain dysfunction in over half of the survivors. The so-called coronary origin Bridge Code is presented, based on the international resuscitation recommendations (2005, 2010). In accordance with a series of strict predictive criteria, this code makes it possible to: (1) select refractory CPR patients with a high or very high presumption of underlying coronary cause; (2) evacuate the patient using mechanical chest compressors [LucasTM, Autopulse®], maintaining coronary and brain perfusion pressures; (3) allow coronary revascularization access during resuscitation maneuvering (PTCA during ongoing CPR); (4) induce early hypothermia; and (5) facilitate post-cardiac arrest intensive care. In the case of treatment failure, the quality of hemodynamic support makes it possible to establish a second bridge to non-heart beating organ donation.

Teaching bedside sonography using peer mentoring: a prospective randomized trial

OBJECTIVES

Bedside sonography is a growing field of medicine, but there is little evidence about how to teach it to medical students. A peer-mentoring system may help preclinical medical students learn bedside sonography.

METHODS

In 2008 and 2009, participating first-year medical students completed an image recognition test at 0, 2, and 4 months and were randomized to an early or a late intervention group. In hands-on sessions, senior medical students taught the early intervention group how to perform a Trinity hypotensive ultrasound protocol between months 0 and 2 and then taught the late intervention group the Trinity protocol between months 2 and 4. Participants completed a practical examination at month 4. We measured the improvement in knowledge after the intervention and retention of knowledge and skills in the early intervention group at month 4. First-year medical students completed precourse and postcourse surveys about comfort and skills with sonography.

RESULTS

Eighty-six first-year medical students enrolled; 79 completed the precourse survey; 54 completed all knowledge tests; 52 completed the practical examination; and 49 completed the postcourse survey. Of the 125 nonparticipants, 109 completed the precourse survey, and 25 completed the postcourse survey. Participants' knowledge scores increased by 30% after the intervention. The early intervention group retained 92% of the knowledge gained. Thirty-six percent of participants were able to complete the Trinity protocol in 15 minutes during the practical examination, with no significant difference between the early and late intervention groups. Participants responded positively about the experience and indicated that hands-on sessions were helpful.

CONCLUSIONS

Peer mentoring is a useful method for teaching sonography to preclinical medical students.

The top five research priorities in physician-provided pre-hospital critical care: a consensus report from a European research collaboration

Background

Physician-manned emergency medical teams supplement other emergency medical services in some countries. These teams are often selectively deployed to patients who are considered likely to require critical care treatment in the pre-hospital phase. The evidence base for guidelines for pre-hospital triage and immediate medical care is often poor. We used a recognised consensus methodology to define key priority areas for research within the subfield of physician-provided pre-hospital critical care.

Methods

A European expert panel participated in a consensus process based upon a four-stage modified nominal group technique that included a consensus meeting.

Results

The expert panel concluded that the five most important areas for further research in the field of physician-based pre-hospital critical care were the following: Appropriate staffing and training in pre-hospital critical care and the effect on outcomes, advanced airway management in pre-hospital care, definition of time windows for key critical interventions which are indicated in the pre-hospital phase of care, the role of pre-hospital ultrasound and dispatch criteria for pre-hospital critical care services.

Conclusion

A modified nominal group technique was successfully used by a European expert group to reach consensus on the most important research priorities in physician-provided pre-hospital critical care.

Out-of-hospital cardiac arrests in young adults in Melbourne, Australia-adding coronial data to a cardiac arrest registry

AIM

We aim to describe the coronial findings of young adults where the out-of-hospital cardiac arrest (OHCA) aetiology was 'presumed cardiac'.

METHODS

Presumed cardiac aetiology OHCAs occurring in young adults aged 16-39 years were identified using the Victorian Ambulance Cardiac Arrest Registry (VACAR) and available coronial findings reviewed.

RESULTS

We identified 841 young adult OHCAs where the Utstein aetiology was 'presumed cardiac'. Of these 740 died and 572 (77%) OHCAs were matched to coroner's findings. On review of the coroner's cause of death, 230 (40.2%) had a 'confirmed cardiac' aetiology, 221 (38.6%) were proven 'non-cardiac', 97 (17%) were inconclusive and 24 (4.2%) cases remained 'open'. 'Confirmed cardiac' causes of OHCA were ischemic heart disease (n=126, 55%), cardiomegaly (n=26, 11.3%), cardiomyopathy (n=25, 11%), congenital heart disease (n=15, 6.5%), cardiac tamponade due to dissecting thoracic aorta aneurysm (n=10, 4.3%), myocarditis (n=8, 3.5%), arrhythmia (n=7, 3%), others (n=13, 5.7%). 'Non-cardiac' causes of OHCA were epilepsy/sudden unexplained death in epilepsy (SUDEP) (n=56, 25%), pulmonary embolism (n=29, 13%), subarachnoid haemorrhage (n=17, 7.7%), other intracranial bleed (n=7, 3.2%), pneumonia (n=17, 7.7%), DKA (n=16, 7.2%), other complications of diabetes mellitus (n=8, 3.6%), complications of obesity (n=9, 4%), haemorrhage (n=12, 5.4%), sepsis (n=8, 3.6%), peritonitis (n=6, 2.7%), aspiration (n=6, 2.7%), renal failure (n=5, 2.3%), asthma (n=5, 2.3%), complications of anorexia (n=3) and alcohol abuse (n=2), thyrotoxicosis (n=2), meningitis (n=1) and others (n=12). Compared with coroner's diagnosed 'non-cardiac' OHCAs, 'confirmed cardiac' were more likely to be witnessed (41% vs 23%, p≤0.01), receive bystander CPR (35% vs 20%, p≤0.001), have a shockable rhythm (27% vs 6.3%, p<0.001) and have EMS attempted resuscitation (62% vs 44%, p<0.001).

DISCUSSION

Linking OHCA registries with coronial databases for aetiology of the arrest will improve the quality of the data and should be considered by all OHCA registries, particularly for young adult OHCA.