Guiding Cardiopulmonary Resuscitation with Focused Echocardiography: A Report of Five Cases

A Protocol for Using Point-of-Care Ultrasound as an Adjunct in Pediatric Cardiac Arrest: Pediatric Ultrasound for Life-Supporting Efforts

ABSTRACT

Pediatric cardiac arrest is a rare but time-critical event that poses significant challenges to health care providers. Initiation of point-of-care ultrasound (POCUS) early in resuscitation can help optimize the location of chest compressions, identify inadequate compressions, evaluate for sonographic pulse, and help direct management. Although several algorithms currently exist to incorporate POCUS into adult cardiac arrest, none, to our knowledge, currently exist for the pediatric population. We propose a novel protocol for POCUS use as an adjunct to existing standard-of-care measures in pediatric cardiac arrest, which we call the Pediatric Ultrasound for Life-Supporting Efforts protocol.

Impact of Point-of-Care Ultrasound on Prehospital Decision Making by HEMS Physicians in Critically Ill and Injured Patients: A Prospective Cohort Study

INTRODUCTION

Several studies have shown the additional benefit of point-of-care ultrasound (POCUS) by prehospital Emergency Medical Services (EMS). Since organization of EMS may vary significantly across countries, the value of POCUS likely depends on the prehospital system in which it is used. In order to be able to optimally implement POCUS and develop a tailored training curriculum, it is important to know how often POCUS is currently used, for which indications it is used, and how it affects decision making. The aims of this study were: (1) to determine the percentage of patients in whom POCUS was used by Dutch Helicopter Emergency Medical Services (HEMS) crews; (2) to determine how often POCUS findings led to changes in on-scene management; and (3) what these changes were.

METHODS

Patients who received prehospital care from December 1, 2020 through March 31, 2021 by a single HEMS crew were included in this prospective cohort study. Clinical data and specific data on POCUS examination, findings, and therapeutic consequences were collected and analyzed.

RESULTS

During the study period, on-scene HEMS care was provided to 612 patients, of which 211 (34.5%) patients underwent POCUS. Of these, 209 (34.2%) patients with a median age of 45 years were included. There were 131 (62.7%) trauma patients, and 70 (33.7%) of the included patients underwent cardiopulmonary resuscitation (CPR). The median reported time of POCUS examination was three (P25-P75 2-5) minutes. Median prolongation of on-scene time was zero (P25-P75 0-1) minutes. In 85 (40.7%) patients, POCUS examination had therapeutic consequence: POCUS was found to impact treatment decisions in 34 (26.0%) trauma patients and 51 (65.4%) non-trauma patients. In patients with cardiac arrest, POCUS was most often used to aid decision making with regard to terminating or continuing resuscitation (28 patients; 13.4%).

CONCLUSION

During the study period, POCUS examination was used in 34.5% of all prehospital HEMS patients and had a therapeutic consequence in 40.7% of patients. In trauma patients, POCUS seems to be most effective for patient triage and evaluation of treatment effectiveness. Moreover, POCUS can be of significant value in patients undergoing CPR. A tailored HEMS POCUS training curriculum should include ultrasound techniques for trauma and cardiac arrest.

Point-of-care ultrasound use in emergencies: what every anaesthetist should know

Point-of-care ultrasound has been embraced by anaesthetists as an invaluable tool for rapid diagnosis of haemodynamic instability, to ensure procedural safety and monitor response to treatments. Increasingly available, affordable and portable, with emerging evidence of improved patient outcomes, point-of-care ultrasound has become a valuable tool in the emergency setting. This state-of-the-art review describes the feasibility of point-of-care ultrasound practice, training and maintenance of competence. It also describes the many uses of point-of-care ultrasound for the anaesthetist and describes the most salient point-of-care ultrasound views for anaesthetic emergencies including: undifferentiated shock; hypoxemia; and trauma. Procedural safety is also discussed in addition to relevant important governance aspects. Cardiac function should be assessed using the parasternal long axis, parasternal short basal/mid-papillary/apical, apical four chamber and subcostal four chamber views, and should include a visual estimation of global left ventricular ejection fraction. Other cardiovascular conditions that can be identified using point-of-care ultrasound include: pericardial effusion; cardiac tamponade; and pulmonary embolism. Pulmonary emergency conditions that can be diagnosed using point-of-care ultrasound include pneumothorax; pleural effusion; and interstitial syndrome. The extended focused assessment with sonography for trauma examination may of value in patients who are hypotensive in order to identify intra-abdominal haemorrhage, pneumothoraces and haemothoraces.

A cadaveric model for transesophageal echocardiography transducer placement training: A pilot study

BACKGROUND

Transesophageal echocardiography (TEE) is used in the emergency department to guide resuscitation during cardiac arrest. Insertion of a TEE transducer requires manual skill and experience, yet in some residency programs cardiac arrest is uncommon, so some physicians may lack the means to acquire the manual skills to perform TEE in clinical practice. For other infrequently performed procedural skills, simulation models are used. However, there is currently no model that adequately simulates TEE transducer insertion. The aim of this study is to evaluate the feasibility and efficacy of using a cadaveric model to teach TEE transducer placement among novice users.

METHODS

A convenience sample of emergency medicine residents was enrolled during a procedure education session using cadavers as tissue models. A pre-session assessment was used to determine prior knowledge and confidence regarding TEE manipulation. Participants subsequently attended a didactic and hands-on education session on TEE placement. All participants practised placing the TEE transducer until they were able to pass a standardized assessment of technical skill (SATS). After the educational session, participants completed a post-session assessment.

RESULTS

Twenty-five residents participated in the training session. Mean assessment of knowledge improved from 6.2/10 to 8.7/10 (95% confidence interval [CI] of knowledge difference 1.6-3.2, P<0.001) and confidence improved from 1.6/5 to 3.1/5 (95% CI of confidence difference 1.1-2.0, P<0.001). There was no relationship between training level and the delta in knowledge or confidence.

CONCLUSIONS

In this pilot study, the use of a cadaveric model to teach TEE transducer placement methods among novice users is feasible and improves both TEE manipulation knowledge and confidence levels.

Performance of an automated ultrasound device in identifying and tracing the heart in porcine cardiac arrest

BACKGROUND

While intra-arrest echocardiography can be used to guide and monitor chest compression quality, it is not currently feasible on the scene of out-of-hospital cardiac arrests. Rapid and automated sonographic localization of the heart may provide first-responders guidance to an optimal area of compression without requiring them to interpret ultrasound images. In this proof-of-concept porcine study, we sought to describe the performance of an automated ultrasound device in correctly identifying and tracing the borders of the heart in three distinct states: pre-arrest, arrest, and late arrest.

METHODS

An automated ultrasound device (bladder scanner) was placed on the chests of 7 swine, along the left sternal border (4th-8th intercostal spaces). Scanner-generated images were recorded for each space during pre-arrest, arrest, and finally late arrest. 828 images of the LV and LV outflow tract were randomized and 150 (50/state) selected for analysis. Scanner tracings of the heart were then digitally obscured to facilitate tracing by expert reviewers who were blinded to the physiologic state. Reviewer tracings were compared to bladder scanner tracings; with concordance between these images determined via Sørensen-Dice index (SDI).

RESULTS

When compared to human reviewers, the bladder scanner was able to identify and trace the borders during cardiac arrest. The bladder scanner performed best at the time of arrest (SDI 0.900 ± 0.059). As resuscitation efforts continued and time from initial arrest increased, the scanner's performance decreased dramatically (SDI 0.597 ± 0.241 in late arrest).

CONCLUSION

An automated ultrasound device (bladder scanner) reliably traced porcine hearts during cardiac arrest. It is possible a device could be developed to indicate where compressions should be performed without requiring the operator to interpret ultrasound images. Further investigation into rapid, automated, sonographic localization of the heart to identify the area of compression in out-of-hospital cardiac arrest is warranted.

Utilization of Point-of-care Echocardiography in Cardiac Arrest: A Cross-sectional Pilot Study

INTRODUCTION

Point-of-care (POC) echocardiography (echo) is a useful adjunct in the management of cardiac arrest. However, the practice pattern of POC echo utilization during management of cardiac arrest cases among emergency physicians (EP) is unclear. In this pilot study we aimed to characterize the utilization of POC echo and the potential barriers to its use in the management of cardiac arrest among EPs.

METHODS

This was a cross-sectional survey of attending EPs who completed an electronic questionnaire composed of demographic variables (age, gender, year of residency graduation, practice setting, and ultrasound training) and POC echo utilization questions. The first question queried participants regarding frequency of POC echo use during the management of cardiac arrest. Branching logic then presented participants with a series of subsequent questions regarding utilization and barriers to use based on their responses.

RESULTS

A total of 155 EPs participated in the survey, with a median age of 39 years (interquartile range 31-67). Regarding POC echo utilization, participants responded that they always (66%), sometimes (30%), or never (4.5%) use POC echo during cardiac arrest cases. Among participants who never use POC echo, 86% reported a lack of training, competency, or credentialing as a barrier to use. Among participants who either never or sometimes use POC echo, the leading barrier to use (58%) reported was a need for improved competency. Utilization was not different among participants of different age groups (P = 0.229) or different residency graduation dates (P = 0.229). POC echo utilization was higher among participants who received ultrasound training during residency (P = 0.006) or had completed ultrasound fellowship training (P <0.001) but did not differ by gender (P = 0.232), or practice setting (0.231).

CONCLUSION

Only a small minority of EPs never use point-of-care echocardiography during the management of cardiac arrest. Lack of training, competency, or credentialing is reported as the leading barrier to use among those who do not use POC echo during cardiac arrest cases. Participants who do not always use ultrasound are less likely to have received ultrasound training during residency.

A Novel Anatomic Landmark to Target the Left Ventricle During Chest Compressions in Cardiac Arrest

Background Resuscitation guidelines recommend that chest compressions be performed over the lower sternum. Current computed tomography and magnetic resonance imaging studies suggest that the current area of compression does not target the left ventricle (LV). Using transthoracic ultrasound, we sought to identify potential anatomic landmarks that would result in compressions over the LV in the majority of our study participants. Methodology We recruited 64 healthy men and women (over the age of 40) from the Simulated Patient Program at the University of Saskatchewan. Using ultrasound, we identified the LV and the associated surface anatomy in terms of intercostal space (ICS) and parasternal or mid-clavicular lines. We also collected biometric data including body mass index, chest circumference, and the corresponding inter-nipple line ICS. Results The LV was located along the left sternal border in 62 (96.9%) participants. The most frequent LV location was along the left sternal border at the sixth ICS in 26 (40.6%) participants, with 13 (20.3%) at the fifth and 10 (15.6%) participants at the seventh ICS. In two (3.1%) participants, the LV was found along the mid-clavicular zone at the fifth ICS. The area from the fifth to seventh ICS on the left sternal border, typically covered by an adult palm centered at the sixth ICS, overlaid 49 of 64 (76.6%, 95% confidence interval [CI]: 64.3-86.2%) identified LV locations. By comparison, centering the heel of the palm over the inter-nipple line at the left sternal border would cover the LV in 46 (71.9%, 95% CI: 59.2-82.4%) participants.  Conclusions A novel area of compression over the left sternal border at the inter-nipple line would result in compressions over the LV in nearly three-quarters of our study participants. Future research should investigate whether this proposed area of compression is applicable to a broader population including those with cardiac and thoracic disease.

A look inside cardiopulmonary resuscitation: A 4D computed tomography model of simulated closed chest compression. A proof of concept

AIM

To mimic chest compression during cardiopulmonary resuscitation (CPR), this study aimed to produce time-resolved 3D (volumetric) reformats of thoracic and upper abdominal tissue movement during incremental closed chest compression/decompression from 0 to 8 to 0 cm.

METHODS

Sequential angiography enhanced computed tomography (CT) scans were acquired from a recently deceased, consented adult cadaver with 1 cm incremental closed chest compression/decompression. Three compression/decompression sequences from 0 to 3 cm, 0 to 5 cm, and 0 to 8 cm, respectively, were scanned using a radio-opaque, manually operated, chest compression device. The multiphase volumetric data sets were compiled into 4D models that allowed for multiplanar reformatted and volume rendered image manipulation.

RESULTS

Time-resolved volumetric (4D) models were produced using freeware to post-process the static CT scans. The 4D models allowed the study of simulated thoracic and upper abdominal content movement during closed chest compression.

CONCLUSIONS

The method described could assist CPR researchers and educators in the development and demonstration of effective CPR protocols.

Cardiac Thrombus Formation During Cardiopulmonary Resuscitation for Cardiac Arrest: Is It Time for Ultrasound-Enhanced Algorithms?

Current guidelines consider thrombosis as a potential (and reversible) cause of cardiorespiratory arrest (CA). However, cardiac thrombus formation (TF) is likely to be the consequence of the forward blood flow ceasing during cardiac standstill. We present the case of a young man who was hospitalized for infective endocarditis, complicated by multiorgan disease and sudden CA on the 5^th day. Prompt cardiopulmonary resuscitation (CPR) warranted a return of spontaneous circulation in 16 min but, unexpectedly, a TF was recognized in the right atrium at echocardiography. The blood clot resolved with rapid administration of endovenous heparin and continued chest compressions. Even though cardiac ultrasound is not ready for a routine use during CPR, the present study confirms a key role in the management of CA patients.