Comparison of manual pulse palpation, cardiac ultrasonography and Doppler ultrasonography to check the pulse in cardiopulmonary arrest patients

Resuscitative Ultrasound and Protocols

The management of patients in shock or arrest is a critical aspect of emergency medicine and critical care. Rapid and accurate assessment is paramount in determining the underlying causes and initiating timely interventions. This article provides a summary of essential ultrasound protocols for the critically ill patient including the extended focused assessment with sonography for trauma (EFAST), rapid ultrasound for shock and hypotension (RUSH), and sonography in hypotension and cardiac arrest in the emergency department (SHoC-ED).

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.

Prehospital Cardiac Ultrasound to Confirm Mechanical Capture in Emergency Transcutaneous Pacing: A Case Report

Point-of-care ultrasound (POCUS) is a safe diagnostic tool that clinicians use to rapidly evaluate critically ill patients.1 POCUS has expanded into the prehospital setting and has been demonstrated to be accurate, feasible, and helpful in guiding clinical decision making.2-4 Additionally, the American College of Emergency Physicians recommends the use of echocardiography to evaluate for ventricular activity in the setting of cardiac arrest.5 There is minimal evidence regarding the use of POCUS to confirm mechanical capture in patients undergoing transcutaneous pacing. This case report highlights the use of POCUS in a patient with bradyasystolic cardiac arrest requiring transcutaneous pacing. Despite electrical capture, the patient had absent central pulses; however, POCUS demonstrated ventricular contractions, indicating mechanical capture. This suggests a role for POCUS for the evaluation of mechanical capture in patients undergoing cardiac pacing.

A new method of pulse control in cardiopulmonary resuscitation; Continuous femoral pulse check

OBJECTIVES

The reliability of manual pulse checks has been questioned but is still recommended in cardiopulmonary resuscitation (CPR) guidelines. The aim is to compare the 10-s carotid pulse check (CPC) between heart massage cycles with the continuous femoral pulse check (CoFe PuC) in CPR, and to propose a better location to shorten the interruption times for pulse check.

METHODS

A prospective study was conducted on 117 Non-traumatic CPR patients between January 2020 and January 2022. A total of 702 dependent pulse measurements were executed, where carotid and femoral pulses were simultaneously assessed. Cardiac ultrasound, end-tidal CO2, saturation, respiration, and blood pressure were employed for pulse validation.

RESULTS

The decision time for determining the presence of a pulse in the last cycle of CPR was 3.03 ± 1.26 s for CoFe PuC, significantly shorter than the 10.31 ± 5.24 s for CPC. CoFe PuC predicted the absence of pulse with 74% sensitivity and 88% specificity, while CPC predicted the absence of pulse with 91% sensitivity and 61% specificity.

CONCLUSION

CoFe PuC provides much earlier and more effective information about the pulse than CPC. This shortens the interruption times in CPR. CoFe PuC should be recommended as a new and useful method in CPR guidelines.

Point-of-Care Ultrasound (POCUS) in Adult Cardiac Arrest: Clinical Review

Point-of-Care Ultrasound (POCUS) is a rapid and valuable diagnostic tool available in emergency and intensive care units. In the context of cardiac arrest, POCUS application can help assess cardiac activity, identify causes of arrest that could be reversible (such as pericardial effusion or pneumothorax), guide interventions like central line placement or pericardiocentesis, and provide real-time feedback on the effectiveness of resuscitation efforts, among other critical applications. Its use, in addition to cardiovascular life support maneuvers, is advocated by all resuscitation guidelines. The purpose of this narrative review is to summarize the key applications of POCUS in cardiac arrest, highlighting, among others, its prognostic, diagnostic, and forensic potential. We conducted an extensive literature review utilizing PubMed by employing key search terms regarding ultrasound and its use in cardiac arrest. Apart from its numerous advantages, its limitations and challenges such as the potential for interruption of chest compressions during image acquisition and operator proficiency should be considered as well and are discussed herein.

Unveiling pseudo-pulseless electrical activity (pseudo-PEA) in ultrasound-integrated infant resuscitation

Point-of-care ultrasound (POCUS) holds immense potential to manage critically deteriorating infants within the neonatal intensive care unit (NICU) and is increasingly used in neonatal clinical practice worldwide. Recent ultrasound-based protocols such as the Sonographic Assessment of liFe-threatening Emergencies-Revised (SAFE-R) and Crashing Neonate Protocol (CNP) offer step-by-step guidance for diagnosing and addressing reversible causes of cardiorespiratory collapse. Traditionally, pulseless electrical activity (PEA) has been diagnosed solely based on absent pulses on clinical examination, disregarding myocardial activity. However, integrating POCUS into resuscitation unveils the concept of pseudo-PEA, where cardiac motion activity is observed visually on the ultrasound but fails to generate a detectable pulse due to inadequate cardiac output. Paradoxically, existing neonatal resuscitation protocols lack directives for identifying and effectively leveraging pseudo-PEA insights in infants, limiting their potential to enhance outcomes. Pseudo-PEA is extensively described in adult literature owing to routine POCUS use in resuscitation. This review article comprehensively evaluates the adult pseudo-PEA literature to glean insights adaptable to neonatal care. Additionally, we propose a simple strategy to integrate POCUS during neonatal resuscitation, especially in infants who do not respond to routine measures.

CONCLUSION

Pseudo-PDA is a newly recognized diagnosis in infants with the use of POCUS during resuscitation. This article highlights the importance of cross-disciplinary learning in tackling emerging challenges within neonatal medicine.

WHAT IS KNOWN

• Point-of-Care ultrasound (POCUS) benefits adult cardiac arrest management, particularly in distinguishing true Pulseless Electrical Activity (PEA) from pseudo-PEA. • Pseudo-PEA is when myocardial motion can be seen on ultrasound but fails to generate palpable pulses or sustain circulation despite evident cardiac electrical activity.

WHAT IS NEW

• Discuss recognition and management of pseudo-PEA in infants. • A proposed algorithm to integrate POCUS into active neonatal cardiopulmonary resuscitation (CPR) procedures.

Do we need standardized management after termination-of-resuscitation attempts? Autoresuscitation in a 67-year-old woman

BACKGROUND

Autoresuscitation is the phenomenon of spontaneous return of circulation after cessation of CPR, also known as the Lazarus phenomenon. Most of the evidence is based on case reports and a few systematic reviews. The occurrence of autoresuscitation may lead to self-reproach and dismay in affected emergency personnel and may rise questions about the correct procedure after terminating resuscitative efforts. In contrast to existing cardiac arrest guidelines there is no standardized approach to terminating resuscitative attempts.

CASE

We report a case of out of hospital autoresuscitation in a 67-year-old female after 60 min of advanced cardiac life support. After shock refractory shockable rhythm, we recorded pulseless electrical activity and fixed pupils, consequently resuscitation was terminated. About 50 min later the patient surprisingly showed signs of life. Due to the suggestive history a coronary angiography was performed, showing severe coronary heart disease which necessitated surgical intervention. After ACBP surgery and intensive care followed by treatment on the cardiological ward, she was finally discharged to neurological rehabilitation.

CONCLUSION

As already proposed by existing literature, there should be at least a 10-min interval of close monitoring after abandoning CPR. Transport of a deceased patient should only take place after secure signs of death can be detected. Further investigation is needed to determine which patients are most likely to benefit from an extended observation period. Our case reports highlights the difficulties in death declaration and the importance of close monitoring after abandoning CPR.

Hands-free continuous carotid Doppler ultrasound for detection of the pulse during cardiac arrest in a porcine model

Background/Purpose

Pulse palpation is an unreliable method for diagnosing cardiac arrest. To address this limitation, continuous hemodynamic monitoring may be a viable solution. Therefore, we developed a novel, hands-free Doppler system, RescueDoppler, to detect the pulse continuously in the carotid artery.

Methods

In twelve pigs, we evaluated RescueDoppleŕs potential to measure blood flow velocity in three situations where pulse palpation of the carotid artery was insufficient: (1) systolic blood pressure below 60 mmHg, (2) ventricular fibrillation (VF) and (3) pulseless electrical activity (PEA). (1) Low blood pressure was induced using a Fogarty balloon catheter to occlude the inferior vena cava. (2) An implantable cardioverter-defibrillator induced VF. (3) Myocardial infarction after microembolization of the left coronary artery caused True-PEA. Invasive blood pressure was measured in the contralateral carotid artery. Time-averaged blood flow velocity (TAV) in the carotid artery was related to mean arterial pressure (MAP) in a linear mixed model.

Results

RescueDoppler identified pulsatile blood flow in 41/41 events with systolic blood pressure below 60 mmHg, with lowest blood pressure of 19 mmHg. In addition the absence of spontaneous circulation was identified in 21/21 VF events and true PEA in 2/2 events. The intraclass correlation coefficient within animals for TAV and MAP was 0.94 (95% CI. 0.85-0.98).

Conclusions

In a porcine model, RescueDoppler reliably identified pulsative blood flow with blood pressures below 60 mmHg. During VF and PEA, circulatory arrest was rapidly and accurately demonstrated. RescueDoppler could potentially replace unreliable pulse palpation during cardiac arrest and cardiopulmonary resuscitation.

Focused Ultrasonography in Cardiac Arrest

Rapid diagnostic tools available to the emergency physician caring for cardiac arrest patients are limited. Focused ultrasound (US), and in particular, focused echocardiography, is a useful tool in the evaluation of patients in cardiac arrest. It can help identify possible causes of cardiac arrest like tamponade and pulmonary embolism, which can guide therapy. US can also yield prognostic information, with lack of cardiac activity being highly specific for failure to achieve return of spontaneous circulation. US may also be used to aid in procedural guidance. Recently, focused transesophageal echocardiography has been used in the emergency department setting.

The 2023 Core Content of advanced emergency medicine ultrasonography

In February 2023, the American Board of Emergency Medicine (ABEM) approved modifications to the Advanced Emergency Medicine Ultrasonography (AEMUS) Core Content, which defines the areas of knowledge considered essential for the practice of AEMUS. This manuscript serves as a revision of the AEMUS Core Content originally published in 2014. The revision of the Core Content for AEMUS training aims to establish standardized education and qualifications necessary for AEMUS fellowship program leadership, clinical application, administration, quality improvement, and research. The Core Content provides the organizational framework and serves as the basis for the development of content for the Focused Practice Examination (FPE) administered by ABEM. AEMUS fellowship directors may reference the Core Content when designing AEMUS fellowship curricula to help prepare graduates for the autonomous practice of AEMUS and the FPE. In this article, an updated revision of the previously published AEMUS Core Content is detailed, and the entire development of the Core Content is presented.

Comparison of carotid artery ultrasound and manual method for pulse check in cardiopulmonary resuscitation

OBJECTIVES

The success of the manual pulse check method frequently employed during cardiopulmonary resuscitation (CPR) is controversial due to its subjective, patient- and operator-dependent, and time-consuming nature. Carotid ultrasound (c-USG) has recently emerged as an alternative, although there are still insufficient studies on the subject. The purpose of the present study was to compare the success of the manual and c-USG pulse check methods during CPR.

METHODS

This prospective observational study was conducted in the critical care area of a university hospital emergency medicine clinic. Pulse checks in patients with non-traumatic cardiopulmonary arrest (CPA) undergoing CPR were performed using the c-USG method from one carotid artery and the manual method from the other. The gold standard in the decision regarding return of spontaneous circulation (ROSC) was the clinical judgment made using the rhythm on the monitor, manual femoral pulse check, end tidal carbon dioxide (ETCO₂), and cardiac USG instruments. The success in predicting ROSC and measurement times of the manual and c-USG methods were compared. The success of both methods was calculated as sensitivity and specificity, and the clinical significance of the difference between the methods' sensitivity and specificity was evaluated Newcombe's method.

RESULTS

A total of 568 pulse measurements were performed on 49 CPA cases using both c-USG and the manual method. The manual method exhibited 80% sensitivity and 91% specificity in predicting ROSC (+PV: 35%, -PV: 64%), while c-USG exhibited 100% sensitivity and 98% specificity (+PV: 84%, -PV: 100%). The difference in sensitivities between the c-USG and manual methods was -0.0704 (95% CI: -0.0965; -0.0466), and the difference between their specificities was 0.0106 (95% CI: 0.0006; 0.0222). The difference between the specificities and sensitivities was statistically significant at analysis performed adopting the clinical judgment of the team leader using multiple instruments as the gold standard. The manual method yielded an ROSC decision in 3 ± 0.17 s and c-USG in 2.8 ± 0.15 s, the difference being statistically significant.

CONCLUSION

According to the results of this study, the pulse check method with c-USG may be superior to the manual method in terms of fast and accurate decision making in CPR.

Diagnostic test accuracy for cessation of circulation during death determination: a systematic review

PURPOSE

To synthesize the available evidence comparing noninvasive methods of measuring the cessation of circulation in patients who are potential organ donors undergoing death determination by circulatory criteria (DCC) with the current accepted standard of invasive arterial blood pressure (IAP) monitoring.

SOURCE

We searched (from inception until 27 April 2021) MEDLINE, Embase, Web of Science, and the Cochrane Central Register of Controlled Trials. We screened citations and manuscripts independently and in duplicate for eligible studies that compared noninvasive methodologies assessing circulation in patients who were monitored around a period of cessation of circulation. We performed risk of bias assessment, data abstraction, and quality assessment using Grading of Recommendations, Assessment, Development, and Evaluation in duplicate and independently. We presented findings narratively.

PRINCIPAL FINDINGS

We included 21 eligible studies (N = 1,177 patients). Meta-analysis was not possible because of study heterogeneity. We identified low quality evidence from four indirect studies (n = 89) showing pulse palpation is less sensitive and specific than IAP (reported sensitivity range, 0.76-0.90; specificity, 0.41-0.79). Isoelectric electrocardiogram (ECG) had excellent specificity for death (two studies; 0% [0/510]), but likely increases the average time to death determination (moderate quality evidence). We are uncertain whether point-of-care ultrasound (POCUS) pulse check, cerebral near-infrared spectroscopy (NIRS), or POCUS cardiac motion assessment are accurate tests for the determination of circulatory cessation (very low-quality evidence).

CONCLUSION

There is insufficient evidence that ECG, POCUS pulse check, cerebral NIRS, or POCUS cardiac motion assessment are superior or equivalent to IAP for DCC in the setting of organ donation. Isoelectric ECG is specific but can increase the time needed to determine death. Point-of-care ultrasound techniques are emerging therapies with promising initial data but are limited by indirectness and imprecision.

STUDY REGISTRATION

PROSPERO (CRD42021258936); first submitted 16 June 2021.

Femoral Arterial Doppler Use During Active Cardiopulmonary Resuscitation

STUDY OBJECTIVE

This study explored femoral arterial Doppler during active cardiopulmonary resuscitation (CPR) to identify and characterize the resumptions of cardiac activity without stopping CPR.

METHODS

This was a proof-of-concept study exploring arterial Doppler during cardiac arrest. Patients in cardiac arrest undergoing active CPR were prospectively enrolled. Arterial Doppler of the common femoral artery was recorded during CPR and during pauses in CPR. CPR-induced arterial tracings and native cardiac-induced tracings were analyzed for rate and peak systolic velocity. Cardiac activity on echocardiogram during pause in CPR was classified as "absent," "disorganized," or "organized." Descriptive data and survival are presented as mean and 95% confidence intervals (CI), as well as sensitivity and specificity of Doppler during active CPR in detecting native cardiac pulsations.

RESULTS

Sixteen patients with 48 paired Doppler recordings during active CPR, pause in CPR, and associated echocardiogram were enrolled. Native cardiac-induced tracings were visible during 39.6% of pauses in CPR (19 of 48) and during 18.8% of the periods of active CPR (9 of 48). Arterial pulsations were more frequently visualized with organized contractions by echocardiogram (10 of 14, 71%) than disorganized contractions (9 of 22, 41%). Arterial Doppler was 100% specific and 50% sensitive in detecting organized cardiac activity during active CPR. Patients with visible native cardiac pulsations during active CPR demonstrated 0% mortality compared with 67% mortality without visible arterial pulsations.

CONCLUSION

Arterial Doppler tracings may identify the resumption of native cardiac activity during active CPR; however, more research is needed.

Doppler ultrasound peak systolic velocity versus end tidal carbon dioxide during pulse checks in cardiac arrest

BACKGROUND

An accurate, non-invasive measure of return of spontaneous circulation (ROSC) is needed to improve management of cardiac arrest patients.

OBJECTIVES

During a pulse check in Emergency Department (ED) cardiac arrest patients, we compared the correlation between 1) end tidal carbon dioxide (ETCO₂) and systolic blood pressure (SBP), and 2) Doppler ultrasound peak systolic velocity (PSV) and SBP. Additionally, we assessed the accuracy of PSV ≥ 20 cm/sec in comparison to previously suggested ETCO₂ ≥ 20 or ≥ 25 mmHg thresholds to predict ROSC with SBP ≥ 60 mmHg.

METHODS

This was a secondary analysis of a previously published prospective observational study of ED cardiac arrest patients with an advanced airway and femoral arterial line in place. During each pulse check, highest SBP, highest PSV, and ETCO₂ at the end of the pulse check were recorded. Spearman correlation coefficients were calculated and compared using a Fisher Z-transformation. Accuracy of previously determined PSV and ETCO₂ thresholds for detecting ROSC with SBP ≥ 60 mmHg were compared using McNemar's tests.

RESULTS

Based on data from 35 patients with 111 pulse checks, we found a higher correlation between PSV and SBP than ETCO₂ and SBP (0.71 vs 0.31; p < 0.001). Diagnostic accuracy of PSV ≥ 20 cm/sec for detecting ROSC with SBP ≥ 60 mmHg was 89% (95% CI: 82%-94%) versus 59% (95% CI: 49%-68%) and 58% (95% CI: 48%-67%) for ETCO₂ ≥ 20 and ≥ 25 mmHg, respectively.

CONCLUSIONS

During a pulse check, Doppler ultrasound PSV outperformed ETCO₂ for correlation with SBP and accuracy in detecting ROSC with SBP ≥ 60 mmHg.

Transesophageal Echocardiography in Patients in Cardiac Arrest: The Heart and Beyond

Point of care ultrasound involves different ultrasound modalities and is useful to assist management in emergent clinical situations such as cardiac arrest. The use of point of care ultrasound in cardiac arrest has mainly been described using transthoracic echocardiography as a diagnostic and as a prognostic tool. However, cardiac evaluation using transthoracic echocardiography might be challenging because of patient-related or technical factors. Furthermore, its use during pulse check pauses has been associated with delays in chest compression resumption. Transesophageal echocardiography (TEE) overcomes these limitations by providing reliable and continuous imaging of the heart without interfering with cardiopulmonary resuscitation. In this narrative review we describe the role of TEE during cardiopulmonary resuscitation in 4 different applications: (1) chest compression quality feedback; (2) rhythm characterization; (3) diagnosis of reversible causes; and (4) procedural guidance. Considering its limitations, we propose an algorithm for the integration of TEE in patients with cardiac arrest with a focus on these 4 applications and extend its use to extracardiac applications.

Paramedic-Performed Carotid Artery Ultrasound Heralds Return of Spontaneous Circulation in Out-of-Hospital Cardiac Arrest: A Case Report

Point-of-Care Ultrasound (POCUS) has been demonstrated to have multiple applications in the care of critically ill and injured patients, especially given its portability and ease of use. These characteristics of POCUS make it ideal for use in the prehospital environment as well. We present a case that highlights a novel application of ultrasound in the prehospital management of out-of-hospital cardiac arrest (OHCA).

Point-of-Care Ultrasound Compression of the Carotid Artery for Pulse Determination in Cardiopulmonary Resuscitation

AIM

To identify whether a novel pulse check technique, carotid artery compression using an ultrasound probe, can reduce pulse check times compared to manual palpation (MP).

METHODS

This prospective study was conducted in an emergency department between February and December 2021. A physician applied point-of-care ultrasound-carotid artery compression (POCUS-CAC) and assessed the carotid artery compressibility and pulsatility by probe compression during rhythm check time. Another clinician performed MP of the femoral artery. The primary outcome was the difference in the average time for pulse assessment between POCUS-CAC and MP. The secondary outcomes included the time difference in each pulse check between methods, the proportion of times greater than 5 s and 10 s, and the prediction of return of spontaneous circulation (ROSC) during ongoing chest compression.

RESULTS

25 cardiac arrest patients and 155 pulse checks were analyzed. The median (interquartile range) average time to carotid pulse identification per patient using POCUS-CAC was 1.62 (1.14-2.14) s compared to 3.50 (2.99-4.99) s with MP. In all 155 pulse checks, the POCUS-CAC time to determine ROSC was significantly shortened to 0.44 times the MP time (P < 0.001). The POCUS-CAC approach never exceeded 10 s, and the number of patients who required more than 5 s was significantly lower (5 vs. 37, P < 0.001). Under continuous chest compression, six pulse checks predicted the ROSC.

CONCLUSIONS

We found that emergency physicians could quickly determine pulses by applying simple POCUS compression of the carotid artery in cardiac arrest patients.

Teachers perception of the use on a low-cost pulse rate sensor for biology education

Information and Communication Technology (ICT) is a commonly used concept in schools, implemented in laboratory work in the form of various digital devices. We evaluated the ICT implementation in cardiovascular physiology in Slovenian primary school education. Surprisingly, we showed a relatively low acceptance rate in biology classes: only 42.8% of involved Slovenian biology teachers used a pulse rate (PR) measuring device. As a part of a Slovenian Project, students designed, developed, and manufactured a device capable of low-cost, automatic, noninvasive, and straightforward PR sampling in real time. The device was named Fingerbeeper, and teachers' perceptions of its efficacy and efficiency were evaluated in the elementary school biology lessons, comparing its ease of use with other commercially available devices: the systems from Vernier, Biopac, and the Gear Sport Samsung smartwatch. The most preferred system was the system from Vernier (36.4%), followed by the Fingerbeeper (29.1%), the system from Biopac (18.2%), and the smartwatch (16.3%). Teachers provided their opinion on the efficiency of the Fingerbeeper in terms of cost compared with the other three measurement devices. Its perception of efficiency was comparable to the other commercially available devices while having the estimated cost of only a few percent of the Biopac or Vernier systems. Considering the general low funding in the public primary schools in Slovenia, the bias toward Fingerbeeper seemed rational, outweighing the superior performance of the commercial systems. Further research and improvement of such low-cost and high-efficiency devices, also in general terms, would lead to broader acceptance and implementation of the ICT in curricula.

Initiation of Invasive Arterial Pressure Monitoring by Critical Care Transport Crews

Noninvasive blood pressure monitoring is convenient in the prehospital setting, but its use in the critically ill patient should be carefully considered given documented inaccuracies. Countless therapeutic patient interventions are based on blood pressure parameters, and the prehospital paramedic, nurse, and physician should strongly consider the use of invasive blood pressure monitoring, especially during critical care transport. Radial artery cannulation for arterial blood pressure monitoring is a safe and effective procedure that can reasonably be performed in the prehospital setting by both physicians and nonphysicians. Critical care transport teams should consider clinical guidelines that outline indications and training to safely implement this as a clinical skill.

Manual Palpation vs. Femoral Arterial Doppler Ultrasound for Comparison of Pulse Check Time During Cardiopulmonary Resuscitation in the Emergency Department: A Pilot Study

BACKGROUND

Manual palpation (MP) is frequently employed for pulse checks, but studies have shown that trained medical personnel have difficulty accurately identifying pulselessness or return of spontaneous circulation (ROSC) using MP. Any delays in identifying pulselessness can lead to significant delays in starting or resuming high-quality chest compressions.

OBJECTIVES

This study explored whether femoral arterial Doppler ultrasound (FADU) decreases pulse check duration during cardiopulmonary resuscitation (CPR) compared with MP among patients in the emergency department (ED) receiving CPR directed by emergency medicine physicians who had received minimal additional didactic ultrasound training.

METHODS

We performed a prospective observational cohort study from October 2018 to May 2019 at an urban community ED. Using convenience sampling, we enrolled patients arriving at our ED or who decompensated during their ED stay and received CPR. For continuous data, median (interquartile range [IQR]) were calculated, and medians were compared using Kruskal-Wallis test.

RESULTS

Fifty-two eligible patients were enrolled and 135 pulse checks via MP and 35 via FADU were recorded. MP observations had a median (IQR) of 11.00 (7.36-15.48) s, whereas FADU had a median (IQR) of 8.98 (5.45-13.85) s. There was a difference between the two medians of 2.02 s (p = 0.05).

CONCLUSIONS

In this study, the use of FADU was superior to MP in achieving shorter pulse check times. Further research is needed to confirm the accuracy of FADU for identifying ROSC as well as to determine whether FADU can improve clinical outcomes.

Singapore Paediatric Resuscitation Guidelines 2021

We present the 2021 Singapore Paediatric Resuscitation Guidelines. The International Liaison Committee on Resuscitation's Pediatric Taskforce Consensus Statements on Science and Treatment Recommendations, which was published in October 2020, and the updated resuscitation guidelines from the American Heart Association and European Resuscitation Council, were reviewed and discussed by the committee. These recommendations were derived after deliberation of peer-reviewed evidence updates on paediatric resuscitation and took into consideration the local setting and clinical practice.

Discrimination between the presence and absence of spontaneous circulation using smartphone seismocardiography: A preliminary investigation

BACKGROUND

Seismocardiography measures the vibrations produced by the beating heart using an accelerometer sensor placed on the chest. We evaluated the ability of smartphone seismocardiography to distinguish between the presence and absence of spontaneous circulation.

METHODS

Seismocardiography signals were obtained using a smartphone placed on the sternum in a convenience sample of 60 adult patients (30 comatose patients with spontaneous circulation and 30 deceased patients). The maximum, minimum, and standard deviation (SD) of acceleration values for head-to-foot, right-to-left, and dorsoventral axes and the three axis-root mean square (RMS) of the acceleration signals were calculated. Blinded observers (n = 156) were each asked to determine the presence or absence of spontaneous circulation based on seismocardiography video clips for each of the 60 patients.

RESULTS

The seismocardiography revealed periodic large positive peaks in the patients with spontaneous circulation, which were absent in the patients without spontaneous circulation. For each of the four output measurements (three independent axes plus the three-axis RMS), the acceleration maxima and SD were significantly higher and the minima significantly lower in the patients with spontaneous circulation than in those without spontaneous circulation (all P < 0.001 except the minimum of three axis-RMS results [P = 0.009]). The observers accurately identified the seismocardiography signals from patients without spontaneous circulation, with a sensitivity of 97.6% (95% confidence interval, 97.0%-98.2%) and a specificity of 98.4% (95% confidence interval, 97.8%-99.0%).

CONCLUSIONS

In conclusion, blinded observers accurately distinguished between seismocardiography signals from patients with and without spontaneous circulation.

Comparison of femoral and carotid arteries in terms of pulse check in cardiopulmonary resuscitation: A prospective observational study

BACKGROUND

There is no gold standard pulse localisation for pulse check in cardiopulmonary resuscitation.

AIM

To compare the femoral and carotid arteries in terms of pulse check in cardiopulmonary resuscitation and recommend the most appropriate pulse localisation in advanced life support guidelines and cardiopulmonary resuscitation training programmes.

MATERIALS AND METHODS

We prospectively conducted the study with patients who developed non-traumatic cardiopulmonary arrest between September 2018 and March 2019. The pulse check team was established and divided into two groups, A and B. Both carotid and femoral arteries were checked simultaneously for pulse by members of groups A and B, with the groups alternating between sites to avoid bias. We used some criteria to make pulse detection more effective. These were ETCO2, rhythm and cardiac ultrasonography.

RESULTS

We evaluated 1289 pulse checks in 102 patients. As a result of the statistical analysis with manual palpations and pulses criteria, which we used to detected the presence of a pulse in CPR, we found that the sensitivity of the carotid artery was significantly higher than that of the femoral artery (p = 0.017), with almost identical specificities.

CONCLUSION

The carotid artery should be recommended as the gold standard localisation for pulse checks in cardiopulmonary resuscitation in CPR training programmes and ACLS guidelines.

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.

Assessing the validity of two-dimensional carotid ultrasound to detect the presence and absence of a pulse

BACKGROUND

Traditional assessment of return of cardiac output in cardiac arrest by manual palpation has poor accuracy. Point of care ultrasound of a major artery has been suggested as an alternative. We conducted a diagnostic accuracy study of two-dimensional carotid ultrasound to detect the presence or absence of a pulse, using cardiopulmonary bypass patients for pulse and pulseless states.

METHODS

A cross-sectional multi-patient, multi-reader repeated measures diagnostic study was conducted. For patients undergoing routine cardiopulmonary bypass, a portable ultrasound was used to record four 10-s videos the common carotid artery, three aimed for a pulse in high (>90 mmHg), medium (70-90 mmHg) and low (<70 mmHg) systolic blood pressure (SBP) ranges, and a pulseless video was recorded on cardiopulmonary bypass. Critical care physicians viewed the videos and were asked to nominate within 10 s if a pulse was present. True pulse-status was determined via the arterial-line waveform.

RESULTS

Twenty-three patients had all four videos collected. Median patient age was 64 (IQR 14), sixteen were male (70%) and median BMI was 27. The median SBP in high-, medium- and low-SBP groups were 120 mmHg, 83 mmHg and 69 mmHg respectively. Forty-six physicians reviewed a subset of 24 videos. Overall sensitivity was 0.91 (95% confidence interval 0.89-0.93) and specificity 0.90 (95% CI 0.86-0.93). Sensitivity was highest in the high-SBP group (0.96, 95% CI 0.93-0.98) and lowest in the low-SBP group (0.83, 95% CI 0.78-0.87).

CONCLUSION

2D ultrasound of the common carotid artery is both sensitive and specific for detection of the presence or absence of a pulse.

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.

Deep Neural Networks for ECG-Based Pulse Detection during Out-of-Hospital Cardiac Arrest

The automatic detection of pulse during out-of-hospital cardiac arrest (OHCA) is necessary for the early recognition of the arrest and the detection of return of spontaneous circulation (end of the arrest). The only signal available in every single defibrillator and valid for the detection of pulse is the electrocardiogram (ECG). In this study we propose two deep neural network (DNN) architectures to detect pulse using short ECG segments (5 s), i.e., to classify the rhythm into pulseless electrical activity (PEA) or pulse-generating rhythm (PR). A total of 3914 5-s ECG segments, 2372 PR and 1542 PEA, were extracted from 279 OHCA episodes. Data were partitioned patient-wise into training (80%) and test (20%) sets. The first DNN architecture was a fully convolutional neural network, and the second architecture added a recurrent layer to learn temporal dependencies. Both DNN architectures were tuned using Bayesian optimization, and the results for the test set were compared to state-of-the art PR/PEA discrimination algorithms based on machine learning and hand crafted features. The PR/PEA classifiers were evaluated in terms of sensitivity (Se) for PR, specificity (Sp) for PEA, and the balanced accuracy (BAC), the average of Se and Sp. The Se/Sp/BAC of the DNN architectures were 94.1%/92.9%/93.5% for the first one, and 95.5%/91.6%/93.5% for the second one. Both architectures improved the performance of state of the art methods by more than 1.5 points in BAC.

The POCUS pulse check: A randomized controlled crossover study comparing pulse detection by palpation versus by point-of-care ultrasound

BACKGROUND

Manual pulse checks (MP) are an unreliable skill even in the hands of healthcare providers (HCPs). In the context of cardiac arrest, this may translate into inappropriate chest compressions when a pulse is present, or conversely omitting chest compressions when one is absent. To date, no study has assessed the use of B-mode ultrasound (US) for the detection of a carotid pulse. The primary objective of this study was to assess the time required to detect a carotid pulse in live subjects using US compared to the traditional palpation method.

METHODS

We conducted a prospective randomized controlled crossover non-inferiority trial. HCPs attended a 15 minute focused US workshop on identification of the carotid pulse. Both pulse check methods were timed for each participant on two different subjects in random order. The primary outcome was time to carotid pulse detection in seconds (s). Secondary outcomes included confidence levels of pulse detection measured on a 100 mm visual analog scale (VAS) and rates of prolonged pulse checks (> 5 s or >10 s). The study was powered to determine whether US pulse checks were not slower than MP by greater than two seconds. The results are presented as the difference in means with a 90% two-sided confidence interval (CI).

RESULTS

111 participants completed the study. Mean pulse detection times were 4.22 s (SD 3.26) by US compared to 4.71 s (SD 6.45) by MP with a mean difference in times of -0.49 s (90% CI: -1.77 to 0.39). There were no significant differences between US and MP in the rates of prolonged pulse checks of greater than 5 s (23% vs 19%, p = 0.45) or 10 s (9% vs 8%, p = 0.81). First attempt at detection of pulse checks was more successful in the US group (99.1% vs 85.6%, p = 0.0001). Prior to training, participants reported higher confidence using MP compared to US; 68 (IQR 48-83) vs 15 (IQR 8-42) mm (p < 0.001). Following the study, participants reported higher confidence levels using US than MP; 91 (IQR 82-97) vs 83 (IQR 72-94) mm (p < 0.001).

CONCLUSIONS

Carotid pulse detection in live subjects was not slower using US as compared to palpation, and demonstrated higher first attempt success rate and less variability in measurement times. A brief teaching session was sufficient to improve confidence of carotid pulse identification even in those with no previous US training. The preliminary results from this study provide the groundwork for larger studies to evaluate this pulse check method for patients in cardiac arrest.