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

The link between carotid artery stenosis and outcomes in patients with refractory out-of-hospital cardiac arrest

BACKGROUND

Mortality of out-of-hospital cardiac arrest (OHCA) remains high. Extracorporeal cardiopulmonary resuscitation (ECPR) has revolutionized OHCA treatment, but our understanding of the ECPR responder's clinical profile is incomplete. Carotid artery stenosis (CAS) is a well-established cardiovascular disease risk factor. The impact of CAS on OHCA outcomes remains unelucidated.

OBJECTIVE

To assess whether CAS burden affects the outcomes of OHCA patients treated with ECPR.

METHODS

This study included patients with OHCA admitted for ECPR consideration, who had carotid ultrasonography performed. A numeric scale was applied to the plaque to create a CAS burden numeric scale. The primary outcome of the study was survival at discharge, compared among the different degrees of CAS. Neurologically intact survival and surrogate markers of neurologic injury were the secondary study endpoints. To assess the independent effect of CAS burden on survival to hospital discharge, we conducted a logistic regression analysis.

RESULTS

Between 2019 and 2023, carotid ultrasonography was performed on 163 patients who were admitted for refractory OHCA. CAS burden was equally distributed between the right and left carotid arteries. Logistic regression analysis indicated that the CAS burden was significantly associated with both overall and neurologically intact survival at discharge (p = 0.004). A linear relationship between the CAS burden and neuron-specific and S-100 levels was identified. Patients with normal carotids were significantly less likely to have encephalopathy on electroencephalograms.

CONCLUSION

CAS burden independently predicts the risk for worse survival and neurologic outcomes in patients suffering refractory OHCA who are treated with ECPR.

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.

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.

The Incremental Role of Multiorgan Point-of-Care Ultrasounds in the Emergency Setting

Point-of-care ultrasonography (POCUS) represents a goal-directed ultrasound examination performed by clinicians directly involved in patient healthcare. POCUS has been widely used in emergency departments, where US exams allow physicians to make quick diagnoses and to recognize early life-threatening conditions which require prompt interventions. Although initially meant for the real-time evaluation of cardiovascular and respiratory pathologies, its use has been extended to a wide range of clinical applications, such as screening for deep-vein thrombosis and trauma, abdominal ultrasonography of the right upper quadrant and appendix, and guidance for invasive procedures. Moreover, recently, bedside ultrasounds have been used to evaluate the fluid balance and to guide decongestive therapy in acutely decompensated heart failure. The aim of the present review was to discuss the most common applications of POCUS in the emergency setting.

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.

Carotid Artery Ultrasound in the (peri-) Arrest Setting—A Prospective Pilot Study

Point-of-care ultrasounds (US) are used during cardiopulmonary resuscitation (CPR) and after return of spontaneous circulation (ROSC). Carotid ultrasounds are a potential non-invasive monitoring tool for chest compressions, but their general value and feasibility during CPR are not fully determined. In this prospective observational study, we performed carotid US during conventional- and extracorporeal CPR and after ROSC with at least one transverse and coronal image, corresponding loops with and without color doppler, and pulsed-wave doppler loops. The feasibility of carotid US during (peri-)arrest and type and frequency of diagnostic findings were examined. We recruited 16 patients and recorded utilizable US images in 14 cases (88%; complete imaging protocols in 11 patients [69%]). In three of all patients (19%) and in 60% (3/5) of cases during CPR plus a full imaging protocol, we observed: (i) in one patient a collapse of the common carotid artery linked to hypovolemia, and (ii) in two patients a biphasic flow during CPR linked to prolonged low-flow time prior to admission and adverse outcome. Carotid artery morphology and carotid blood flow characteristics may serve as therapeutic target and prognostic parameters. However, future studies with larger sample sizes are needed.