Checking the pulse in the 21st century: Interobserver reliability of carotid pulse detection by point-of-care ultrasound

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.

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.

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.