The current cardiopulmonary resuscitation(CPR) guidelines recommend that the heart rhythm be checked every two minutes during CPR for cardiac arrest patients. Also it is very important to stop compressing the chest in less than 10 seconds when checking heart rhythm and pulse.

However, manual palpation, which is used as a standard for return of spontaneous circulation(ROSC), has been reported that the accuracy is not high in several studies. It is quite often necessary to perform pulse palpation for longer than the 10 second recommended by the guidelines to make a judgment.

Recently, a case study was published in which the presence of spontaneous circulation was confirmed by evaluating the carotid artery compressibility and pulsatility with an ultrasound probe when checking the rhythm of cardiac arrest patients. However, there has been no clinical study on actual cardiac arrest patients.

The current cardiopulmonary resuscitation(CPR) guidelines recommend that the heart rhythm be checked every two minutes during CPR for cardiac arrest patients. Also it is very important to stop compressing the chest in less than 10 seconds when checking heart rhythm and pulse.

However, manual palpation, which is used as a standard for return of spontaneous circulation(ROSC), has been reported that the accuracy is not high in several studies. It is quite often necessary to perform pulse palpation for longer than the 10 second recommended by the guidelines to make a judgment.

Ultrasound is a key technique that guides to discern and treat causes of cardiac arrest patients. Recently, a case study was published in which the presence of spontaneous circulation was confirmed by evaluating the carotid artery compressibility and pulsatility with an ultrasound probe when checking the rhythm of cardiac arrest patients.

However, this is just a case study. There has been no clinical study on actual cardiac arrest patients whether it is possible to accurately determine the ROSC by evaluating the carotid artery compressibility and pulsatility by ultrasound. Also there has been no clinical studies on actual cardiac arrest patients comparing the time taken to evaluate the ROSC of carotid ultrasound and manual palpation.

Inclusion Criteria:

• Patients who underwent CPR among cardiac arrest patients 18 years of age or older who visit the emergency room
• Patients who applied carotid ultrasound to determine the presence of carotid artery compression and pulse

Exclusion Criteria:

• Patients who have stated their intention to do not resuscitation for future treatment (including cardiopulmonary resuscitation)
• Patients who have difficulty applying carotid ultrasound due to head and neck trauma
• Patients who have difficulty applying carotid ultrasound due to deformed neck structure by surgery or head and neck cancer
• Return of spontaneous circulation before ultrasound application
• Patients who could not evaluate carotid artery compressibility and pulsatility by ultrasound