Revolutionizing OHCA response: MCHD’s novel use of carotid ultrasound
Montgomery County Hospital District shares their findings trialing carotid ultrasound during CPR to enhance cardiac arrest response
By Ryan Richardson, MD; Casey Patrick, MD; James Seek, LP; Nick Smith, LP; Kevin Crocker, LP; Himanshu Gupta, MD; Joshua Rasco; Robert Dickson, MD
Staffed by about 300 paramedics and supported by 12 regional first-responder organizations, Montgomery County Hospital District (MCHD) EMS is a publicly funded 911 provider for Montgomery County, Texas, covering 1,100 square miles just north of Houston. MCHD answers more than 90,000 calls a year.
This article follows an MCHD crew responding to a call for cardiac arrest.
Manual pulse palpation during CPR is known to have poor reliability, and cardiac ultrasonography is one option to detect a pulse earlier and more accurately than palpation . Point-of-care ultrasound use during CPR is associated with prolonged pulse checks, which has a negative effect on patient outcomes .
MCHD recently began trialing carotid ultrasound during CPR to attempt to increase the reliability of pulse detection while minimizing pulse check duration.
Family called 911 for a 58-year-old male complaining of chest pain. The call was updated prior to first responders and EMS arrival to cardiac arrest after the patient collapsed and was unresponsive.
MCHD’s dispatch center (Alarm) is an accredited International Academies of Emergency Dispatch in both Fire and EMS, and is staffed by trained EMTs.
For this call, Alarm initiated telephone-assisted CPR per Emergency Medical Dispatch standards as the field crews discussed potential differential diagnosis considerations:
The crews also discussed role delegation for both EMS and first responders (FRO).
Scene findingsThe FRO unit and EMS arrived simultaneously at a single-story residence without apparent safety concerns. They were waved in by family and found a single male patient in his 50s lying supine in a front room with a family member performing CPR.
- Gasping, cyanotic and pulseless
Our patient has a history of diabetes and hypertension. He’s been unable to fill any medications for the past year due to finances. He is a current cigarette smoker and has no known drug allergies. The witnesses relate our patient had a sudden onset of chest pain associated with profuse sweating and shortness of breath that began just prior to the 911 call. He collapsed shortly after and was unresponsive.
Chest compressions were taken over by first responders, and the patient was placed on the monitor, revealing a coarse ventricular fibrillation, which was defibrillated, and CPR resumed. Standard ACLS medications for ventricular fibrillation were administered (epinephrine and amiodarone) while chest compressions continued. The resuscitation continued for about 20 minutes before our patient was successfully defibrillated to an organized rhythm.
During resuscitation, the MCHD crew utilized ultrasound of the carotid artery to guide the response to interventions. During this procedure, the carotid artery is found in the transverse plane using a Butterfly IQ device. Once acquired for the pulse check, our crews performed both a manual and US pulse check at usual intervals. CPR was continued until ROSC was observed by the carotid US view during a pulse check at 21 minutes into the case.
Our patient was packaged for transfer. Hemodynamic support was provided with push dose epinephrine, fluids and norepinephrine drip. The patient’s airway was secured with a tracheal tube, and he was placed on mechanical ventilation at lung-protective settings. A post-ROSC 12-lead ECG revealed anterior-lateral STEMI.
Clinical course and outcome
A STEMI activation was initiated using the Pulsara EMS mobile notification application, and the patient was transported emergency traffic to a local STEMI receiving center. He underwent emergency cardiac catheterization with angioplasty and stenting of the culprit lesion. Post-intervention, our patient was transferred to the ICU. He received hemodynamic support and targeted temperature management, and was ultimately discharged home with minimal neurologic disability CPC-1.
MCHD carotid ultrasound quality initiativeWe conducted a retrospective, before and after review of ultrasound video clip images from patients who underwent CPR following OHCA during a 13-month period between January 2022 and February 2023. The Butterfly IQ device was used throughout.
During the initial study phase (January 2022-May 2022), subxiphoid or parasternal long-axis cardiac views along with manual pulse were solely utilized to evaluate for perfusion.
In June 2022, carotid ultrasound was introduced in addition to traditional cardiac views. Paramedics evaluated for carotid pulsatility utilizing the 2-D vascular mode. An independent abstractor reviewed all video clips to identify image accuracy and time delays during acquisition. We defined a compression delay as any visualized pause greater than 10 seconds.
What we found
During the study period, 177 patients in total were analyzed, with 98 undergoing cardiac and 79 carotid POCUS imaging. From these patients, there were 144 cardiac and 90 carotid video clips. A compression delay of greater than 10 seconds was noted in 75/144 (52%) of cardiac, but only 29/90 (32%) of carotid ultrasound videos. Adequate image accuracy was obtained in 109/144 (76%) and 79/90 (88%) of cardiac and carotid cases, respectively.
Utilization of prehospital carotid ultrasonography in OHCA to assess for perfusion during CPR resulted in 20% fewer chest compression delays during pulse checks compared to traditional cardiac view capture. Additionally, POCUS image accuracy was not compromised by utilizing a carotid US view.
Carotid ultrasound summary points
- A post-ROSC 12-lead ECG is a vital piece of information to obtain if sustained ROSC is achieved during resuscitation. Ideally, this should occur about 10 minutes post-ROSC .
- STEMI patients should get complete monitoring and precautions during transport, including placement of pacer/defibrillation pads due to their high risk for lethal dysrhythmia .
- Cardiac ultrasound in OOHCA may result in compression delays over 10 seconds during pulse checks.
- Carotid ultrasound during resuscitation for OOHCA may result in fewer compression delays.
- Carotid ultrasound imaging may improve provider acquisition of adequate image capture.
Read next: POCUS finds success in EMS
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2. Huis In ‘t Veld MA, Allison MG, Bostick DS, Fisher KR, Goloubeva OG, Witting MD, Winters ME. Ultrasound use during cardiopulmonary resuscitation is associated with delays in chest compressions. Resuscitation. 2017 Oct;119:95-98.
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About the authors
Ryan Richardson, MD, is an emergency medicine resident at HCA Houston Healthcare in Kingwood, Texas.
Robert Dickson, MD, is EMS medical director at Montgomery County Hospital District EMS and faculty at HCA Houston Healthcare in Kingwood, Texas.
Casey Patrick, MD, is medical director for Harris County ESD 11 Mobile Healthcare and assistant medical director for the Montgomery County Hospital District EMS in Conroe, Texas.
Himanshu Gupta MD, is an emergency medicine resident at HCA Houston Healthcare in Kingwood, Texas.
James Seek LP is the assistant chief at MCHD.
Kevin Crocker LP is the chief of quality at MCHD.
Nick Smith LP is the clinical chief at MCHD.
Joshua Rasco is a 2nd-year medical student at Sam Houston State Osteopathic School of Medicine.