Feasibility of Doppler Ultrasound for Pulse Detection in Out-of-Hospital Cardiac Arrest Patients

Doppler Ultrasound Pulse Detection in Out-of-Hospital Cardiac Arrest Patients: A Feasibility Study.

The goal of this prospective observational study is to investigate the feasibility of using doppler point-of-care ultrasound on the femoral artery with a portable device to assess the presence of a pulse in patients suffering from cardiac arrest in the out-of-hospital environment. The main question is how often researchers are successful in acquiring the necessary ultrasound signal in the out-of-hospital environment.

Study Overview

• Status: Recruiting
• Conditions: Cardiac Arrest, Out-Of-Hospital
• Intervention / Treatment: Other: Point-of-care vascular ultrasound

Detailed Description

In this prospective observational study, a dedicated research team will be dispatched to cardiac arrest patients treated in the prehospital environment by emergency medical services (EMS). The team will use a portable ultrasound device to identify the femoral artery and conduct a pulsed wave (PW) doppler measurement during chest compressions as well as during chest compression pauses for rhythm analysis and save the recorded images. These ultrasound pulse checks will be conducted in parallel with the normal treatment of the patient, including manual pulse checks, and will only be conducted if ultrasound is possible without interference in the resuscitation. All treatment decisions will rest with the treating EMS team.

• Study Type: Observational
• Enrollment (Estimated): 50

Contacts and Locations

• Study Contact: Name: Philipp Metelka, MD; Phone Number: +43 699 10659528; Email: philipp.metelka@meduniwien.ac.at
• Study Contact Backup: Name: Christina Hafner, MD, PhD; Phone Number: +43 650 8801561; Email: christina.hafner@meduniwien.ac.at

Study Locations

• Austria
  • Vienna, Austria, 1030
    • Recruiting
    • Emergency Medical Service of Vienna
    • Contact: Daniel Grassmann, MD; Phone Number: +43 664 9138434; Email: daniel.grassmann@wien.gv.at

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: N/A

• Sampling Method: Non-Probability Sample

Study Population

The study population comprises non-pregnant adults suffering out-of-hospital cardiac arrest of any cause who are treated with CPR by emergency medical services.

Description

Inclusion Criteria:

• Out-of-hospital cardiac arrest treated by EMS
• Minimum age of 18 years

Exclusion Criteria:

• Pregnancy or suspected pregnancy
• Disapproval of the treating EMS team
• Adults under legal guardianship
• Inability to perform femoral artery doppler ultrasound due to limited access to the patient and possible interference with the treating EMS team
• Inability to perform femoral artery doppler ultrasound due to injuries or anatomic abnormalities in the femoral region or necessary emergent medical interventions in the femoral region
• Decision to transfer the patient to the hospital with ongoing CPR for emergent procedures such as extracorporeal CPR before femoral artery doppler ultrasound could be attempted
• Inability to safely perform femoral artery doppler ultrasound due to environmental hazards

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Included patients	Other: Point-of-care vascular ultrasound; Point-of-care ultrasound will be used to image the femoral vessels and to perform a pulsed-wave doppler measurement of blood flow during chest compressions and during pauses for rhythm and manual pulse checks.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Feasibility of femoral artery doppler ultrasound	If an ultrasound image of the femoral artery of sufficient quality for Doppler ultrasound can be obtained, the primary outcome will be considered to be positive.	During cardiac arrest, up to 45 minutes

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Time until ultrasound signal acquisition	The time until successful acquisition of the doppler ultrasound signal will be measured in 2-minute CPR-intervals and 30-second intervals (e.g. second CPR-interval, first 30 seconds).	During cardiac arrest, up to 45 minutes
Discordance between doppler ultrasound and manual pulse checks.	The presence of a doppler ultrasound flow signal during rhythm analysis and the result of the manual pulse check that is performed in parallel by the treating EMS team will be evaluated and analyzed for discordance.	During cardiac arrest, up to 45 minutes
Correlation of the result of manual pulse checks with doppler peak systolic velocity	The correlation of the result of manual pulse checks performed by the treating EMS team with the peak systolic velocity measured by doppler ultrasound will be analyzed.	During cardiac arrest, up to 45 minutes
Patient factors influencing probability of successful doppler ultrasound image acquisition	Patient factors sex, age, approximated bodyweight and suspected cause of cardiac arrest will be analyzed for correlation with successful doppler ultrasound image acquisition.	After cardiac arrest, through study completion (a maximum of 1 year)
Inter-observer variability in determining the quality of the doppler ultrasound signal.	The sonographer on site will assess the quality of the acquired doppler ultrasound images, as well as two ultrasound experts who will be blinded to the performing sonographer. The difference between these assessments will be analyzed.	After cardiac arrest, through study completion (a maximum of 1 year)

Collaborators and Investigators

• Sponsor: Medical University of Vienna
• Collaborators: Ludwig Boltzmann Institute Digital Health and Patient Safety; Emergency Medical Service of Vienna
• Investigators: Principal Investigator: Philipp Metelka, MD, Medical University of Vienna

Study record dates

Study Major Dates

• Study Start (Actual): January 4, 2024
• Primary Completion (Estimated): March 31, 2024
• Study Completion (Estimated): April 30, 2024

Study Registration Dates

• First Submitted: January 2, 2024
• First Submitted That Met QC Criteria: January 31, 2024
• First Posted (Actual): February 8, 2024

Study Record Updates

• Last Update Posted (Actual): February 8, 2024
• Last Update Submitted That Met QC Criteria: January 31, 2024
• Last Verified: January 1, 2024

More Information

Terms related to this study

• Keywords: Ultrasound; Doppler Ultrasound; Cardiac Arrest; Out-Of-Hospital Cardiac Arrest; OHCA; Femoral Artery; POCUS; Point-Of-Care Ultrasound; Pulse Check; POCUS Pulse Check
• Additional Relevant MeSH Terms: Heart Diseases; Cardiovascular Diseases; Heart Arrest; Out-of-Hospital Cardiac Arrest
• Other Study ID Numbers: 1549/2023

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No