No Pause, No Problem? Using Doppler Ultrasound to Detect ROSC Without Pausing Compressions for Pulse Check
/Cardiac arrest care hinges on high‑quality CPR, but pulse checks remain a stubborn source of interruptions — often longer than the recommended 10 seconds and repeated every two minutes. What if we could detect ROSC without ever pausing compressions? This diagnostic accuracy study evaluates whether femoral arterial Doppler waveforms obtained during active CPR can predict arterial line pulsatility at the next pulse check. Join Dr. Qin as she reviews how well Doppler‑detected pulsatility and anterograde flow signal true cardiac activity — and whether ultrasound could offer a future where pulse checks no longer slow us down.
Rolston DM, Bielawa N, Huang X, et al. Arterial Doppler Ultrasound Blood Flow Waveforms During Chest Compressions to Detect Arterial Line Pulsatility. Ann Emerg Med. 2026;87(4):412-423. doi:10.1016/j.annemergmed.2025.09.018
Background
High-quality CPR is a cornerstone of outcomes in cardiac arrest
While minimizing interruptions in chest compressions is key, pulse checks can often lead to prolonged interruptions, occurring every 2 minutes and often lasting longer than the recommended 10 seconds
What if there was a way to detect ROSC without actually stopping CPR to do so?
Objectives
Primary objective: Assess the accuracy of femoral arterial Doppler ultrasound waveforms during chest compressions to detect any femoral arterial line pulsatility at the subsequent pulse check
Secondary objective: Comparison of systolic blood pressure at subsequent pulse check of “pulsatility through compressions” and “anterograde dominant flow” to determine whether these waveforms could be used to differentiate arterial line pulsatility with SBP≥60 (with SBP > 60 being equivalent to ROSC per existing literature, vs SBP < 60 being consistent with no ROSC and likely pseudo-PEA or PEA again per existing literature)
Study Design
Retrospective single-center diagnostic accuracy study on a prospectively collected convenience sample (in other words, a retrospective secondary analysis of data collected for another study that was prospectively collection)
Diagnostic accuracy study: Evaluates how effectively a new test (e.g. arterial Doppler ultrasound waveform) can identify a diagnosis or condition compared to the established “gold standard” (e.g. pulsatility on arterial line)
Convenience sampling: Selecting patients that are readily available, rather than according to a strict randomization or selection protocol (cardiac arrest patients that had an arterial line placed and had ultrasound-trained faculty present to collect/interpret ultrasound waveforms)
Inclusion criteria:
Adult (18+ years)
Non-traumatic cardiac arrest, both OHCA and IHCA were included
Femoral arterial line in place
Doppler ultrasound trained EM attending was available
Exclusion criteria:
Candidate for ECMO
Arterial line was not functioning at time of pulse check
Statistical analysis:
Diagnostic accuracy = true positives plus true negatives, divided by total number of Doppler waveforms and arterial line pulse checks analyzed
True positive = pulsatility through compressions or anterograde dominant blood flow were present and the arterial line had both a waveform and SBP reading
True negative = bidirectional and minimal blood flow were present and arterial line had no waveform or SBP reading
Sensitivity, specificity, positive likelihood ratio, negative likelihood ratio
Sensitivity analysis to assess unadjusted diagnostic test characteristics of the waveforms to detect arterial line pulsatility with SBP≥60mmhG
Bootstrapping was used to estimate the confidence interval when the sensitivity or specificity in the sample is 100% (useful in small sample sizes or if data follows a non-normal distribution)
Linear mixed effects model was used to account for correlation within subjects (using multiple clips from each individual patient)
STUDY PROTOCOL
Prior to beginning the study, all research personnel (ultrasound faculty, ultrasound fellows, critical care faculty) received a 45-minute training in the study and ultrasound protocol by the PI
During active CPR and prior to pulse check, common femoral artery was identified using a linear probe on vascular or nerve preset (no additional settings including Doppler angle were adjusted)
Probe re directed until adequate waveforms identified during active CPR
Waveforms were recorded prior to pausing chest compressions and during the entirety of the pulse check (using multiple clips if needed)
Two independent reviewers evaluated and categorized waveforms during active compressions within 30 seconds prior to a pulse check
In a small subset of patients, there were only a few seconds of chest compressions prior to pulse check so blinding was not possible
Third reviewer was used in case of disagreement
waveforms (see original published manuscript for pictures with examples for each waveform)
1.) Pulsatility through chest compressions
Definition: Intrinsic pulses generated from cardiac contractility is seen between regular chest compression-generated blood flow
Meaning: Enough cardiac contractility is present to generate additional anterograde pulsatile blood flow in the presence of chest compressions
2.) Anterograde dominant blood flow
Definition: Peak systolic velocity in one direction was more than 20% larger than peak systolic velocity in the opposite direction
Meaning: More blood is moving anterograde from underlying cardiac contractility generating forward blood flow, than retrograde from recoil of the chest
3.) Bidirectional blood flow
Definition: Positive peak systolic velocity of anterograde blood flow was equivalent within 20% of the negative peak systolic velocity of retrograde blood flow (anything <20% would be difficult to distinguish quickly during active CPR)
Anterograde = blood flow due to chest compression
Retrograde = blood flow due to thoracic recoil
Meaning: Blood is moving equally in both directions so there is no underlying intrinsic cardiac contractility
4.) Minimal blood flow
Definition: Positive peak systolic velocity and negative peak systolic velocity were both less than 20 cm/s (which was found in a previous study to be associated with SBP<60, inadequate compression-generated blood pressure)
Meaning: Poor chest compression-generated blood flow or minimal blood flow due to stagnation of blood/clotting
Results (warning: complicated stats!)
Demographics and basic information
Between 6/18/2019 and 8/13/2024, a total of 44 patients with 123 Doppler ultrasound waveforms with subsequent arterial line pulse checks were analyzed
The study population was primarily older (mean age 74.8 years), male (68.2%), non-wite (47.7%), out-of-hospital cardiac arrest (68.2%), and initially presented in PEA (52.3%) or asystole (25%)
The majority received mechanical compressions with a LUCAS device in both the pre-hospital and ED settings (52.3%), while some received manual compressions in the pre-hospital setting (36.4%) or the entirety of the resuscitation (11.4%)
Does use of Doppler ultrasound help?
Overall diagnostic accuracy of Doppler ultrasound waveforms to detect the presence or absence of any A-line pulsatility at the subsequent pulse check = 88.9% (95% CI 81.3-93.7)
Sensitivity of pulsatility through compressions + anterograde dominant flow for detecting presence of any A-line pulsatility 97.7% (95% CI 87.7-99.6)
Specificity of bidirectional blood flow + minimal blood flow = 81.5% (95% CI 69.3-89.6)
Positive LR of pulsatility through compressions and anterograde dominant flow was 5.29 (95% CI 3.34-8.68)
Negative LR of bidirectional blood flow + minimal blood flow = 0.03 (95% CI 0-0.15)
OVERALL RESULTS: Sensitivity analysis of pulsatility through compressions + anterograde dominant flow for detecting pulse with SBP≥60
Accuracy = 70% (95% CI 61.5-78)
Sensitivity = 100% (95% CI 86.7-100)
Specificity = 61.7% (95% CI 51.9-71.5)
Positive LR = 2.61 (95% CI 1.77-3.45)
Negative LR = 0 (95% CI 0-0.18)
Potential Impact on clinical practice
Yes! Use of Dopper ultrasound to examine blood flow waveforms during active chest compressions provide an opportunity to detect intrinsic cardiac contractility (ROSC) without a pulse check!
Previous study found 100% specificity for visualized pulsatility through compressions for detecting organized echocardiographic cardiac activity but only 50% sensitivity
By adding anterograde blood flow in this study, improved sensitivity for A-line pulsatility and ROSC with SBP≥60
Future studies?
Continuing compressions in non-shockable rhythms until pulsatility through compressions or anterograde dominant blood flow is seen, then perform arterial Doppler ultrasound for pulse check
Assess patient outcomes with use of these waveforms and skipping pulse checks (vs standard of care with pulse checks)
Could lead to more patient-centered approach to CPR
Limitations
Limited sampling
Single center
Small sample size, repeated measures per patient (multiple rounds of CPR)
Convenience sample, not all-comers
Retrospective study
Could not directly compare monitor data to ultrasound clips
Many patients with an A-line did not have clips during active compressions (previous study in which this data was collected was focused on during the pulse check)
Small minority of cases could not be blinded as some clips did not have enough time prior to pulse check, and thus included the pulse check which may have influenced interpretation
Excluded patients who could not have an A-line placed may result in selection bias (obesity, PAD, rapid ROSC, poor prognosis)
Study personnel with extensive experience with arterial Doppler ultrasonography, thus may not be generalizable to all EDs
Only used femoral A-lines, thus may not be generalizable to A-lines placed at other sites (e.g. radial, brachial)
Retrograde flow (from recoil) may be overestimated in LUCAS vs manual compressions
AUTHORSHIP
Written by: Gina Qin, MD, PGY-3 University of Cincinnati Department of Emergency Medicine
Writing, Editing, Posting, and Audio Editing by Anita Goel, MD; Associate Professor, APD of UC EM Residency Program, and Co-editor of Tamingthesru.com
Cite as: Qin,G; Goel, A. No Pause, No Problem? Using Doppler Ultrasound to Detect ROSC Without Pausing Compressions for Pulse Check. TamingtheSRU.com. www.tamingthesru.com/blog/journal-club/using-doppler-ultrasound-for-pulse-checks-during-cpr. 6/1726.
