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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Date data sharing statement initially provided
Type of registration
Prospectively registered

Titles & IDs
Public title
Validity of pulsatile flow assessment by carotid artery ultrasound
Scientific title
Assessing the validity of two-dimensional ultrasound to detect the presence or absence of a pulse
Secondary ID [1] 297706 0
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
cardiac arrest 312010 0
Condition category
Condition code
Emergency medicine 310577 310577 0 0

Study type
Description of intervention(s) / exposure
Ten-second two-dimension ultrasound videos of the carotid artery at mean arterial pressure of 20-30mmHg, 40-50mmHg, 60-70 mmHg during cardiac surgery off bypass to be reviewed by critical care resident doctor
Intervention code [1] 313937 0
Diagnosis / Prognosis
Comparator / control treatment
The gold standard / comparator will be the presence of a pulse on an arterial line. When we collect the ultrasound images we will know if a pulse is present or not and this will be used to determine whether an video has a pulse or not, against which the physician-readers will be compared
Control group

Primary outcome [1] 319430 0
Specificity of carotid ultrasound to detect no pulse as assessed by detection of no pulse in patients not on bypass when compared to there also being no pulse on the arterial line, for the total sample
Timepoint [1] 319430 0
in ten seconds
Primary outcome [2] 319757 0
Sensitivity of carotid ultrasound to detect a pulse as assessed by detection of a pulse in patients not on bypass when compared to there also being a pulse on the arterial line for the total sample
Timepoint [2] 319757 0
at 10 seconds
Secondary outcome [1] 368149 0
a comparison of the specificity of carotid ultrasound to detect no pulse as assessed by detection of no pulse in patients not on bypass for each mean arterial pressure range (20-30mmHg, 40-50mmHg, 60-70 mmHg) compared to the presence / absence of a pulse on the arterial line, as assessed by Youdin's Index
Timepoint [1] 368149 0
10 seconds
Secondary outcome [2] 368151 0
a comparison of the sensitivity of carotid ultrasound to detect no pulse as assessed by detection of no pulse in patients not on bypass for each mean arterial pressure range (20-30mmHg, 40-50mmHg, 60-70 mmHg) compared to the presence / absence of a pulse on the arterial line, as assessed by Youdin's Index
Timepoint [2] 368151 0
10 seconds

Key inclusion criteria
There will be two groups of participants:

1. Carotid ultrasound participants. These participants will be from consenting cardiac surgery volunteers. All cardiac surgery patients who will be placed on bypass during their surgery, including valve replacement or coronary artery bypass grafts. Age > 18. Ability to offer informed consent.

2. Critical care physician readers. These participants will be consenting volunteer critical care physicians who will be asked to review a maximum of 30 of the carotid ultrasound video clips. Any post-graduate critical care physician who uses ultrasound in their clinical practice, whether for focussed echocardiography, central line placement or trauma assessment.
Minimum age
18 Years
Maximum age
No limit
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
Cardiac surgery participants: Previous surgery involving the great blood vessels including aorta or carotid arteries. Patients who the cardiac surgeon considers to be inappropriate due to a high surgical risk, patients with an intra-aortic balloon pump, and patients with known carotid artery stenosis.

Critical care physician readers: No previous experience with ultrasound.

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
The randomisation will be the order in which the ultrasound scans are presented to the readers. Readers of the ultrasound scans will not know whether the images they are viewing have a pulse or not, nor the ratio of pulse to no-pulse in the images they review. The entire sample of ultrasound images will be block randomised, so that the order is different for each reader, but each scan is not reviewed more than once by an individual reader.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
will be by R code : RandomSeq <-, c(video =y, iter =z)))
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?

The people assessing the outcomes
Intervention assignment
Single group
Other design features
Not Applicable
Type of endpoint(s)
Statistical methods / analysis
All data analysis will be performed using R statistical analysis software. Diagnostic test criteria will be generated an analysed using the epitests package. Youden’s index and the comparison of Youden’s index between different mean arterial pressure will be performed using either the cutpoint R or optimalcutpoints packages and also the DTCompare package. A significance level of 0.05 will be considered significant.

Missing data plan.

We plan to reduce the amount of potential missing data by collecting only information relevant to the study and its outcomes.

As this is a paired-patient study, ideally we will collect a video from all three MAP ranges (20-30mmHg, 40-50mmHg, 60-70 mmHg) from each patient. In the situation where we are not able to collect all three MAP ranges from each patient, we will use a complete case analysis approach and removing all of the patient in who three videos could not be obtained. It is anticipated that this will occur infrequently, so that in seeking a maximum of 30 patients we should obtain all four videos for our minimum sample size of 24.

If we cannot obtain a carotid US video of the three MAP ranges in more than six patients, we will then look at either widening the MAP ranges in subsequent videos or changing to an available-case approach and combining all available videos so that the final video data-set has an equal proportion of videos numbers per MAP range, but in an unpaired approach. This would not alter the method of analysis but would reduce the power of the study. Of this were to occur we would consult a statistician for advice on the number of readers than would be required to adequately power the study (something we could not do until after the carotid US videos are collected).

Recruitment status
Not yet recruiting
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment in Australia
Recruitment state(s)
Recruitment hospital [1] 13371 0
St George Hospital - Kogarah
Recruitment postcode(s) [1] 25971 0
2217 - Kogarah

Funding & Sponsors
Funding source category [1] 302230 0
Name [1] 302230 0
St George Hospital, Kogarah
Address [1] 302230 0
Gray St,
NSW 2217
Country [1] 302230 0
Primary sponsor type
St George Hospital, Kogarah
Gray St,
2217 NSW, Australia
Secondary sponsor category [1] 302085 0
Name [1] 302085 0
Address [1] 302085 0
Country [1] 302085 0

Ethics approval
Ethics application status
Ethics committee name [1] 302910 0
South Eastern Sydney Local Health District Human Research Ethics Committee
Ethics committee address [1] 302910 0
Prince of Wales Hospital
G71 East Wing , Edmund Blacket Building
NSW 2031
Ethics committee country [1] 302910 0
Date submitted for ethics approval [1] 302910 0
Approval date [1] 302910 0
Ethics approval number [1] 302910 0

Brief summary
Current cardiac arrest algorithms require assessment of the return of spontaneous circulation (ROSC) following rhythm checks by observation for patient movement or spontaneous respirations, both of which may be absent in sedated and paralysed patients. Healthcare professionals may also check for a pulse in the presence of an organized rhythm, however manual pulse checks have been demonstrated to be unreliable, even when performed by health professionals.

There have been two papers published from St George Hospital (Sydney) related to the use of ultrasound (US) of central pulses and whether they may be an alternative to manual pulse checks. The first was a case report where US of the femoral artery demonstrated ROSC and guided subsequent resuscitation, following cardiac arrest in a patient where manual pulses were absent. The second was an investigation into the inter-rater reliability of carotid US in detecting the return of a pulse, using cardiac surgery patients coming off bypass (where they go from no-pulse to a pulse). This showed a high intraclass correlation (0.86) for two-dimension (2D) ultrasound when detecting the return of a pulse.

This current study seeks to extend on these previous efforts by assessing the validity of carotid US in detecting the presence/absence of a pulse. We hope to use cardiac surgery patients as a human model for the presence and absence of a pulse by obtaining 2D US of the carotid arteries when not on bypass (when there is a pulse), and on bypass (when a pulse is not present). We will then present these videos to critical care physicians who are familiar with US and would be likely to perform an US in a cardiac arrest. We will assess the validity using diagnostic test criteria for subgroups of MAP, and the cohort as a whole. Our gold standard will be presence or absence of a pulsatile waveform on the participants radial artery pressure monitoring.
Trial website
Trial related presentations / publications
Public notes
Germanoska, B., Coady, M., Ng, S., Fermanis, G., & Miller, M. (2018). The reliability of carotid ultrasound in determining the return of pulsatile flow: A pilot study. Ultrasound, 26(2), 118–126.

Miller, M., Grant, P., Cases, M. K. A., 2015. Return of spontaneous circulation confirmed by two dimensional ultrasound following pulseless electrical activity arrest. Anaesthesia Cases. Wiley Online Library

Principal investigator
Name 91814 0
Dr Matthew Miller
Address 91814 0
Department of Anaesthesia
St George Hospital
Gray St,
NSW 2217
Country 91814 0
Phone 91814 0
+61 2 9113 1111
Fax 91814 0
Email 91814 0
Contact person for public queries
Name 91815 0
Dr Matthew Miller
Address 91815 0
Department of Anaesthesia
St George Hospital
Gray St,
NSW 2217
Country 91815 0
Phone 91815 0
+61 2 9113 1111
Fax 91815 0
Email 91815 0
Contact person for scientific queries
Name 91816 0
Dr Matthew Miller
Address 91816 0
Department of Anaesthesia
St George Hospital
Gray St,
NSW 2217
Country 91816 0
Phone 91816 0
+61 2 9113 1111
Fax 91816 0
Email 91816 0

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No/undecided IPD sharing reason/comment
they will be mostly large video files which will be too big to share, however we will be asking permission to share the data from participants. If the ethics committee agree that we can share the data with the participants permission, we will do so
What supporting documents are/will be available?
No other documents available
Summary results
No Results