Cardiac ArrestTOMCATNCT04838418
Transorbital Ultrasound and Other Markers for Prognosis Prediction After Cardiac Arrest
An observational study of Cardiac Arrest, run by University Hospital Pilsen at 1 site in Czechia.
Trial summary
In sudden cardiac arrest patients with return of spontaneous circulation, brain damage is one of the main determinants of short-term mortality and poor prognosis (CPC 3-5). It is important to properly select group of patients in whom treatment is futile. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Cardiac Arrest
- What is being tested?
- Optic nerve sheath diameter measured by transorbital ultrasound
- Type of treatment
- Surgery or procedure
- How many people
- 80 participants
- Where
- 1 siteCzechia
- Study dates
- 4 Jan 2021to 1 Dec 2026
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Male and female patients after cardiac arrest with subsequent ROSC, 18 years of age and older
Who may be able to join
- age of 18 years or older
- out of hospital cardiac arrest of non-traumatic cause with CPR and subsequent ROSC
- Glasgow coma scale (GCS) ≤ 7 or sedation 30 minutes after ROSC achievment
Who cannot join
- unavailable first measurment of the optic nerve sheath diameter (ONSD) measured by transorbital ultrasonography 24±6 hours after ROSC achievement
- refractory cardiac arrest
- craniocerebral injury
- intracranial tumor
- active intracranial bleeding
- haemorrhagic stroke and/or subarachnoid haemorrhage in the last 3 months
Show all 10Show fewer
- facial trauma affecting the eye area
- active neuroendocrine tumor, small cell lung cancer, non-small cell lung
- CPC 3-5 before cardiac arrest
- sclerosis multiplex and/or optic neuritis of other etiology
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Transorbital Ultrasound and Other Markers for Prognosis Prediction After Cardiac Arrest (TOMCAT)
In sudden cardiac arrest patients with return of spontaneous circulation, brain damage is one of the main determinants of short-term mortality and poor prognosis (CPC 3-5). It is important to properly select group of patients in whom treatment is futile. According to current guidelines, multimodal approach is recommended. Optic nerve sheath diameter measured by ultrasound is non-invasive, fast, low-cost and readily available bed-side method, but evidence for its use as neuroprognostication modality is limited to only few small studies. The aim of this study is to evaluate validity of ONSD as neuroprognostication method at larger cohort of patients, compare it with other established methods and compare ultrasound and CT measurement of ONSD.
Read the detailed description
Additional relevant MeSH terms:
cardiac arrest, cardiovascular diseases, optic nerve sheath diameter.
- Conditions
- Cardiac Arrest
- Being tested
- Optic nerve sheath diameter measured by transorbital ultrasound
- Medical subject headings
- Heart Arrest
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Optic nerve sheath diameter measured by transorbital ultrasoundProcedure or surgery
Optic nerve sheath diameter measured 3 mm behind eyeball. For every eyeball 2 measurements in axial and 2 measurements in sagital projections are performed. Summary value for every eyeball is arithmetic mean from these 4 measurements.
What is being measured
The primary outcome is the main question the study is designed to answer.
Value of ONSD for short-term neurological outcome prediction
Assessment of the correlation between the optic nerve sheath diameter measured by transorbital ultrasonography and neurological outcome of patients (quantified by the CPC scale) after out of hospital cardiac arrest with subsequent ROSC
Measured: 30 days
Value of ONSD for short-term mortality prediction
Assessment of the correlation between optic nerve sheath diameter measured by transorbital ultrasonography and mortality during a 30-day follow-up.
Measured: 30 days
Secondary outcomes (7)
Comparison of ONSD and electrophysiologic modalities for neurological outcome prediction
Assessment of the correlation between the optic nerve sheath diameter measured by transorbital ultrasonography and negative prognostic markers obtained by somatosensory evoked potentials examination and EEG in patients remaining in a coma even after the end of therapeutic hypothermia and sedation.
Measured: 96 hours
Comparison of ONSD measurements by ultrasonography and computed tomography
Assessment of accuracy of the optic nerve sheath diameter measured by ultrasonography compared to CT measurement performed 48 ± 12 hours after achievment of ROSC.
Measured: 48 hours
Correlation between ONSD and fundoscopic signs of papillary edema
Assessment of the correlation between the optic nerve sheath diameter measured by transorbital ultrasonography and grade of optic nerve papillary edema quantified by the Frisen scale on fundoscopic examination performed 48 ± 12 hours after achievment of ROSC.
Measured: 48 hours
Correlation between ONSD and thickness of retinal nerve fibers measured by OCT
Assessment of the correlation between the optic nerve sheath diameter measured by transorbital ultrasonography and thickness of retinal nerve fibers measured by optical coherence tomography at time intervals of 1, 3 and 5 months after achievment of ROSC.
Measured: 5 months
Effect of blood carbon dioxide on ONSD
Assessment of the correlation between the optic nerve sheath diameter measured by transorbital ultrasonography and paCO2 and ETCO2 values at the time of measurement.
Measured: 72 hours
Value of ONSD for long-term neurological outcome and mortality
Assessment of the correlation between the optic nerve sheath diameter measured by transorbital ultrasonography and mortality and neurological outcome of patients (quantified by the CPC scale) at 6 months after ROSC.
Measured: 6 months
Correlation between blood NSE, copeptin and selected RNAs
Assessment of the correlation between blood NSE, copeptin and selected micro-RNAs measured at defined time intervals from ROSC, to neurological outcome prediction in patients after out of hospital cardiac arrest with subsequent ROSC.
Measured: 6 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted9 Apr 2021
- Study start4 Jan 2021
- Primary completion1 Dec 2026 (estimated)
- Study completion1 Dec 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Cardiac ArrestStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 80 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University Hospital Pilsen
- Sponsor type
- University, hospital or other
- Collaborators
- Na Homolce Hospital
- Responsible party
- Sponsor
- Investigators
- Štefan Volovár, MUDr., Principal investigator, University hospital Plzen
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04838418
- Sponsor's protocol ID
- TOMCAT
- Acronym
- TOMCAT
- Status last verified
- Apr 2026
- First submitted
- 6 Apr 2021
- Last updated
- 9 Apr 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 9 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Transorbital Ultrasound and Other Markers for Prognosis Prediction After Cardiac Arrest (TOMCAT)
- ClinicalTrials.gov ID
- NCT04838418
- Acronym / sponsor ID
- TOMCAT / TOMCAT
- Conditions
- Cardiac Arrest
- Study type
- Observational
- Recruitment status
- Active, not recruiting
- Enrolment
- 80 participants (estimated)
- Lead sponsor
- University Hospital PilsenUniversity, hospital or other
- Collaborators
- Na Homolce Hospital
- Study start
- 4 Jan 2021 (actual)
- Primary completion
- 1 Dec 2026 (estimated)
- Study completion
- 1 Dec 2026 (estimated)
- First posted
- 9 Apr 2021 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
In sudden cardiac arrest patients with return of spontaneous circulation, brain damage is one of the main determinants of short-term mortality and poor prognosis (CPC 3-5). It is important to properly select group of patients in whom treatment is futile. According to current guidelines, multimodal approach is recommended. Optic nerve sheath diameter measured by ultrasound is non-invasive, fast, low-cost and readily available bed-side method, but evidence for its use as neuroprognostication modality is limited to only few small studies. The aim of this study is to evaluate validity of ONSD as neuroprognostication method at larger cohort of patients, compare it with other established methods and compare ultrasound and CT measurement of ONSD.
Detailed description
Additional relevant MeSH terms:
cardiac arrest, cardiovascular diseases, optic nerve sheath diameter.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Male and female patients after cardiac arrest with subsequent ROSC, 18 years of age and older
Key inclusion criteria (3 listed)
- age of 18 years or older
- out of hospital cardiac arrest of non-traumatic cause with CPR and subsequent ROSC
- Glasgow coma scale (GCS) ≤ 7 or sedation 30 minutes after ROSC achievment
Key exclusion criteria (10 listed)
- unavailable first measurment of the optic nerve sheath diameter (ONSD) measured by transorbital ultrasonography 24±6 hours after ROSC achievement
- refractory cardiac arrest
- craniocerebral injury
- intracranial tumor
- active intracranial bleeding
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Optic nerve sheath diameter measured by transorbital ultrasoundOptic nerve sheath diameter measured 3 mm behind eyeball. For every eyeball 2 measurements in axial and 2 measurements in sagital projections are performed. Summary value for every eyeball is arithmetic mean from these 4 measurements. | Procedure or surgery | – |
Primary outcome
Value of ONSD for short-term neurological outcome prediction
Time frame: 30 days
Assessment of the correlation between the optic nerve sheath diameter measured by transorbital ultrasonography and neurological outcome of patients (quantified by the CPC scale) after out of hospital cardiac arrest with subsequent ROSC
Value of ONSD for short-term mortality prediction
Time frame: 30 days
Assessment of the correlation between optic nerve sheath diameter measured by transorbital ultrasonography and mortality during a 30-day follow-up.
7 secondary outcomes
Comparison of ONSD and electrophysiologic modalities for neurological outcome prediction
Time frame: 96 hours
Comparison of ONSD measurements by ultrasonography and computed tomography
Time frame: 48 hours
Correlation between ONSD and fundoscopic signs of papillary edema
Time frame: 48 hours
Correlation between ONSD and thickness of retinal nerve fibers measured by OCT
Time frame: 5 months
Effect of blood carbon dioxide on ONSD
Time frame: 72 hours
Value of ONSD for long-term neurological outcome and mortality
Time frame: 6 months
Correlation between blood NSE, copeptin and selected RNAs
Time frame: 6 months
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 9 Apr 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Štefan Volovár, MUDr. principal investigator
University hospital Plzen
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Cardiac Arrest, run by University Hospital Pilsen at 1 site in Czechia.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 10 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: under way, not looking for participants, as of the sponsor's last update on 9 Apr 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Czechia. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Value of ONSD for short-term neurological outcome prediction (time frame: 30 days). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 9 Apr 2026; AzTrials last refreshed its copy on 8 Nov 2026.