An observational study in Cardiac Arrest (CA) and Carotid Doppler, sponsored by Inonu University. Not yet recruiting. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-11-05.
Sponsored by Inonu University · Observational
Out-of-hospital cardiac arrest (OHCA) is one of the most critical conditions in emergency medicine, causing high mortality and severe neurological sequelae due to the sudden cessation of circulation. Among the hundreds of thousands of patients affected worldwide, a significant proportion die or face permanent neurological impairment from hypoxic-ischemic brain injury, even after return of spontaneous circulation (ROSC). Therefore, early and reliable assessment of brain injury after cardiac arrest is of great importance both for clinical decision-making and for the effective use of treatment resources.
Various methods are currently used to predict neurological prognosis after cardiac arrest, including computed tomography, magnetic resonance imaging, electroencephalography, and biochemical markers (NSE, S100B). However, some of these methods are expensive, have limited availability, or can be difficult to apply in the management of critically ill patients. In this context, bedside ultrasonography and cerebral oximetry, being applicable at the bedside, non-invasive, and repeatable, stand out as valuable alternative tools for clinicians.
Carotid Doppler ultrasonography provides indirect information about cerebral perfusion by measuring parameters such as peak systolic velocity (PSV), end-diastolic velocity (EDV), mean velocity (MV), pulsatility index (PI), and resistive index (RI) in the common carotid arteries. High PI and RI values indicate increased intracranial pressure or impaired cerebral vasomotor response, and these findings may be associated with poor neurological outcome. Similarly, transcranial Doppler (TCD) performed via the transtemporal approach reflects the integrity of cerebral autoregulation and cerebral perfusion pressure through middle cerebral artery (MCA) flow velocities and pulsatility values.
Optic nerve sheath diameter (ONSD) measurement is an increasingly widespread ultrasound application serving as a non-invasive indicator of elevated intracranial pressure. The optic nerve sheath is known to widen in the presence of cerebral edema, and this finding is thought to be associated with neurological deterioration.
Non-invasive cerebral oximetry (rSO2) continuously monitors frontal cerebral oxygen saturation, allowing early detection of periods of cerebral hypoxia. Inadequate cerebral oxygenation after cardiac arrest has been shown to be directly associated with poor prognosis. However, comprehensive studies interpreting this parameter together with Doppler ultrasonography findings are still lacking.
The primary aim of this study is to prospectively investigate the predictive value of carotid Doppler (internal, external, and common carotid arteries), TCD-MCA, and ONSD measurements, together with non-invasive cerebral oximetry values, for 60-day mortality and neurological outcome (Cerebral Performance Category, CPC scale) in patients admitted to the ICU due to OHCA. Secondary aims include examining the correlations between these parameters and determining the earliest and most reliable prognostic cut-off values.
The results of this study are expected to contribute to early neurological prognostication and patient management in ICU patients after OHCA
926 studies on the registry are indexed under Heart Arrest; 226 are open to participants now.
This study's planned enrollment of 28 is below the median of 200 across 376 observational studies indexed under Heart Arrest.
Browse Heart Arrest studies →Inonu University is the lead sponsor of 394 studies on the registry; 95 are open to participants now.
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Adult patients admitted to the intensive care unit after out-of-hospital cardiac arrest.
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Exclusion Criteria:
Adult patients (≥18 years) admitted to the intensive care unit after out-of-hospital cardiac arrest who are hemodynamically stable with PaCO2 35-45 mmHg. Carotid Doppler, transcranial Doppler (MCA), and optic nerve sheath diameter are measured within the first 24 hours, at 72 hours, and on days 5-7. Cerebral oximetry (rSO2) is monitored continuously during the first 72 hours.
Diagnostic Test: Carotid Doppler Ultrasonography, Transcranial Doppler, Optic Nerve Sheath Diameter Measurement, and Cerebral Oximetry
Non-invasive bedside measurements performed alongside routine ICU care. Carotid Doppler ultrasonography (internal, external, and common carotid arteries) records peak systolic velocity, end-diastolic velocity, mean velocity, pulsatility index, and resistive index. Transcranial Doppler of the middle cerebral artery and optic nerve sheath diameter are measured within the first 24 hours, at 72 hours, and on days 5-7 after ICU admission. Cerebral oxygen saturation (rSO2) is monitored continuously with near-infrared spectroscopy during the first 72 hours, with the lowest and mean values recorded every 6 hours.
Association Between Carotid Doppler Indices and Neurological Outcome (CPC) After Out-of-Hospital Cardiac Arrest
Pulsatility index and resistive index of the internal, external, and common carotid arteries, measured within the first 24 hours, at 72 hours, and on days 5-7 after ICU admission, will be analyzed for their association with neurological outcome assessed by the Cerebral Performance Category (CPC) scale.
Time frame: 60 days after ICU admission
Association Between Carotid Doppler Indices and Mortality After Out-of-Hospital Cardiac Arrest
Peak systolic velocity, end-diastolic velocity, mean velocity, pulsatility index, and resistive index of the internal, external, and common carotid arteries, measured within the first 24 hours, at 72 hours, and on days 5-7 after ICU admission, will be analyzed for their association with all-cause mortality.
Time frame: 60 days after ICU admission
Association Between Optic Nerve Sheath Diameter and Neurological Outcome and Mortality
Optic nerve sheath diameter measured by ultrasonography within the first 24 hours, at 72 hours, and on days 5-7 will be analyzed for its association with CPC-based neurological outcome and mortality.
Time frame: 60 days after ICU admission
Association Between Cerebral Oximetry (rSO2) and Neurological Outcome and Mortality
Lowest and mean regional cerebral oxygen saturation (rSO2) values recorded every 6 hours during the first 72 hours of ICU stay, measured by near-infrared spectroscopy, will be analyzed for their association with CPC-based neurological outcome and mortality.
Time frame: First 72 hours of ICU stay for measurement; outcomes assessed at 60 days
No study locations are listed for this record.
Plan to share: No — Individual participant data will not be shared because patient data are anonymously coded and will not be shared with third parties, in line with the ethics committee approval. Aggregate results will be published in a peer-reviewed journal.
No publications or documents are linked to this record.
Start is estimated for Nov 2026; primary completion for Dec 2027, 13 months later.
Of 169 non-industry observational studies under Heart Arrest, half reached primary completion within 39 months of starting (the median), counting those still running; a quarter within 19 and three quarters within 90. This study's planned 13 months is below that.
Counting every sponsor, half of 176 studies reached it within 41 months; a quarter within 18 and three quarters within 90.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is not yet recruiting, as verified in Nov 2026. You cannot join it, but the record below documents what was studied.
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