Postoperative DeliriumNCT07249047
Association of Optic Nerve Sheath Diameter and Postoperative Delirium
A study testing Optic nerve sheath diameter (ONSD) ultrasound in people with Postoperative Delirium, run by London Health Sciences Centre Research Institute OR Lawson Research Institute of St. Joseph's.
Trial summary
Postoperative delirium is a sudden and reversible disturbance of mental function, occurring after surgery, characterized by confusion, inattention, and fluctuating mental status, which can manifest as agitation or lethargy. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Postoperative Delirium
- What is being tested?
- Optic nerve sheath diameter (ONSD) ultrasound
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 300 participants
- Where
- No sites listed yet
- Study dates
- 1 Feb 2026to 31 Dec 2027
- Phase
- Interventional
- 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
Who may be able to join
- A d u l t s ≥ 1 8 y e a r s .
- Scheduled for cardiac surgery requiring cardiopulmonary bypass (CPB) (e.g., Coronary artery bypass graft (CABG), valve, combined procedures, aortic surgery).
- Anticipated postoperative admission to the Cardiac ICU with expected stay >48 hours.
- Preoperative ability to undergo ocular ultrasound examination (closed-eyelid scanning).
- Provided informed consent to participate in this study.
Who cannot join
- Known or suspected open-globe injury, penetrating ocular trauma, or intraocular foreign body.
- Recent ocular surgery or intravitreal intervention within the past 6 weeks (if surgeon advises against periocular pressure).
- Ocular conditions that invalidate ONSD measurement (e.g., severe proptosis, advanced optic neuropathies, orbital tumors) or obstruct ultrasound window (extensive periocular dressings, severe periorbital edema).
- Known intracranial pathology expected to significantly alter baseline ONSD (e.g., large mass lesion with midline shift, obstructive hydrocephalus) or presence of external ventricular drain at baseline.
- Severe facial trauma or unstable cervical spine precluding safe positioning for ocular ultrasound.
- P r e g n a n c y .
Show all 9Show fewer
- Inability to perform serial ONSD assessments at scheduled timepoints (e.g., continuous prone positioning) despite reasonable accommodations.
- Enrollment in a conflicting interventional trial that mandates deviations from delirium assessment or ONSD protocol.
- Inability to communicate in the English language.
Trial locations and contacts
No sites are listed yet. Contact the study team or a site near you to ask about taking part.
About this study
Official title: Correlation Between Optic Nerve Sheath Diameter Measured by Ultrasound and Delirium in Cardiac Surgery
Postoperative delirium is a sudden and reversible disturbance of mental function, occurring after surgery, characterized by confusion, inattention, and fluctuating mental status, which can manifest as agitation or lethargy. It is a common post-operative complication, especially in older adults, and is associated with longer hospital stays and worse recovery outcomes. Validated delirium screening tools such as the Intensive Care Delirium Screening Checklist (ICDSC) and the Richmond Agitation and Sedation Scale (RASS) are widely used tools to assess delirium. However, the sensitivity of these screening tools can be variable when used in real-world practice and may miss early cases of delirium. The optic nerve sheath is a protective sheath that encloses part of the optic nerve that is located at the back of the eye. Measurement of the optic nerve sheath diameter is usually done using ultrasound to detect increased cranial pressure. Previous studies that have been conducted have shown that increased ONSD may be associated with occurrence of postoperative delirium. The purpose of this study is to determine if there is an association between optic nerve sheath diameter (ONSD) and the occurrence of delirium after surgery. This study will be conducted at the London Health Sciences Centre and will include 300 patients.
Read the detailed description
Delirium is one of the most frequent and serious complications after cardiac surgery, with reported incidence between 15-30% depending on patient population, procedure type, and diagnostic method. It is associated with prolonged ICU and hospital length of stay, increased risk of institutional discharge, higher readmission rates, long-term cognitive impairment, and mortality. Validated delirium screening tools such as the Confusion Assessment Method for the ICU (CAM-ICU) and the Intensive Care Delirium Screening Checklist (ICDSC) are widely used, but their sensitivity in real-world practice can be variable, sometimes missing early cases despite high specificity. This contributes to delayed recognition and potentially worse outcomes.
Ultrasound measurement of the optic nerve sheath diameter (ONSD) has emerged as a non-invasive surrogate marker for intracranial pressure (ICP). Several meta-analyses confirm good diagnostic accuracy of ONSD ultrasound compared to invasive ICP monitoring. Concordance studies also demonstrate strong agreement between ultrasound and MRI ONSD measurements, particularly when standardized measurement protocols are used (e.g., 3 mm posterior to the retina, bilateral averaging). These findings support the reliability of ONSD ultrasound as a bedside monitoring tool.
In critical care, early broadening of ONSD has been associated with delirium, coma, and death within 28 days. Importantly, the first cardiac surgery-specific study that prospectively examined patients undergoing open-heart surgery and found that increased peri-operative ONSD was independently associated with postoperative delirium. Their findings suggest that ONSD may serve not only as a marker of raised ICP but also as a predictive biomarker for delirium in the cardiac surgical population. Taken together, the burden of postoperative delirium in cardiac surgery, the limitations of current screening methods, and the growing evidence supporting ONSD as a surrogate of cerebral dynamics provide the rationale for this study. We hypothesize that perioperative or early ICU ONSD enlargement will be associated with the development of delirium, and that ONSD monitoring may help identify high-risk patients earlier, guiding preventive strategies.
Informed, written consent will be obtained prior to the start of surgery. The participant's surgical plan will not be altered in any way. Participants that are enrolled in this study will have their surgery proceed according to plan and will be placed under general anesthesia using standard of care practices. Cardiopulmonary bypass will be implemented in accordance with standard of care practices.
For the ONSD ultrasound, the ultrasound will be performed using a linear probe 7.5-13 MHz and will follow standard practice for this procedure. Patients will have closed eyelids covered with a Tegaderm adhesive for eye protection. Ultrasound gel will be applied to the patient's eyelids. The ultrasound probe will be gently placed on the patient's eyelids and to locate the optic nerve and measure ONSD. The ultrasound scan will be performed 3 mm posterior to retina with 4 measurements taken at each time point to allow for a mean result to be determined. Average time for each measurement is 1 minute. Each ultrasound will take 10-15 minutes to complete. This ONSD ultrasound will be performed at the following time points:
- Prior to the start of surgery
- At the start of cardiopulmonary bypass (CPB)
- At the end of cardiopulmonary bypass
- Admission to the ICU
- 1 hour after ICU admission
- 6 hours after ICU admission
- 24 hours after ICU admission
- Daily until hospital discharge for delirious patients or daily until discharge from the ICU for non-delirious patients.
Delirium will be assessed by administering the Intensive Care Delirium Screening Checklist (ICDSC) to patients twice daily until discharge from ICU. This ICDSC will be administered in person. The study team will also collect information such as the patient's age, biological sex, height, weight, medications, medical history, surgical details, results of preoperative and postoperative blood work, pain scores that are collected as part of standard of care practices, and details of their postoperative recovery.
- Conditions
- Postoperative Delirium
- Being tested
- Optic nerve sheath diameter (ONSD) ultrasound
- Keywords
- Post operative delirium, Optic nerve sheath diameter, Anesthesia
- Medical subject headings
- Emergence Delirium
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Optic nerve sheath diameter (ONSD) ultrasoundProcedure or surgery
Optic nerve sheath diameter (ONSD) ultrasound to be performed to measure diameter of the optic nerve sheath. Administration of the Intensive Care Delirium Screening Checklist (ICDSC) twice daily until discharge from the ICU.
| Study group | Role | What they receive |
|---|---|---|
| Optic nerve sheath diameter (ONSD) ultrasound | Experimental | Optic nerve sheath diameter (ONSD) ultrasound to be performed at the following time points:
1. Prior to the start of surgery
2. At the start of cardiopulmonary bypass (CPB)
3. At the end of cardiopulmonary bypass
4. Admission to the ICU
5. 1 hour after ICU admission
6. 6 hours after ICU admission
7. 24 hours after ICU admission
8. Daily until hospital discharge for delirious patients or daily until discharge from the ICU for non-delirious patients.
Delirium will be assessed by administering the Intensive Care Delirium Screening Checklist (ICDSC) to patients twice daily until discharge from ICU. Receives: Procedure: Optic nerve sheath diameter (ONSD) ultrasound |
What is being measured
The primary outcome is the main question the study is designed to answer.
Impact of optic nerve sheath diameter on postoperative delirium
This will be measured by comparing the diameter of the optic nerve sheath to the results of the Intensive Care Delirium Screening Checklist (ICDSC) that will be used to measure delirium in patients. The ICDSC will provide a score of 0-8 for patients. Scores of 4 or higher will be considered to be indicative of postoperative delirium.
Measured: Days 1-3 postoperatively
Secondary outcomes (4)
Impact of optic nerve sheath diameter on hospital length of stay
This will be measured by noting how long the patient is in hospital following surgery and comparing that to optic nerve sheath diameter.
Measured: Days 1-7 postoperatively
Impact of optic nerve sheath diameter on mortality
This will be measured by noting if a participant has died and comparing that to optic nerve sheath diameter.
Measured: Days 1-7 postoperatively
Impact of optic nerve sheath diameter on time spent on a ventilator
This will be measured by noting how long the patient is required to use a ventilator (if applicable) following surgery and comparing that to optic nerve sheath diameter.
Measured: Days 1-7 postoperatively
Impact of optic nerve sheath diameter on the need for re-intubation
This will be measured by noting if a participant requires re-intubation following surgery and comparing that to optic nerve sheath diameter.
Measured: Days 1-7 postoperatively
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted25 Nov 2025
- Study start1 Feb 2026 (estimated)
- Primary completion1 Dec 2027 (estimated)
- Study completion31 Dec 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (17)Papers the sponsor has linked to this study.
- Other trials for Postoperative DeliriumStudies of the same condition, open and under way.
- More trials run by London Health Sciences Centre Research Institute OR Lawson Research Institute of St. Joseph'sThe sponsor's other registered studies.
- 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
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Diagnosis
- Allocation
- Not applicable
- Intervention model
- Single group
- Model description
- Optic nerve sheath diameter (ONSD) ultrasound
- Masking
- None (open label)
- Enrolment
- 300 participants (estimated)
Sponsor and investigators
- Lead sponsor
- London Health Sciences Centre Research Institute OR Lawson Research Institute of St. Joseph's
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Mauricio Giraldo, London Health Sciences Centre Research Institute OR Lawson Research Institute of St. Joseph's
- Investigators
- Mauricio Giraldo, MD, Principal investigator, London Health Sciences Centre
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07249047
- Sponsor's protocol ID
- ONSD & Delirium
- Status last verified
- Dec 2025
- First submitted
- 17 Nov 2025
- Last updated
- 23 Dec 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Mattimore D, Fischl A, Christophides A, Cuenca J, Davidson S, Jin Z, Bergese S. Delirium after Cardiac Surgery-A Narrative Review. Brain Sci. 2023 Dec 7;13(12):1682. doi: 10.3390/brainsci13121682.
PubMed 38137130Koster S, Hensens AG, Schuurmans MJ, van der Palen J. Consequences of delirium after cardiac operations. Ann Thorac Surg. 2012 Mar;93(3):705-11. doi: 10.1016/j.athoracsur.2011.07.006. Epub 2011 Oct 10.
PubMed 21992939Mangusan RF, Hooper V, Denslow SA, Travis L. Outcomes associated with postoperative delirium after cardiac surgery. Am J Crit Care. 2015 Mar;24(2):156-63. doi: 10.4037/ajcc2015137.
PubMed 25727276Chen H, Mo L, Hu H, Ou Y, Luo J. Risk factors of postoperative delirium after cardiac surgery: a meta-analysis. J Cardiothorac Surg. 2021 Apr 26;16(1):113. doi: 10.1186/s13019-021-01496-w.
PubMed 33902644van Eijk MM, van den Boogaard M, van Marum RJ, Benner P, Eikelenboom P, Honing ML, van der Hoven B, Horn J, Izaks GJ, Kalf A, Karakus A, Klijn IA, Kuiper MA, de Leeuw FE, de Man T, van der Mast RC, Osse RJ, de Rooij SE, Spronk PE, van der Voort PH, van Gool WA, Slooter AJ. Routine use of the confusion assessment method for the intensive care unit: a multicenter study. Am J Respir Crit Care Med. 2011 Aug 1;184(3):340-4. doi: 10.1164/rccm.201101-0065OC. Epub 2011 May 11.
PubMed 21562131Devlin JW, Skrobik Y, Gelinas C, Needham DM, Slooter AJC, Pandharipande PP, Watson PL, Weinhouse GL, Nunnally ME, Rochwerg B, Balas MC, van den Boogaard M, Bosma KJ, Brummel NE, Chanques G, Denehy L, Drouot X, Fraser GL, Harris JE, Joffe AM, Kho ME, Kress JP, Lanphere JA, McKinley S, Neufeld KJ, Pisani MA, Payen JF, Pun BT, Puntillo KA, Riker RR, Robinson BRH, Shehabi Y, Szumita PM, Winkelman C, Centofanti JE, Price C, Nikayin S, Misak CJ, Flood PD, Kiedrowski K, Alhazzani W. Clinical Practice Guidelines for the Prevention and Management of Pain, Agitation/Sedation, Delirium, Immobility, and Sleep Disruption in Adult Patients in the ICU. Crit Care Med. 2018 Sep;46(9):e825-e873. doi: 10.1097/CCM.0000000000003299.
PubMed 30113379Robba C, Santori G, Czosnyka M, Corradi F, Bragazzi N, Padayachy L, Taccone FS, Citerio G. Optic nerve sheath diameter measured sonographically as non-invasive estimator of intracranial pressure: a systematic review and meta-analysis. Intensive Care Med. 2018 Aug;44(8):1284-1294. doi: 10.1007/s00134-018-5305-7. Epub 2018 Jul 17.
PubMed 30019201Dubourg J, Javouhey E, Geeraerts T, Messerer M, Kassai B. Ultrasonography of optic nerve sheath diameter for detection of raised intracranial pressure: a systematic review and meta-analysis. Intensive Care Med. 2011 Jul;37(7):1059-68. doi: 10.1007/s00134-011-2224-2. Epub 2011 Apr 20.
PubMed 21505900Shirodkar CG, Munta K, Rao SM, Mahesh MU. Correlation of measurement of optic nerve sheath diameter using ultrasound with magnetic resonance imaging. Indian J Crit Care Med. 2015 Aug;19(8):466-70. doi: 10.4103/0972-5229.162465.
PubMed 26321806Steinborn M, Fiegler J, Ruedisser K, Hapfelmeier A, Denne C, Macdonald E, Hahn H. Measurement of the Optic Nerve Sheath Diameter in Children: Comparison Between Transbulbar Sonography and Magnetic Resonance Imaging. Ultraschall Med. 2012 Dec;33(6):569-573. doi: 10.1055/s-0031-1273491. Epub 2011 Aug 25.
PubMed 21870318Zhi H, Cui X, Zhang F, Wang S, Liang X, Wang B, Cui J, Li Y. [Bedside ultrasound monitoring of optic nerve sheath diameter is a predictive factor for 28-day coma, delirium and death in etiologically diverse critically ill patients]. Zhonghua Wei Zhong Bing Ji Jiu Yi Xue. 2024 Oct;36(10):1088-1094. doi: 10.3760/cma.j.cn121430-20230511-00362. Chinese.
PubMed 39586729Kaynar A, Komurcu O, Bahsi E, Aydin AO, Karal IH, Akyurt D, Tulgar S, Suren M. Optic nerve sheath diameter is associated with postoperative delirium in patients undergoing open heart surgery. BMC Anesthesiol. 2025 Jul 1;25(1):309. doi: 10.1186/s12871-025-03194-9.
PubMed 40596877Mount CA, Das JM. Cerebral Perfusion Pressure. 2023 Apr 3. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2026 Jan-. Available from http://www.ncbi.nlm.nih.gov/books/NBK537271/
PubMed 30725956Peduzzi P, Concato J, Kemper E, Holford TR, Feinstein AR. A simulation study of the number of events per variable in logistic regression analysis. J Clin Epidemiol. 1996 Dec;49(12):1373-9. doi: 10.1016/s0895-4356(96)00236-3.
PubMed 8970487Vittinghoff E, McCulloch CE. Relaxing the rule of ten events per variable in logistic and Cox regression. Am J Epidemiol. 2007 Mar 15;165(6):710-8. doi: 10.1093/aje/kwk052. Epub 2006 Dec 20.
PubMed 17182981
Study at a glance
From the registry record, last updated by the sponsor on 23 Dec 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Correlation Between Optic Nerve Sheath Diameter Measured by Ultrasound and Delirium in Cardiac Surgery
- ClinicalTrials.gov ID
- NCT07249047
- Acronym / sponsor ID
- ONSD & Delirium
- Conditions
- Postoperative Delirium
- Keywords
- Post operative delirium, Optic nerve sheath diameter, Anesthesia
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 300 participants (estimated)
- Lead sponsor
- London Health Sciences Centre Research Institute OR Lawson Research Institute of St. Joseph'sUniversity, hospital or other
- Study start
- 1 Feb 2026 (estimated)
- Primary completion
- 1 Dec 2027 (estimated)
- Study completion
- 31 Dec 2027 (estimated)
- First posted
- 25 Nov 2025 (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.
Postoperative delirium is a sudden and reversible disturbance of mental function, occurring after surgery, characterized by confusion, inattention, and fluctuating mental status, which can manifest as agitation or lethargy. It is a common post-operative complication, especially in older adults, and is associated with longer hospital stays and worse recovery outcomes. Validated delirium screening tools such as the Intensive Care Delirium Screening Checklist (ICDSC) and the Richmond Agitation and Sedation Scale (RASS) are widely used tools to assess delirium. However, the sensitivity of these screening tools can be variable when used in real-world practice and may miss early cases of delirium. The optic nerve sheath is a protective sheath that encloses part of the optic nerve that is located at the back of the eye. Measurement of the optic nerve sheath diameter is usually done using ultrasound to detect increased cranial pressure. Previous studies that have been conducted have shown that increased ONSD may be associated with occurrence of postoperative delirium. The purpose of this study is to determine if there is an association between optic nerve sheath diameter (ONSD) and the occurrence of delirium after surgery. This study will be conducted at the London Health Sciences Centre and will include 300 patients.
Detailed description
Delirium is one of the most frequent and serious complications after cardiac surgery, with reported incidence between 15-30% depending on patient population, procedure type, and diagnostic method. It is associated with prolonged ICU and hospital length of stay, increased risk of institutional discharge, higher readmission rates, long-term cognitive impairment, and mortality. Validated delirium screening tools such as the Confusion Assessment Method for the ICU (CAM-ICU) and the Intensive Care Delirium Screening Checklist (ICDSC) are widely used, but their sensitivity in real-world practice can be variable, sometimes missing early cases despite high specificity. This contributes to delayed recognition and potentially worse outcomes.
Ultrasound measurement of the optic nerve sheath diameter (ONSD) has emerged as a non-invasive surrogate marker for intracranial pressure (ICP). Several meta-analyses confirm good diagnostic accuracy of ONSD ultrasound compared to invasive ICP monitoring. Concordance studies also demonstrate strong agreement between ultrasound and MRI ONSD measurements, particularly when standardized measurement protocols are used (e.g., 3 mm posterior to the retina, bilateral averaging). These findings support the reliability of ONSD ultrasound as a bedside monitoring tool.
In critical care, early broadening of ONSD has been associated with delirium, coma, and death within 28 days. Importantly, the first cardiac surgery-specific study that prospectively examined patients undergoing open-heart surgery and found that increased peri-operative ONSD was independently associated with postoperative delirium. Their findings suggest that ONSD may serve not only as a marker of raised ICP but also as a predictive biomarker for delirium in the cardiac surgical population. Taken together, the burden of postoperative delirium in cardiac surgery, the limitations of current screening methods, and the growing evidence supporting ONSD as a surrogate of cerebral dynamics provide the rationale for this study. We hypothesize that perioperative or early ICU ONSD enlargement will be associated with the development of delirium, and that ONSD monitoring may help identify high-risk patients earlier, guiding preventive strategies.
Informed, written consent will be obtained prior to the start of surgery. The participant's surgical plan will not be altered in any way. Participants that are enrolled in this study will have their surgery proceed according to plan and will be placed under general anesthesia using standard of care practices. Cardiopulmonary bypass will be implemented in accordance with standard of care practices.
For the ONSD ultrasound, the ultrasound will be performed using a linear probe 7.5-13 MHz and will follow standard practice for this procedure. Patients will have closed eyelids covered with a Tegaderm adhesive for eye protection. Ultrasound gel will be applied to the patient's eyelids. The ultrasound probe will be gently placed on the patient's eyelids and to locate the optic nerve and measure ONSD. The ultrasound scan will be performed 3 mm posterior to retina with 4 measurements taken at each time point to allow for a mean result to be determined. Average time for each measurement is 1 minute. Each ultrasound will take 10-15 minutes to complete. This ONSD ultrasound will be performed at the following time points:
- Prior to the start of surgery
- At the start of cardiopulmonary bypass (CPB)
- At the end of cardiopulmonary bypass
- Admission to the ICU
- 1 hour after ICU admission
- 6 hours after ICU admission
- 24 hours after ICU admission
- Daily until hospital discharge for delirious patients or daily until discharge from the ICU for non-delirious patients.
Delirium will be assessed by administering the Intensive Care Delirium Screening Checklist (ICDSC) to patients twice daily until discharge from ICU. This ICDSC will be administered in person. The study team will also collect information such as the patient's age, biological sex, height, weight, medications, medical history, surgical details, results of preoperative and postoperative blood work, pain scores that are collected as part of standard of care practices, and details of their postoperative recovery.
Study design
- Primary purpose
- Diagnosis
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
- Model description
- Optic nerve sheath diameter (ONSD) ultrasound
| Arm | Type | Receives |
|---|---|---|
| Optic nerve sheath diameter (ONSD) ultrasound | Experimental | Procedure: Optic nerve sheath diameter (ONSD) ultrasoundOptic nerve sheath diameter (ONSD) ultrasound to be performed at the following time points: 1. Prior to the start of surgery 2. At the start of cardiopulmonary bypass (CPB) 3. At the end of cardiopulmonary bypass 4. Admission to the ICU 5. 1 hour after ICU admission 6. 6 hours after ICU admission 7. 24 hours after ICU admission 8. Daily until hospital discharge for delirious patients or daily until discharge from the ICU for non-delirious patients. Delirium will be assessed by administering the Intensive Care Delirium Screening Checklist (ICDSC) to patients twice daily until discharge from ICU. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (5 listed)
- A d u l t s ≥ 1 8 y e a r s .
- Scheduled for cardiac surgery requiring cardiopulmonary bypass (CPB) (e.g., Coronary artery bypass graft (CABG), valve, combined procedures, aortic surgery).
- Anticipated postoperative admission to the Cardiac ICU with expected stay >48 hours.
- Preoperative ability to undergo ocular ultrasound examination (closed-eyelid scanning).
- Provided informed consent to participate in this study.
Key exclusion criteria (9 listed)
- Known or suspected open-globe injury, penetrating ocular trauma, or intraocular foreign body.
- Recent ocular surgery or intravitreal intervention within the past 6 weeks (if surgeon advises against periocular pressure).
- Ocular conditions that invalidate ONSD measurement (e.g., severe proptosis, advanced optic neuropathies, orbital tumors) or obstruct ultrasound window (extensive periocular dressings, severe periorbital edema).
- Known intracranial pathology expected to significantly alter baseline ONSD (e.g., large mass lesion with midline shift, obstructive hydrocephalus) or presence of external ventricular drain at baseline.
- Severe facial trauma or unstable cervical spine precluding safe positioning for ocular ultrasound.
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 (ONSD) ultrasoundOptic nerve sheath diameter (ONSD) ultrasound to be performed to measure diameter of the optic nerve sheath. Administration of the Intensive Care Delirium Screening Checklist (ICDSC) twice daily until discharge from the ICU. | Procedure or surgery | Optic nerve sheath diameter (ONSD) ultrasound |
Primary outcome
Impact of optic nerve sheath diameter on postoperative delirium
Time frame: Days 1-3 postoperatively
This will be measured by comparing the diameter of the optic nerve sheath to the results of the Intensive Care Delirium Screening Checklist (ICDSC) that will be used to measure delirium in patients. The ICDSC will provide a score of 0-8 for patients. Scores of 4 or higher will be considered to be indicative of postoperative delirium.
4 secondary outcomes
Impact of optic nerve sheath diameter on hospital length of stay
Time frame: Days 1-7 postoperatively
Impact of optic nerve sheath diameter on mortality
Time frame: Days 1-7 postoperatively
Impact of optic nerve sheath diameter on time spent on a ventilator
Time frame: Days 1-7 postoperatively
Impact of optic nerve sheath diameter on the need for re-intubation
Time frame: Days 1-7 postoperatively
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 23 Dec 2025.
- Background: PubMed 38137130Mattimore D, Fischl A, Christophides A, Cuenca J, Davidson S, Jin Z, Bergese S. Delirium after Cardiac Surgery-A Narrative Review. Brain Sci. 2023 Dec 7;13(12):1682. doi: 10.3390/brainsci13121682.
- Background: PubMed 21992939Koster S, Hensens AG, Schuurmans MJ, van der Palen J. Consequences of delirium after cardiac operations. Ann Thorac Surg. 2012 Mar;93(3):705-11. doi: 10.1016/j.athoracsur.2011.07.006. Epub 2011 Oct 10.
- Background: PubMed 25727276Mangusan RF, Hooper V, Denslow SA, Travis L. Outcomes associated with postoperative delirium after cardiac surgery. Am J Crit Care. 2015 Mar;24(2):156-63. doi: 10.4037/ajcc2015137.
- Background: PubMed 33902644Chen H, Mo L, Hu H, Ou Y, Luo J. Risk factors of postoperative delirium after cardiac surgery: a meta-analysis. J Cardiothorac Surg. 2021 Apr 26;16(1):113. doi: 10.1186/s13019-021-01496-w.
- Background: PubMed 21562131van Eijk MM, van den Boogaard M, van Marum RJ, Benner P, Eikelenboom P, Honing ML, van der Hoven B, Horn J, Izaks GJ, Kalf A, Karakus A, Klijn IA, Kuiper MA, de Leeuw FE, de Man T, van der Mast RC, Osse RJ, de Rooij SE, Spronk PE, van der Voort PH, van Gool WA, Slooter AJ. Routine use of the confusion assessment method for the intensive care unit: a multicenter study. Am J Respir Crit Care Med. 2011 Aug 1;184(3):340-4. doi: 10.1164/rccm.201101-0065OC. Epub 2011 May 11.
- Background: PubMed 30113379Devlin JW, Skrobik Y, Gelinas C, Needham DM, Slooter AJC, Pandharipande PP, Watson PL, Weinhouse GL, Nunnally ME, Rochwerg B, Balas MC, van den Boogaard M, Bosma KJ, Brummel NE, Chanques G, Denehy L, Drouot X, Fraser GL, Harris JE, Joffe AM, Kho ME, Kress JP, Lanphere JA, McKinley S, Neufeld KJ, Pisani MA, Payen JF, Pun BT, Puntillo KA, Riker RR, Robinson BRH, Shehabi Y, Szumita PM, Winkelman C, Centofanti JE, Price C, Nikayin S, Misak CJ, Flood PD, Kiedrowski K, Alhazzani W. Clinical Practice Guidelines for the Prevention and Management of Pain, Agitation/Sedation, Delirium, Immobility, and Sleep Disruption in Adult Patients in the ICU. Crit Care Med. 2018 Sep;46(9):e825-e873. doi: 10.1097/CCM.0000000000003299.
- Background: PubMed 30019201Robba C, Santori G, Czosnyka M, Corradi F, Bragazzi N, Padayachy L, Taccone FS, Citerio G. Optic nerve sheath diameter measured sonographically as non-invasive estimator of intracranial pressure: a systematic review and meta-analysis. Intensive Care Med. 2018 Aug;44(8):1284-1294. doi: 10.1007/s00134-018-5305-7. Epub 2018 Jul 17.
- Background: PubMed 21505900Dubourg J, Javouhey E, Geeraerts T, Messerer M, Kassai B. Ultrasonography of optic nerve sheath diameter for detection of raised intracranial pressure: a systematic review and meta-analysis. Intensive Care Med. 2011 Jul;37(7):1059-68. doi: 10.1007/s00134-011-2224-2. Epub 2011 Apr 20.
- Background: PubMed 26321806Shirodkar CG, Munta K, Rao SM, Mahesh MU. Correlation of measurement of optic nerve sheath diameter using ultrasound with magnetic resonance imaging. Indian J Crit Care Med. 2015 Aug;19(8):466-70. doi: 10.4103/0972-5229.162465.
- Background: PubMed 21870318Steinborn M, Fiegler J, Ruedisser K, Hapfelmeier A, Denne C, Macdonald E, Hahn H. Measurement of the Optic Nerve Sheath Diameter in Children: Comparison Between Transbulbar Sonography and Magnetic Resonance Imaging. Ultraschall Med. 2012 Dec;33(6):569-573. doi: 10.1055/s-0031-1273491. Epub 2011 Aug 25.
- Background: PubMed 39586729Zhi H, Cui X, Zhang F, Wang S, Liang X, Wang B, Cui J, Li Y. [Bedside ultrasound monitoring of optic nerve sheath diameter is a predictive factor for 28-day coma, delirium and death in etiologically diverse critically ill patients]. Zhonghua Wei Zhong Bing Ji Jiu Yi Xue. 2024 Oct;36(10):1088-1094. doi: 10.3760/cma.j.cn121430-20230511-00362. Chinese.
- Background: PubMed 40596877Kaynar A, Komurcu O, Bahsi E, Aydin AO, Karal IH, Akyurt D, Tulgar S, Suren M. Optic nerve sheath diameter is associated with postoperative delirium in patients undergoing open heart surgery. BMC Anesthesiol. 2025 Jul 1;25(1):309. doi: 10.1186/s12871-025-03194-9.
- 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.
Mauricio Giraldo, MD principal investigator
London Health Sciences Centre
Questions about this trial
What is this clinical trial studying?
A study testing Optic nerve sheath diameter (ONSD) ultrasound in people with Postoperative Delirium, run by London Health Sciences Centre Research Institute OR Lawson Research Institute of St. Joseph's.
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 5 inclusion and 9 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: opening soon, as of the sponsor's last update on 23 Dec 2025. Status can change between updates, so confirm with the study contact before making plans.
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?
Contact Mauricio Giraldo, MD (5196858500 ext. 19873, mauricio.giraldo@lhsc.on.ca), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Impact of optic nerve sheath diameter on postoperative delirium (time frame: Days 1-3 postoperatively). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07249047, which also lists 17 linked publications.
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 23 Dec 2025.