Association of Optic Nerve Sheath Diameter and Postoperative Delirium
NCT ID: NCT07249047
Last Updated: 2025-12-23
Study Results
The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.
Basic Information
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NOT_YET_RECRUITING
NA
300 participants
INTERVENTIONAL
2026-02-01
2027-12-31
Brief Summary
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Detailed Description
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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:
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. 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
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Keywords
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Study Design
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NA
SINGLE_GROUP
DIAGNOSTIC
NONE
Study Groups
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Optic nerve sheath diameter (ONSD) ultrasound
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.
Optic nerve sheath diameter (ONSD) ultrasound
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.
Interventions
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Optic nerve sheath diameter (ONSD) ultrasound
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.
Eligibility Criteria
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Inclusion Criteria
* 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.
Exclusion Criteria
* 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 .
* 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.
18 Years
ALL
No
Sponsors
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London Health Sciences Centre Research Institute OR Lawson Research Institute of St. Joseph's
OTHER
Responsible Party
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Mauricio Giraldo
Anesthesiologist, Assistant Professor
Principal Investigators
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Mauricio Giraldo, MD
Role: PRINCIPAL_INVESTIGATOR
London Health Sciences Centre
Central Contacts
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References
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Chen 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.
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.
Koster 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.
Mangusan 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.
van 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.
Devlin 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.
Robba 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.
Dubourg 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.
Shirodkar 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.
Steinborn 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.
Zhi 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.
Kaynar 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.
Mount CA, Das JM. Cerebral Perfusion Pressure. 2023 Apr 3. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from http://www.ncbi.nlm.nih.gov/books/NBK537271/
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Yang H, Zhang L, Huang P, Luo Y. [Investigation of intracranial pressure in intensive care unit patients with delirium assessed by bedside ultrasound]. Zhonghua Wei Zhong Bing Ji Jiu Yi Xue. 2022 Jun;34(6):635-639. doi: 10.3760/cma.j.cn121430-20220523-00504. Chinese.
Mowafy SMS, Bauiomy H, Kohaf NA, Abd Ellatif SE. The Role of Ultrasonographic Assessment of Optic Nerve Sheath Diameter in Prediction of Sepsis-Associated Encephalopathy: Prospective Observational Study. Neurocrit Care. 2025 Aug;43(1):308-317. doi: 10.1007/s12028-024-02187-9. Epub 2025 Jan 15.
Other Identifiers
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ONSD & Delirium
Identifier Type: -
Identifier Source: org_study_id