ONSD Trajectory in Rebound ICH (ONSD/ INH)

Optic Nerve Sheath Diameter Trajectory During Osmotherapy Weaning as a Predictor of Rebound Intracranial Hypertension in Traumatic Brain Injury

The goal of this prospective observational study is to determine whether the trajectory of optic nerve sheath diameter (ONSD) after osmotherapy weaning can predict rebound intracranial hypertension in adult patients with traumatic brain injury requiring osmotherapy for elevated intracranial pressure. The main questions it aims to answer are:

Does the trajectory of ONSD during osmotherapy weaning predict the development of rebound intracranial hypertension? What is the diagnostic accuracy of serial ONSD measurements for the early detection of rebound intracranial hypertension? Researchers will compare patients who develop rebound intracranial hypertension with those who do not to determine whether changes in ONSD trajectory differ significantly between the two groups.

Participants will:

Undergo serial bedside ocular ultrasound examinations for ONSD measurement at predefined time points after osmotherapy weaning.

Receive standard clinical management for traumatic brain injury according to institutional protocols; no additional therapeutic intervention will be administered.

Undergo routine neurological assessments, laboratory investigations, and neuroimaging as clinically indicated.

Be followed for the occurrence of rebound intracranial hypertension and relevant clinical outcomes during their ICU stay

Study Overview

• Status: Not yet recruiting
• Conditions: Traumatic Brain Injury; Cerebral Edema; Rebound Intracranial Hypertension
• Intervention / Treatment: Diagnostic test: Optic Nerve Sheath Diameter Ultrasonography

Detailed Description

Traumatic brain injury (TBI) is a major cause of morbidity and mortality worldwide. Cerebral edema and elevated intracranial pressure (ICP) are common secondary complications that require prompt management to prevent further neurological injury. Osmotherapy with hypertonic saline or mannitol is routinely used to reduce ICP; however, withdrawal or weaning of osmotherapy may be associated with rebound intracranial hypertension, which can worsen neurological outcomes if not recognized early.

Optic nerve sheath diameter (ONSD), measured by bedside ocular ultrasonography, is a non-invasive surrogate marker of raised intracranial pressure. Although ONSD has been shown to correlate with ICP in several clinical settings, the predictive value of serial ONSD measurements during osmotherapy weaning for identifying rebound intracranial hypertension has not been adequately investigated.

• Study Type: Observational
• Enrollment (Estimated): 100

Contacts and Locations

• Study Contact: Name: Mostafa Mohamed Sakr, Critical care MSC; Phone Number: +201069610038 +201002338765; Email: sasasakr6@gmail.com

Study Locations

• Egypt
  • Qalyobia
    • Banhā, Qalyobia, Egypt
      • Benha university hospital
      • Contact: Mostafa M Abdelgwad, MSC; Phone Number: +201002338765; Email: sasasakr6@gmail.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Adult patients with traumatic brain injury admitted to the intensive care unit who require osmotherapy for cerebral edema management. Eligible patients will undergo serial optic nerve sheath diameter measurements and computed tomography evaluation according to the study protocol.

Description

Inclusion Criteria:

• Adults (≥18 years) with blunt traumatic brain injury admission GCS ≤12
• (or GCS 13-15 with CT signs of elevated ICP including midline shift ≥5 mm, effaced cisterns, or significant cerebral edema)
• clinical decision to initiate 20% mannitol osmotherapy

Exclusion Criteria:

• Ocular conditions precluding ONSD measurement (glaucoma, prior ocular surgery,
• globe or optic nerve trauma,
• periorbital edema, orbital masses, optic nerve sheath cysts);
• planned decompressive surgery or evacuation of mass lesion within 48 hours; limitation of life-sustaining therapy; pregnancy; contraindications to mannitol (baseline sodium >155 mEq/L, osmolality >320 mOsm/kg, eGFR <30 mL/min); penetrating TBI; or concurrent spinal cord injury with shock.

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

Intervention / Treatment

Traumatic Brain Injury Patients Undergoing Osmotherapy Weaning; Adult patients with traumatic brain injury receiving osmotherapy for intracranial hypertension who undergo protocol-defined osmotherapy weaning. Participants will undergo serial optic nerve sheath diameter (ONSD) measurements before and after osmotherapy reduction or discontinuation and will be followed prospectively for the development of rebound intracranial hypertension and related clinical outcomes.

Diagnostic test: Optic Nerve Sheath Diameter Ultrasonography; Serial ultrasonographic measurement of optic nerve sheath diameter (ONSD) will be performed bilaterally using a standardized transorbital ultrasound technique immediately before osmotherapy reduction or discontinuation (baseline) and at 4, 6, 12, and 24 hours after weaning. Additional measurements may be obtained if clinical deterioration suggestive of rebound intracranial hypertension occurs. ONSD measurements are performed for observational purposes only and will not influence routine clinical management.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Prediction of rebound intracranial hypertension using serial ONSD measurements	Within 24 hours after osmotherapy reduction or discontinuation

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Mortality	Death from any cause occurring during the patient's ICU stay following traumatic brain injury and during the study observation period.	From ICU admission until ICU discharge or death, assessed for up to 28 days.
2. Length of ICU Stay:	The total duration of ICU admission measured in days from ICU admission until ICU discharge or death.	From ICU admission until ICU discharge or death, assessed for up to 28 days.
Need for rescue ICP therapy:	Requirement for additional ICP-lowering interventions beyond restarting osmotherapy due to suspected or confirmed rebound intracranial hypertension. Rescue therapies include: (a) barbiturate infusion (thiopental or pentobarbital), (b) therapeutic hypothermia (target temperature ≤35°C), or (c) controlled hyperventilation (PaCO₂ <30 mmH	Within 48 hours after osmotherapy weaning.
Glasgow Coma Scale trajectory post-weaning	Neurological status assessed using the Glasgow Coma Scale (GCS). The GCS total score ranges from 3 to 15, with higher scores indicating better neurological function. A decrease of ≥2 points from the baseline GCS score after osmotherapy discontinuation is considered neurological deterioration suggestive of rebound intracranial hypertension.	Measured at baseline (immediately before osmotherapy weaning), then at 4, 6, 12, and 24 hours after weaning (aligned with ONSD measurement time points). The primary analysis will use change in GCS from baseline to 24 hours as a continuous variable.
Time to rebound intracranial hypertension	The interval (in hours) from complete osmotherapy discontinuation (T0) to the first documented episode of rebound intracranial hypertension. Rebound is identified by either: (a) decline in GCS of ≥2 points from baseline not attributable to other causes, or (b) worsening on brain imaging showing increased cerebral edema or mass effect.	Assessed continuously during the first 48 hours after osmotherapy weaning. For patients who do not develop rebound, time will be censored at 48 hours.

Collaborators and Investigators

• Sponsor: Benha University

Study record dates

Study Major Dates

• Study Start (Estimated): September 1, 2026
• Primary Completion (Estimated): September 1, 2027
• Study Completion (Estimated): October 1, 2027

Study Registration Dates

• First Submitted: July 10, 2026
• First Submitted That Met QC Criteria: July 19, 2026
• First Posted (Actual): July 23, 2026

Study Record Updates

• Last Update Posted (Actual): July 23, 2026
• Last Update Submitted That Met QC Criteria: July 19, 2026
• Last Verified: July 1, 2026

More Information

Terms related to this study

• Keywords: Osmotherapy; Cerebral edema; ONSD; Rebound ICH
• Additional Relevant MeSH Terms: Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Wounds and Injuries; Craniocerebral Trauma; Trauma, Nervous System; Brain Injuries; Brain Injuries, Traumatic; Brain Edema
• Other Study ID Numbers: MD_6.5.2026

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No