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.