Intraosseous access in neurological emergencies: a critical narrative review and research framework.

Timely vascular access is critical in neurological emergencies, where delays in treatment may worsen secondary brain injury and functional outcomes. Intraosseous access offers a rapid alternative when intravenous cannulation is difficult, delayed, or unsuccessful, but its role in neurocritical care remains incompletely defined. PubMed, ScienceDirect, and Scopus were searched from inception through August 2025, with a targeted evidence update through 10 September 2026. This critical narrative review examines the feasibility, pharmacologic considerations, safety, evidence quality, and research gaps surrounding intraosseous access across acute ischemic and hemorrhagic stroke, status epilepticus, traumatic brain injury, neurological infections, metabolic encephalopathy, pediatric neurological emergencies, and cardiac arrest as an indirect neurologic outcome model. Available evidence supports intraosseous access as a technically feasible emergency route in selected scenarios, particularly when vascular access delay may postpone time-sensitive therapy. However, most data are derived from case reports, animal pharmacokinetic studies, heterogeneous emergency cohorts, or extrapolation from resuscitation and trauma literature. Direct evidence demonstrating improved neurologic outcomes remains very limited and varies substantially by condition. Intravenous access should remain preferred when rapidly obtainable, while intraosseous access should be viewed as a temporary rescue bridge rather than a routine early intervention. Prospective condition-specific studies are needed to evaluate drug delivery, timing, insertion site, complications, workflow integration, and meaningful neurologic outcomes before neuro-focused intraosseous protocols can be broadly recommended.