Comparison of propofol and propofol-ketamine anesthesia on optic nerve sheath diameter in endovascular cerebral aneurysm procedures: a prospective randomized study.
Şahin E, Gökbulut Özaslan N, Erdem G, Özkaya G • BMC anesthesiology • 2026
Propofol and propofol-ketamine anesthesia showed comparable ONSD trajectories over time in patients undergoing elective endovascular treatment of unruptured intracranial aneurysms, while the propofol-ketamine regimen was associated with reduced propofol consumption and differential perioperative hemodynamic and cerebral oxygenation profiles.
Key Findings
Results
The temporal trajectory of optic nerve sheath diameter (ONSD) did not differ significantly between the propofol and propofol-ketamine groups.
40 adults were randomized to a propofol group (P, n=20) or a propofol-ketamine group (KP, n=20)
Primary outcome was analyzed using a linear mixed-effects model including group, time, and group × time interaction
The group × time interaction for mean ONSD was not statistically significant
The main effect of group was also not significant, whereas the main effect of time was significant
Standardized anesthetic protocols and ventilation targeting normocapnia were used in both groups
Results
Total propofol consumption was significantly lower in the propofol-ketamine (KP) group compared to the propofol-only group.
The study was a prospective, randomized, single-center, observer-blinded trial
Remifentanil use showed a non-significant trend toward reduction in the KP group
Baseline demographic and clinical characteristics were comparable between groups
The reduction in propofol consumption is consistent with the known opioid- and anesthetic-sparing properties of ketamine as an adjunct
Results
Exploratory analyses revealed significant group × time interactions for selected hemodynamic, ventilation-related, anesthetic depth, and cerebral oxygenation parameters.
Significant group × time interactions were found for diastolic blood pressure (DBP), mean arterial pressure (MAP), end-tidal CO2 (EtCO2), bispectral index (BIS), and mean regional cerebral oxygen saturation (rSO2)
Heart rate and SpO2 trajectories were comparable between groups and did not show significant group × time interactions
These secondary outcomes were analyzed using exploratory mixed-effects models
The authors note these are exploratory findings and should be interpreted with caution given the small sample size
Methods
The study was conducted in patients undergoing elective endovascular treatment of unruptured intracranial aneurysms, a population requiring careful management of intracranial pressure and cerebral perfusion.
ONSD measured by ultrasonography was used as a noninvasive surrogate marker of intracranial pressure (ICP)
ONSD, rSO2, BIS, and hemodynamic variables were recorded at predefined perioperative time points
The study was a single-center trial with a total of 40 participants
All procedures were elective and involved unruptured intracranial aneurysms treated endovascularly
Conclusions
The authors concluded that larger neurosurgical trials are required before firm conclusions regarding safety and clinical feasibility of propofol-ketamine anesthesia in this setting can be drawn.
The study was not powered to evaluate safety outcomes or rare adverse events
The propofol-ketamine regimen showed exploratory evidence of differential perioperative hemodynamic and cerebral oxygenation profiles
The study was retrospectively registered at ClinicalTrials.gov (identifier NCT07542015) on April 14, 2026
The small cohort size is explicitly acknowledged as a limitation precluding firm conclusions
What This Means
This research suggests that using a combination of propofol and ketamine for anesthesia during minimally invasive brain aneurysm repair does not cause greater increases in pressure around the brain compared to using propofol alone. The researchers measured the width of the optic nerve sheath — a structure that swells when pressure inside the skull rises — using ultrasound in 40 patients. Both groups showed similar patterns of change in this measurement over the course of the procedure, suggesting neither anesthetic approach is more likely than the other to raise intracranial pressure in this context.
However, the study did find that patients who received the propofol-ketamine combination needed significantly less propofol overall, and there were some differences between groups in blood pressure, carbon dioxide levels, depth of anesthesia, and brain oxygen levels over time. These differences suggest the two approaches produce somewhat different physiological profiles during surgery, even if the end effect on the optic nerve sheath measurement was similar. Ketamine's ability to reduce the amount of other anesthetic drugs needed is a potentially useful property in neurosurgical settings.
This research suggests that propofol-ketamine anesthesia may be a viable alternative to propofol alone for these procedures, but the study involved only 40 patients at a single center and was not designed to detect rare complications or safety differences. The authors emphasize that much larger studies are needed before any strong recommendations about the safety or clinical advantages of this combined approach can be made for patients undergoing brain aneurysm treatment.
Şahin E, Gökbulut Özaslan N, Erdem G, Özkaya G. (2026). Comparison of propofol and propofol-ketamine anesthesia on optic nerve sheath diameter in endovascular cerebral aneurysm procedures: a prospective randomized study.. BMC anesthesiology. https://doi.org/10.1186/s12871-026-04158-3