Perioperative Albumin Administration and Mortality After Craniotomy: A Nationwide Cohort Study

Background/Objectives: Albumin is commonly given during craniotomy to support intravascular volume and limit cerebral oedema, but randomised data in traumatic brain injury have suggested harm. Its association with survival after craniotomy is unknown. Methods: Using Korean National Health Insurance Service claims, we identified adults who underwent craniotomy in 2022–2023. Exposure was albumin prescription on the day of surgery, and the primary endpoint was 30-day mortality. We used propensity score overlap weighting with hospital fixed effects. Results: Of 25,097 patients, 3168 (12.6%) received albumin. In the overlap-weighted cohort, albumin was associated with higher 30-day mortality (6.6% vs. 3.8%; odds ratio [OR] 1.81, 95% confidence interval [CI] 1.44–2.29; absolute difference 2.9 percentage points, 95% CI 0.9–4.8) and in-hospital mortality (OR 1.96, 95% CI 1.53–2.52). The association was observed for intracranial neoplasm, cerebrovascular disease and traumatic brain injury. Albumin dose was not associated with mortality (OR per 10 g 0.99, 95% CI 0.96–1.01). Conclusions: Perioperative albumin was associated with higher mortality after craniotomy, without a dose–response relationship. Residual confounding by indication and a direct adverse effect could not be distinguished. These findings should not change practice or be cited as evidence of harm, but they provide no support for routine albumin use.