Postoperative seizures occurred in 6.3% of 8332 elective brain tumor craniotomies.
Intraoperative MAP below 65 mmHg was linked to higher postoperative seizure risk.
Longer duration of MAP under 65 mmHg increased postoperative seizure risk.
Hypotension severity and duration showed dose–response relationships with seizures.
Intraoperative hypotension remained an independent risk factor after adjustment.
Background
Post-craniotomy seizures after brain tumor resection are common and associated with worse outcomes, yet the association with intraoperative hypotension remains unclear.
Methods
We conducted a retrospective cohort study of patients undergoing elective craniotomy for brain tumors at West China Hospital, Sichuan University, from January 1, 2018, to May 31, 2024. Intraoperative hypotension was assessed by nadir mean arterial pressure (MAP). MAP was analyzed as a continuous variable, dichotomized at 65 mmHg, categorized into six nadir groups (<50, 50–55, 55–60, 60–65, 65–70, ≥70 mmHg), and evaluated by cumulative duration of MAP <65 mmHg. The primary outcome was postoperative seizures.
Results
Among 8332 patients, 6563 (78.8%) had hypotension and 528 (6.3%) developed seizures. Each 1-SD decrease in MAP (12 mmHg) was associated with an increased seizure risk [aOR (adjusted odds ratio), 1.09; 95% CI, 1.02–1.14; P = .02]. Compared with no hypotension (MAP≥65 mmHg), intraoperative hypotension (MAP<65 mmHg) was associated with a higher risk of postoperative seizures (aOR, 1.29; 95% CI, 1.01–1.70; P = .04). A sensitivity analysis using the Youden index–derived cutoff (64 mmHg) demonstrated a consistent association (aOR, 1.34; 95% CI, 1.05–1.72; P = .02). A dose-response relationship was observed, with progressively higher seizure risk at lower MAP levels (P for trend <0.001). Longer durations of MAP <65 mmHg were associated with increased seizure risk (P for trend <0.001).
Conclusions
Intraoperative hypotension was independently associated with postoperative seizures after brain tumor resection. Moreover, both the severity and duration of hypotension showed dose-response relationships.