Association between elevated preoperative red cell distribution width and mortality after brain tumor craniotomy

Background: Red cell distribution width (RDW) has been recognized as a potential inflammatory biomarker, with elevated levels associated with adverse outcomes in various diseases. However, its role in predicting outcomes after brain tumor craniotomy remains unclear. We aimed to assess whether preoperative RDW influences mortality and postoperative complications in patients undergoing brain tumor craniotomy. Methods: This retrospective cohort study analyzed serum RDW levels in patients undergoing brain tumor craniotomy at West China Hospital. RDW was evaluated in two forms: RDW-CV and RDW-SD, and was categorized into four quartiles for analysis by using logistic regression and multivariate analysis to adjust for confounding. Results: The study encompassed 10,978 patients undergoing brain tumor craniotomy. our analysis revealed no significant difference in 30-day mortality across various RDW-CV levels. However, we observed a dose-response relationship with preoperative RDW-CV levels in assessing long-term mortality risks. Specifically, patients with RDW-CV levels of 12.6-13.2% (HR 1.04, 95% CI 1.01-1.18), 13.2-13.9% (HR 1.12, 95% CI 1.04-1.26), and > 13.9% (HR 1.34, 95% CI 1.18-1.51) exhibited a significantly higher hazard of long-term mortality compared to those with RDW-CV < 12.6%. When preoperative RDW-CV was analyzed as a continuous variable, for each 10% increase in RDW-CV, the adjusted OR of long-term mortality was 1.09 (95% CI 1.05-1.13). we also observed significant associations between preoperative higher RDW-CV levels and certain postoperative complications including acute kidney injury (OR 1.46, 95% CI: 1.10-1.94), pneumonia infection (OR 1.19 95% CI: 1.05-1.36), myocardial infarction (OR 1.32, 95% CI: 1.05-1.66), readmission (OR 1.15, 95% CI: 1.01-1.30), and a prolonged length of hospital stay (OR 1.11, 95% CI: 1.02-1.21). For RDW-SD levels, there was no significant correlation for short-term mortality, long-term mortality, and postoperative complications. Conclusions: Our study showed elevated preoperative RDW-CV is significantly associated with increased long-term mortality and multiple postoperative complications, but no such association is observed with RDW-SD. These findings show the prognostic importance of RDW-CV, reinforcing its potential as a valuable tool for risk stratification in the preoperative evaluation of brain tumor craniotomy patients.