Impact of preoperative anemia on outcomes in patients undergoing elective cranial surgery

The objective of this study was to assess whether preoperative anemia in patients undergoing elective cranial surgery influences outcomes in the immediate perioperative period (≤ 30 days).The National Surgical Quality Improvement Program (NSQIP) was used to identify 6576 patients undergoing elective cranial surgery between 2006 and 2011. Propensity scores were used to match patients with moderate to severe anemia (moderate-severe) or mild anemia with patients without anemia. Logistic regression analysis was used to predict the outcomes of interest. Sensitivity analyses were used to limit the sample to patients without perioperative transfusion as well as those who underwent craniotomy for definitive resection of a malignant brain tumor.A total of 6576 patients underwent elective cranial surgery, of whom 175 had moderate-severe anemia and 1868 had mild anemia. Patients with moderate-severe (odds ratio 1.8, 95% CI 1.1-2.8) and mild (odds ratio 1.5, 95% CI 1.3-1.7) anemia were more likely to have prolonged length of stay (LOS) in the hospital compared to those with no anemia. Similarly, in patients who underwent craniotomy for a malignant tumor resection (n = 2537), anemia of any severity was associated with prolonged LOS, but not postoperative complications nor death.Anemia is not associated with an overall increased risk for adverse outcomes in patients undergoing elective cranial surgery. However, patients with anemia are more likely to experience prolonged hospitalization postoperatively, resulting in increased resource utilization.