Preoperative prescription opioid use as an independent predictor of 90-day mortality and adverse events in craniotomy and craniectomy patients.

Objective: A growing body of literature suggests that preoperative opioid exposure is an independent predictor of poor outcomes in surgical patients. No outcomes data exist on preoperative opioid use and craniotomies/craniectomies. The objective of this study was to determine the impact of preoperative opioid use on 90-day adverse events after craniotomy or craniectomy.
Methods: A single-center retrospective cohort study of 2445 patients undergoing a craniotomy/craniectomy between January 1, 2013, and October 1, 2018, was conducted. Baseline demographics, pre- and postoperative opioid use (morphine milligram equivalents [MMEs]), and surgical metrics were recorded. Patients were categorized based on whether they took prescription opioids preoperatively, defined as within 1 month of surgery, or were opioid naive. The outcomes were mortality and adverse events 90 days after craniotomy/craniectomy.
Results: Overall, 26.6% of patients composed the preoperative opioid group. The median daily MME intake among this group was 34.6 (IQR 14.1-90) MMEs. Lower employment rates (p < 0.001), uninsured status (p = 0.016), and intravenous drug use (p = 0.006) were associated with preoperative opioid use. Preoperative opioid use was associated with increased venous thromboembolism (p = 0.001), acute kidney injury (p = 0.002), acute respiratory failure (p < 0.001), myocardial infarction (p = 0.002), delirium (p < 0.001), and infection (p < 0.001). Preoperative opioid use was an independent predictor of overall 90-day adverse events (OR 1.643, 95% CI 1.289-2.095; p < 0.001) and 90-day mortality (OR 1.690, 95% CI 1.254-2.277; p < 0.001).
Conclusions: Preoperative opioid use was independently associated with 90-day postoperative adverse events and mortality. Opioid use increases vulnerability in craniotomy/craniectomy patients and necessitates close monitoring to improve outcomes.