Opiate Use Patterns Following Surgery for High Grade Glioma.

Introduction: Opiate drugs are commonly prescribed for postoperative pain relief following craniotomy. The aim of this study was to assess opiate use in patients undergoing craniotomy for high-grade glioma and to identify risk factors contributing to prolonged opiate use.

Methods: A retrospective chart review was conducted on adult patients undergoing craniotomy for high-grade glioma between January 2016 and January 2020. Medical records were assessed for history of pain syndrome, and alcohol, nicotine, and other substance use. Opiate length of utilization and dose measured by morphine equivalent dose (MED) was collected. Statistical analyses were conducted using R Statistical Software (v4.1.2; R Core Team 2021).

Results: A total of 295 patients met inclusion criteria, with 26.4% undergoing biopsy and 73.6% undergoing craniotomy for resection. The average immediate postoperative MED/day was 20.3 (SD 21.5) and average duration of outpatient opiate use was 15.1 days (SD 63.1 days). Male sex and history of tobacco use were associated with increased MED/day in the postoperative period. A stratified analysis showed that, for patients undergoing craniotomy, MED/day was significantly increased with male sex and history of tobacco use. For patients undergoing biopsy, MED/day was significantly increased with history of other substance use. History of pain syndrome significantly increased the odds of opiate prescription renewal. Age significantly reduced the odds of opiate prescription renewal.

Conclusions: Postoperative opiate use in this cohort is modest. Increased opiate use is associated with comorbidities known to modulate pain perception. Prospective studies should be conducted to provide more robust data.