Opiate utilization and predictive factors in patients undergoing surgery for gliomas

Abstract INTRODUCTION Opiate dependence is a national crisis. The use of opiate in patients diagnosed with gliomas undergoing surgery is not well understood. OBJECTIVE The objective of this study was to evaluate opiate use in patients undergoing surgery for gliomas and risk factors for prolonged opiate use. METHODS A retrospective chart review was conducted on patients ≥ 18 years who underwent surgery for glioma from 1/2016 to 1/2020. Clinical data was collected and opiate dose was calculated as morphine equivalent dose (MED). Clinical data prior to surgery, during surgery, and post-operative setting were collected. Descriptive statistics (means, frequencies, and percentages) were used to characterize the study population. Chi-square, with Fisher’s exact test, was used to determine associations for categorical variables. Linear and negative binomial regression models were used to predict MED doses with patient characteristics. RESULTS 180 patients were included in the analysis. The median MED at the time of surgery was 23.5 (IQR: 1.6, 72.5). 57 patients (46.04%) continued to take opiates after surgery. During adjuvant treatment the median MED was 45 (IQR: 45- 45) and the median length patients remaining on opiates was 59 days (IQR: 33- 168.5), with the longest usage being 1459 days. History of substance use, chronic headaches and other pain syndromes were not associated with increased use of opiates at the time of surgery. However, these factors were associated with higher morphine use after surgery. Male had a slightly higher dose (< 0.001) at the time of surgery compared to women. Peri-operative use at the time of surgery did not predict the MED and length of opiate use as outpatient. CONCLUSION Nearly half of the patients continued to use opiate beyond the peri-operative setting as outpatient at a higher median MED on median period of 59 days suggesting opportunities for improvement in opiate management post operatively.