What Perioperative Factors Are Associated with High-risk Daily Morphine Milligram Equivalent Totals in Spinal Decompressions?

Introduction: Current general Morphine Milligram Equivalent (MME) recommendations endorse the lowest effective dose of ≤ 50 MME/day. We sought to understand how many patients undergoing decompressive surgery received opioids at higher risk doses and which patient demographic and historical factors could predict this higher risk.

Methods: Retrospective analysis was conducted on 85 patients that underwent spinal decompressive surgery within a multi-center network over 2 years.

Results: Overall mean MME per day was 56.1 ± 41. “High MME” was defined as greater than the overall upper quartile value, 75.03 MME/day. A total of 21 patients were determined to have “High MME” during their inpatient stay. Patients with high MMEs were significantly younger (mean age 50.9 ± 17.5) than those with lower MMEs/day (69.2 ± 12.2). Patients with high MMEs were also significantly more likely to carry a psychiatric diagnosis (43.8% vs 13.2%). Patients who had high MMEs had lower ASA scores (2.4 ± 0.5 vs 2.7 ± 0.6) and reported higher pain scores (4.6 ± 2.8 vs 2.6 ± 3.4) than patients with lower MMEs/day. There were no significant demographic or intraoperative factors between the two groups, nor any significant difference in LOS. The final model identified for each unit decrease in age grouping increased the risk of high MME 0.31 times or 69.4%. A psychiatric comorbidity increased the risk of high MME by 8.7 times.

Conclusion : Patients with high MME/day who underwent spinal decompression were significantly younger with lower ASA scores, and higher preoperative pain scores than those with lower MME/day. The incidence of psychiatric comorbidity was also higher in those with high MMEs. Psychiatric comorbidity in younger patients predicted a significant increased risk of higher MME. Pre-operative opioid risk education and mitigation strategies should be considered in patients with high MME risk, especially in younger patients and those with psychiatric comorbidities.