(177) Perioperative Gabapentin Use and Adverse Clinical Events in Older Adults After Major Surgery: A Retrospective Cohort Study

Saturday, August 27, 2022

8:00 AM – 6:00 PM CEST

Location: Hall C

Publication Number: 851

Presenting Author(s)

Chan Mi Park
– Harvard School of Public Health, Boston, Massachusetts, United States

Co-Author(s)

Jessica Lie
– Harvard T.H.Chan School of Public Healh, United States
SHARON K. Inouye, MD, MPH
– Professor of Medicine, Harvard Medical School, Boston, MA, Boston, MA, United States
Edward Marcantonio
– Divisions of Gerontology and General Medicine, Beth Israel Deaconess Medical Center, Boston, MA, United States
Eran D. Metzger, MD
– Adjunct Scientist, Hinda and Arthur Marcus Institute for Aging Research, Hebrew SeniorLife, Harvard Medical School, Boston, MA, Boston, MA, United States
Brian Bateman
– Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine, Stanford, CA, USA, United States
Su Been Lee
– Brigham and Women’s Hospital, United States
Raisa Levin
– Brigham and Women's Hospital, United States
Dae Hyun Kim
– Hinda and Arthur Marcus Institute for Aging Research, Hebrew SeniorLife, Harvard Medical School, United States

Background: Gabapentin is widely used for postoperative pain management based on clinical trials that showed the benefit of gabapentin in achieving pain control and reducing opioid use. However, these trials are insufficiently powered to evaluate adverse outcomes.

Objectives: We investigated the adverse clinical events potentially associated with postoperative gabapentin use in older patients.

Methods: This retrospective study used the Premier Healthcare Database that included 1,044,883 patients who were ≥65 years old and underwent major surgery in 2009-2018. We performed 1:1 propensity score matching to compare postoperative gabapentin users vs. non-users, defined by exposure to gabapentin on postoperative days 0, 1, or 2. The primary outcome was delirium, identified using diagnosis codes, and secondary outcomes were new antipsychotic use, pneumonia, and in-hospital mortality, which were measured from postoperative day 3 to discharge. We used logistic regression to estimate the odds ratio (OR) and 95% confidence interval (CI) in the entire sample and by clinically important subgroups.

Results: After propensity score matching, we identified 132,362 pairs of gabapentin users and non-users (mean age [standard deviation], 74.4 [6.8] years; 169,037 [63.9%] women). Compared with non-users, gabapentin users had significantly increased rates of delirium (4,732 [3.6%] vs 3,738 [2.8%]; OR [95% CI], 1.28 [1.22-1.33]), new antipsychotic use (1,172 [0.9%] vs 923 [0.7%]; OR [95% CI], 1.27 [1.17-1.39]), and pneumonia (1,762 [1.3%] vs 1,507 [1.1%]; OR [95% CI], 1.27 [1.06-1.52]), with no difference in in-hospital mortality (404 [0.3%] vs 402 [0.3%]; OR [95% CI], 1.01 [0.88-1.15]). The association between gabapentin use and delirium appeared to be stronger for those with age < 80 years (OR, 1.32 vs 1.18), high comorbidity burden (OR, 1.33 vs 1.22), and chronic kidney disease (OR, 1.42 vs 1.26).

Conclusions: Postoperative gabapentin use was associated with increased risk of delirium, antipsychotic use, and pneumonia in older adults after major surgery. These results warrant careful risk-benefit assessment before prescribing gabapentin for postoperative pain management.