Abstract SNACC-61

Return to Poster Listing

Does chronic GABA analog usage confer acute post operative pain reduction after spinal fusion surgery? A retrospective analysis

Nair S, Abramowicz A, Galeano E, Houten J
Montefiore Medical Center, Bronx, NY, USA

Introduction:Gabapentin and Pregabalin G/P)are used as analgesic adjuncts in the peri-operative setting.Spinal spondylosis-related compressive and pain syndromes are often treated surgically.We hypothesized that long-term pre-operative G/P use mitigates immediate post-operative pain(IPS)after spinal fusion surgery.We investigated the effect of pre-operative long-term G/P on IPS.
Methods:With IRB approval and using the proprietary software we located and analyzed all the patients who had spinal fusion surgeries performed by a single surgeon from 01/2011 to 09/2013.Within this cohort,those patients who were given a prescription for G/P within 90 days prior to surgery were studied.We divided the patients into the anterior cervical fusion group with and without pre-operative G/P and a posterior fusion group,both cervical and lumbar, again with and without pre-operative G/P.Anesthesia records were reviewed for type of intraoperative opioid(Remifentanil vs.other)and pre-operative opioid usage.A median IPS was derived by averaging all the available pain scores in the first 24 hours after surgery, separately for the anterior and posterior fusions.For each record positive for G/P use, we reviewed two randomly selected records from the non-G/P patient group undergoing the same type of surgery.For statistics, we used non-parametric t-test and chi-square, where appropriate.
Results:The surgeon performed 394 spine surgeries.Micro-discectomy(47),simultaneous anterior and posterior fusion (15)and costo-transversectomy(2)were excluded from analysis; 162 anterior cervical fusions and 168 posterior fusions were included.16 patients in the anterior fusion group and 15 in the posterior fusion group were taking G/P pre-operatively.All the patients had propofol-based anesthesia.Other variables analyzed are shown in Table 1.The 2 posterior fusion groups did not differ.The median pain scoresin the posterior groups with and without G/P were 4(3, 6) and 4(2, 6) respectively,p = 0.593(IPS). The anterior fusion groups differed (Table 1).In the anterior groups, the median pain scores with and without G/P were 4(2, 6)and 2(0, 4)respectively,p = 0.029.
Discussion:Although acute pre-operative gabapentinoid administration improves IPS,our findings are contradictory.Anterior cervical fusions result in less post-operative pain than posterior fusions.We found that the anterior cervical fusion pre-operative long-term Gabapentinoid users were more likely to be on pre-operative opioids. Although Remifentanil was used less frequently in this group,it had higher composite 24 hour pain scores than the G/P non-users;thus G/P use may be simply a marker for chronic pain.We found no difference in IPS in the posterior fusion groups.Although we have not calculated the postoperative opioid usage, our finding may be related to the fact that posterior fusion patients routinely receive opioid PCA, but anterior fusion patients do not. Our findings warrant a prospective evaluation.

  • SNACC-61 Image 1

Back to Top