(43) The Effect of Gabapentin on the Reduction of Postoperative Pain and Opioid Use After Orthognathic Surgery

Abstract:
Problem: Opioid naïve patients often receive their first exposure to these medications after oral and maxillofacial surgery procedures, including orthognathic surgery. Considering the current opioid crisis in our nation, clinicians have been attempting to find alternatives to manage postoperative pain.
Materials and

Methods: A total of 43 patients from 2 senior surgeons were enrolled in a prospective study to assess the role of gabapentin use in the reduction of opioid consumption and postoperative symptoms after orthognathic surgery, over postoperative days (POD) one to three. Twenty-three patients were enrolled in the study group and 21 in the control. The study group was given 11 tabs of 300 mg of gabapentin to take over the first 5 days after surgery with one dose (300 mg) on the night of surgery and two doses (600 mg) on days two to five. Patients self-reported data by filling out daily diaries. Post-op symptoms related to sleepiness, bruising, swelling, numbness, nausea and pain were listed in the diaries. Pain was recorded on a 7-point Likert scale (1 = no pain; 7 = worst pain) while all other symptoms were measured on a 5-point scale ranging from not at all (1) to a great deal (5). Upon the return of the diaries, the diaries were captured and saved in an ACCESS datafile. Post-surgery data was merged with clinical and demographic information using the patient unique ID number. The first three days after surgery were assessed. Summary statistics and analyses on reported outcomes between the two groups were performed using exact chi-square and Mantel Haenszel tests for categorical and quantitative variables, respectively. Level of significance was set at .05 for all analyses.

Results: 43 patients who met inclusion and exclusion criteria were selected and sorted into control (CG) and treatment groups (TG). Thirteen of 21 (62%) of subjects in the CG completed the patient diaries for POD 1-3 along with 14 of 22 (64%) in the TG, which is an overall attrition rate of 37% (Figure 1). On a scale of 1-5, with 5 being the less desirable outcome, TG reported higher levels of swelling and numbness, however nausea significantly decreased for the TG on POD3 (Figure 2A). There were no reported differences in all reported variables of pain between the two groups (Figure 2B). However, significantly higher usage of opioids, Ibuprofen and Tylenol were found in TG compared to the CG. On POD1, the average reported usage of Norco (1.9 vs 0.46, P = .004), Ibuprofen (3.2 vs 1.8, P = .001), and Tylenol were higher (3.4 vs 1.6, P = .015). By POD 3, this trend continued for Norco and Ibuprofen, however Tylenol usage was not statistically different (Figure 3).

Conclusions: Based on these results, the use of gabapentin in the postoperative setting did not significantly reduce pain scores. There is some evidence that gabapentin usage caused an increase in opioid consumption to achieve similar levels of pain control. Although gabapentin use did result in a decrease in nausea, other associated symptoms were increased compared to the CG, specifically numbness and swelling. These results are confounded by the small sample size and high attrition rate. Based on the study results, we do not find gabapentin effective in reducing post-operative opioid consumption following orthognathic surgery.
Figure 1Figure 2Figure 3The effect of gabapentin on the reduction of post-operative pain and opioid use after orthognathic surgery