2728 - Factors Influencing Post-Operative Pain in Gynecologic Cancer Patients Receiving High Dose Rate Brachytherapy: An ERAS Risk Factor Analysis
Presenter(s)
D. Colson-Fearon1, K. Aziz2, U. G. Gardner Jr3, X. S. Chen4, R. Prasad5, R. Thomsen5, R. L. Stone6, and A. N. Viswanathan3; 1Johns Hopkins University School of Medicine, Baltimore, MD, 2Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University, Baltimore, MD, 3Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, 4Case Western Reserve University, Cleveland, OH, 5ohns Hopkins University School of Medicine, Department of Anesthesiology and Critical Care Medicine, Baltimore, MD, 6Johns Hopkins Hospital, Department of Gynecology and Obstetrics-Gynecologic Oncology, Baltimore, MD
Purpose/Objective(s): Brachytherapy applicator insertion followed by treatments given over several hours to days can be associated with significant discomfort, anxiety, and pain. This study aimed to investigate risk factors for post-operative pain control to inform techniques for optimizing analgesia.
Materials/Methods: We reviewed records of gynecologic cancer patients who underwent both general and epidural anesthesia prior to MRI-guided brachytherapy applicator insertion in a dedicated MR simulation suite followed by overnight admission to the Johns Hopkins Hospital and treatment with high dose rate (HDR) brachytherapy between January 2019 and July 2022. Multiple variables inclusive of demographic information, disease characteristics analgesia, parameters of brachytherapy, and pain score were collected. Pain scores were analyzed continuously and as a binary variable with well controlled pain coded as pain score of =5. Potential risk factors for poor pain control on post-operative day 0 were identified and investigated with univariate logistic and linear regressions. Factors found to have a p value of = 0.2 in univariable analysis were considered for inclusion in multivariable models. A Jonckheere-Terpstra test for trend was used to investigate the relationship between number of catheters and pain score.
Results: 146 patients with 177 brachytherapy admissions were identified for inclusion in the analysis, in which 57 admissions (32.2%) had poorly controlled pain on post-operative day 0. On multivariable logistic analysis, the primary factor associated with poor pain control was number of catheters (5 to 9 catheters - OR: 5.85 [1.56 – 21.9]; 10 to 14 catheters – OR: 10.9 [2.65 – 44.7]; 15 to 19 catheters - OR: 8.78 [1.98 – 39.0]; 20 or more – OR: 21.6 [2.14 -218.4]). On linear regression, each additional catheter correlated with a 0.10 (95% CI: 0.01 – 0.19) increase in pain score. Notably, on test for trend increasing number of catheters was associated with an increase in average pain score (p = 0.001). Additionally, on logistic regression, having a pre-operative pain regimen requiring opioids (OR: 3.16 [1.27 – 7.84]) was also associated with poorer pain scores. Lastly, age greater than 64 (OR: 0.21 [0.07 – 0.59]) was associated with improved pain control.
Conclusion: In gynecologic patients receiving brachytherapy, predictors of adequate analgesia were fewer catheters, not using opioids for outpatient pain control prior to admission, and older age. This indicates that identification of predictive factors may inform optimization of inpatient analgesics. Given the importance of brachytherapy for local control, further studies are warranted to advance evidence-based guidelines for analgesia and catheter optimization, including real time MRI-compatible catheter tracking.