S558 Association of Chronic Opioid Use With Dyssynergic Defecation: Dose and Exposure Effects

Abstract

Introduction: While opioids can be effective management for analgesia, GI side effects can limit tolerability. Chronic opioid use (OU) is associated with opioid-induced constipation (OIC) through slowing of GI transit. Studies have noted possible associations between OU and dyssynergic defecation (DD). The aim of this study was to identify chronic OU amongst patients who underwent anorectal manometry (ARM) testing to determine dose or exposure related effects on anorectal function. Methods: We conducted a retrospective study of patients who had ARM from January 2015 to October 2021. OU was determined by pre-procedure questionnaire and medical record review. OU was considered at least one month of use at time of ARM and was standardized based on morphine milliequivalents (MMEs). Results: Demographics are summarized in Table. Of 773 patients undergoing ARM, 12.7% had chronic OU. OU was associated with having DD; Type 1 DD being most common (p< 0.001). Chronic OU patients were older than patients without OU (p< 0.001). ARM in chronic OU patients was performed more often for constipation, constipation and fecal incontinence, and constipation and diarrhea when compared to patients without OU (p=0.04). Chronic OU patients were more likely to have abnormal balloon expulsion time (BET) defined as > 60 seconds (p< 0.001). Within OU, patients were divided into low and high dose of opiates for likelihood of DD findings on ARM (Figure). The lowest group dosing that reached significance defined low OU as 0-10 MME and high OU as ≥10 MME (p=0.005). Of the 34 low dose patients, 67.6% had DD; of the 64 high dose patients, 95.3% had DD (p=0.004). High dose OU was associated with fewer normal ARM tests and more Type I-III DD (p=0.005). Of the chronic OU, high dose patients were more likely to have abnormal defecation index (DI) defined as < 1.4 compared to low dose patients (p=0.006). Conclusion: Our data suggests a correlation between OU and ARM indications as well as OU and DD. We also found that 10 MME was the opioid dose threshold above which there is a greater association with anorectal dysfunction. Chronic OU patients suffered from constipation, were older, and had greater abnormal BET than those without OU, suggesting exposure-dependent association with OU. DI was abnormal at high dose OU compared to low dose OU, suggesting dose-dependent association with OU. Our study suggests that OIC can be associated with DD in addition to the known delayed colonic transit.Figure 1.: Presence of Dyssynergic Defecation in Low Dose Opioid Use and High Dose Opioid Use Groups (Blue: Normal ARM, Orange: Dyssynergic Defecation on ARM) [p=0.004] Table 1. - Distributions and Variables for Non-Opioid Users and Opioid Users in Patients undergoing Anorectal Manometry Non-Opioid(n=675) All Opioid(n=98) p-Value Low Dose (0-10 MME) Opioid(n= 34) High Dose ( > 10 MME) Opioid(n=64) p-Value Gender Male 142 (20%) 24 (24%) 0.43 7 (20.6%) 17 (26.6%) 0.62 Female 533 (80%) 74 (66%) 27 (79.4%) 47 (73.4%) Age (mean) y 48.7 + 16.0 56.0 + 16.9 < 0.001 55.9 + 17.0 56.0 + 17.0 0.98 ARM Indication Constipation 511 (75.6%) 78 (79.6%) 0.04 24 (70.6%) 54 (84.4%) 0.14 Fecal Incontinence 120 (17.8%) 13 (13.3%) 8 (23.6%) 5 (7.8%) Constipation and Fecal incontinence 23 (3.5%) 5 (5.1%) 1 (2.9%) 4 (6.2%) Fecal Urgency 8 (1.2%) 0 - - Incomplete Defecation 2 (0.3%) 0 - - Diarrhea 10 (1.5%) 0 - - Constipation and Diarrhea 1 (0.1%) 2 (2%) 1 (2.9%) 1 (1.6%) ARM Result Normal 281 (41.6%) 14 (14.3%) < 0.001 11 (32.4%) 3 (4.7%) 0.005 Type I DD 174 (25.8%) 43 (34.9%) 10 (29.4%) 33 (51.6%) Type II DD 33 (4.9%) 9 (9.2%) 2 (5.9%) 7 (10.9%) Type III DD 116 (17.2%) 18 (18.4%) 6 (17.6%) 12 (18.8%) Type IV DD 71 (10.5%) 14 (14.3%) 5 (14.7%) 9 (14.1%) Defecation Index Abnormal (< 1.4) 502 (74.3%) 80 (81.6%) 0.13 21 (61.8%) 59 (92.2%) 0.006 Normal ( >1.4) 174 (25.7%) 18 (18.4%) 13 (38.2%) 5 (7.8%) Balloon Expulsion Time Abnormal ( >60sec) 238 (35.3%) 64 (65.3%) < 0.001 21 (61.8%) 43 (67.2%) 0.65 Normal (< 60 sec) 436 (64.7%) 34 (34.7%) 13 (38.2%) 21 (32.8%) Sensory Threshold Low 155 (22.9%) 26 (26.5%) 0.50 11 (32.4%) 15 (23.4%) 0.33 Normal 339 (50.1%) 43 (43.9%) 16 (47.1%) 27 (42.2%) High 182 (26.9%) 29 (29.6%) 7 (20.6%) 22 (34.4%) Mean sphincter pressure (resting) mmHg 64.60 + 23.6 63.50 + 25.3 0.66 58.6 + 25.3 66.1 + 25.2 0.16 Max sphincter pressure (squeeze) mmHg 157.5 + 68.0 147.0 + 62.9 0.15 138.6 + 64.9 151.5 + 61.8 0.33