Prevention of AD During Anorectal Procedures
The second most common cause of AD is pain or irritation within the colorectal area. Constipation, hemorrhoids, and anal fissures are all frequently observed in people with SCI and contribute to episodes of AD (Teasell et al. 2000; McGuire & Kumar 1986; Hawkins et al. 1994; Teichman et al. 1998). Digital stimulation, a common component of bowel routines in individuals with SCI, can also trigger AD (Furusawa et al. 2007), especially in the presence of hemorrhoids and/or anal fissures. Additionally, rectosigmoid distension and anal manipulation are common iatrogenic triggers of AD (Cosman & Vu 2005).
Discussion
Two RCTs (Cosman & Vu 2005; Cosman et al. 2002) compared the effect of topical local anesthesia to the anorectal area to a nonmedicated control gel for the prevention of AD during anorectal procedures. Cosman et al. (2002) found that AD was not abolished with the use of topical lidocaine; however, the same investigators later demonstrated that intersphincteric anal block with lidocaine was effective in limiting anorectal procedure-associated AD (Cosman & Vu 2005). Further, Cosman et al. (2002) found that anoscopy, which involves stretching the anal sphincters, was a more potent stimulus for AD than flexible sigmoidoscopy, which involves gaseous distention of the rectosigmoid. In an RCT by Furusawa et al. (2009), investigators found that topical lidocaine applied to the rectum prior to digital bowel stimulation significantly reduced systolic blood pressure and reports of AD over the duration of the bowel program when compared to the control group. Similarly, Solinsky and Linsenmeyer (2018) found that intravesical lidocaine decreased the incidence and severity of AD following catheter change.
Conclusion
There is level 1 evidence (from 1 RCT) (Cosman & Vu 2005) that lidocaine anal block significantly limits the AD response in susceptible patients undergoing anorectal procedures.
There is level 1 evidence (from 1 RCT) (Cosman et al. 2002) that topical lidocaine does not limit or prevent AD in susceptible patients during anorectal procedures.
There is level 1 evidence (from 1 RCT) (Furusawa et al. 2009) that topical lidocaine may help to prevent AD during gentle bowel stimulation.
There is level 2 evidence (from 1 prospective controlled trial) (Solinsky & Linsenmeyer 2018) that the incidence and severity of AD during catheter change were reduced after treatment with intravesical lidocaine.
