Botulinum Toxin A (BoNT A) injections is a minimally invasive yet effective treatment for patients suffering from overactive bladder resistant to conventional therapy (i.e. behavioral therapy, physiotherapy and oral medication). 
The procedure can be performed in outpatient setting under local anesthesia, but is then often associated with pain, and discomfort. 
Because of it's slightly more alkaline pH and mineral composition we thought, that Ringers solution is capable to elevate pain perception threshold while being used as bladder irrigation solution. The objective of current pilot study was to test out the anesthetic capability of Ringer's solution for intradetrusor BoNT A injections.

42 patients aged 36-90 y.o. (36-female and 6- male) underwent intradetrusor 100U BoNT A (BOTOX™ Allergan, Irvine. CA 92612) injections for non-neurogenic overactive bladder in time period from February till December 2020 at the single day/outpatient deepartment of Moscow City Hospital named after S.I. Spasokukotsky. Patients were randomly assigned into control (n=22) and "Ringer's" (n=20) groups.
BoNT A in both groups was prepared according to standard 100U BOTOX™ reconstitution and dilution procedure and injected at 10 sites using Laborie cystoscopy injection needle. 
After the procedure each patient filled out a questionnaire and rated experienced pain and discomfort on a visual analogue scale (VAS) adopted for Russian language (where 0 would be no pain at all and 10 - most extreme pain and discomfort ever experienced).

In comparison to control group (BoNT A injections performed under Lidocain+Chlorhexidin containing gel and 0,9% NaCl irrigating solution), patients in the Ringer's group showed an improvement on VAS by at least 2-3 points (mean score went from 8-9 to 5-6). Those patients (N=4), who underwent repetitive BoNT injections noted that under Ringer's solution pain was more localized momentary and more tolerable in comparison to previous experience.

Current study was not without its numerous lmitatioons. Patients of particullary olger age may have altered bladder wass sensation due to neurogenic and/or diabethic tissue alterations. They were not thoroughly screened previously. 
The use of Ringer's solution for bladder irrigation is a feasible way to reduce pain and discomfort for patients undergoing intradetrusor BoNT A injections under local anesthesia for overactive bladder in outpatient setting. 
Preliminary results of a current study showed promissing results as a proof of concept. 
The use of Ringer's solution as well as other alternative solutions for cystoscopic irrigation warrent further multicentric studies.

More widespread use of Ringer's solution as a local anesthetic irrigation media may allow to perform more procedures in outpatient/ambulatory settings, thereby minimizing associated costs, risks and hospital (bed) resources, which tend to be vitally important during current Covid-19 pandemic.