Hypothermic lidocaine compared with normothermic lidocaine during cystoscopy as assessment for prostatic urethral lift–UroLift. A prospective single-blinded randomized study

Abstract

Introduction: Outpatient cystoscopy is a common procedure performed in urology practice. Rigid cystoscopy, however, even with the use of local anesthetic has been reported to cause mild-to-moderate pain in 76% of men. In our practice, minimally invasive treatment options for several disorders, such as the UroLift System (Teleflex, Pleasanton, CA, USA) or Rezu-m (Boston Scientific, Marlborough, MA, USA) for benign prostatic hyperplasia, have led to increasing numbers of procedures being performed as day surgeries under local anesthetic, but these involve rigid cystoscopes. Finding ways to improve the intraoperative experience of patients could increase the number of suitable patients opting to be treated this way. Lidocaine provides local anesthesia by preventing the transmembrane flow of sodium ions in nerve cells. Before taking effect, however, stimulation of nociceptors during administration can cause notable pain. This effect is reported to have been lessened by the addition of an alkalizing agent, such as sodium bicarbonate, or warming the gel to body temperature. Li et al investigated the use of alkalinized lidocaine gel for use during rigid cystoscopy. Patients who were administered lidocaine gel containing sodium bicarbonate reported substantially reduced visual analog scale (VAS) scores compared with those who received non-alkalinized lidocaine gel (mean 1.3 ± 0.9 versus 5.28 ± 1.99). However, this approach is not well assessed in men undergoing cystoscopy. Warming of lidocaine before injection also reduced intraprocedural pain, but the findings are not consistent, and whether the same effect is seen during intraurethral instillation is less clear. Flexible cystoscopy is generally well tolerated. Some studies suggest that anesthesia is unnecessary, although a meta-analysis of studies involving 411 men found that pain was likely to be reduced using lidocaine gel. Given the better tolerance of flexible cystoscopy, we used this approach to perform a proof-of-concept randomized study to investigate whether cooling of lidocaine gel alters pain levels during administration and cystoscopy procedures compared with room temperature lidocaine.