Lidocaine gel should be more effective in reducing urethral pain during urodynamic study in men

Abstract

Re: Stav K, Taleb E, Sabler IM, Siegel YI, Beberashvili I, Zisman A. Liquid paraffin is superior to 2% lidocaine gel in reducing urethral pain during urodynamic study in men:A pilot study. Neurourol Urodyn. 2014;34:450-3.Dear Editor in Chief, With great interest we read the article by Stav K on the effectiveness of lubricant and topical anesthetics in reducing urethral pain during urodynamic study. 1 We want to ask whether we should give up topical anesthetics or try to make it more effective?Topical anesthetics have been used in urology since 1884, when Pease described using ''cocaine in a sensitive urethrawith charming results.'' In 1949, Haines and Grabstald applied topical 2% lidocaine intraurethrally in 250 patients undergoing cystoscopy ''without untoward results and with good, rapid anesthesia.'' Similarly, in 1953, Persky and Davis reported 2% lidocaine to be a ''safe, rapid, and adequate anesthetic'' in a case series of 622 cystoscopies. 2There are also controversial issues regarding the need for local anesthesia during urethral instrumentation. Birch tested 2% lidocaine against plain lubricating gel for cystoscopy in a placebo-controlled trial of 138 patients, and concluded that the topical anesthetic is no more effective than ''good lubrication.'' Ho tested 2% lidocaine gel against plain aqueous gel in a placebo-controlled trial of 100 male patients undergoing flexible cystoscopy, and concluded that lidocaine gel causes urethral pain rather than preventing it, and now Stav et al. suggest that lidocaine gel is no better than plain lubricants. 1 Is intraurethral topical anesthesia not necessary or it is not effective enough? It is clear that the superficial layer of the uroepithelium is not tolerant against friction and is sensitive to various injuries, thus intraurethral instrumentation is a potentially painful procedure. Lubricant reduces friction by creating a slippery barrier between the urethra and instruments to attenuate the mechanical injury, whereas lidocaine acts on these suburothelial nerves by inhibiting neuronal impulse propagation and/or generation. Lidocaine gel emerged based on its simultaneous role as both lubricant and local anesthetic Pharmacologically, lidocaine enters the hydrophobic component of the neural membrane and prevents the transmembrane flow of sodium ions necessary for initiation and propagation of action potential. In local block anesthesia, anesthetics must first traverse both the perineural sheath and nerve membrane, whereas in topical application, the anesthetic has to remain on the mucosal surface for a substantial period of time, before it penetrates through the mucosa to reach pain receptors. Therefore, the onset of action of topical anesthetic needs a relatively long time. Pharmacokinetically, the absorption of topical lidocaine is slow, with a peak level reached at 15-60 min and better pain control established 25 min later than normal 2% lidocaine gel instillation. If one starts the catheterization too early, for example, after only 4 min, lidocaine gel cannot sho...

The effects of a heating pad on anxiety, pain, and distress during urodynamic study in the female patients with stress urinary incontinence

“…Several approaches relieve anxiety, pain, and distress such as reading an information leaflet, lubricant, and local anesthetic during catheterization. [14][15][16][17] Other effective and nonpharmacologic alternative treatment modalities also can be considered.…”