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June 2004, Vol. 11, No. 6



Comparison of Topical Anesthetics and Lubricants Prior to Urethral Catheterization in Males: A Randomized Controlled Trial

John Siderias, DO, Flavio Guadio, MD, Adam J. Singer, MD Abstract

Although male urethral catheterization in the emergency department (ED) is both common and painful, few studies have evaluated the use of topical anesthesia prior to catheterization. Objectives: To determine whether pretreatment of the urethra with topical lidocaine reduces the pain associated with urethral catheterization. Methods: This was a prospective, double-blind, randomized clinical trial of 36 alert, cooperative male adult patients requiring urethral catheterization, without allergies to the study medications or contraindications to their use, from a suburban university-based ED. Patients in the experimental group had topical lidocaine 2% gel injected in their urethras, whereas control patients received intraurethral lubrication only. Standardized catheterization with a no. 16 Foley was performed followed by pain assessment. The primary outcome measured was pain of catheterization on a 100-mm visual analog scale. Other outcomes included ease of insertion and procedural bleeding. Results: The authors evaluated 36 patients evenly distributed between study groups. Mean age was 62 years (range 22­85). Compared with controls, patients pretreated with lidocaine experienced significantly less pain of catheterization (38 6 28 mm vs. 58 6 30 mm; mean difference 20 mm; 95% confidence interval [95% CI] = 0.4 to 32; p = 0.04) and less pain of injection (23 6 17 mm vs. 40 6 25 mm; mean difference 17 mm; 95% CI = 3 to 32 mm; p = 0.02). There were no differences in the number of attempts and incidence of adverse events between the groups. Conclusions: Use of topical lidocaine gel reduces the pain associated with male urethral catheterization in comparison with topical lubricants only. Key words: urethral catheterization; topical anesthetics; lidocaine; Foley catheter. ACADEMIC EMERGENCY MEDICINE 2004; 11: 703­706.

In 2001, an estimated 2.2 million urethral catheterizations were performed in emergency departments (EDs) throughout the United States, making it one of the most common procedures performed in the ED.1 Indications for use of bladder catheters include relief of urinary retention and monitoring of urinary output. Insertion of a catheter into the bladder through the urethra may result in significant pain and discomfort for patients. In a study comparing commonly performed procedures in the ED, insertion of a bladder catheter was found to be the fourth most painful procedure.2 Moreover, urinary catheterization has been reported to be significantly more painful in men than women.3 Thus, methods to reduce the pain and discomfort associated with urethral catheterization are clearly indicated. Topical anesthesia has been used successfully prior to insertion of other tubes, such as nasotracheal

intubation in the awake patient4 and nasogastric intubation.5 An informal survey of nurses and residents in our hospital suggested that most practitioners do not routinely use topical anesthesia prior to urethral catheterization. Indeed, of 31 urethral catheterizations included in a prior study, only four patients received any anesthetic.2 However, we are unaware of prior studies evaluating the utility of topical anesthesia specifically for urethral catheterization in the ED. The objective of the present study was to evaluate whether the preparation of the urethra with a topical anesthetic gel would reduce the amount of pain and discomfort experienced by male adult patients during insertion of a bladder catheter.


Study Design. A randomized controlled trial design was used to compare the pain and ease of urethral catheterization with prior preparation of the urethral mucosa with a topical anesthetic or a surgical lubricant alone. This project was approved by the institutional review board. Study Setting and Population. The trial was conducted in the ED of the Stony Brook University Hospital in Stony Brook, New York, a tertiary care center with an annual census of 75,000 patient visits

From the Department of Emergency Medicine, Stony Brook University and Medical Center, Stony Brook, NY (JS, FG, AJS). Received October 14, 2003; revision received December 1, 2003; accepted December 3, 2003. Address for correspondence and reprints: Adam J. Singer, MD, Department of Emergency Medicine, Stony Brook University, HSC L3-058, Stony Brook, NY 11794-835. Fax: 631-444-6233; e-mail: [email protected] doi:10.1197/j.aem.2003.12.025


Siderias et al.



per year. Patients were eligible for enrollment if they were males older than 18 years, required a bladder catheter, were able to assess their pain, and did not require immediate catheterization. Patients were excluded if they were allergic to lidocaine, required immediate catheterization, had structural abnormalities of their urethras, or were unable to cooperate with pain assessments (e.g., mental delay or an altered mental status). Women were excluded because they have been reported to experience less pain from urethral catheterization than men do.3 Also, because of anatomic differences, it is not possible to clamp the urethra in females. A convenience sample of patients was enrolled when one of the investigators was present in the ED. Study Protocol. After obtaining written informed consent, the next in a series of opaque, consecutively numbered envelopes was opened to reveal the patient assignment. Envelopes were prepared by hospital pharmacy personnel not connected to the ED or the enrollment process, and assignments were generated by a computerized random-numbers program. Envelopes contained even proportions of experimental and control assignments. The study gels were prepared by an independent nurse who was not involved in patients' care and were placed in unmarked syringes. The appearances of the two study gels were indistinguishable. In patients assigned to the experimental group, the urethra was pretreated with 15 mL of lidocaine 2% gel (Uro-Jet, International Medication Systems Limited, El Monte, CA). In the control group, the urethra was pretreated with 15 mL of a sterile water-based surgical lubricant (Surgilube, E. Fougera and Co., Melville, NY). The study solution was injected into the urethra with a no. 18 G angiocatheter that was gently inserted into the distal external meatus of the urethra. After injection of the study gel, the end of the penis was held closed for 15 minutes with a special urological plastic penile clamp or the patient's hand. We chose to wait 15 minutes to allow adequate time for onset of the lidocaine's anesthetic effects.6,7 The physician then inserted a no. 16 Foley catheter into the bladder with use of standard technique. All investigators were instructed in the methods of catheterization and injection of the topical solution prior to study initiation. If unsuccessful, the practitioner was allowed a second attempt at catheterization prior to obtaining a formal urological consultation. The pain and ease of catheterization were determined, and the presence of any postcatheterization bleeding was noted. Patients were also asked whether they would prefer similar pretreatment of the urethra with future urethral catheterizations. Measures. Immediately after injecting the study gel, patients were asked to rate the pain of the injection on

a previously validated 100-mm visual analog scale (VAS) marked ``most painful'' at the high end.8 Patients rated the pain of urethral catheterization separately on a similar VAS immediately following the procedure. The physician inserting the catheter rated the ease of passage with a previously described five-point Likert scale (effortless, easy, fair, difficult, and very difficult).9 The physician also indicated how many attempts were made before successful passage of the catheter as well as whether any postprocedural bleeding from the urethra occurred. Administration of pain ratings was performed by a trained research assistant10 masked to the study intervention. Research assistants entered the patient's room only after completion of the catheterization, and their interaction with the patients was limited to instructing them on the use of the VAS. A standardized closed-question data form was completed on all patients including relevant demographic and clinical data. Data Analysis. Data were entered into SPSS 11.0 for Windows (SPSS, Inc., Chicago, IL) for statistical analysis. For both pretreatment characteristics and outcomes, continuous variables were compared by using a two-tailed Student's t-test. The chi-square or Fisher's exact test was used to compare categorical variables. Sample size calculations were based on prior estimates of the pain associated with urethral catheterization.2 The sample size necessary to detect a 20-mm between-group difference in pain of catheterization with a power of 0.8 and a of 0.05 using a two-tailed t-test was 18 in each group. A difference of 13­18 mm has been shown to be the minimum clinically significant difference in pain scores using the VAS.11 Post hoc analysis of variance was performed controlling for patient age.


During the study period, 36 patients were enrolled in the study. Of patients consenting to participate in the study, 18 were randomized to the treatment group (topical anesthetic) and 18 to the control group (lubricant alone). The patients' mean age was 62 years (range 22­85). Urinary retention was the most common indication in both study groups. The baseline demographic characteristics of the patients in the two study groups were similar; however, patients in the group treated with lidocaine were younger than those in the lubricant group (56 6 17 vs. 67 6 12 years, respectively; p = 0.03). Compared with controls, patients pretreated with lidocaine gel experienced significantly less pain of catheterization (38 6 28 mm vs. 58 6 30 mm; mean difference 20 mm; 95% CI = 0.4 to 32; p = 0.04) (Figure 1). Patients pretreated with lidocaine also experienced less pain during the injection of the topical solution



June 2004, Vol. 11, No. 6



Figure 1. Box-plot of pain of catheterization in the study patients. The middle bar is the median, and the box includes the interquartile range. The whiskers approximate the 95% confidence intervals.

(23 6 17 mm vs. 40 6 25 mm; mean difference 17 mm; 95% CI = 3 to 32 mm; p = 0.02). The difference in pain of catheterization was significant even after controlling for between-group differences in age. Age was not significant in this analysis. Urethral catheterization was noted to be easier in patients pretreated with lidocaine (60% effortless vs. 41% effortless in the control group) (Table 1). However, this difference was not statistically significant (p = 0.32). There were no between-group differences in the number of patients who required two attempts prior to successful catheterization (lidocaine 1 vs. surgical lubicant 3; p = 0.28) or the incidence of postprocedural bleeding (lidocaine 4 vs. surgical lubricant 4; p = 1.00). When given a choice, more patients pretreated with lidocaine would prefer

similar pretreatment for future catheterizations than those treated with the lubricant (62% vs. 38%; p = 0.048).


The results of the current study indicate that pretreatment of the urethra with topical lidocaine gel significantly reduces the pain associated with this bladder catheterization in adult males in the ED. Furthermore, the pain of intraurethral injection of lidocaine is significantly less than that of a standard surgical lubricant. Finally, most patients pretreated with intraurethral lidocaine, when given a choice, would request similar pretreatment in the future. Topical anesthetics have been used in urology since 1884, when Professor R. W. Pease described using ``cocaine in a sensitive urethra. . .with charming results.''12 In 1949, Haines and Grabstald applied topical 2% lidocaine intraurethrally in 250 patients undergoing cystoscopy ``without untoward results and with good, rapid anesthesia.''13 Similarly, in 1953, Persky and Davis reported 2% lidocaine to be a ``safe, rapid, and adequate anesthetic'' in a case series of 622 cystoscopies.14 These early investigations, however, were not placebo-controlled. In 1994, Birch et al. tested 2% lignocaine against plain lubricating gel for cystoscopy in a true placebo-controlled trial of 138 patients. Finding no significant difference in pain scores between the two groups, the authors concluded that the topical anesthetic is no more effective than ``good lubrication'' for reducing the pain of modern cystoscopy.7 The apparent contradiction between the earlier

TABLE 1. Indications and Outcomes

Lidocaine Group (n = 18) Urinary retention, no. (%) Pain of anesthetic injection (SD), mm Pain of catheterization (SD), mm Effortless insertion, no. (%) One attempt only, no. (%) Urologic consults, no. (%) Bleeding, no. (%) No. (%) patients who would prefer similar pretreatment in the future NS = not significant. 15 (83.3%) 23 (17) 38 11 17 0 4 (28) (61.1%) (94.4%) (22.2%) Lubricant Group (n = 18) p-value 13 (72.2%) 40 (25) 58 7 15 0 4 (30) (41.2%) (83.3%) (22.2%) NS 0.02 0.04 NS NS NS NS

11 (61.1%)

7 (38.8%)



Siderias et al.



studies and Birch's findings may be reconciled by the explanation that the more painful the procedure, the more demonstrable the effect of topical anesthesia. The rigid, larger-bore cystoscopes used by Haines and Grabstald presumably produced more discomfort than the modern, flexible cystoscope. Therefore, patients in the earlier studies may have benefited more from the effect of topical lidocaine. Overall, the pain of cystoscopy in the study by Birch et al. was significantly less than that observed in our study (14 and 17 mm in those treated with lignocaine and plain gel, respectively). Although it is unclear why the pain of flexible cystoscopy was less than for urethral catheterization, the relatively low pain levels in the flexible cystoscopy study probably account for the lack of any observed differences between the anesthetic and lubricant groups.


The current study shows that intraurethral injection of topical lidocaine gel prior to male urethral catheterization results in significantly less pain than use of a surgical lubricant alone. Furthermore, patients preferred pretreatment with lidocaine over surgical lubricant. Widespread use of topical anesthetics prior to urethral catheterization in males is recommended.

The authors thank Dr. Henry C. Thode, Jr., for his assistance in the statistical analysis of these data.


1. McCaig LF, Burt CW. National Hospital Ambulatory Medical Care Survey: 2001 Emergency Department Summary. Advanced data from vital health statistics; no. 335. Hyattsville, MD: National Center for Health Statistics, 2003. 2. Singer AJ, Richman PB, La Vefre R, McCuskey CF, Thode HC. Comparison of patient and practitioner's assessment of pain from commonly performed emergency department procedures. Ann Emerg Med. 1999; 33:652­8. 3. Singer AJ, Kowalska A, Richman PB, et al. Gender differences in pain associated with urethral catheterization [abstract]. Acad Emerg Med. 1998; 5:535. 4. Gross JB, Hartigan ML, Schaffer DW. A suitable substitute for 4% cocaine before blind nasotracheal intubation: 3% lidocaine­0.25% phenylephrine nasal spray. Anesth Analg. 1984; 63:915­8. 5. Singer AJ, Konia N. Comparison of topical anesthetics and vasoconstrictors versus lubricants prior to nasogastric intubation: a randomized controlled trial. Acad Emerg Med. 1999; 6:184­90. 6. van der Burght M, Schonemann NK, Laursen JK, Arendt-Nielsen L, Bjerring P. Onset and duration of hypoalgesia following application of lidocaine spray on genital mucosa. Acta Obstet Gynecol Scand. 1994; 73:809­11. 7. Birch BRP, Ratan P, Morley R, Cumming J, Smart CJ, Jenkins JD. Flexible cystoscopy in men: is topical anesthesia with lignocaine gel worthwhile? Br J Urol. 1994; 73:155­9. 8. Wallenstein SL. Scaling clinical pain and pain relief. Broman B (ed). Pain Measurement in Man: Neuropsychological Correlates of Pain. New York: Elsevier Science, 1984, pp 389­96. 9. Chuah SY, Crowson CP, Dronfield MW. Topical anaesthesia in upper gastrointestinal endoscopy [comment]. Br Med J. 1991; 303:695. 10. Hollander JE, Singer AJ. An innovative strategy for conducting clinical research: the Academic Associate Program. Acad Emerg Med. 2002; 9:134­7. 11. Todd KH, Funk KG, Funk JP. Clinical significance of reported changes in pain severity. Ann Emerg Med. 1996; 27:485­9. 12. Otis FN. The hydrochlorate of cocaine in genito-urinary procedures. N Y Med J. 1884; 40:635­7. 13. Haines JS, Grabstald H. Xylocaine: a new topical anesthetic in urology. J Urol. 1949; 62:901­2. 14. Persky L, Davis HS. Xylocaine as a topical anesthetic in urology. J Urol. 1953; 70:552­4.


Our study is limited by its small size. Thus, the difference in ease of insertion in favor of lidocaine might have been significant given a larger sample size. Furthermore, the small sample size limited our ability to detect differences in adverse events. Most importantly, the sample was large enough to detect a significant difference in the primary outcome, the pain of catheterization. Catheterization was performed by physicians, whereas nurses perform most catheterizations in many institutions. Thus, it is unclear whether our results can be generalized to other practitioners and institutions. Catheterization was performed 15 minutes after application of lidocaine. A prior study in women suggests that the onset of lidocaine occurs between 1 and 4 minutes and lasts 12­45 minutes. Thus, it is possible that the results would have been different if we had chosen an earlier time point for catheter insertion such as 5­10 minutes after application of lidocaine. There was a statistically significant between-group difference in the patients' ages. However, it is unclear whether a difference of 12 years at these ages is clinically relevant. Furthermore, age was not a significant covariate in the analysis of variance. Finally, our study did not include a control group in which no pretreatment was given prior to catheterization. However, we do not believe that this would have been ethical, given the evidence that some form of lubrication is important.


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