Chapter 15. Prevention of Nosocomial Urinary Tract Infections (continued)
Subchapter 15.2. Use of Suprapubic Catheters
As discussed in Subchapter 15.1, the use of indwelling urethral catheters results in substantial morbidity and mortality. Given the medical and social morbidity associated with urethral catheters, many clinicians have considered suprapubic catheterization as an alternative to catheterization via the urethra. Suprapubic catheters are inserted in the lower abdomen, an area with less bacterial colonization than the periurethral region, so that the risk for infection is thought to be lower than with urethral catheters. Furthermore, although the suprapubic placement of urinary catheters represents a minor surgical procedure, patients may find the result more comfortable8,9 and, as reviewed below, the development of infectious complications is reduced. Subchapter 15.1 discusses the use of silver alloy urinary catheters. The focus of this chapter is the use of suprapubic catheters as compared with standard urethral indwelling catheters in adults.
Suprapubic catheterization typically involves the percutaneous placement of a standard urinary catheter directly into the bladder. The procedure is performed by urologists using sterile technique. It is generally performed in the operating room and is considered minor surgery.
Prevalence and Severity of Target Problem
In addition to the infectious complications (and their associated costs) discussed in Subchapter 15.1, the use of urethral catheters causes substantial patient discomfort. In a recent study at a Veteran Affairs Medical Center, 42% of catheterized patients surveyed reported that the indwelling catheter was uncomfortable, 48% complained that it was painful, and 61% noted that it restricted their activities of daily living.7 Restricted activity reduces patient autonomy and may promote other nosocomial complications, such as venous thromboembolism and pressure ulcers. In addition, 30% of survey respondents stated that the catheter's presence was embarrassing, and in unsolicited comments that supplemented the structured questionnaires several noted that it "hurts like hell."7
Opportunities for Impact
Since catheter-related urinary tract infection (UTI) is the leading cause of nosocomial infection in the United States and is associated with increased morbidity and costs, any intervention that reduces the incidence of catheter-related UTI is potentially important. Currently, it is unknown what proportion of patients who require indwelling urinary catheters receive suprapubic catheters, however, this practice is uncommon.
There have been twelve prospective studies,8,9,11-17 all but one randomized,15 comparing the efficacy of suprapubic catheters with standard, non-coated catheters (Table 15.2.1). In all of these studies, the patient was the unit of analysis. The patient populations for these studies varied but generally included patients with acute urinary retention and those undergoing various surgical procedures. Since most of the patients evaluated resided in acute care hospitals, the average duration of catheterization was generally less than 14 days.
All the trials focused on the outcome of bacteriuria. Several of the studies also assessed patient satisfaction and the incidence of mechanical complications. The definition of bacteriuria varied somewhat in the studies. However, low-level growth from a catheterized specimen (i.e., 102 colony forming units (CFU)/mL) usually progresses within days to concentrations of greater than 104 CFU/mL, unless antibiotic therapy is given.18 Unfortunately, none of the studies was adequately powered to detect a significant difference in the clinically more important outcomes of catheter-related bacteremia or death. Though bacteriuria is a surrogate endpoint,19 it is probably appropriate to use since it is a component of the only causal pathway in the disease process between suprapubic catheterization and an important clinical outcome (e.g., symptomatic UTI or catheter-related bacteremia).
Evidence for Effectiveness of the Practice
As shown in Table 15.2.1, studies comparing suprapubic catheterization with urethral catheterization have produced mixed results.8,9,11-17,20-22 Six trials reported lower rates of bacteriuria in patients with suprapubic catheters,11,13,15,16,21,22 and 4 trials indicated greater patient satisfaction with suprapubic as opposed to urethral catheters.8,13,16,20 In 3 of the studies, however, mechanical complications were higher in those receiving suprapubic catheters.12,15,16 Of note, 3 studies found that patients given suprapubic catheters have significantly decreased incidence of urethral strictures compared with patients who received urethral catheters.15,23,24 However, the use of prophylactic antibiotics in patients receiving urethral catheters for transurethral resection of the prostate has been shown to significantly reduce the incidence of strictures in the anterior urethra.25
Potential for Harm
As stated above, the primary problem associated with suprapubic catheter use involves mechanical complications associated with insertion, most commonly catheter dislodgement or obstruction, and failed introduction. The safe insertion of suprapubic indwelling urinary catheters depends on trained personnel.
Costs and Implementation
The cost of each suprapubic urinary catheter tray is comparable to the cost of each standard, non-coated urethral catheter tray. However, the overall initial costs of using suprapubic catheters will no doubt be greater since procedure-related costs are substantially higher for suprapubic than urethral catheters. Nurses are able to place urethral catheters at the bedside, but urologists must place suprapubic catheters, and the procedure typically occurs in the operating room. Additionally, it is unclear whether urologists are currently proficient at the insertion of suprapubic catheters given how infrequently they are used. If suprapubic catheters are shown to be effective, they may have a positive impact on patient care. The cost of training individuals in inserting and maintaining the suprapubic catheter is likely to be substantial.
When compared with standard urethral indwelling catheters, suprapubic urinary catheters may reduce urinary catheter-related bacteriuria. Additionally, patient satisfaction may be greater with suprapubic catheters, although there is also evidence that patients placed with suprapubic catheters more frequently experience certain mechanical complications. On the other hand, urethral catheters are likely to lead to a higher incidence of urethral strictures. Given these mixed results, conclusions regarding the overall benefit of routine suprapubic catheterization cannot currently be made. However, it would be reasonable to consider conducting a formal meta-analysis of the published trials to answer the question, "Compared with urethral indwelling catheters, are suprapubic catheters less likely to lead to UTI (as measured by bacteriuria) and more likely to lead to enhanced patient satisfaction?" Using explicit inclusion criteria and accepted quantitative methods, a meta-analysis26-28 can often help clarify the features of individual studies that have divergent results.29 In addition, a possible interaction between gender of the patient and type of catheter is of interest since different pathophysiologic mechanisms underlie the development of urethral catheter-related infection in men and women.30 The possibility of adequately evaluating effects within subgroups (e.g., those undergoing certain surgical procedures) because of an increased sample size is one of the benefits of meta-analysis.31
If formal meta-analysis suggests that suprapubic catheters are less likely to lead to urinary tract infection and more likely to enhance patient satisfaction, at least in some clinical settings, then these catheters should be considered in the management of certain patients. On the other hand, if the meta-analysis finds that urethral catheters are superior to suprapubic catheters, then use of suprapubic catheters, albeit currently quite limited, should be further reduced.
Table 15.2.1. Prospective studies comparing suprapubic with urethral catheters
|Study||Design, Outcomes||Patient Population*||Bacteriuria (%)b||Odds Ratio (95% CI)b||Commentsc|
|Shapiro, 198216||Level 1, Level 2||General surgical patients with urinary retention||2/25 (8)||21/31 (68)||0.04|
|Pseudorandomized (urethral catheters used in every third patient) study; suprapubic group had less pain but more mechanical complications|
|Andersen, 198513||Level 1, Level 2||Women undergoing vaginal surgery||10/48 (21)||20/44 (45)||0.32|
|Patients rated acceptability of suprapubic catheters greater|
|Ichsan, 19879||Level 1, Level 2||Patients with acute urinary retention||3/29 (10)||11/37 (30)||0.27|
|None of the suprapubic group complained of discomfort compared with 17 of the patients given urethral catheters|
|Sethia, 198711||Level 1, Level 2||General surgical patients requiring urine output monitoring||2/32 (6)||16/34 (47)||0.08|
|Decrease in bacteriuria was more significant in women than in men|
|Schiotz, 198912||Level 1, Level 2||Women undergoing vaginal surgery||8/38 (21)||5/40 (12)||1.87|
|26% of suprapubic group versus 5% of urethral group had mechanical complications|
|Horgan, 199215||Level 2, Level 2||Men with acute urinary retention due to prostatic enlargement||10/56 (18)||12/30 (40)||0.33|
|21% of suprapubic group versus 3% of urethral group had dislodgement; 0% of suprapubic group versus 17% of urethral group developed urethral strictures|
|O'Kelley, 19958||Level 1, Level 2||General surgical patients requiring abdominal surgery||3/28 (11)||3/29 (10)||1.04|
|Study design unclear, but probably not randomized; suprapubic catheters caused significantly fewer days of catheter-related pain|
|Ratnaval, 199614||Level 1, Level 2||Men undergoing colorectal surgery||1/24 (4)||3/26 (12)||0.33|
|Suprapubic group had fewer voiding difficulties|
|Bergman, 198721||Level 1, Level 2||Women undergoing vaginal surgery for stress incontinence||4/24 (17)||17/27 (63)||0.26|
|Length of hospital stay was significantly less (by 1 day) in the suprapubic catheter group|
|Abrams, 198020||Level 1, Level 2||Men with urinary retention||21/52 (40)||13/50 (26)||1.6|
|12% of suprapubic catheter group found catheter uncomfortable compared with 64% in the standard urethral catheter group (p<0.001)|
|Vandoni, 199422||Level 1, Level 2||Patients requiring surgery for various indications||0/19 (0)||6/24 (25)||0|
|All patients given pre-catheterization antibiotics; slight decrease in pain and discomfort in suprapubic group but not significant (authors do not provide actual satisfaction data)|
|Perrin, 199717||Level 1, Level 2||Patients undergoing rectal surgery||12/49 (24)||29/59 (49)||0.34|
|12% of suprapubic group reported catheter discomfort compared with 29% of urethral group|
* Studies enrolled both men and women unless otherwise noted.
a Indicates the ratio of patients who developed bacteriuria to the total number of participants assigned to each group.
b Odds of developing bacteriuria in the suprapubic versus urethral catheter groups; CI indicates confidence interval.
c Mechanical complications consisted of failed introduction of catheter, and catheter dislodgement or obstruction.
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