Safer insertion of suprapubic catheters: summary of a safety report from the National Patient Safety AgencyBMJ 2011; 342 doi: https://doi.org/10.1136/bmj.d924 (Published 24 February 2011) Cite this as: BMJ 2011;342:d924
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Re: Safer insertion of suprapubic catheters: summary of a safety report from the National Patient Safety Agency
To the Editors:
We want to commend this safety report on suprapubic tube placement, but want to also raise awareness about another major safety issue surrounding ballon catheters. The first report of iatrogenic injury from intra-urethral urinary catheter balloon inflation was by Sellet in 1971 (1). Four decades later, these injuries continue to occur regularly (2), yet incidence remains under-reported (3). Lack of incidence data precludes a cost-analysis of this problem, and, may explain why manufacturers have not been motivated to consider and implement safety-oriented design changes to the urethral catheter. We sought to address these limitations: we estimated incidence by reporting the national incidence of non-infectious catheter related complications, and, to address the need for practical safety-oriented design solutions, we engineered and tested a catheter design that prevents and mitigates urethral balloon-inflation trauma.
We performed a retrospective cross-sectional analysis for non-infectious catheter related complications from 2006 to 2008 using discharge data from the Nationwide Inpatient Sample (NIS; a 20% stratified sampling of non-federal US hospitals).4
Standard (BARDTM) 16 Fr. catheters were modified as follows: I. The catheter surface was marked with colored safety-markings: a green band reminds the user to advance the catheter until the marking reaches the (male) urethral meatus; a visible red mid-shaft marking warns of balloon displacement into the urethra. II. We attenuated a 1.5 cm segment of the balloon-port wall circumferentially, and colored this area red. When the retention balloon is inflated prematurely, within the urethra, this external segment expands (“safety-balloon”), thereby 1) minimizing pressure upon the urethra, and 2) visually alerting the operator. (Figure 1)
We inflated the retention balloon of modified and unmodified catheters within both the bladder, prostatic, and bulbar urethra of fresh human cadavers, and, within an ex vivo model of the urethra. We recorded intra-balloon pressures throughout, including during expansion of the “safety-balloon.”
From 2006 to 2008, 111,353 patients (mean age: 68.4 years +18.8) experienced non-infectious catheter related complications. Most (86.6%) were male, and 46.2% required a subsequent procedure (eg. cystoscopy or suprapubic tube placement).
After inflation within the bladder, balloon-port pressure was nearly identical among modified and unmodified catheters, and the “safety-balloon” remained un-inflated. However, upon inflation within the prostatic and bulbar urethra: mean balloon-port pressure in our modified catheter prototypes was 60% lower than in the unmodified catheters, and, the “safety balloon” visibly expanded (as expected).
Over 20% of US inpatients undergo urethral catheter placement by nurses and doctors with variable training and experience with urethral catheters. (5) Intra-urethral balloon inflation is positively associated with two key metrics of quality outcomes: increased hospital stay and nosocomial urinary tract infection. (6) Our analysis of NIS data confirms that balloon inflation injuries continue to occur at substantial frequency. Because incidence is based on self-report, the true incidence is likely even higher. In the present era of hospital “zero-tolerance” for key preventable iatrogenic injuries, redesign of the urethral catheter is timely.
Study limitations include those associated with the use of claims data, such as potential improper coding, confounding, and lack of clinical detail. However, even if only half the incidence data are accurate, the incidence of non-infectious catheter related complications remains unacceptably high, particularly given that these injuries can be avoided with proper placement technique and simple catheter modifications, such as those we describe.
The modifications we describe (catheter markings to guide placement, a mechanism to lower intra-urethral balloon pressure, and highly-visible surface markings that “alert” the operator when intra-urethral inflation has occurred), reflect traditional safety strategies: injury prevention, reduction, and alert.
In our view, it is reasonable for iatrogenic urethral injury due to balloon inflation within the urethra to be added to the growing list of “never events.” Both hospitals and patient advocates should demand that manufacturers market urethral catheters that optimize safety.
1. Sellett T. Iatrogenic urethral injury due to preinflation of a Foley catheter. JAMA. Sep 13 1971;217(11):1548-1549.
2. Buddha S. Complication of urethral catheterisation. Lancet. Mar 5-11 2005;365(9462):909.
3. Kashefi C, Messer K, Barden R, Sexton C, Parsons JK. Incidence and prevention of iatrogenic urethral injuries. J Urol. Jun 2008;179(6):2254-2257; discussion 2257-2258.
4. HCUP Nationwide Inpatient Sample (NIS). Healthcare Cost and Utilization Project (HCUP). 2007-2009. Agency for Healthcare Research and Quality, Rockville, MD.
5. Gould CV UC, Agarwal RK, Kuntz G, Pegues DA, . Guideline for prevention of catheter-associated urinary tract infections 2009. Atlanta (GA): Centers for Disease Control and Prevention (CDC) Healthcare Infection Control Practices Advisory Committee (HICPAC); 2009.
6. Aaronson DS, Wu AK, Blaschko SD, McAninch JW, Garcia M. National incidence and impact of noninfectious urethral catheter related complications on the Surgical Care Improvement Project. J Urol. May;185(5):1756-1760.
Competing interests: Conflict of Interest and Disclosure Statement: Drs. Garcia, Wu, and Aaronson: U.S. and International Patents Pending. Drs. Garcia and Aaronson: Co-founders (Safe Medical Design LLC).
Suprapubic catheterisation (SPC) during day light hours poses few
concerns because there is urological cover. The problem lies during the
night or on weekends, when in smaller hospitals that often adopt a
hospital and night rota, there is less support. During these on-call
systems the responsibility usually lies with the on-call surgical SHO/CT
There have been concerns regarding the lack of confidence and support
for these doctors with insertion of a SPC during out-of-hours duty as
highlighted by your article. This has perhaps recently prompted the
Intercollegiate Surgical Curriculum Programme (ISCP)1; the training body
responsible for core surgical training, to include SPC in the Technical
Skills and Procedures section of the syllabus that a trainee must be able
to perform. Trainees should be formally taught and have experience in SPC
in order to complete there core training. With these improvements in
training, it will be interesting to see whether this has an impact on the
audit awaiting completion by the British Association of Urological
Surgeons on complications related to SPC.
Competing interests: No competing interests
Acute retention of urine is very distressing condition. If the
urethral catheterisation fails then on call team is faced with a difficult
clinical situation. The temptation to insert a supracath should be checked.
An experienced urologist's expertise should be sought. In community and
remote areas, such patiens should be admitted and the senior most member
of the on call surgical team should be contacted.
An elective supra-pubic catheterisation needs full assessment, indication
needs to be properly discussed with the patient and carer and is best done
on an elective operation list. Ultra-sound guided supracath insertion
should be done under supervision of expert sonographer. All care should be
taken to fill the bladder and check that no bowel is interposed between
bladder and abdominal wall. Lower abdominal operation is specially at
increased risk of bowel injury.
The neuropathic urinary bladder is usually contracted and non-distensible. This may cause failure of the procedure. As indicated in the
flow chart, if Urinary Bladder is non-palpable, then open procedure should
be adopted. To overcome acute retention, careful Urinary bladder
aspiration should only be attempted.
Competing interests: No competing interests