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BackTable / OBGYN / Article
Special Topics in UTIs: Indwelling Catheter Colonization, Catheter UTI Treatment, Urosepsis & Antibiotic Resistance
Taylor Spurgeon-Hess • Updated Jun 10, 2024 • 210 hits
As a clinician, what do you do when it’s not your “run of the mill” urinary tract infection (UTI)? While UTIs are common and treatable, there are many manifestations, complications, and causes that providers may encounter that they may not be as familiar with. BackTable host Dr. Suzette Sutherland and pelvic medicine and reconstructive surgery specialist Dr. Anne Cameron cover exceptional UTI cases, including the management of patients with permanent catheters, the presentation and incidence of urosepsis, and the current state of resistance for antibiotics commonly utilized as catheter UTI treatment.
This article features excerpts from the BackTable OBGYN Podcast. We’ve provided the highlight reel in this article, and you can listen to the full podcast below.
The BackTable OBGYN Brief
• Nearly 100% of patients with indwelling catheters experience bacterial colonization within three months; positive urine cultures from these catheters are expected.
• Asymptomatic bacteriuria does not require treatment, whereas symptomatic UTIs with specific symptoms like dysuria, bladder pain, urgency, frequency, new onset incontinence, fever, or flank pain should be treated with antibiotic therapy.
• Prophylactic daily oral antibiotics are ineffective at preventing UTIs in patients with indwelling catheters; however, gentamicin bladder installations, which involve diluting gentamicin in saline and instilling it into the bladder, significantly reduce UTI rates.
• Urosepsis from untreated cystitis is extremely rare, affecting less than 1% of cases due to the differences between the bacterial strains that cause cystitis and pyelonephritis, respectively.
• Urosepsis primarily affects immunosuppressed individuals, transplant patients, or those with anatomic abnormalities and is more common in hospital settings due to systemic illness and catheter use.
• Pyelonephritis typically presents with systemic symptoms such as fever, flank pain, nausea, and vomiting, without lower urinary tract symptoms, whereas cystitis involves bladder pain, urgency, and frequency.
• There have been no significant new classes of antibiotics developed in recent decades, with research focusing on variations of existing drugs. Multidrug-resistant organisms are increasing rapidly, outpacing the development of new antibiotics and rendering some treatments ineffective as empiric therapy.
Table of Contents
(1) Patients with Indwelling Catheters: Bacterial Colonization & UTI Management
(2) Urosepsis vs. Pyelonephritis: Risk Factors & Affected Patient Populations
(3) The Worsening Problem of Antibiotic Resistance
Patients with Indwelling Catheters: Bacterial Colonization & UTI Management
Patients with indwelling catheters invariably become colonized with bacteria, with nearly 100% colonization at three months. It is crucial to differentiate between asymptomatic bacteriuria and symptomatic urinary tract infections (UTIs). Asymptomatic bacteriuria found incidentally on urinalysis and culture does not require treatment. However, symptomatic UTIs present with dysuria, bladder pain, urgency, frequency, new onset incontinence, fever, or flank pain. Cognitive decline alone (without urinary symptoms) is not a reliable indicator of UTI.
Prophylactic daily antibiotics are ineffective and harmful in these patients as they change gut flora and contribute to resistance. Alternatively, gentamicin bladder installations show promise in reducing UTI rates by 60-70%. This technique involves diluting gentamicin in saline, instilling it into the bladder, and allowing it to dwell for 30 minutes before drainage.
[Dr. Anne Cameron]
People who have indwelling permanent catheters, those patients are invariably colonized with bacteria. The common wisdom in that 5% of people with a catheter get colonized per day so that at three months, virtually 100% of indwelling catheters have a colonized bladder. There is really nothing you can do about that. It is the expectation that a urine culture from a Foley catheter, even a new Foley catheter will be positive.
I also want to emphasize if you are going to get a culture in someone with a Foley catheter, you need to change that Foley catheter at the time of the culture because otherwise, you're culturing the catheter itself rather than the contents of the bladder. Invariably these people have a positive culture. Now, if they have no symptoms, that's called asymptomatic bacteriuria. It's expected, it's well-known and it's not harmful. Now, if they do have symptoms of a UTI, then we can actually use the culture data to help guide their care.
[Dr. Suzette Sutherland]
Oftentimes I know your patient population, you see a lot of this. You've cared for a lot of these types of patients over the years. This idea of making sure that the patient is actually having symptoms and not just a positive urine culture, as you said, this is something that we talk to primary care physicians all the time and even sometimes rehab physicians. Many are educated about this concept, but others not.
Every time somebody with a catheter goes into the emergency room, has to go in for some reason, grandma's not thinking very well. Has a change in mental status. Then they check her urine and they say, "Oh, you have a UTI, we'll give you antibiotics and send you home." How many times has that happened to patients of yours, Dr. Cameron?
[Dr. Anne Cameron]
I think it's happening all the time, unfortunately. Again, if someone has a catheter in place, you can guarantee that the culture is going to be positive. Having a positive culture really doesn't help you figure out what's going on with this person. Asymptomatic bacteriuria is really classically presenting with smelly urine and cloudy urine. Those aren't UTI symptoms. Those are symptoms of just bacteria being present.
The things that we worry about are when those bacteria are actually affecting the person. They're actually affecting their bladder, affecting their kidneys. Those are very different symptoms. Those patients have dysuria. Those patients have bladder pain. They have urgency, frequency. They might have new onset incontinence. They could have fever, flank pain. Those are all symptoms of the bacteria in the urinary tract actually impacting the patient rather than just brewing in the urine, which is asymptomatic bacteriuria.
The concept of cognitive decline or mental cloudiness occurring all alone causing a urinary tract infection has been proven to be not reliable. Older adults who have dementia and have cognitive decline can have cognitive decline whether or not they have bacteria in their urine. What is really making this person better when they get admitted to the hospital and treated for a UTI is actually the supportive care and hydration. Most of these people are dehydrated and they need reorientation and better care and the antibiotics you gave them are not really accomplishing anything. Cognitive changes all by themselves are not a symptom of a urinary tract infection. If someone has new incontinence and bladder pain and cognitive decline or a fever, certainly that is a UTI. Cognitive decline or confusion all by itself is not a urinary tract infection. This has actually been very well studied in the infectious disease literature.
…
[Dr. Anne Cameron]
Indwelling catheters are very problematic in those patients who get either recurrent UTIs or catheter clogging and catheter clogging is just another way of saying colonization of the urine because the catheter clogging is due to bacterial colonization causing precipitate in the urine. They're both the same thing. Those patients can be extremely difficult to treat because the biofilm that's present on the catheter and even if you change their catheter frequently, that biofilm just reforms within hours. These patients are often in a difficult position because they're dependent on the catheter, they can't get rid of the catheter, but the catheter itself is the source of the urinary tract infections.
I try to get those patients treated with a suprapubic tube rather than a urethral catheter and not because they have a different infection rate, but because I can put a bigger catheter in someone's suprapubically. You shouldn't put anything bigger than a 16 French in the urethra, but you can put a 20 or a 22 French suprapubically. The lumen of that catheter is much bigger and it drains better so it's less likely to get clogged.
I also have those patients learn how to irrigate their own catheter with some saline and a tumi syringe. This will keep them out of the emergency department. They get a little clog, a little mucus in their catheter and instead of this being crisis, they can manage this themselves or their caregivers can help them. This is invaluable because these people otherwise have nowhere else to turn for help and that ends up being the emergency department.
For recurrent UTIs, there is really robust literature on daily oral prophylaxis and how it absolutely does not work. If you give these people daily Bactrim, daily Cipro, daily Keflex, daily whatever you want, it does not reduce the risk of UTI 1 iota. It's a zero efficacy. It doesn't do anything at all. Please don't do that. All you're doing is causing harm, changing their gut flora and making them resistant. This is actually contraindicated. In the Neurogenic Lower Urinary Tract Dysfunction Guidelines, we address that and say, please don't do this. Do not give them daily oral antibiotics because they don't work in people with indwelling catheters.
Novel strategies that you were alluding to when we were speaking a little earlier are to do gentamicin bladder installations. This is gentamicin, which is an antibiotic that is quite historical and is somewhat toxic when given IV because it can impair kidney function, it can because autotoxicity. Given intravesically, so basically diluted in saline and squirted into the bladder through a catheter, it's not absorbed through the urinary tract at all. We have serum studies to prove that doesn't happen. Even in those patients who've had bladder augments, they don't absorb it. That's why we don't ever use gentamicin orally, right?
If you swallow gentamicin, you absorb none of it. That's why we know it really isn't absorbed anywhere through any mucosal layer. You leave that indwelling in the bladder for 30 minutes. I often have them use a catheter plug for 30 minutes and then drain the bladder. This works pretty well. I have many patients who are getting consistent catheter clogging, recurrent UTIs.
When they have gentamicin bladder installations, they can self-manage either when they're getting a little infected, so when they notice their urine gets smellier or cloudier, they self-treat for a week at that time. Most of my patients actually just do it every day as a preventative. The rate of UTI in that population when they go from just the way they were to the gentamicin, so the before and after, the UTI rate usually goes down by around 60 or 70%. You're not going to get rid of all their UTIs, but that's a big improvement.
[Dr. Suzette Sutherland]
Your recommendation then would be for daily bladder washes, as you described, indwelling about 30 minutes. What's the dose that you recommend for the prevention?
[Dr. Anne Cameron]
It's around 15 milligrams to 30 milligrams, but I diluted 480 milligrams of gentamicin diluted in a liter of normal saline, and I have them put either 30 or 60 cc's in their bladder. Some people have too small of a bladder to tolerate the 60 CC's, and I'll have them use 30, but I recommend 60 cc's once a day. In a catheterized patient, that can be any time of day that's convenient. In my self-catheterizing patients, I have them do it just before bed. They would catheterize their bladder, drain it completely, and then squirt the antibody in through the same catheter they did our catheterization, and then leave it indwelling overnight.
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Urosepsis vs. Pyelonephritis: Risk Factors & Affected Patient Populations
Urosepsis is a rare but serious condition that can arise from untreated urinary tract infections (UTIs), particularly pyelonephritis, which differs significantly from cystitis. Cystitis rarely progresses to urosepsis due to the distinct types of bacteria involved; E. coli may cause both, but the bacteria possess differing pili and fimbriae.
Patients who present with fever, flank pain, nausea, and vomiting without lower urinary tract symptoms are more likely experiencing pyelonephritis, as these bacteria bypass the bladder and affect the kidneys directly. Urosepsis primarily affects those with anatomic abnormalities, immunosuppression, or hospital-acquired infections. Understanding the distinct presentations and risk factors for urosepsis is crucial for appropriate management and dispelling the myth that untreated cystitis in the general population commonly leads to sepsis.
[Dr. Suzette Sutherland]
They are having symptoms especially elevating to fever. It's the fever causing the cognitive decline, not really just the urine culture. Along that same line, certainly in that patient population, but also in just general patient populations, we've had some newsworthy events where someone got urosepsis and then died pretty quickly and that hit the mainstream a few years ago. Can you speak to this a little bit? What's the incidence of somebody getting a routine what we call population-acquired or community-acquired UTI and if you don't treat it, this idea that it can develop into sepsis and you can die? How common is that?
[Dr. Anne Cameron]
That is actually quite rare and it's rare because it's different bacteria. Someone getting a bladder infection, a cystitis, and that being left untreated for a day or two turning into urosepsis pyelonephritis is less than 1%. The reason that is because the bacteria that because cystitis are different than the bacteria that because pyelonephritis. They're completely different bacteria and they may all be E.coli, but they have different pili and different fimbriae on the bacteria. People who have pyelonephritis, they don't present with bladder pain, urgency, frequency, and then get a fever and then get flank pain. These people present with fever, flank pain, and they're feeling terrible, nausea, vomiting, they feel absolutely awful. Most of them have no lower urinary tract symptoms. The bacteria basically bypassed the bladder and went straight to the kidneys. Those people are very different. They present clinically very differently.
The people who do get a cystitis that turns into pyelonephritis often have some anatomic abnormality. Those are people who've had kidney transplants and kidney transplant patients all have reflux into their transplant kidney. That's how a transplanted kidney is placed into the bladder. That's normal to have reflux, but it puts them at high risk of pyelo. Also, some people have reflux congenitally or have had some bladder surgery. They might have outlet obstruction, they may be catheterizing, and their bladder functions differently. Those people, a cystitis can turn into a pyelonephritis. In the general population with a normal bladder, cystitis really does not cause pyelonephritis.
[Dr. Suzette Sutherland]
Again, in your practice, how many times have you had a patient referred to you from the emergency room who had urosepsis and the whole family comes in with them and says, "I had urosepsis." Let's define what urosepsis is, even separate from pyelonephritis, and what the incidence of that really is.
[Dr. Anne Cameron]
Urosepsis or just sepsis in general is someone has a proven infection. Either there's a clinical finding of bacteria or there's a culture finding bacteria and they have something called SIRS criteria, which is systemic inflammatory responses syndrome. Those people either have a fever, so a temperature above 38 degrees Celsius, or sometimes they can have a low body temperature because that can be a sign of overwhelming infection. They have to have an elevated heart rate or an elevated respiratory rate or have an elevated white count.
They need to have at least two of those criteria plus evidence of an infection for that to be sepsis. Because you can have sepsis from multiple sources. You can have a bloodstream infection, you can have pneumonia, all of those things can cause sepsis. Urosepsis is when you have a positive urine culture with at least two of those SIRS criteria.
[Dr. Suzette Sutherland]
Then we think that systemic process started or was initiated by what's happening in the urine, right?
[Dr. Anne Cameron]
Right.
[Dr. Suzette Sutherland]
By definition then, that's urosepsis. When I break it down even for patients or even do some educational things for primary care providers, we look at cystitis, that's the bladder. We look at pyelonephritis, that's the kidney. Then sepsis is more of that goes beyond those two organs into the systemic system causing all of the kinds of systemic things that we think about that are associated with a standard sepsis. It's extremely rare, especially in the general population to get a community-acquired urinary tract infection. If it's untreated, "I'm so worried to not treat it with these antibiotics because I'm afraid I'm going to get sepsis and die." We just need to dispel that myth.
[Dr. Anne Cameron]
That's correct. Cystitis or a bladder infection, it's exquisitely rare for that to cause urosepsis, a pyelonephritis, or a kidney infection. Because the kidneys are so intimately related with the bloodstream, it's very easy for a pyelonephritis to turn into sepsis, but not a cystitis in and of itself. It's really pyelonephritis that leads to urosepsis.
The people that are at risk of urosepsis are those who are immune suppressed, your transplant patient, your patient taking immune suppression for rheumatologic conditions, and people who've been in the hospital. Urosepsis in the hospital happens not rarely and that's because these people have catheters in, they're systemically unwell, their immune system is being challenged by whatever process is going on. An outpatient ambulatory person in the community getting urosepsis is very rare.
The Worsening Problem of Antibiotic Resistance
The development of new antibiotics has significantly stalled, with no major breakthroughs in decades. This stagnation is due to a lack of resources and profitability in antibiotic research and development, resulting in only slight variations of existing antibiotics being introduced. Meanwhile, bacteria are rapidly developing multidrug resistance, posing a growing challenge in treating infections. Older antibiotics, such as phosphomycin, are being reconsidered due to their low resistance levels, but the overall antibiotic resistance problem continues to worsen. Effective stewardship of existing antibiotics is crucial, involving judicious use and thorough education of both practitioners and patients to mitigate resistance.
[Dr. Anne Cameron]
Unfortunately, antibiotic drug development has really stalled. There are currently no big developments in the antibiotic creation in the world at this time. There were some low-hanging fruit. For example, the penicillins were developed, the fluoroquinolones, and these all happened in the 1970s, '80s, '90s, and they were developing antibiotics every year or so. The resources put towards antibiotic development are not there and it's not very profitable for companies to develop antibiotics, so there's actually very little work being done on the development of new antibiotics. It's mostly just variants of antibiotics we already have. They extend the spectrum a little bit, but there's not been any breakthroughs in decades.
[Dr. Suzette Sutherland]
Therein lies the problem. There's more multidrug-resistant organisms that are happening every day. These organisms are getting smarter when they see these antibiotics and build their own armor against these antibiotics, and yet, there aren't new antibiotics being developed that can penetrate these organisms. It becomes a very scary reality here that we have, not just in the area of urology, but just overall in the area of infectious disease.
That's why we are so adamant about being really good stewards of our antibiotic resources, using them judiciously, using them appropriately, right? Then educating not only practitioners about that, but the patients so they understand too. Are you aware of any new antibiotic drug classes that are coming down the pike? I know there was an oral, maybe, another fluoroquinolone, possibly, but I'm not up on where that research is today and I wondered if you had more insight. Is there anything that you're aware of?
[Dr. Anne Cameron]
I'm not aware of any new classes of antibiotics. They're constantly working on slight variations on what is already out there. The biggest development in antibiotics lately has been the resuscitation of old antibiotics that used to be in the archives. Phosphomycin, for example, that was rarely used up until recently because it's a historic antibiotic that now we realize has very little resistance because it's not been used for so long, whereas the antibiotic resistance that bacteria are developing is accelerating at a logarithmic pace. Antibiotic resistance is different than it was five years ago. It's worse than it was five years ago. The bacteria that were classically resistant to classes of antibiotics are now so resistant that you can't use those antibiotics as empiric therapy.
Podcast Contributors
Dr. Anne Cameron
Dr. Anne Cameron is a urologist and assistant professor with University of Michigan Medical School in Ann Arbor.
Dr. Suzette Sutherland
Dr. Suzette Sutherland is the director of female urology with UW Medicine in Seattle, Washington.
Cite This Podcast
BackTable, LLC (Producer). (2023, December 27). Ep. 42 – Recurrent UTIs: Controlling Those Nasty Little Bladder Infections [Audio podcast]. Retrieved from https://www.backtable.com
Disclaimer: The Materials available on BackTable.com are for informational and educational purposes only and are not a substitute for the professional judgment of a healthcare professional in diagnosing and treating patients. The opinions expressed by participants of the BackTable Podcast belong solely to the participants, and do not necessarily reflect the views of BackTable.
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