2 studies evaluate the predictors and costs of urosepsis post-ureteroscopy

Urosepsis is a common complication for patients who undergo ureteroscopy to treat kidney stones. Due to this condition’s negative impact on patients’ quality of life, researchers and clinicians continue to explore preventive measures to mitigate the risk of sepsis both before and after surgery.

In 2 recent studies1,2 led by Naeem Bhojani, MD, FRCSC, and Ben H. Chew, MD, MSc, investigators performed a meta-analysis to identify predictors of sepsis as well as the cost of sepsis for patients with stone disease. The outcomes emphasize serious considerations for clinicians performed and patients undergoing ureteroscopy. Bhojani is an associate professor of urology, clinical research scholar FRQ-S, and endourologist at the Centre Hospitalier de l'Université de Montréal, Quebec. Chew is an associate professor of urologic sciences at the University of British Columbia, Vancouver.

Please discuss the background behind these studies.

Bhojani: Ben and I were interested in looking at complications after ureteroscopy, and actually, when you look at the literature, there's not much on specifically sepsis after ureteroscopy. And so, we actually did meta-analyses that came out earlier this year. We just wanted to confirm what we had found on the meta-analyses. So, we were able to get access to a very large dataset, the IBM marketplace dataset from the United States. We were able to study it and see if we could find similar results to what we found in our meta-analysis.

Chew: Our meta-analyses did find about a 5% risk of sepsis. We were quite happy that we were able to actually confirm this finding with this large, real-world data set.

Bhojani: And the interesting thing with the meta-analyses was that—I mean, obviously, it's a pooled incident—the rate that we found in those articles was between 0.5% all the way up to 18%. Like Dr. Chew just said, here we're confirming that it's about 5% to 5.5%, which is really exciting.

What is the current incidence of sepsis after ureteroscopy?

Chew: I would say it's 5%. Naeem, what did you think of that number when you first saw it?

Bhojani: I was surprised from the meta-analyses. I was very surprised. It's interesting because when we speak to many urologists, they're also very surprised. They don't seem to see that rate, but I think now we've confirmed it.

Chew: It seems high that 1 in 20 of your patients will actually get septic. But when you look back and look at your own numbers, if you're able to track all those patients, sometimes they go to another hospital, sometimes they present elsewhere. I think it's a real number, and this is real-world data that shows that this is probably the right number.

What were some of the notable findings from these studies? Were any of them surprising to either of you or your co-authors?

Chew: I'll tackle the systematic review. There were 6 predictors of urosepsis after ureteroscopy. One of them was having a stent placed preoperatively. And also, if you had a positive preoperative urine culture, and people with ischemic heart disease, and diabetes. Also, people who were [of] older age, and then people who have longer procedure time. Those are the 6 predictors from the systematic review.

Bhojani: When we looked at that, in the large data set, we found similar results. Diabetes was a predictor, older age was a predictor, comorbidity was a predictor as well—similar results to what we found in the systematic review.

Chew: I think we were able to track more in the MarketScan database was whether or not patients were already an inpatient. And patients who were an inpatient at baseline or had inpatient visits within that time for other reasons actually did worse as well, too. So, I think this goes along with them having a higher comorbidity score. You're in and out of the hospital for other reasons, perhaps even the stone. And certainly, they don't do as well, and they have a higher risk of sepsis.

Bhojani: And then, of course, if they had a history of sepsis in the past was also a predictor of sepsis after ureteroscopy. [The cost] was [also] 1 of the things that we thought was quite impactful. A normal ureteroscopy is almost $18,000 USD. But if there's a septic event, it goes up to almost $50,000. And if they have a severe septic event, almost $70,000. So, not only is sepsis a very morbid and associated condition, but it's also very expensive.

What is the significance of these studies’ findings for the practicing urologist as well as for the patient? What are the ways in which urologists can mitigate the risk of post-operative sepsis?

Chew: I think it's to be aware of this. And I think that we've identified these 5 to 6 factors now that you should really be aware of. We need to have more personalized medicine looking at each of these cases and not just have a cookie cutter approach that everyone gets this amount of antibiotics or no antibiotics. We need to realize that patients with higher comorbidity score need to be treated more likely to have sepsis. And for me, I think the easier one, the easiest thing, the low-hanging fruit, is really those with a preoperative stent and preoperative sepsis. If someone comes in with preoperative sepsis and gets a stent, they are at higher risk of getting sepsis afterwards. Naeem, you've done some data on how long the stent should stay in. So, when do you recommend or based on your opinion, when a patient should get the definitive ureteroscopy?

Bhojani: That's a great question, Ben. If you can get them in the operating room in 2 weeks after [the] placement of a stent, that would be ideal. But we know that once you get past a month, [there are] increasing complications, increased costs. There are a lot of associated factors when you wait longer. So, I definitely agree with you. Ben, what would you do if you had a patient who had these predictors of sepsis? Is there anything you modify in terms of your preparation for that surgery?

Chew: The guidelines say that you just need some perioperative antibiotics right around the time of [surgery]. I just give 1 dose, usually of sulfasalazine at the time for most uncomplicated patients. But I think these patients are a completely different ballgame. We need to follow up on their cultures, on what they had when they became septic. They perhaps need to have their preoperative antibiotics tailored to whatever that organism was. You should consider even giving —the studies show—between 2 to 5 days of some preoperative antibiotics as well, too. Would you give antibiotics postoperatively to all your patients? Or would you treat these ones differently?

Bhojani: [For] these patients, especially the ones who worry me with multiple predictors of sepsis postoperatively, I definitely try to limit the surgery time because we know that's 1 of the predictors. I'll even keep them in house for 24 hours just to make sure they don't become septic. Postoperative antibiotics is tricky. I haven't started doing that. Not yet anyways. How about yourself?

Chew: I haven't done that either just on a routine basis. Some of the studies show that they could benefit from postoperative antibiotics. I must admit, I've not always done that, particularly if things look okay while I'm in there. If things do look a little bit cloudy, they will have some inflammation, obviously from the stents, but sometimes that's hard to judge. But they don't always get septic, and they don't always need antibiotics postoperatively. I think that could be, in my opinion, a result of picking good antibiotics beforehand based on their preoperative cultures. Naeem, what else would you change? What else would you think we should do for our patients based on this data?

Bhojani: Consent. Really explain [to] patients the risks associated with ureteroscopy. We have a tendency to minimize them. Like you said, 1 in 20 can have a septic event. And so, consenting patients, explaining [to] them the risks associated with the procedure, especially if they have risk factors, so that they understand the implications and try to prepare them as best you can.

Chew: The other thing I would change is [since] OR time is very precious here, the practice of pre-stenting patients to make the secondary ureteroscopy easier may not be indicated based on these data. Now, we don't know exactly why these stents were placed from this dataset. Was it an initial preoperative sepsis, which we know places them at higher risk? Or was it that they came in, had an obstructing stone, had a stent placed, and then are going for ureteroscopy definitively, usually by someone else who's more comfortable doing ureteroscopy? There is some good quality of life data showing that if you come in and get a stent and then come back for ureteroscopy, those patients really do have a much poorer quality of life because you have the stent in for a much longer time than if you just underwent a primary ureteroscopy. Of course, if you're septic you need to put a stent in just to drain the infected system and give antibiotics, but I would like to perhaps discourage the use of preoperative stenting, just on the basis of trying to get people out of trouble and bringing them back for a secondary "easier ureteroscopy.” They are at higher risk for getting sepsis.

Bhojani: Absolutely agree. [When] a patient comes in with a stone, as long as they're not infected, I definitely try to remove the stone and not just pre-stent.

What is the take-home message for the practicing urologist?

Bhojani: I think Ben said it best. We shouldn't use a cookie cutter approach. We should really try to adapt, know what we're doing to the specific patient based on their risk factors, prepare them appropriately, and understand that it's a dangerous complication. We should do everything we can to prevent it.

Chew: I think identifying any preoperative urine cultures. We really should kind of dig in and, hopefully, there's some type of either state, national, or provincial system where you can look at what urine cultures they've had. We certainly tried to track those down to give them the best preoperative antibiotics at the time of surgery. And then, I think all the other things—that if they are stented, try and get them done within 2 weeks, if possible, after they've overcome their sepsis episode. And other studies show before 4 weeks, so somewhere between 2 to 4 weeks. And if you do it after that, the risk of sepsis really does go up.

I think the other thing is consent. Like Naeem said, making sure they know about this, but also limiting your operating time. We know that longer times will basically result in higher rates of sepsis. Why is that? Is it just the mere fact of us being there with our irrigation? Can we somehow decrease that pressure? We need some more studies done on intrarenal pressure to look at whether or not this actually affects the rate of sepsis or not. And, with this, what type of irrigation are you using? If you're just using it for a shorter time, that's obviously going to be a lot better. And that's been shown in this study—that shorter operative times are certainly going to be better for the patient. So, we don't know if it's intrarenal pressure. Using a ureteral access sheath would be helpful because we know from other studies that that actually helps decrease the intrarenal pressure. And then, perhaps, should we even be staging some of these stones? If we go over some of these times, should we be going ahead and stopping and bringing the patient back another time?

Is there anything else you feel our audience should know about these studies?

Chew: Sepsis is real, and it's around 5%. I was surprised too, but this is what the actual data shows, and we should be aware of it.

Bhojani: I agree.

References

1. Bhojani N, Paranjpe R, Cutone B, et al. Identifying predictors of sepsis post-ureteroscopy in a US-based population: results from the Endourological Society TOWER Collaborative. Paper presented at: 38th World Congress of Endourology; September 23-25, 2021; Hamburg, Germany. Abstract MP32-02

2. Bhojani N, Paranjpe R, Cutone B, et al. What is the cost of sepsis after ureteroscopy? Results from the Endourological Society TOWER Collaborative. Paper presented at: 38th World Congress of Endourology; September 23-25, 2021; Hamburg, Germany. Abstract MP32-03