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50: Bad to the Bone
Episode 5015th August 2022 • Febrile • Sara Dong
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Drs. Emily Niehaus and Laura Certain take on the challenging topic of vertebral osteomyelitis 

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Sara Dong:

Hi everyone.

Sara Dong:

Welcome to Febrile, a cultured podcast about all things infectious disease.

Sara Dong:

We use consult questions to dive into ID clinical reasoning, diagnostics, and antimicrobial management.

Sara Dong:

I'm Sara Dong, your host and a Med-Peds ID fellow.

Sara Dong:

Here on Febrile, we use patient cases and chat with ID discussants to learn more about high yield ID topics.

Sara Dong:

And I can't believe it, but we'll take any excuse to celebrate because this is the 50th episode of Febrile.

Sara Dong:

Thanks to everyone who listens to the show, to everyone who has supported, created, contributed or joined for prior episodes, and to those who have shared Febrile with a friend.

Sara Dong:

Today, I am joined by my co-host Emily Niehaus.

Sara Dong:

Emily completed her medical school training at the Emory University School Medicine followed by Internal Medicine residency at the University of Utah.

Sara Dong:

Emily was a resident when she created this episode, but since recording, she has now become a brand new ID fellow at Duke University!

Sara Dong:

As our guest discussant today, we are joined by Laura Certain.

Sara Dong:

She is an Assistant Professor of Medicine in the Division of Infectious Diseases and an Adjunct Assistant Professor of Orthopedics at the University of Utah and Chief of Infectious Diseases at the Salt Lake City VA Medical Center.

Sara Dong:

She received her MD and PhD degrees from the University of Washington in Seattle and her Internal Medicine residency and Infectious Disease fellowship training at Massachusetts General Hospital in Boston.

Sara Dong:

After fellowship, she completed a post-doctoral research fellowship, studying prosthetic joint infections in an animal model, and then moved to Utah in 2017 to focus more on clinical care of humans with orthopedic infections and a little bit less on mice.

Sara Dong:

She is currently the Vice President of the Muscoloskeletal Infection Society, a national organization of orthopedic surgeons, infectious disease physicians, and microbiologists with interest in orthopedic infections.

Sara Dong:

Welcome to the show, guys, how are you doing?

Laura Certain:

Doing great.

Laura Certain:

Thanks for having us.

Emily Niehaus:

Hi, Sara.

Emily Niehaus:

Doing really well.

Sara Dong:

Great.

Sara Dong:

Before we jump into the case, we always ask about a little piece of culture.

Sara Dong:

Uh, are you guys willing to share something that you have enjoyed recently?

Laura Certain:

Sure.

Laura Certain:

So, and just so people can get to know our voices.

Laura Certain:

I'm Dr.

Laura Certain:

Laura Certain, I'll be the discussant for this case.

Laura Certain:

And the other voice you're hearing is, uh, Emily Niehaus.

Laura Certain:

So I love to read, um, as a way to escape.

Laura Certain:

Uh, and one of the best books I've read recently is, uh, The Lincoln Highway by Amor Towles.

Laura Certain:

Highly recommend it.

Laura Certain:

I also recommend The Gentleman in Moscow, which he also wrote.

Sara Dong:

What about you, Emily?

Emily Niehaus:

Okay, cool.

Emily Niehaus:

Um, I am gonna recommend a piece of culture, I don't know how high quality it is, but the TV show, um, Inventing Anna, um, which is highly entertaining.

Emily Niehaus:

And, um, I feel.

Emily Niehaus:

Kind of a, uh, based on a true story.

Emily Niehaus:

I don't know how realistic, but a lot of intrigue.

Sara Dong:

Yeah.

Sara Dong:

It's a, uh, one of those stories that it just seems crazy that it ever happened, even even if they made up some of it, it, it feels, um, a little unbelievable.

Emily Niehaus:

mm-hmm

Emily Niehaus:

. Sara Dong: All right.

Emily Niehaus:

Well, I'll hand it over to you, Emily to get us started.

Emily Niehaus:

Okay.

Emily Niehaus:

So we're gonna just dive right into our case.

Emily Niehaus:

We have a 65 year old male who has a history of diabetes, uh, CKD, BPH, osteoarthritis, and then had a recent hospitalization for COVID who presents to the emergency department for one month of low back pain and three days of fever.

Emily Niehaus:

And that was documented up to 101 at home.

Emily Niehaus:

He's had some mild intermittent chronic back pain for many years, but four weeks ago, this became persistent and it's progressively worsened since that time.

Emily Niehaus:

He doesn't describe any lower extremity weakness, numbness, saddle paraesthesia, or radiating pain down his legs.

Emily Niehaus:

He has some chronic issues with nocturia and sensation of incomplete bladder empty.

Emily Niehaus:

But no new urinary or bowel incontinence and no recent pain or burning with urination.

Emily Niehaus:

He denies chills, uh, night sweats, lethargy, nausea, or weight loss.

Emily Niehaus:

And his review systems is otherwise negative.

Emily Niehaus:

So on his exam, uh, he has a temperature of 38.1.

Emily Niehaus:

Blood pressure of 142/82, and his heart rate's 94 and he's saturating, uh, 96% on room.

Emily Niehaus:

Complete exam is notable for, uh, spinal tenderness to palpation over the upper lumbar spine and range of motion on both extension and flexion was limited, mostly due to discomfort.

Emily Niehaus:

He had normal sensation to light touch over bilateral lower extremities and straight leg tests were negative as well.

Emily Niehaus:

And his notable workup in labs showed a white count of 12.2.

Emily Niehaus:

A hemoglobin of 10.5 and platelets of 420 and a creatinine of 2.5 with a BUN of 45, which is around his most recent baseline.

Emily Niehaus:

And his inflammatory markers, he had an ESR of 45, uh, CRP of 12, uh, imaging that he had initially, um, a chest x-ray with no acute cardiopulmonary process demonstrated.

Emily Niehaus:

And then an MRI of his lumbar spine was obtained in the emergency department as well.

Emily Niehaus:

And this showed marrow edema and enhancement within the L2 and L3 vertebral bodies with no notable loss of, um, body height.

Emily Niehaus:

And he had abnormal signal and enhancement throughout the L2-L3 disc space.

Emily Niehaus:

He had no epidural fluid collection and, um, he'd also had edema in enhancement within the paraspinous musculature.

Emily Niehaus:

So at this point, we are the infectious disease team and called by the primary team who's admitting this patient due to concern for infectious process.

Emily Niehaus:

Um, so the first question is how does this presentation compare to the usual presentation you might expect for discitis, um, or osteomylitis.

Laura Certain:

All right.

Laura Certain:

Thank you for that presentation.

Laura Certain:

And I would say this is probably a fairly common scenario that all ID fellows have been called about probably within their first week of ID fellowship.

Laura Certain:

um, and I'd say, honestly, the thing that makes this case a little bit different, this presentation, a little different, or, um, A bit atypical is actually the fever.

Laura Certain:

So fever is, can be present in vertebral osteo.

Laura Certain:

Um, but it is not always, it's only maybe half the time that you'll get a fever.

Laura Certain:

So it's important to remember that if a, let's say this patient presented with just the back pain, like everything else is exactly the same, but no fever, you would still be worried about, um, vertebral osteo.

Laura Certain:

So it's important to remember that a patient was sort of new onset back pain, that's persistent or steadily worsening over the course of weeks, certainly warrants further workup.

Laura Certain:

And usually that workup involves, um, uh, spinal MRI.

Laura Certain:

Sometimes people will start with x-rays, but really, if you're worried about vertebral osteo, then a spinal MRI is the imaging modality of choice.

Laura Certain:

We often also get, um, the inflammatory markers, so sed rate (ESR) and CRP, um, they are fairly sensitive, but not that specific obviously.

Laura Certain:

And if it's an infection with kind of a low virulence organism, they may be normal or only mildly elevated.

Laura Certain:

So again, they can make you sort of more or less worried about a patient , but they almost never tell you what to do for your patient, is how I think about ESR and CRP.

Laura Certain:

Um, so in this case, I would say it's a typical presentation.

Laura Certain:

Um, and we can be fairly suspicious that the MRI findings are infectious in etiology.

Emily Niehaus:

Great.

Emily Niehaus:

Okay.

Emily Niehaus:

So we're gonna learn some more about this guy.

Emily Niehaus:

So his medical history is in a little more detail.

Emily Niehaus:

He has diabetic and hypertensive nephropathy.

Emily Niehaus:

And he had a recent progression of his CKD to stage four.

Emily Niehaus:

He has diabetes, that's fairly well controlled recently with an A1C of 7.6.

Emily Niehaus:

And he is, uh, using insulin to control that.

Emily Niehaus:

Uh, he has BPH and he takes tamulosin for that, but has no, um, acute urinary retention issues and osteoarthritis mostly affecting his knees and he takes Tylenol and has intermittent joint injections for that.

Emily Niehaus:

Recently, uh, he had a hospitalization for COVID two months ago.

Emily Niehaus:

And during this hospital stay, he was treated in the ICU for a few days, requiring high flow nasal cannula, um, did receive a few days of antibiotics and, um, has now fully recovered with no oxygen needs.

Emily Niehaus:

He has, uh, no medication allergies.

Emily Niehaus:

And, um, his social history.

Emily Niehaus:

So he reports that he was born in Mexico.

Emily Niehaus:

Um, he worked in construction between the United States and Mexico for the last 20 years.

Emily Niehaus:

Um, but then moved to the US full time five years ago, to be closer to his family.

Emily Niehaus:

He's lived for extensive periods of time in Northern Mexico, Southern California, Arizona, and Utah.

Emily Niehaus:

He has no history of injection drug use.

Emily Niehaus:

He drinks about 10 beers a week.

Emily Niehaus:

He's a never smoker.

Emily Niehaus:

Uh, and he did have periods of homelessness while living in the US in the eighties, but very distantly, um, and no known exposure to a person diagnosed with TB.

Emily Niehaus:

For other exposures, he did interestingly live on a ranch with livestock in Mexico for the last several years before coming to the us, um, with some intermittent exposure to the animals.

Emily Niehaus:

Um, and he's unsure if he's ever consumed unpasteurized dairy products.

Emily Niehaus:

So now that we have all this information, um, my question is what are this patient's important risk factors for vertebral osteomyelitis and how may these risk factors or other components of its medical or social history impact your differential diagnosis for the microbiology of this possible infection?

Laura Certain:

All right.

Laura Certain:

Lots of fun clues in that, uh, further history.

Laura Certain:

So in general, the pathophysiology of vertebral osteomyelitis is that a transient bacteremia or not so transient bacteremia finds a site of prior damage in the spine and then sets up shop and causes this chronic osteo infection.

Laura Certain:

So the typical patient, at least that we see in the US is an older person with some sort of preexisting degenerative disease of the spine.

Laura Certain:

And usually in humans, that's the cervical or lumbar spine.

Laura Certain:

That's where we typically have, um, wear and tear in our spine.

Laura Certain:

So those are, that's the most common side of sort of the routine pyogenic vertebral osteo.

Laura Certain:

. Um, and so you can obviously get direct extension from a surgical site after spine surgery, but in the person with no prior trauma or no prior known intervention than the spine,

Laura Certain:

usually it's headed to a site of, um, prior, um, wear and tear damage.

Laura Certain:

So in, and I will say that this patient's, um, chronic medical conditions probably make him sort of on the mild, mildly immune compromised side with his CKD.

Laura Certain:

And so that may also have put him more at risk for infection.

Laura Certain:

now Staphylococcal species are by far the most common cause.

Laura Certain:

Um, but Strep and Gram negatives make up a sizable portion.

Laura Certain:

And so because of, um, the pathophysiology coming from bacteremia, IV drug use is a significant risk factor though not an issue for this patient.

Laura Certain:

Um, this patient had a recent hospitalization for COVID, so that probably meant he had some sort of lines put in, IVs probably at some point, maybe for his remdesivir or whatever.

Laura Certain:

So in theory, he could have had a bacterimia associated with that.

Laura Certain:

He could have had a superimposed bacterial pneumonia that might have made him transiently bacteremic.

Laura Certain:

Given his BPH, maybe he had a UTI recently that he just forgot about, or hasn't told us about and had bacteremia from.

Laura Certain:

So I think any of those things could have led to a transient bacteremia that has now caused for vertebral osteomyelitis.

Laura Certain:

So in the US, we are normally seeing sort of routine run of the mill bacterial, um, vertebral osteomyelitis.

Laura Certain:

In other parts of the world, um, Brucella and TB, uh, make up a large proportion of cases.

Laura Certain:

So it's important to keep those in mind.

Laura Certain:

And now this patient, for example, he's not sure about his consumption of, uh, unpasteurized dairy products, uh, and has, uh, lived in parts of the world where TB is more common.

Laura Certain:

So certainly you could consider TB, um, vertebral osteo or Potts disease.

Laura Certain:

Traditionally that is thought to involve the thoracic vertebrae more often, but obviously TB can do kind of whatever it wants.

Laura Certain:

So just cuz it's not thoracic doesn't mean that it's not TB.

Laura Certain:

Of note, I was, um, in preparing for this, uh, podcast, I was looking at studies and there was a study from Turkey, looking at their cases of, um, vertebral osteo and 45% of them were Brucella and 29% were TB.

Laura Certain:

So just to get, which of course is not at all our experience in the US.

Laura Certain:

Right.

Laura Certain:

Um, and I also should note that Brucella, my husband calls it Mediterranean cheese disease because he, uh, helped me study for the boards.

Laura Certain:

And that's one of the few things he remembers is that Brucella is Mediterranean cheese disease.

Laura Certain:

um, that and tularemia is aerosolized rabbit disease.

Laura Certain:

But in any event, um, so, uh, in this patient, Brucella and TB, you know, possible.

Laura Certain:

Um, so worth considering you could send an interferon gamma release assay.

Laura Certain:

Granted that is not, that's a test for latent TB.

Laura Certain:

You should not be using it to diagnose active TB, but actually in that study from Turkey, the, a positive PBD had a sensitivity of 0.66, and specificity of 0.97 for diagnosing TB vertebral osteo, which is better than I would've thought.

Laura Certain:

So in a population where it's common, maybe it is helpful.

Laura Certain:

This patient also has risk for endemic fungi, especially Cocci[dioides], um, having spent time in Southern California, Arizona, et cetera.

Laura Certain:

So that certainly can cause um, vertebral osteo , Cocci can cause bone and joint infections.

Laura Certain:

Um, but it's pretty darn rare.

Laura Certain:

So you could consider sending Cocci serologies or looking for other, you know, uh, serum markers of endemic fungi.

Laura Certain:

But again, most likely this guy is gonna have a routine run of the mill, um, standard bacterial vertebral osteo.

Emily Niehaus:

Awesome.

Emily Niehaus:

That's great review.

Emily Niehaus:

And, um, so let's see what happened to this guy.

Emily Niehaus:

So he was admitted, um, to the general medicine service and he did have orthopedics, uh, spine service that was consulted for him in the emergency room.

Emily Niehaus:

They didn't recommend surgery at this moment, um, because he had a normal neurologic exam, but they were gonna follow him through his hospital, stay and look for some dynamic change.

Emily Niehaus:

When he gets to the floor, he's hemodynamically stable.

Emily Niehaus:

And, um, I just wanna start broadly, what workup and treatment would you first recommend, um, for this patient?

Laura Certain:

So all patients presenting, uh, with concern for vertebral osteo should get blood cultures.

Laura Certain:

Because if you get lucky, or I don't know if this is lucky, but if they have a Staph aureus bacteremia, not exactly so lucky for the patient mm-hmm , but it does mean that they don't have to have their spine biopsied, so in that sense, it's lucky.

Laura Certain:

Cause again, IDSA guidelines would say, um, that if you have positive blood cultures with an organism that is known to cause vertebral osteo such as Staph aureus, or Staph lugdunensis, then you can stop there.

Laura Certain:

You can just assume that that is the culprit bug and you do not need to pursue further, um, diagnostic workup in terms of identifying the culprit pathogen.

Laura Certain:

Um, so you definitely would want blood cultures prior to starting antibiotic.

Laura Certain:

As we discussed above, you might send some other tests depending on risk factors.

Laura Certain:

So test serum markers for, and serologies for fungal infections.

Laura Certain:

If you think it might be that again, you can send an interferon gamma release assay, though.

Laura Certain:

You might get yelled at, by other ID attendings who insist that that is for latent TB testing only, and you should not be sending it in patients where you're considering active TB, but really this person is probably headed for, uh, a bone biopsy.

Laura Certain:

So probably you're gonna be calling your IR colleagues, uh, to get a sample of the infected tissue to send for culture and path if they can.

Laura Certain:

Sometimes they don't get a ton of tissue.

Laura Certain:

So you're sometimes limited by amounts.

Laura Certain:

Um, obviously if there's abscess, you want them to drain the abscess and in a pinch, maybe you might end up with a surgical biopsy, but almost certainly the first step is a CT guided biopsy and you should be holding antibiotics in a stable patient until you have a microbiologic diagnosis.

Laura Certain:

That said, I mean, so there's a lot of emphasis on holding antibiotics until you get the biopsy done.

Laura Certain:

A single dose of vancomycin or whatever is unlikely to actually affect the biopsy results that much.

Laura Certain:

But don't tell anybody that because no, just tell them they keep holding antibiotics until you've got those tissue samples and potentially until you actually have a diagnosis.

Laura Certain:

Because the sensitivity of these bone biopsy is not great.

Laura Certain:

There's a huge range out there in the literature, but maybe 50 50 that you're gonna get your answer from a single biopsy.

Laura Certain:

And so then.

Laura Certain:

if that biopsy is negative, right?

Laura Certain:

Doesn't give you the answer or grows like one colony of Staph epidermidis, and you're like, well, is that real?

Laura Certain:

Is that not real?

Laura Certain:

You're left, basically trying to convince people to do it again.

Laura Certain:

um, or convincing the surgeons to do an open biopsy or just treating empirically.

Laura Certain:

So I think there are studies that show increased yield with a second needle biopsy, um, or an open biopsy.

Laura Certain:

I feel like in practice, usually they get their one biopsy,

Laura Certain:

as soon as they're done, they get started on empiric antibiotics, and sometimes they'll get the answer and sometimes they just get treated empirically.

Emily Niehaus:

Yeah.

Emily Niehaus:

So you, that was exactly where this patient was heading.

Emily Niehaus:

he, um, he ended up getting blood cultures.

Emily Niehaus:

He did get a dose of a vancomycin and ceftriaxone in the emergency room.

Emily Niehaus:

And then, um, they were held, cultures were awaited.

Emily Niehaus:

He was stable.

Emily Niehaus:

And by day three, he had no growth on his blood cultures.

Emily Niehaus:

So, um, he underwent a CT guided biopsy.

Emily Niehaus:

The cultures of that eventually grew methicillin resistant Staphylococcus aureus, and his pathology was also consistent with acute osteomyelitis.

Emily Niehaus:

So at that point, his antibiotics, he was, uh, started on vancomycin and now the ortho team signed off because there's no plan for surgical management, just medical management.

Emily Niehaus:

So the question is what is our medical management and how should we approach this, um, duration of antibiotics and monitoring going forward?

Laura Certain:

So the typical duration for vertebral osteo is six weeks of antibiotics.

Laura Certain:

Um, uh, there was a randomized clinical trial, uh, published in the Lancet in 2015.

Laura Certain:

Um, showing that six weeks was non-inferior to 12 weeks of antibiotics for pyogenic vertebral osteo.

Laura Certain:

So that has made six weeks pretty much the standard course, whether to treat with PO or IV antibiotics.

Laura Certain:

I feel like in the post OVIVA era, you can switch to PO whenever you want, if you have antibiotic that has good oral bioavailability, that will treat the infection.

Laura Certain:

Of note in that Lancet paper looking at duration of treatment, the most common regimen was actually a quinolone plus rifampin so not IV antibiotics.

Laura Certain:

In this patient, um, his kidney disease may make it a little bit challenging to treat, right.

Laura Certain:

So vancomycin is fine, but may be difficult to monitor.

Laura Certain:

You're gonna wanna be real careful that he doesn't get supratherapeutic on his vanco.

Laura Certain:

You could consider daptomycin instead.

Laura Certain:

High dose Bactrim (trimethoprim-sulfamethaxazole) I'd probably avoid in this patient,

Laura Certain:

that seems like it could be challenging, uh, in somebody with renal disease.

Laura Certain:

If his isolate was susceptible and his drug drug interactions didn't preclude it, levofloxacin + rifampin could be an option for him as well.

Laura Certain:

Linezolid is pretty hard to tolerate for six weeks and tedizolid is pretty hard to get.

Laura Certain:

So I think for him, he is probably likely to be discharged on vancomycin and then monitored thereafter.

Laura Certain:

Now a lot of people will trend, uh, sed rate and C R P uh, to try to give, to see who's responding and how things are going.

Laura Certain:

And they can give you some sense of who's responding to therapy, but it's not clear what to do if they don't respond.

Laura Certain:

So there's data that like, if they don't fall, those are patients who are likely to quote unquote, fail therapy or have a recurrence of infection after you stop.

Laura Certain:

But it's not clear that treating them for longer is gonna solve the problem or whether they just need surgical debridement for source control.

Laura Certain:

So we, we look at them, but again, they can make you more or less worried.

Laura Certain:

They never tell you what to do.

Laura Certain:

I think, and in speaking of recurrence, I mean, you do wanna make sure that the patient didn't have an undrained abscess, right?

Laura Certain:

That's something that might mean make them more likely to fail medical management only if they had an undrained abscess, um, also renal disease and diabetes can make patients more likely to fail.

Laura Certain:

So this and the fact that this patient has MRSA, all of that is a little bit worrisome in terms of his overall prognosis.

Laura Certain:

So I think in general, for this patient, you would probably put 'em on vanco[mycin] or dapto[mycin],.

Laura Certain:

Check blood work weekly and see how he responds clinically.

Laura Certain:

We typically do not get repeat imaging.

Laura Certain:

A lot of patients will ask like, well, shouldn't I get an MRI at the end of my therapy to make sure that I'm all better and the answer is no, you should not do that.

Laura Certain:

Uh, especially if the patient is feeling better, if their pain is getting better, their inflammatory markers are coming down, et cetera.

Laura Certain:

Um, patients get better long before their imaging does.

Laura Certain:

And so the imaging will likely, still be abnormal at the end of those six weeks, so if everything else is pointing in a good direction, you just stop therapy.

Laura Certain:

You do not get repeat imaging.

Laura Certain:

Now, if you are worried about someone like their inflammatory markers aren't coming down, they're having persistent or worsening pain.

Laura Certain:

that's a time when I do get repeat imaging, because maybe they have developed an abscess, maybe they've developed a drainable fluid collection.

Laura Certain:

Uh, so that would be important to know because that you're not gonna solve that problem with antibiotics likely, you need your surgical colleagues to intervene.

Emily Niehaus:

Okay.

Emily Niehaus:

Well, so our patient, um, he did, um, he was discharged on three weeks of vancomycin followed, um, with labs.

Emily Niehaus:

And, uh, outpatient follow up with ID.

Emily Niehaus:

Um, he was actually transitioned to doxycycline after three weeks, um, to complete his course.

Emily Niehaus:

And initially, uh, his symptoms had improved.

Emily Niehaus:

He was feeling good at that first follow appointment around like two week mark.

Emily Niehaus:

And then at six week follow up appointment.

Emily Niehaus:

Um, he described, uh, new radiating lightning, like pain down his left leg, um, and his back pain just wasn't better.

Emily Niehaus:

He didn't have any fevers or chills that he was describing and his vital signs were normal in clinic.

Emily Niehaus:

His exam was similar to when he was first evaluated.

Emily Niehaus:

It's like spinal tenderness.

Emily Niehaus:

Um, and then his inflammatory markers kind of throughout his course did not, um, change drastically.

Emily Niehaus:

And actually at this six week point, his ESR is 40 and that was 45 initially.

Emily Niehaus:

And his CRP is 15.

Emily Niehaus:

So that was 12 initially.

Emily Niehaus:

And then now, because of concern for an unresolved infection, a repeat MRI was obtained and that showed progressive end plate destruction of L2-L4 and a new epidural fluid collection, um, with a phlegmon or abscess at the level of two to three, and this was contributing to spinal canal stenosis..

Emily Niehaus:

So at this point, orthopedic surgery was called and reviewed the imaging and he ended up being admitted to the hospital for a planned decompression infusion of his spine.

Emily Niehaus:

Um, the surgery was performed and then he had operative cultures of both the abscess and the bone, again, that grew MRSA.

Emily Niehaus:

And he was started back on vancomycin after the surgery.

Emily Niehaus:

Um, but didn't receive any antibiotics beforehand.

Emily Niehaus:

So now this patient has had, uh, initial failed course of treatment.

Emily Niehaus:

Um, and now has hardware implanted.

Emily Niehaus:

So how should we address ongoing as a treatment failure at this point?

Laura Certain:

Yeah.

Laura Certain:

So this is unfortunately a not uncommon scenario.

Laura Certain:

You sort of treat the person appropriately at the get go, but you know, Staph are devious and sometimes they just win despite the antibiotics.

Laura Certain:

Um, and so now he's had a surgical debridement, so that's good that probably gonna help with his source control, but they've also stuck a bunch of new hardware directly into that infected space, which always makes us worried, um, about, uh, creation of biofilm on that on the hardware, making it harder to, um, eradicate the infection.

Laura Certain:

So this patient is looking at another prolonged course of antibiotics.

Laura Certain:

Exactly how long is not clear, but there was, um, a retrospective study of patients who had had hardware placed into an infected space, who had pyogenic vertebral osteomyelitis, and needed hardware placed for stabilization of their infected spine.

Laura Certain:

And in that study, longer was better.

Laura Certain:

So there were fewer recurrences in the patients who got more than eight or who got at least eight weeks of antibiotics after their surgery.

Laura Certain:

So I usually do at least eight weeks in these patients.

Laura Certain:

whether or not to add rifampin often comes up and I will say, I have also surveyed my ortho ID colleagues to ask them whether or not they would add rifampin in situations such as these and some do.

Laura Certain:

And some do not.

Laura Certain:

I think most feel that if there aren't contraindications to it, like they're not on Coumadin or some other, um, difficult to manage drug, drug interactions, and they tolerate the rifampin, it's probably worth adding it because it has well it's controversial and they're definitely the pro rifampin and the anti rifampin teams in ID.

Laura Certain:

I think there is data out there to suggest that it does help with biofilm related infections and therefore if your patient can tolerate it and there are no contraindications, it's reasonable to try.

Laura Certain:

I do not uniformly add rifampin in this scenario.

Laura Certain:

Um, but I do try to treat for at least eight weeks.

Emily Niehaus:

Good.

Emily Niehaus:

Yeah.

Emily Niehaus:

So we'll just kind of wrap things up with this case, um, to kind of give the ending result here.

Emily Niehaus:

Our patient was treated with eight weeks of antibiotics.

Emily Niehaus:

Rifampin was added, so he was able to tolerate that and he completed his antibiotics, had no further infectious symptoms, his pain improved, and his inflammatory markers also improved.

Emily Niehaus:

So overall good results.

Emily Niehaus:

So that's kind a conclusion to our first case.

Emily Niehaus:

I just kind of wanted to explore additional like hypothetical alternative situation that's a very common reason for consult as well for, or, um, spine infections.

Emily Niehaus:

Um, so we kind of discussed someone who had surgery and hardware implanted for a primary infectious process, but wanna discuss the alternative situation where someone had hardware implanted for a primary orthopedic indication and then subsequently developed infectious symptoms at that site.

Emily Niehaus:

So, how would you approach that scenario differently than what we've already discussed?

Laura Certain:

Thank you.

Laura Certain:

Yes.

Laura Certain:

That's a very common and also very challenging situation.

Laura Certain:

And one of the reasons it's challenging is cuz there's actually very little data to tell us how best to treat these patients.

Laura Certain:

Like I keep looking and I feel like maybe I'm U I must be using the wrong search terms or missing something because I keep trying like, surely someone has looked at this in some sort of thorough way, but no, I mean, as far as I can show the evidence out there is mainly, um, retrospective data from single centers and everybody's defined things a little bit differently and what they consider early infection versus late infections, superficial versus deep etc

Laura Certain:

so it's really challenging because we don't have any great data to guide our management of these patients.

Laura Certain:

Now it is, um, true that some people will distinguish between, um, a superficial infection versus a deep infection.

Laura Certain:

So superficial meaning that it was sort of above the fascia thought to be mainly just a skin and, and superficial soft tissue infection after surgery.

Laura Certain:

And those are usually treated with a relatively short course of antibiotics.

Laura Certain:

But what we're usually consulted on is when there's concern for deeper infections.

Laura Certain:

So infection of the surgical site that goes below the fascia, where they're concerned that it's an involving the bone and, or the hardware, or at least was really, really close to the bone and the hardware . And so they were worried that, uh, that bacteria are gonna, um, weasel their way in and like again, cause a concern for a chronic infection around the hardware in the bone.

Laura Certain:

So that's usually what we're talking about is these deep surgical site infections and usually early onset ones.

Laura Certain:

So usually ones that are presenting within the first three months.

Laura Certain:

Um, and usually even sooner than that after their initial fixation surgery.

Laura Certain:

Obviously, yes, people could have an infection at the site that would present further out from surgery, but that is much less common.

Laura Certain:

So usually what we're talking about is a relatively early, um, surgical site infection after spinal fusion surgery, where there's concern that the infection has progressed to involve the deep space and therefore could be involving the bone and, or the hardware.

Laura Certain:

so in terms of treating them, obviously the surgeons typically take 'em back to the, or open everything up, wash it out as best they can, take samples.

Laura Certain:

And that helps us know how to treat these patients.

Laura Certain:

Cuz we'll know the bug.

Laura Certain:

In terms of duration, uh, that is anyone's guess . And again, on these, uh, retrospective studies, the range of treatment was quite broad.

Laura Certain:

Um, some people will treat for six weeks, some people three months, some people keep patients on oral suppressive therapy for six months to a year, or maybe even indefinitely.

Laura Certain:

And I think for me, the decision on how long to treat people often is the shared decision making with the patient and the surgeon, because I don't know when every last bacteria has been eradicated from their spine, there is no test that's gonna tell me that they are cured and some fraction, it may be a small fraction, but some fraction of these patients, especially if they had a Staph infection may relapse after we stop therapy.

Laura Certain:

. And so I have to have that conversation with the patient and the surgeon about, well, if we stop antibiotics and you have a relapse, what is that gonna mean for you?

Laura Certain:

What surgery are you gonna need to have?

Laura Certain:

And what would that mean for your life?

Laura Certain:

So we'll often have a shared discussion about what the surgery would mean for them and how much they hate being on the antibiotics that they're on.

Laura Certain:

And that will help guide, uh, our management.

Laura Certain:

I also take into consideration the age of the patient.

Laura Certain:

So for example, if I have a otherwise healthy 35 year old who had spine fixation surgery, and it was a relatively small, um, section of their spine, Not a cervical to pelvis fixation, for example, but like a healthy person who had, you know, maybe three lumbar vertebrae fused, got an early postop MSSA infection got washed out and I put them on levofloxacin and rifampin for three months.

Laura Certain:

And at the end of that time, they're feeling great.

Laura Certain:

Their inflammatory markers have been normal for eight weeks.

Laura Certain:

Um, and they've had no issues then.

Laura Certain:

Um, I usually stop and see how they do.

Laura Certain:

In someone who was slower to respond to therapy or in whom I am more worried about what another surgery would mean for them medically, like they're more frail, they're elderly, et cetera, or their spine surgery was much more extensive to begin with.

Laura Certain:

I am more likely to keep them on long term oral antibiotics.

Laura Certain:

I also will sometimes keep patients on oral antibiotics or some kind of suppressive therapy until their spine has fused so that, um, if the infection were to recur, the hardware could be taken out, but spinal fusion can take six to 12 months from the time of their initial surgery.

Laura Certain:

So that's not a particularly short timeframe.

Sara Dong:

Yeah.

Sara Dong:

Yeah.

Sara Dong:

I think that's so important, weighing, like you said, the surgery versus I love how you framed it as how much they hate being on antibiotics.

Sara Dong:

I was thinking, as you were saying that it's totally true.

Sara Dong:

I've seen patients on the adult side and we have those conversations, but also when we have hardware infections in younger patients, it's obviously not feasible to have them on antibiotics forever.

Sara Dong:

um, and it's, it's like figuring out what is that appropriate timeframe.

Sara Dong:

And every time it just kind of feels like you're making it up still.

Sara Dong:

And maybe one day we'll feel a little bit more confident, but I'll think of a different way to say it other than we're making it up.

Sara Dong:

We're making our best guess.

Sara Dong:

But in many ways, that's, that's kind of what we're doing.

Laura Certain:

Yeah.

Laura Certain:

And I will say obviously the duration of therapy, both for hardware involvement or native vertebral osteo would be different if they did have TB or a fungal infection.

Laura Certain:

Obviously we've been talking in this episode mainly about, um, run of the mill bacterial infections.

Laura Certain:

Obviously you might consider much longer durations if it were a fungal infection or mycobacterial infection, those are sort of a different beast.

Laura Certain:

I think what I usually say to patients is some variation on, I have no way of knowing whether or not you're cured.

Laura Certain:

If we stop antibiotics and your infection comes back, you will need more surgery.

Laura Certain:

what do you wanna do?

Laura Certain:

yeah.

Laura Certain:

If I have the data to tell them what I think the chances are of their infection coming back, I will share that with them.

Laura Certain:

So for prosthetic joint infections, for example, we can often say like, well, typically people treated with a two stage exchange have a recurrence risks of X or whatever.

Laura Certain:

Unfortunately, we usually don't really have that data.

Laura Certain:

And so I'm kind of taking my guess of what I think their chances are.

Sara Dong:

well, you guys tackled a very big topic and I will leave it open one more time.

Sara Dong:

Is there anything else that you think people should know when we're thinking about spinal infections, osteomyelitis or anything that we've missed along the way?

Laura Certain:

I think we definitely hit the highlights.

Laura Certain:

I think, uh, this like all, um, orthopedic infections, which are my jam, uh, are.

Laura Certain:

It's important to have conversations with your surgical colleagues.

Laura Certain:

So whether that's neurosurgery or ortho spine, um, especially in a patient who is sort of failing medical therapy or about whom you are worried will be failing medical therapy, it's worth having that, um, conversation, um, with the surgeon because often, you know, the only real indication for surgery or one of the first indications for surgery is that they are having neurologic changes or severe, um, compression of the spinal cord, but sometimes you need surgery for source control.

Laura Certain:

Sometimes it's important to have that conversation with the surgeons and explain why you're worried that antibiotics alone are not gonna be adequate in this patient or why you're worried that antibiotics alone are not working in this particular patient.

Sara Dong:

Yeah, that's a great point.

Sara Dong:

All right.

Sara Dong:

Well, thank you guys so much for coming.

Sara Dong:

You're welcome back anytime, we need to cover a lot more ortho ID topics.

Sara Dong:

We'll get there slowly.

Laura Certain:

Sara would be delighted anytime to talk about ortho ID topics or whatever general ID topics.

Laura Certain:

I be happy to be back.

Laura Certain:

It's been fun.

Emily Niehaus:

Thanks Sarah.

Sara Dong:

Thanks for tuning in everyone.

Sara Dong:

Don't forget to check out the website, febrilepodcast.com to find the Consult Notes, which are written complements of the show with links to references, our library of ID infographics, and a link to our merch store.

Sara Dong:

Please reach out if you have any suggestions for future shows or wanna be more involved with Febrile.

Sara Dong:

Thanks for listening.

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