Non-gonococcal Septic Arthritis: Initial Treatment and Management

00:01 So we're confident in our diagnosis.

00:03 Here's one important point though, even though his gram stain was negative, which may have been what could have steered you away from non-gonococcal septic arthritis, don't hang your hat on just the gram stain.

00:15 We need to wait for the culture to come back.

00:17 In the meantime, we're absolutely gonna start antibiotics while waiting for that culture to come back.

00:23 In terms of thinking about the initial treatment and which antibiotics to use, the bacteria that cause the bacteria that cause non-gonococcal septic joint are Staph. aureus, Staph. aureus and Staph. aureus.

00:34 Yes there are some other organisms that can cause it, absolutely you may see gram negative organisms, you may see streptococcus but Staph is gonna be your most likely agent.

00:44 And because of that, we have a very low threshold to put on vancomycin to treat potentially methicillin-resistant Staph. aureus which is increasingly common.

00:53 So looking at this algorithm, starting at the top, if you have results on the gram stain: gram positive cocci or gram negative rods, that may steer you.

01:01 But if it's negative, you just automatically presume you're gonna have Staph and start somebody on Vancomycin.

01:07 If the gram stain is positive, then you can make a bifurcation here on the road if you clearly see gram positive cocci, obviously you'll start Vancomycin.

01:16 If you clearly see gram negative rods alone, then you're thinking about E.coli, Serratia, Klebsiella, etcetera then it's okay to specifically treat with Ceftriaxone while awaiting further speciation of your microbial cultures.

01:31 So, again management: You're gonna obtain the blood cultures, start antibiotics while waiting for more information.

01:37 Once you get more information from the culture data, you can narrow your antibiotics.

01:42 You may need to perform serial aspirations.

01:44 This is often the case if there is a real septic joint, you may want to confirm that the infection has fully resolved especially if you're talking about hardware or prosthetic joint.

01:55 And if need be, you can get Infectious Disease on board as well, because the management of prosthetic joints can be particularly challenging.

02:02 Okay, so let's highlight a few key points.

02:04 Acute monoarticular arthritis is the classic presentation for non-gonococcal arthritis and the knee is the most common.

02:11 Look for risk factors: injection drug use, sickle cell disease, prosthetic joints which necessitate getting an ID consult.

02:19 and any recent surgery that could've made the patient bacteremic You're looking for a large effusion.

02:24 it should be a hot, inflamed joint.

02:26 and certainly your polymorphonuclear cells would really be above 50,000 unless for some reason they've recently received antibiotics.

02:34 Fourthly, Staph aureus - that's the big bug and that's why you'll need Vancomycin on board You can see strep, you may see gram negatives but look for Staph and because of that, Vancomycin is your starting antibiotic or you can narrow to Ceftriaxone or something down the road once you got to more data.

02:51 You may need to irrigate the joint depending upon which joint is involved.