Zero to GP - GP Revision Podcast

Gout - Essential GP Revision

• Thomas Watchman • Season 1 • Episode 17

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0:00 | 16:16
SPEAKER_00

Hi, and welcome back to the Zero to GP podcast. This is Tom, and in this episode, I'm going to be going through Gout. As always, the format is I'll present you with cases and ask questions. I want you to come up with your answer, and then we'll see whether your answer is correct and go through the explanation. If you're preparing for your AKT exam, highly recommend the AKT revision book and using zero2gp.com where we've got multiple choice questions, short answer questions, flashcards, notes, and everything you need for your AKT preparation. I've also got an AKT revision course coming up in London on the 13th of September this year with me, where we go through the really high yield essential stuff you need to know, including statistics, admin, and all that kind of stuff. So that's a day-long course with me, 13th of September. And there's a link to find more in the description. But for now, let's get straight into this episode on gout. So the first case is a 62-year-old man, and he wakes up with severe pain in his foot. He's got no history of trauma, so he's not knocked it, it's come out of nowhere. And he shows you his foot, and you can see there's a big red swelling at the base of the big toe. So you take a look at this, and hopefully immediately your brain says, this looks like it could be gout. So you're suspecting gout. The first question I have for you is what's the cause of gout? What's actually happening here? The basic pathophysiology. So what's happening here is uric acid crystals are being deposited in the joint, and this is leading to joint inflammation. So you've got a 62-year-old man and you're suspecting a gout flare. So now we're going to go through a bit about gout flares and the treatment. So my first question is, or my next question is, what's the most common joints that are affected by an acute flare of gout?

SPEAKER_01

There are three commonly affected joints.

SPEAKER_00

We've already talked about the base of the big toe, the metatarsophalangeal joint at the base of the big toe. That's probably the most common. The next is the base of the thumb, so the carpometacarpal joint at the base of the thumb. And the third one is the wrist. So these are kind of the big three that you need to remember are commonly affected by gout. So you've got somebody with an acute gout flare. My next question is what's the first line treatment options? So the nice clinical knowledge summaries give you three options for treating an acute flare of gout.

SPEAKER_01

What are those options?

SPEAKER_00

So, like I say, there's three main options. The first one, which is what you'd kind of use if somebody's got no um no history of gastrointestinal problems, asthma, they're they're otherwise well, they're healthy, no kidney problems, or uncontrolled hypertension. In that case, you would use NSAIDs. NSAIDs work really the best overall. So for example, you could give neproxin, and when you prescribe NSAIDs at a high dose, often we co-prescribe a proton pump inhibitor like a meprazole or lanzoprazole to protect the stomach while taking the high doses of NSAIDs. So a typical treatment is neproxin plus a meprozole, and you do that until the gout is settled. The second option you have is colchicine, which is often used if uh NSAIDs are not suitable. Colchicine is a bit limited, and we'll talk more about colchicine in a moment. But um the other thing that limits it is you prescribe usually 500 micrograms two to four times a day, but the BNF for an acute flare of gout says it's only a maximum of six milligrams total per course. So if you're prescribing 500 micrograms four times a day, that's two milligrams a day, so you can only use a three-day course. And then once you've completed that six milligram course, you then have to wait three days before you can use colchicine again. So it's a little bit limited in how much you can give. The third option is a corticosteroid, for example, oral prednisolone, which also works well, but uh with any corticosteroids, there are side effects. Okay, on to the next question, which is what's the common side effect of gout? The most common side effect that I tend to warn people about when prescribing oh sorry, not gout, colchicine. So the most common side effect when prescribing colchicine that you would warn patients about. So the key thing is gastrointestinal upset, so that you can get nausea, abdominal pain, or diarrhea. And these side effects tend to be dose dependent. So if you're using a lower dose, they'll get less less side effects, and the higher the dose, the more side effects. The next question is what's the major risk with colchicine? What would make you nervous about prescribing colchicine to somebody? Colchicine is extremely toxic in overdose. So if you have somebody who's coming back with some confusion, heart failure, arrhythmias, or just generally unwell, think about colchicine toxicity. Okay, on to the next case. We've got a 67-year-old woman, and she presents with an acute, hot, and painful knee. So you can see her knee is swollen, red, hot, it feels very warm, and let's say she's otherwise okay in herself. My question to you is what are the key hot, swollen joint differentials? So in this woman, she's 67, she's coming with an acute, hot, swollen, and painful knee. What four main differentials are you gonna think about here? The four key differentials are septic arthritis, so infection in that knee joint, gout, another one called pseudo gout, which is actually which is actually calcium pyrophosphate crystals in the joint, as opposed to uric acid crystals, and reactive arthritis. So next question is what diagnostic test are you gonna need if there's some doubt about the diagnosis to determine what the diagnosis is? So what's the key diagnostic test for these differentials? The key test is joint fluid aspiration. So if you've got a patient who presents with an acute hot painful joint, if you're suspecting, if you have any suspicion this could be septic arthritis, they need immediate transfer to hospital so they can have joint fluid aspiration to see if there's any bugs growing in that joint fluid. The next question is what if you do this joint fluid aspiration, what's the key finding in gout? So you you've got this person with a hot swollen joint, they go to hospital, they have the joint fluid aspirated and sent to the lab. What would you expect to find in a patient with gout? The key finding here is monosodium urate crystals in the joint fluid. And these crystals are needle-shaped and they're negatively birefringent of polarized light. I don't know why, but this is a real common and popular exam question to say, are the joint the joint fluid has shown needle-shaped crystals that are negatively birefringent. If you see that in your exams, think about gout. The crystals in pseudo-gout are rhomboid-shaped and positively birefringent. So this is a key way to differentiate them when you see this in your MCQ exams. Okay, so onto a new case. You've got a 62-year-old man and he's got previous gout flares. He's come in with a couple of gout flares over the past few years. What's the specific blood test that you would do in this patient for gout? The blood test is you check the serum urate. And in gout, in somebody who's got frequent flares of gout, you would expect a raised serum urate. You can get gout flares even with a normal serum urate, but typically it's raised. The next question is what are the modifiable risk factors for gout? So non-modifiable risk factors would be things like being male, having a family history, and increased age. There's nothing you can do about those. What would be the modifiable risk factors, things that you could potentially change? The first one is alcohol. So commonly, um if you're taking a history from somebody who has is presenting with gout, ask about alcohol, because that's a common lifestyle factor. Another one is diuretics. So thiozoide diuretics or loop diuretics can increase the risk of gout. Specific things in the diet, so they talk about a high purine diet, which is found in meats, things like liver or pate and um certain seafoods, and being obese. On the note of diet, the nice clinical knowledge summaries say that uh just having a well-balanced diet is important, but there's no specific diet that's been shown to reduce the um reduce the frequency of gout. Although you'd probably advise them not to eat things with lots of purine in them, so uh you know, avoid liver and pate and things like that. The next question is what preventative options do we have, things that we can give the patient or prescribe that can reduce the frequency of gout flares The two key preventative drugs are allopurinol and verbuxostat. These are both options for preventing gout flares. They work by reducing the uric acid level in the blood. The next question is when would you start these preventative options? So you can you can start these preventative options even if they've had one flare of gout. Um and you would start them at least two to four weeks after the flare of gout settles. You don't want to start them during an acute flare because they can make that flare worse, or shortly after a flare because they can they can cause the flare to reoccur. My next question is what would you co-prescribe, or what could you co-prescribe with these preventative uh options for gout. The nice clinical knowledge summaries suggest co-prescribing culchine alongside when you're starting these preventative options. That's because these preventative options can cause or trigger a flare-up of gout. So you start cultisine to help prevent that flare-up from happening. And you carry on with the cultusine until they reach their treatment target.

SPEAKER_01

So the next question is what is the treatment target for these preventative measures?

SPEAKER_00

So these preventative options are um titrated to help bring down the serum urate. And the goal is to get the serum urate below 360 micromoles per liter. Okay, so let's move on to the next one, which is a 36-year-old man. He's had previous flare-ups of gout, and he presents with lumps on his elbow. So he's got these little nodule, sort of painless nodules on his elbows. And they can be quite big. Um, they can get quite big. But this patient has multiple little nodules on his elbows. What's the likely diagnosis?

SPEAKER_01

What's the likely cause of these nodules?

SPEAKER_00

These nodules are likely to be gouty tofi. So these are subcutaneous uric acid deposits under the skin, and they form painless, uh, firm nodules under the skin, although they can become painful during an acute gout flare.

SPEAKER_01

So in this patient, what would be the treatment target?

SPEAKER_00

So we said before the treatment target for uh the standard patient with gout would be less than 360 micromoles per liter. But in somebody with gouty to fi, we're a bit more aggressive with our treatment target. So we want the serum urate to get below 300 micromoles per liter. And gouty tofi, they can affect other areas. So here we've got a patient with gouty tofi on his elbows, but you can get them on the outer ear, so on the helix of the ear, or you can get these gouty to fi throughout the hands, affecting the small joints of the hands. So I hope this episode has been helpful. Um, do remember there's that zero to or the AKT revision course coming up in September this year, on the 13th of September in London. I hope to see you there. More information in the description of this episode, and I hope to see you in the next episode, which will be in about a week's time.