15_16 #67 Gram Positive Cocci Infections & TherapyDr. Liappas

11/2/151600-1700

Note taker #19

Gram Positive Cocci Infections & Therapy, Part 3

Slide 48So if you don’t have vascular insufficiency, then it’s some kind of pretty major trauma. And there’s direct inoculation of bacteria into the bone area. It’s usually multiple organisms but we usually think about staph here too because it’s always on the skin. It’s usually somewhat difficult to treat because there’s some trauma, some kind of wound you just developed but you do have good blood flow which means you can give antibiotics and they’re going to get there where you want them to be.

Slide 49Here are some good examples. Here’s a bad break. If you bone sticking out of your leg, and bacteria get into the bone, that bone is most likely going to get infected and these will become osteomyelitis from bad traumas, or even consequences of the trauma. So you go in and you actually put the bone together but if one of those screws or the plate get infected – so you can see here are some plates and some screws (right picture) that’s holding the bone together with some cracks left over down here – then those can get infected and can cause osteomyelitis too.

Slide 50If you haven’t seen a pressure ulcer, it’s very common and you’re going to see this in the hospital. You’ll have to know about stages, but in real life, this happens if someone is elderly, they have poor muscle function, they’re not being turned often enough. They start off very superficial which is a little bloch, usually on a bony prominous, around the hips or the back and slowly degrade down to where you get bone exposed, usually where bones are prominent. These are preventable in the hospital but basically where the bone is eroded through.

Slide 51If you do have vascular insufficiency then you don’t have to have a big wound; you just need a small injury that then progresses because of mixed infections from you not noticing it. You have an ulcer and the ulcer gets infected, often chronic and usually associated with neuropathy as well as peripheral vascular disease.

Slide 52Here’s an example. You have the wound here, and definitely some discoloration, which means that the toe is dead. So when you get the x-ray it shows that the toe is basically gone. This person would be lucky if they kept their foot. All of the white color and bluish is because of poor vascular disease, and is basically dead tissue. This opening you see in

the x-ray causing all of the bony destruction is the thing that may have brought the patient to the hospital, but probably not leave with their foot.

Slide 53In the opposite direction, you might see small wounds like this, usually on places where the shoes rub or in this case, a sign of chronic osteomyelitis which can happen, which is when the wound never closes and kind of stays open and drains.

Slide 54If you have insufficiency, you have to think about surgical management because there is little you can do. If you give a person antibiotics but you have no blood flow, you take the antibiotics in and it doesn’t get to where you need it to go, so often surgery is necessary in these cases. Usually the big thing here is to get the person to be able to walk, so if you can take enough of the infection away so you can put a prosthetic on, they can at least walk again and be functional.

Slide 55 – Poll Everywhere

Slide 56As we talk about skin and bone and into joint, think about the joint as an extension as well. Think about the bone as being this very vascular area, the synovium is also very vascular. So between the bones there are these joint spaces. They are quite protected; they don’t have a lot of communication, they don’t have a lot of immunology so they are very protected, wonderful places for bacteria to hide out.

Slide 57This is where bacteria, as they can land into bone, they can land into your joints too. So usually when we see inflamed joints, we are very concerned about an infection from the get go, unless the patient has known rheumatoid arthritis or some other known arthritis. And usually this vascular membrane, these synovial membranes are very permeable so bacteria can get into them very easily.

Slide 58It’s not uncommon to admit a patient for pneumonia. They still have a fever; they’re blood cultures are fine. Everything looks fine from the x-ray standpoint, you pull back the sheet and you realize they have a big swollen knee because the bacteria that was in the blood from the pneumonia got into the knee joint. And until you drain the knee joint, the fever won’t go away. So always think about these inflammatory arthritis. So we call this infectious arthritis as an inflammation in the joint. There’s a lot of bacterial causes and non-bacterial causes. It can be viral as well. All inflamed joints need to be evaluated, which is the big thing to talk away from today. You cannot let the sunset on an inflamed joint, because if it is an infection, it has to be drained out and cleaned out in the OR.

Slide 59What we have here in terms of a takeaway point in the red here is that the aspiration is a necessary component to evaluating an inflamed joint. You might not have blood cultures,

or other markers, so if it’s red and swollen, that can extend it. You drain the fluid off, and it’s not only good so you can make a diagnosis but you can also improve the patient; they'll feel much better after you drain the fluid.

What kind of predisposing factors – all down here. So you can put in an abnormal joint, so that’s one way bacteria could be stuck to a joint that was put in from the outside. You can definitely have intravenous drug use; anything that puts bacteria into your blood stream, intentionally or non-intentionally. STDs is another one but we’re really talking about gonorrhea in general.

Slide 60Here are some lists of bacteria that can do this. Here, basically anyone who is under 30 who is sexually active you need to think gonorrhea first. So the sexual history has to be very detailed, very complete, and this is where you don’t be shy. In adults we have to think about others: s. pneumoniae because they get pneumonia, and s. aureas is pretty much from anything but in particular any wounds on the skin or any penetrating trauma.

Slide 61What’s your clinical presentation? It’s a swollen joint. There’s fever and possible effusion. If you palpated this person’s joint, you would be able to feel the patella going up and down. They wouldn’t be able to straighten it out; obviously it would be very warm, unable to extend it much.

Slide 62Our fellow drew pus out of someone’s shoulder joint, but you can see how thick and cloudy it is. It’s supposed to be clear, and read through it.

Slide 63It’s often purulent and it usually has more than 50,000 white cells per CC. Most of those white cells are neutrophils, so it’s very neutrophilic if it’s bacteria doing this. Usually there’s not a lot of glucose because the bacteria is eating up the glucose. This is similar to the pattern you’ll see in any kind of fluid that comes from an infection that’s sterile initially: the glucose is low, the protein is elevated. Here the grams stain cultures are very helpful, usually not as helpful for gonorrhea but can be very helpful to make your diagnosis from your gram staining cultures.

Clinical Cases – Gram Positive CocciSlide 1 – nothing said

Slide 2I want you to get an idea of the clinical presentation. Everything is real life.

Slide 3 – “Read from the slide”

Slide 4

Here’s the x-ray. Here's the heart, the diaphragm, these are lungs. It should be same on both sides with air all the way down to the base, and there isn't on the left side. What you can see is a right lower lobe consolidation, a right lower lobe process – it could be blood, pus, whatever.

Slide 5 – Poll everywhere

Slide 6So what is on this gram stain? This is a gram stain of the sputum, so you’re going to notice the pink backgrounds, and lots of neutrophils. So in your sputum, you should not have a lot of neutrophils – that’s not normal. The gram stain is picking up gram positive, diplococci, lancet-shaped. The patient has rusty sputum, and he had a fever and cough, and all the signs of systemic inflammation on an elderly man.

Slide 7 – Poll EverywhereAgain, gram positive, diplococci. Enterococci doesn’t usually cause pneumonia. This is a stool bacteria – it can cause infections where stool can get on your skin but very rarely does it cause pneumonia. Colonizing the upper respiratory tract is very common for strep pneumo. Most bacteria have resistance to antibiotics and especially strep pneumo which has resistance to penicillin. And the toxin that is the sandpaper rash is more like a toxic shock kind of syndrome which this is not.

Slide 8 – “Read from the slide”

Slide 9 – “Read from the slide”

Slide 10 – Poll EverywhereMost of you picked S. pyogenes, which would be completely dead on both vancomycin and menopanem. So the answer is E. fecium. This is an organism that can be incredible resistant, sticky, and its only virulent factor is that it can stick around basically and survive in bad situations. Also, she’s on an antibiotic in which there is enterococcus resistance to.

Slide 11This is a central line. The clue to this case was how did she get bowel bacteria in her blood. You should always ask the question, if I see bacteria in the blood, where did it come from? In this case, you gave her a conduit. She had diarrhea, there was stool all over her. You gave her oral vancomycin and selected out vancomycin resistant enterococci and then you put in a catheter into her femoral vein, and you let the bacteria go up the catheter into her blood stream. So again, totally classic, very common situation.

These are catheters which have three different ports. They’re usually about 12-17 cm long, and they go into your vein, into your femoral vein or into your jugular vein or subclavian vein.

Slide 12 - picture

What do you see? Pustules, some that are healed over.

Slide 13 – Poll everywhereIf you put a warm compress on them, and let the pus drain out, they would most likely just go away. If the patient was severely immunocompromised, has a fever, has systemic signs, some reason to give antibiotics because in folliculitis, depending on how deep it is, you can just drain them and it’ll get better. So you often do not need antibiotics.

Slide 14 – “Read from the slide”

Slide 15 – Poll EverywhereThe wounds on the arms are popping scars. Initially you’ll see them along the course of the vein, sometimes in the neck or the groin. But eventually, you’ll see them randomly. Usually, if the person is right handed, you’ll see them more on the left side. These are basically places where you have run out places to inject the drug and you perform subcutaneous injections, and the shoulder is also a common place, wherever you can reach. You tend to not go into the back because the skin on the back is too thin and you can't get much of a high from that. So this is a classic presentation. So if you give the patient 45 tablets of oxycodone, and tell him to come back in two weeks, they can sell that for a large amount of heroin or they can crush it up and use it themselves.

You can call other emergency rooms, but it’s rarely done anymore.

If you perform a neurological exam, and you listen for a murmur before ordering blood cultures, you’re giving the person the benefit of the doubt. You’re saying OK, it appears to be drug seeking behavior, but it could also mean they could have something going on. They don’t have a fever, or any systemic signs, but that’s only half the time. A lot of people have palpation issues but that’s non-specific too, so I agree that you should make sure there’s nothing else.

Slide 16Here you get an MRI. In this case, the spinal cord is not fine. The infection is pushed back and it’s pushing into the spinal cord, and these are very dangerous. When the drug abusers to go to the OR, they have terrible pain management issues, they have a lot of high tolerance to narcotics and dealing with the patients afterwards is difficult because you need to put one of these huge catheters in them, which gives them a great opportunity to overdose in the hospital. It’s a constant battle to make sure they stay safe while you take care of them. And these patients will need 6 to 8 to 12 weeks of antibiotics, so these patients will be with you for some time. And they’ll need to go into rehab in addition to all of that.

Slide 17 – “Read from the slide”

Slide 18 – Poll everywhereProducing a capsule is classic staph aureus virulence factor.

Slide 19Staph aureus is a very virulent organism. It’s one that people don’t usually keep on their skin. It’s very transient, but drug abusers are 8 to 10 times more likely to have staph aureus on their skin and in particular, MRSA on their skin. So they are often are high risks to get these infections like skin infections.

Slide 20 – Poll EverywhereSo when you have staph aureus in your blood, you’re worried about all of these things. But the biggest one is potential for antibiotic resistance, and it’s really MRSA you’re worried about. Almost all the patients we see with drug abuse have MRSA, and not just the regular staph aureus. The bacteria not being cleared from the circulation or there may be also other sites of infection are also very common with staph aureus. You’ll see this when you hear about endocarditis, but anything connected to the blood stream can be seeded. If we find one place that’s been seeded, we look for other places as well. If we find it in the heart valve, we also look at the spine and other places as well, because it’s the same idea.

Slide 21So a quick reminder if you haven’t heard about it, we look at vancomycin, hetero-resistant, these VRSAs, you definitely have to worry about these organisms. This picture down there is not for memorization or testing purposes, but when I mentioned that there was VRSA, there’s the VAN gene that gets into MRSA, and thus becomes VRSA. These are incredibly rare occurrences.

Slide 22Just to put that point to you that there’s different kinds of MRSA. In the clinical settings, you’ll have to know about this. We see hospital acquired MRSA, which have to do with catheters and things we have to do to patients, and then there’s this community acquired situations where it’s soft tissues and there are pneumonias, and then some of these particular things. Just remember that there are different versions of MRSA as well.

Slide 23I’m just showing you a few pictures of how bad MRSA can be. Pneumonia from strep pneumo was pretty sick, and what happens with staph aureus is that it has so many virulent factors, that if it gets into the lung, what you get are these diffuse processes. This person has much more catheter action going on, other things going in them, intubated. But what you see is basically no normal lung.

Slide 24And if you did a CT scan it’s basically like Swiss cheese. The only normal lung is over here and everything else is staph aureus chewing its way through the lung tissue. These patients are normally bacteremic, have terrible courses, and do terribly because they basically have no lung function left.

Slide 25 – “Read from the slide”

Slide 26You do a foot exam, and on the bottom of her foot, you see this. This is common with diabetics; they usually don’t know what’s going on underneath.

Slide 27 – Poll Everywhere

Slide 28That big ulcer underneath has denoted the bone a lot. You might not notice it from the skin, but the wound is much deeper than you think it is. It is very classic. Maybe this diabetic person may have told you she’s stepped on a nail months ago and hasn’t noticed it. There has been a case where you still find the nail attached to the person’s foot and they still don’t know it’s there. There is some lucency here but at least the cortex is OK.

Slide 29 – Poll EverywhereBecause she has diabetes that’s poorly controlled, you don’t need major trauma. She may have had major trauma so this answer may not be incorrect, but what we’re really looking for here is someone who has contiguous with vascular insufficiency, a diabetic patient that they have a minor trauma and overlooked something happen. They didn’t have to have a wound or an injury or a surgery, so you’d have to get a good history and ask the right questions. The most classic thing is unchecked soft tissue infection.

Slide 30These guys in general, if you do good surgery you can clean them up. The idea here is to preserve the foot, so it might look terrible initially. They’ll take toes off; they’ll try to preserve as much of the foot as possible. You’ll start to learn this terminology of transmetatarsal where half of the foot is removed below the knee or above the knee. But with good care, these will heal up and they’ll do well. Hopefully you’ll save the foot.

[Student question] It’s not a maggot; it’s a drain.

[Student question] One of my patients had burned her foot. And this happened to one of my patients. He tried to warm his foot on a heater, and he’s diabetic; it was the top of the foot in his case. But if you had gotten the history, I had put my foot on a heater a couple of weeks ago to heat it up, and this is actually a burn, then the answer would be it’s a major trauma. But in most cases, if you have poor vascular flow, it’s just minor trauma. That’s the point of the question.