Empyema with Dr. Aaron Garrison

The treatment of pediatric empyema pneumonia, includes both a medical, and surgical approach. But the decision making and treatment algorithms, can be a little complex. And that's why today we are going to review the management options with an expert. It’s really changed in the last ten years about how we take care of this process. That's Dr. Aaron Garrison, a pediatric surgeon at Cincinnati Children's Hospital. He's going to walk us through everything you need to know, about the management and treatment of empyema, and other parapneumonic processes in children. There are a lot of chest x-rays in this episode, so be sure to watch in the Stay Current app. We have all the images posted below the media player. Stick around. This is the Stay Current Podcast. So first, we should review some terminology. There are subtle, yet important differences in terms surrounding lung pathology. Simple just means, um, fluid, complicated means it needs an intervention. So some kind of chest tube, or thoracentesis or any kind of intervention is, uh, puts you into a complicated, uh, parapneumonic effusion. To take matters further, an empyema refers to purulence or pus in that pleural space. Acidotic, um, protein in there because of a lot of inflammation, so those of the, the, blood vessels are more permeable, so you get a lot of trans- a lot of exudate in the pleural space, um, which leads to white cells and pus. When considering what causes lung disease in children, we have to look at the numbers. Community acquired pneumonia is the leading cause of hospitalization in the US, and it's the leading cause of death in children less than five years old worldwide. But, we can't always nail down that causative pathogen. Interestingly, of all the pneumonia that we see, only 15% of those kids will have a bacterial pathogen detected. There are some standard pathogens that we should consider as the most common. Those include Staphylococcus aureus, Strep pneumo, and Haemophilus influenzae. When there is infection and inflammation from these bugs, things get a little out of whack. You get more, uh, fluid generated and decreased, um, absorption and so you get an imbalance of fluid and, um, generation of, uh, compression in the pleural space. So wait, I think I'm missing a few steps. Children get infected with one of these bugs. They accumulate pleural fluid. But then, how does the empyema form? Well, there's three stages of empyema formation. So in the first couple days, two to three days is kind of the exudative phase. That's when you get, uh, fluid generated, it's sterile, it's not infected. And it's not, um, for sure that you're going to progress to the next stage, but if you're still, uh, don't have good source control or if the infection progresses, then you progress, uh, progress to the next stage. Oh, okay. That makes sense. But, at what stage am I catching this empyema when I get into the operating room? The fibrinopurulent stage and this, I think this is the one that you see when you're actually in the OR with these patients. So, that's between two days and two weeks about. Um, and that's because those cells, they get into the pleural space, they make clot, they make fibrin, they make, um, all those white cells just kind of lead to a more, uh, purulent, um, thick environment. Scroll down below the media player. We have a link to videos showing the intraoperative VATS view. The video sort of shows what, what the fibrinopurulent stage is like, right? So there's all this clot and, um, or just plugs and this is for those of you who aren't in the OR all the time, um, what it looks like when we do a VATS, the lung is just kind of compressed down. There's not a whole lot of space between the lung and the, um, pleural and the, um, chest wall, uh, and it's filled with, um, that rind. The real problem here is the compromised lung volumes once this collection organizes. And so you get a thick rind and your lung becomes entrapped and won't, won't expand. There are other pneumatic processes caused by these same bugs. So it's, uh, Staphylococcus aureus is the most likely cause of, uh, pneumatoceles. Scroll down below the media player. There you can see the x-ray of this pneumatocele, and all of the other diagnoses that we'll be talking about today. So, infectious wise, I think, uh, a pneumatocele you should think staphylococcus aureus. Um, but kids who have been on oscillators and high, high ventilatory pressures are likely more likely to generate them, um, as a result. That area of air space in the right lower lobe, looks pretty concerning. Interestingly, a lot of these will go away on their own. You don't need to intervene on them unless they're causing shift or, um, get super infected. Okay, so pneumatoceles aside. Let's say, I have a pediatric patient that presents with fevers, cough, unilateral breath sounds, and mild respiratory distress. With this history, a two view chest x-ray is a really good place to start and you're trying to figure out specific characteristics. Basically trying to see if there's an effusion, right? If, if it's going to be free flowing, if it's loculated, and if you're going to need, um, another, another study. Right. So, we got that image and it looks like this. You can also find it below. That looks pretty concerning for an effusion. Probably parapneumatic from the patient history. I have a few choices on what imaging comes next. Yeah, the ultrasound is probably better than the CT scan and in fact is more sensitive to pick up whether or not their septations and, um, uh, in the plural space. So we would probably pick an ultrasound as the next test. It also does not have radiation exposure. This ultrasound, looks pretty septated. A lot of these effusions need a chest tube for drainage or even a VATS, but not all of them. This is from the American College of Chest Physicians, um, where they look at the size of the effusion on x-ray, they look at whether or not you grow, have grown bacteria or not on thoracentesis, the pleural fluid chemistry and then they make a category and they tell you whether the outcome is, um, high risk or low risk. Um, and then those that are severe are recommended drainage. While guidelines like that are helpful, always remember to take into account the full clinical picture for each child because when choosing between a VATS and a chest tube for an empyema, there's a lot to consider. This is a topic that we've actually covered before with Dr. St. Peter in a previous podcast. So after this, be sure to give it a listen and the full article is linked below. Their study was, was this where they had clinical, uh, confirmation of an empyema, meaning like white cells greater than 10,000. They put in one chest tube, they do, uh, three doses of TPA and then they would ultrasound or CT and see whether or not they, uh, need to go on to VATS or just, uh, continue antibiotics. This study is pretty practice changing. It shows that a chest tube in fibrinolytics such as tissue plasminogen activator or a TPA are not inferior to the standard VATS when looking at clinical outcomes. What they found was, was that there was really no difference, um, in, in hospital admissions, decreased cost with the, uh, chest tube and, um, um, that really overall kids just get less sick when you're not doing a VATS on them. The trends are pretty clear. The rate of primary VATS are going down and the rate of chest tubes and TPA are going up. The rate of patients that fail chest tubes with TPA that then require a VATS, they're about the same around 5%. But, we don't have an algorithm to predict those cases successfully yet. The published protocol by Dr. St. Peter was three days of TPA, 24 hours apart. At Cincinnati Children's, we have a slightly different protocol. We give six doses, 12 hours apart. And additionally, we don't use DNAase. DNAase is just a mucolytic, it just breaks up, it works differently, but, um, there was a study in kids that it didn't make much difference. Now, we cannot go through a lecture without Dr. Todd Ponsky's input on how these ideas can change his clinical practice. And he's right. We need to think about how are we going to select which kids go down this TPA algorithm in the first place. For some, a chest tube alone could control their symptoms. Take a patient. They have a clear effusion, they're sick. You put in a drainage tube, and you don't do TPA, you just watch them for the next 24 hours and if they're not getting sick, you don't give TPA, you just watch them. So, if they're getting better, they may not need TPA. But if they don't clinically improve in 24 hours, we should proceed with the TPA protocol. This is a newly revised algorithm at Cincinnati Children's to include all of these treatment pathways. Don't worry, we've linked it below. But remember, there are some contraindications to TPA usage. Those are the two main contraindications: necrotizing pneumonia, bronchopleural fistulas and then, um, significant parenchymal disease and chronic changes are relative contraindications. Now, for these kids that fail a TPA and chest tube approach, they're still going to need a VATS for definitive therapy and that does account for some kids. When positioning these kids in the operating room, remember to position them appropriately. Put them in the lateral decubitus position with an axillary roll. Proper positioning in a small child can really help open up the chest. Let's see what it looks like when you get inside. And then this is really what a decortication is is once you get down to all the, all the, um, peel, you just take that off the lungs so that it, that it expands. Now often, empyemas and effusions are a parapneumatic process from infectious pathogens that cause pneumonia. But for young kids, think ages one to three, we can't forget the chance of an airway foreign body. Those can also cause recurrent infections and chronic pneumonia. The most common culprit, peanuts. And peanuts can't be seen on chest x-ray. Initial imaging for an airway foreign body, can look like air trapping, but you need a high index of suspicion for these patients because finding the foreign body on x-ray, is pretty rare and a normal chest x-ray can't rule out a foreign body aspiration. That's why these kids usually end up in the operating room for bronchoscopy and removal of that foreign body. If you have a high index of suspicion, every kid pretty much went to the OR for a bronch. The thing is, the majority of these kids, hadn't aspirated at all. And so Dr. Ponsky looked into figuring out if we could diagnose foreign body aspiration another way. New literature is showing that a CT scan has, um, and our study was 100% reliability to show you a airway foreign body, sensitive uh both positive and negative predictive value. In this study, only about 40% of patients who had bronchoscopy for an inhaled foreign body actually had one present. And the majority of the other 60% of patients, they had reactive airway disease. And that was only made worse by the intraoperative manipulation by bronchoscopy. Instead, CT imaging could be used to diagnose inhaled foreign body before taking them to the operating room. Even with the minimal amount of radiation exposure, this approach saves operating room time, sedation, and cost for a large proportion of children. Check out the linked article below. Okay, let's switch gears and talk about another infectious lung pathology. Air fluid level it's a pulmonary abscess. Um, got a CT scan to confirm that. For otherwise healthy kids with a pulmonary abscess, they don't need surgical treatment at all. Take home message, pulmonary abscesses almost always respond to just antibiotics, don't need drainage. Drainage of pulmonary abscesses can lead to bronchopleural fistula and those can lead to a persistent air leak. Sometimes they close on their own, but other times, they may require advanced intervention, maybe a broncho valve or to seal. Thanks for joining us for a review of the management of pediatric empyema and other pneumatic pathology. Remember, check the link below for access to the entire lecture, and to find the articles discussed in this episode, along with the images. Follow us on social media, like and subscribe to our YouTube channel, download the Stay Current app, wherever you listen to your podcast, leave us a comment. Tell us what you like, what you didn't like, what do you want to hear about in future episodes. Until then, this is Britney and remember, knowledge should be free.