Overview and Care of Pneumonectomy Patients

Podcast Transcript

Announcer:

Welcome to Cleveland Clinic Cardiac Consult, brought to you by the Sydell and Arnold Miller Family Heart, Vascular and Thoracic Institute at Cleveland Clinic.

Daniel Raymond, MD:

My name's Dan Raymond. I'm one of the thoracic surgeons and the quality officer at Cleveland Clinic. Today we're going to talk about pneumonectomy. You can imagine our circulatory system is one big river that's flowing and it branches and it comes back together, branches and come back together. But the flow at every point needs to be the same. So what's coming out of your aorta has to be the same as what's coming out of your pulmonary artery. The difference is what is the compliance in the system, the pressure in the system. So the pulmonary circulation is handling the same volume of blood as the systemic circulation. It's just a very low compliance system, lower pressure. It's about a third of standard pressure.

Now, when you do a pneumonectomy, you can imagine that river goes like this and then comes back together. What we're doing is cutting off one of those branches. So all of a sudden, one lung has to see all the blood flow in the body. So that can be a very tenuous situation because can that lung compensate for that sudden change in the amount of flow?

So what we fear in pneumonectomies is too much volume, volume overload. So you'll see us sending people up not on IV fluids, diuresis them, running them dry as a chip. What we're trying to do is minimize the chances of them developing pulmonary edema because if they have one lung and they develop pulmonary edema, we're in big trouble.

The other component of it is when it goes and you cut off one of those branches, all of a sudden the resistance that the right side of the heart has to work on has doubled. So the right side of the heart has to work harder. So when you see me come upstairs and look at a pneumonectomy patient, the first thing I do is I look at their heart rate. It's because the heart rate is a reflection of how happy the right ventricle is. Because the right ventricle, it's a thinner-walled structure. It doesn't have the ability to increase its stroke volume as much. It's more of a rate dependent structure. So if someone is persistently tachycardic, that starts making me nervous because that's telling me that the RV's under strain.

So what we have to do is try to do everything to protect that RV, protect that lung. So minimize blood flow, and then try to do things that prevent an increase in afterload, meaning pulmonary vascular resistance. How you do that is if you watch for tachycardia and you avoid pulmonary hypertension.

What's the most potent pulmonary vasodilator? Do you know what it is? You use it every day. Oxygen. So that's why, in pneumonectomy patients, I want their SATs a little higher and not tolerate lower SATs because again, hypoxia hypercarbia means pulmonary vascular vasoconstriction. It means increased afterload on the RV and that can lead to RV failure. So that using oxygen, we're using it as a medicine in this circumstance to be a pulmonary vasodilator. That's why someone who has a pneumonectomy cannot tolerate not looking well from a pulmonary hygiene standpoint. They don't have enough blood flow at that point. If you compromise flow through that existing lung, if you start to see vasoconstriction, that heart's going to fail. So that's where pulmonary hygiene is critical. Pain control is critical and watching those parameters and trying to think about what am I doing to decrease that pulmonary vascular resistance? Can I get that oxygen up?

Sometimes you'll see it. If they're sating 92 and you get the oxygen up, they start sating 96, their heart rate will come down. It's because their RV's like, thank you. But it's pain control, it's pulmonary hygiene. Again, aspiration prevention. That's why we tend to keep pneumonectomies NPO because again, one event could be devastating in that population and then DVT prophylaxis.

The other nuance of pneumonectomy is that when you take the lung out, you have a big empty space. So this is our typical patient after a pneumonectomy and at different hospitals, everyone has a different way of dealing with this space. Now, managing this space is actually kind of interesting because what do you want this space to be is you want this space to be kind of at atmospheric pressure. The worst thing, if you put a chest tube in there and you put it on suction, it would suck the heart over and it could kink off the SVC IVC, patient arrests. So sudden movements in the SVC can be catastrophic in these patients. So that's why we don't use a chest tube system because we don't want that to happen. There's actually a specific pneumonectomy vac that doesn't have a suction apparatus on it. It has two water seals that go like this, and the patient breathes and it goes like this.

So that's why we have the Rob-Nel in there. What we're doing is we're watching that mediastinum day one, day two, and we're looking to see where is it going? So what's happening? Why would the mediastinum move at this point? So when they cough, what are they doing? Creating positive pressure. You have air in this space. That air is getting pushed out of that space through the incisions that were made for the pneumonectomy. So that's why you see them start to develop subcu air. So in our pneumonectomy, subcu air is very common. Lobectomy is not a good thing. Pneumonectomies, we kind of expect to see some. You don't want to see a lot of it, but it's them pressurizing. But what can happen is if you have someone with a big barrel chested man, very strong, and if they cough, cough, cough, they can push so much air out and generates such negative pressure in their chest, they'll suck their mediastinum over and lead to a sudden hemodynamic change. So that's one of the things to think about if you have a post-op day one, post-op day two pneumonectomy with a sudden hemodynamic change is did they shift their mediastinum? You can answer that with a chest X-ray. In an absolute emergency, all you have to do is open the stopcock on the Rob-Nel. Because that will allow the pressure to equalize to atmosphere, and their mediastinum should shift back over. So what we're doing is we're taking out air, putting in air.

Now over time, in the order of weeks to months, you see this space fill with fluid. So what you should see is a gradual increase in that fluid level and so a fluid level is normal. That's one of the things we tell pneumonectomy patients. Don't let anyone ever stick a needle in that space, talk to me first. That's what we expect to see and then ultimately, what happens over the course of two years is the fluid resorbs and the heart slowly gets pulled over. So the heart ends up against that chest wall, but because it hasn't done it suddenly, all the vessels have a chance to compensate for that.

Now, what we worry about is a fluid level that's decreasing. That's bad, and it means that fluid is going somewhere. What that typically indicates is a bronchopleural fistula, and that's the staple line closing. The airway has broken down and that person can literally drown on the fluid they have in their chest. So if someone calls up and they said, "I'm coughing up water," you'd say, "You're calling an ambulance right now." You're going to have them lay with their pneumonectomy side down, so gravity doesn't encourage fluid to go over to the other side. You put a chest tube in that side as soon as they get into the hospital to drain all the fluid out of that chest so that they don't drown. The only solution to that is a Claggett window. That is a feared complication. It is more common on the right side because the airway itself sticks out into the chest on the right side. On the left side, the airway is kind of hidden behind the aorta. So when you do a pneumonectomy on the left side, the whole stump kind of gets sucked in and all the mediastinal structures collapse around it. So it helps support it. On the right side, it's just hanging out in the breeze. So we tend to see more stump leaks on the right side. But a very feared and dreaded complication. It's a very unusual procedure.

Pneumonectomies can have CPAP and BiPAP. I mean, we're not worried about conduit distension. So if they're CPAP, BiPAP, totally fine for pneumonectomies. You'll hear some people say, "Oh, you can't because positive pressure is pushing against that staple line, and you could cause staple line failure." Possibly, but I would much rather that they not have hypoxia. So CPAP, BiPAP, totally fine in that circumstance.

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